Term
| Bacterial pathogens- Gram Negative |
|
Definition
Escherichia Coli (E. Coli)
Salmonella |
|
|
Term
| Bacterial Pathogens- Gram Positive |
|
Definition
Streptococcus
Staphylococcus |
|
|
Term
| Bacterial Pathogens- Non Staining |
|
Definition
Mycobacteria (TB)
Spirochetes (Syphilis) |
|
|
Term
|
Definition
| Plasma Membrane, Periplasmic space, peptidoglycan |
|
|
Term
|
Definition
| Plasma Membrane, Periplasmic Space, Peptidoglycan, Outer membrane (liposaccharide and protein) |
|
|
Term
|
Definition
| Has nucleus and other organelles inside the cell (human) |
|
|
Term
| Eurkaryotic- fungi and molds |
|
Definition
Candida (yeast infections)
Pneumocystis (PCP pneumonia) |
|
|
Term
|
Definition
Giardia (diarrhea)
Malaria
Toxoplasma (Brain, cat) |
|
|
Term
|
Definition
Obligate intracellular pathogens
RNA or DNA packaged in a protein coat.
Small - 20 to 300 nm (Cells 10 - 100x
bigger).
Takes over the machinery of the host cell
Generates new viruses from the
instruction in viral DNA or RNA.
Not alive - no metabolic activity |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Growth of the agent within a
host resulting in damage and
disease |
|
|
Term
|
Definition
Time from
acquiring the agent to the time that
symptoms are observed |
|
|
Term
|
Definition
cell damage, loss of health
by a specific agent |
|
|
Term
|
Definition
loss of health, malaise, loss
of normal function |
|
|
Term
|
Definition
|
|
Term
| DALY (disability adjusted life years) |
|
Definition
measure of morbidity and mortality
associated with a disease |
|
|
Term
|
Definition
An increase in the number
of cases of a disease over that rate
usually found. A rapidly spreading
new disease. Swine Flu |
|
|
Term
|
Definition
Commonly distributed in a
region. A common infection.
Malaria is endemic in Tanzania,
Africa |
|
|
Term
|
Definition
|
|
Term
|
Definition
The number of new cases of a disease.
The number of persons becoming ill in
a given time period
EX-HIV infection is about 3 million per
year new infections |
|
|
Term
|
Definition
The total number of cases old and
new.
The total number of ill people in the
population.
Ex- The total number of HIV infected
people in the world is 40 million |
|
|
Term
|
Definition
Group of symptoms
Can be a group of symptoms without a
known cause
Can be a group of symptoms which
could be the result of several agents
Common cold - many viruses |
|
|
Term
|
Definition
Set of symptoms, syndrome seen in an
initial set of patients.
Not perfect - can be altered or revised
Not all patients will have ALL
symptoms
Predictive value - if a patient overall
fits the case definition, he/she is
likely to have that disease |
|
|
Term
| Three Areas of Disease Research |
|
Definition
Diagnosis – detection
Treatment – drugs
Prevention – vaccines |
|
|
Term
|
Definition
| Severe Acute Respiratory Syndrome |
|
|
Term
| SARS is closely related to corona viruses found in |
|
Definition
Civet cats (a badger like
creature found in Asia).
Horseshoe bat (fruit loving) |
|
|
Term
| Corona viruses may be endemic to many |
|
Definition
|
|
Term
| How does SARS enter humans? |
|
Definition
| Unknown, Civet cat and Horseshoe are both food items though. |
|
|
Term
| SARS is transmitted to nursing personnel |
|
Definition
| through the air or body fluid or contact |
|
|
Term
| Cases of SARS worldwide/ Deaths |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Cause mild respiratory illness - resembles the
common cold.
Circulate in the population. |
|
|
Term
|
Definition
Single stranded RNA virus
3 RNA segments |
|
|
Term
|
Definition
Human pathogens
Animal reservoir
animal can be symptomatic
or asymptomatic
Rabies, plague, Lyme disease, West
Nile. |
|
|
Term
|
Definition
Mice
Rats
Squirrels
Chipmunks
Human infection is an accident. |
|
|
Term
| How is hantavirus contracted by humans? |
|
Definition
| inhalation of airborne particles of the droppings, saliva, or urine of rodents. |
|
|
Term
|
Definition
| the immune and respiratory systems. |
|
|
Term
|
Definition
|
|
Term
| Hantavirus Fever with Renal Syndrome (HFRS) |
|
Definition
Less than 15% fatal
Treated with ribavirin
Mostly Far-East
Incidence rises twice a year -
rice and wheat dried for harvest -
increases in exposure to rat and
mouse excreta |
|
|
Term
|
Definition
|
|
Term
|
Definition
young, healthy people acquired it in the four corners
Death rate 69% |
|
|
Term
| Reason for 1993 outbreak of HPS |
|
Definition
1992 - Significant rainfall
Large pinon nut crop
Large, rapidly multiplying
deer mouse population
More excreta
More accidental
human infections |
|
|
Term
|
Definition
Deer mouse -
Peromyscus maniculatus
(deer mouse)
Most common host,
Large amount of virus
No symptoms
No person to person transmission |
|
|
Term
|
Definition
|
|
Term
|
Definition
No bias -
sex
race
ethnicity
Usually healthy adults -
average age 33
Correlates with exposure to mice |
|
|
Term
| Positive Diagnosis of HPS |
|
Definition
Flu symptoms over 48 hours
White blood cell count
increases & platelets decrease
Exposure to mice excreta
Cells are cultured positive for
Hantavirus |
|
|
Term
|
Definition
Admittance to hospital ICU
While being tested
Antivirals administered
Ventilator used
Full recovery if treatment is timely
Death rate still about 50% |
|
|
Term
|
Definition
Acid fast Bacteria
Very slow growing
almost all Europeans infected in 1800's |
|
|
Term
|
Definition
No symptoms
Not infectious to others
10 % lifetime risk of
disease |
|
|
Term
|
Definition
Symptomatic
Infectious
Untreated 50% die |
|
|
Term
|
Definition
Productive, prolonged cough
Chest pain
Coughing up blood
Fever
Chills
Night sweats
Appetite loss
Weight loss
Easy fatigability |
|
|
Term
|
Definition
16 million cases/year
1.7 million deaths |
|
|
Term
| 3 biggest killers in the world |
|
Definition
|
|
Term
|
Definition
PPD (1920s) skin test for exposure
Chest x-ray (1930s?)
Culture (1880s) |
|
|
Term
|
Definition
: BCG (~1930) bovine (cow) TB
live attenuated bacterium
120 million doses annually |
|
|
Term
|
Definition
6 months, 4 drugs
Directly observed therapy (DOTS)
Last drug appeared in 1960s
Drug resistance is rising |
|
|
Term
|
Definition
Patient Compliance
Reinfections
Rapid progression in some patients
Highly infectious patients
High rates of ongoing transmission
Drug resistance (later lecture)
Developing countries |
|
|
Term
Amantadine
blocks this process |
|
Definition
The M2 protein (matrix) is an
Ion channel protein that allows for
proton entry and acidification of
the virus and release of viral RNA
Into the nucleus. |
|
|
Term
Oseltamivir (aka Tamiflu)
blocks this process |
|
Definition
The virus exits by using the NA
(neuraminidase) protein, which
cleaves the virus from the host
cell |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
only
humans, very
mild illness |
|
|
Term
| Type A virus Classification |
|
Definition
Classified by two genes - H and N
Avian = Bird
16 versions of H
9 versions of N
Human
usually H1N1, H1N2 and H3N2 |
|
|
Term
|
Definition
Gradual accumulation of point mutations:
High error rate of viral RNA polymerase
Selective pressure at antigenic sites
New variants appear yearly
Limited pre-existing immunity
Partial protection conferred by previous
infection |
|
|
Term
|
Definition
Sudden, drastic change in antigenicity
Due to reassortment with avian strains
Avian H and/or N adapt to human cells
No pre-existing immunity
Can lead to pandemic |
|
|
Term
|
Definition
Genetic Shift - Reassortment
Can be a double shift
Change H and N at the same time
Highly virulent
Human to human transmission |
|
|
Term
|
Definition
~250,000 to 500,000 deaths per year worldwide
Most deaths in elderly >65 years of age in
industrialized countries
Yearly cycle: Fall, Winter, Spring
Highly contagious
person to person transmission
mists or sprays by coughing and sneezing |
|
|
Term
|
Definition
Incubation time - 1 - 2 days
(Hantavirus = 1 to 2 weeks)
Duration - 3 to 4 days |
|
|
Term
|
Definition
ARDS - acute respiratory distress
Pneumonia
Hospitalization
Death |
|
|
Term
|
Definition
Influenza damages lining of lungs
Lungs become infected with
Streptococcus pneumoniae
Staphylococcus aureus |
|
|
Term
|
Definition
Amantadine
Rimantadine
Prescription
only work with type A viruses
must be taken before or within 48 h of
symptoms |
|
|
Term
|
Definition
Tamiflu
Relenza
Must be taken within 48hours of symptoms
works with types A and B |
|
|
Term
|
Definition
Inactivated virus
Grown in chicken eggs
Killed through chemical means
Purified and tested
Usually 70-90% effective
30-40 % in frail elderly |
|
|
Term
|
Definition
Best in Fall
Safe, effective
Side effects
Soreness at site
Guillain-Barre Syndrome -
temporary CNS paralysis
1-2 per million vaccines
6% death
(New vaccines - oral, nasal, recombinant) |
|
|
Term
| Should NOT get a Flu vaccine if |
|
Definition
-Allergic to eggs
- previous reaction to vaccine
-history of GBS
-ILLNESS WITH FEVER |
|
|
Term
|
Definition
Every year, variants emerge due to
genetic drift
If you have had H3N2, you have some
immunity to other H3N2 viruses
Bigger danger is new HN due to genetic
shift
New Avian Flu is H5N1 |
|
|
Term
| Vaccine Failure 2007-2008 |
|
Definition
3 strains- H1N1, H3N2, Malaysia strain
Failed because only 40% matched flu variants
B and one A were bad matches |
|
|
Term
| Vaccine Failure 2007-2008 |
|
Definition
3 strains- H1N1, H3N2, Malaysia strain
Failed because only 40% matched flu variants
B and one A were bad matches |
|
|
Term
| Vaccine shortage 2009-2010 |
|
Definition
Only two distributors for vaccine, one could not produce that year
Priority was given to pregnant people, elderly, chronic disease
Many high risk people still did not get it |
|
|
Term
| 1918-1919 Influenza Pandemic |
|
Definition
50 million deaths worldwide
more than directly caused by World War I
675,000 deaths in USA
2.5% mortality (usually <0.1%) in USA
5% mortality in India |
|
|
Term
| Details Of 1918-1919 flu pandemic |
|
Definition
High mortality in young adults
(older immune?)
Rapid development of severe
pneumonia with cyanosis (blue face)
from asphyxia; very high fever
(105°C)
Death in 1-2 days |
|
|
Term
| 1918 Influenza in Seattle |
|
Definition
17000 deaths in Seattle, 300 in first 6 weeks
Surgical mask required by law |
|
|
Term
|
Definition
Called “Spanish Influenza” because Spain
did not have wartime censorship, so they
reported it |
|
|
Term
|
Definition
winter 2004-2005
1000s of poultry killed by new lethal strain
of influenza = Bird Flu = H5N1
100 million were killed to prevent spread
1.5 million in Hong Kong alone
$10 to 15 billion losses in poultry |
|
|
Term
|
Definition
As of August, 2012
608 confirmed cases of avian (bird) flu in
humans
359 deaths (60% mortality rate)
Human exposures:
Farms, live poultry markets |
|
|
Term
|
Definition
Reassortment with human strains
- in a dually-infected person or pig
New variant
human-to-human
No immunity to H5N1
Estimated deaths:
2 to 50 to 150 million |
|
|
Term
|
Definition
Asymptomatic
Symptoms resemble flu or mono
Usually lasts 6‐12 weeks
Highly infectious
Tests negative by antibody test |
|
|
Term
|
Definition
HIV positive ‐ antibodies detectable
Still infectious, but maybe less so
Generally good health
Everyone infected is a carrier
Lasts for years
NOT a quiet time for the virus
• 10
10
new virus / day
• T‐cells destroyed every day
• HIV mutants accumulate |
|
|
Term
| Late stage: pre AIDS/ AIDS |
|
Definition
Acquired
ImmunoDeficiency
Syndrome
Weight loss, night sweats, fever, malaise, loss
of appetite, diarrhea, swollen glands
Drop in CD4 count
Destruction of lymph glands
Breakdown of the immune system
OIs begin, Death |
|
|
Term
|
Definition
HIV positive test
AND
CD4 count <200 per l of blood
or
AIDS‐related opportunistic infections |
|
|
Term
| Human Immunodeficiency Virus (HIV) |
|
Definition
• Infectious agent that results in loss of immune defenses.
• Essential part of AIDS definition.
• Does not directly causes diseases. |
|
|
Term
| Acquired ImmunoDeficiency Syndrome (AIDS) |
|
Definition
Acquired ImmunoDeficiency Syndrome
• Collection of diseases that is acquired as a result of HIV infection.
• Opportunistic infections (OI) ‐ varies by person, real cause of
disease/death |
|
|
Term
|
Definition
|
|
Term
|
Definition
1) Binding (gp120‐CD4‐coreceptor)
2) Fusion/Entry
3) Reverse transcription (RNA DNA)
4) Integration (provirus)
5) Transcription (in nucleus)
6) Translation (in cytoplasm)
7) Assembly and Budding
8) Protease cleavage (maturation) |
|
|
Term
|
Definition
DRIFT:
Error‐prone RNA viral reverse transcriptase (RT)
Introduces 0.2‐2 mutations per genome per cycle
SHIFT:
Recombination between RNAs or viruses
Rate of roughly every 2 kb |
|
|
Term
|
Definition
HIV replicates ~ 24 h
Produces 10
10
new virions a day
Rapidly develops a “quasispecies”
New variants escape immune
surveillance |
|
|
Term
|
Definition
| Risk is 1 in 300 coital acts |
|
|
Term
| Conditions for HIV Transmission |
|
Definition
HIV present
HIV present if sufficient quantity
HIV must get into blood stream |
|
|
Term
| HIV Diagnostics- Antibody tests |
|
Definition
Detects antibody to HIV in blood or body fluids
• ‘Window Period’ ‐ the period of time between HIV infection and the production of antibodies. During
this time, an antibody test may give a ‘false negative’ result. |
|
|
Term
| HIV Diagnostics- RNA/DNA PCR test |
|
Definition
Detects genetic material of HIV
• Also known as ‘viral load test’ and HIV NAAT (nucleic acid amplification testing)
• Highly sensitive, permits early detection
• Used for screening blood/organ donations, used on newborn babies |
|
|
Term
| HIV Diagnostics- p24 antigen test |
|
Definition
Detects p24 capsid protein in blood serum
• No longer used in US or Europe because of low sensitivity |
|
|
Term
|
Definition
First anti‐HIV drug (1990s)
NRTI, thymidine analog
• Delays onset of AIDS
• Reduces mother‐to‐infant transmission, few if any side effects to fetus
no AZT, 24% w/AZT, 8%
Originally developed to treat cancer
Does not interfere with normal T‐cell function
Side effects |
|
|
Term
HAART
Highly Active AntiRetroviral Therapy |
|
Definition
Triple therapy = 2 NRTIs + 1 Protease inhibitor
Effective in about 70% of patients
Restores immune system
Delays disease progression
Issues:
• Non‐compliance
• Drug regimen is difficult (many pills, side‐effects)
• Expensive
• Drug resistance |
|
|
Term
|
Definition
Drug therapies reduce HIV virus levels
They prolong lives
But . . .
Not all patients can tolerate them
The infection is not cured
Drug resistance is growing
HIV infection still means 100% mortality |
|
|
Term
|
Definition
| Too many varying strains, hard to find one that can treat all of the different types in different areas. |
|
|
Term
| Humans are walking Pteri dishes! |
|
Definition
Humans are walking petri plates:
constant temperature - 37°C
moist
nutrients, glucose
Only stop against growth of
infections is human immune
system |
|
|
Term
| Immune suppression caused by HIV |
|
Definition
Immune system stops working -
things start growing
Depends on what is already there,
and what comes along
HIV causes a decline in the CD4+ T cells
(subset of T cells) that control
organisms colonizing humans |
|
|
Term
| Opportunistic Infections in regards to AIDS |
|
Definition
OIs associated with Pre-AIDS and AIDS
OIs previously defined AIDS |
|
|
Term
|
Definition
Immune system starts to show signs of damage
Infections not life-threatening |
|
|
Term
| Early markers of failing immune system |
|
Definition
Candida
Oral hairy leukoplakia
Herpes zoster (shingles)
Bacilliary Angiomatosis |
|
|
Term
|
Definition
yeast / fungus
related to bakers yeast
dimorphic
most common OI in AIDS
90-95% of AIDS patients will
have candidiasis at least once |
|
|
Term
|
Definition
Colonization (at birth)
Disease
oral and esophagus - in AIDS
pseudomembranous
erythematous
vaginal
blood and organs - not in AIDS |
|
|
Term
| Candida Infection treatment |
|
Definition
antifungals
prescription
over the counter
Resistance was a problem before HAART |
|
|
Term
|
Definition
DNA Virus - Epstein-Barr Virus
• mononucleosis - saliva transfer
• latent until immune system
compromised
Early sign of failing immune system
Frequently confused with candidiasis
Treatment -
acyclovir, topical antivirals |
|
|
Term
|
Definition
DNA Virus - Varicella zoster
chicken pox virus
latent until immune system compromised
shingles = reactivation
Blisters on path of nerve extremely painful
Treatment -
antivirals like acyclovir
severe cases - IV
Prevention of recurrence - acyclovir |
|
|
Term
|
Definition
Cause - bacteria “Rochalimaea”
Skin nodules - similar to
Kaposi’s sarcoma
Blood vessels grow out -
tumor-like masses
Bone, spleen, lymph and liver |
|
|
Term
| Bacilliary angiomatosis- Rochalimaea henselae |
|
Definition
cat scratch disease
cats have bacteria in
blood
transmitted by fleas
(avoid cats?) |
|
|
Term
| Bacilliary angiomatosis- Rochalimaea quintana |
|
Definition
lice carry the bacteria
very common in
homeless
trench fever in WWI |
|
|
Term
| Treatment for Bacilliary angiomatosis |
|
Definition
antibiotics
treatment for other OI
usually controls for BA |
|
|
Term
| OIs that appear with CD4+ T cells below 200 cells/uL |
|
Definition
| Tuberculosis Pneumocystis carinii Kaposi’s Sarcoma |
|
|
Term
|
Definition
Fungus / yeast
(was thought to be a protozoa)
Most common life-threatening OI
Life cycle is not known
Cell culture still not possible
Usually a lung infection
Pneumocystis carinii pneumonia (PCP)s Infects lungs occur early in life |
|
|
Term
|
Definition
drugs available
easy to develop allergic reaction
alternative - aerosolized drug |
|
|
Term
|
Definition
First identified in older men of Mediterranean
or Jewish descent
Tumors of blood vessels - purple or black spots
Skin - usually cosmetic, can involved internal organs |
|
|
Term
|
Definition
DNA virus – KSHV / KSV
related to herpes
sexual transmission (?) |
|
|
Term
| Kaposi's Sarcoma Treatment |
|
Definition
radiation
chemotherpy
antivirals |
|
|
Term
| OIs that appear with CD4+ T cells below 100 cells/uL |
|
Definition
Blastomyces Coccidioides Histoplasma
Penicilium CMV Apthous ulcers |
|
|
Term
|
Definition
Blastomyces
Coccidioides
Histoplasma
Penicilium
Hyphae at room temperature
Yeast cells in humans
Start out as lung infections
Can move into blood.
Frequently go to skin (cooler) |
|
|
Term
|
Definition
Associated with
swamps, marshes,
decaying plantlife |
|
|
Term
| Coccidioides Distribution |
|
Definition
US& South America
Construction,
agriculture
archeological digs,
earthquakes |
|
|
Term
|
Definition
| associated with bird dung |
|
|
Term
|
Definition
Fungus - related to fungus that
produces penicillin
Only found in Southeast Asia
Very common there
Carried by bamboo rats |
|
|
Term
|
Definition
CMV - herpes like DNA virus
50% of all adults already infected
Attacks eyes, colon, throat, others
CMV retinitis - blindness
Protease inhibitors for HIV may
increase chance of CMV retinitis |
|
|
Term
|
Definition
Blisters - oral and genital
Apthous = speck, flake or blister
Cause unknown (immune response)
3% of AIDS patients
Increased in HAART therapy
Treatment - thalidomide
problems with pregnancy |
|
|
Term
| OIs that appear with CD4+ T cells below 50 cells/uL |
|
Definition
MAC
Cryptococcus
Cryptosporidium
Toxoplasmosis |
|
|
Term
| Mycobacterium avium complex (MAC) |
|
Definition
related to M. tuberculosis
water and soil born
Non-HIV = respiratory
HIV = usually disseminated
Night sweats, fevers, weight loss,
diarrhea, painful intestines
50% of late stage AIDS have MAC
Treatment - antibiotics
which also control BA |
|
|
Term
|
Definition
Cause - yeast/fungus
Cryptococcus neoformans
Lung to Brain
Soil contaminated with
bird droppings (pigeons)
(Seattle has few pigeons)
Fairly rare in general
Common in homeless, city dwellers
Treatment
difficult to treat brain
resistance
need prevention forever after
(Australia and Vancouver Island) |
|
|
Term
|
Definition
Parasitic protozoan
Cryptosporidium parvum
Intestines - many animals
Contaminated water or
fecal / oral contact
Avoid fecal / oral contact
and contaminated water |
|
|
Term
| Cryptosporidiosis problems |
|
Definition
Non-HIV - self-curing diarrhea
HIV - months, explosive, watery,
No good treatment for the disease
Minneapolis - 1993, 100 deaths
Major push by EPA to eliminate
Cryptosporidium from water sources
(Water filters for immune-compromised ?) |
|
|
Term
|
Definition
Parasitic protozoan
Related to malaria
Targets brain and lungs
One of the most common CNS
infections in the world |
|
|
Term
|
Definition
Common methods of infection:
cat feces / litter boxes
uncooked meat
steak tartar - French
Major problem if any infection
occurs while pregnant
In HIV, treatment effective
Need continuous prevention after |
|
|
Term
|
Definition
Frequency of OI
drastically decreased
HIV is developing
resistance to HAART
OIs are returning slowly
Will same OIs come back |
|
|
Term
| STD = Sexually Transmitted Disease |
|
Definition
| more recent term due to broader range |
|
|
Term
| STI = Sexually Transmitted Infection |
|
Definition
infected person can transmit without having
disease |
|
|
Term
|
Definition
old terminology from
Roman goddess of love (Venus) |
|
|
Term
|
Definition
One in five people in the US has an STD
2/3 of all STDs occur in people 25 years and
younger
One in four new STI occurs in teenagers
At least one in four Americans will contract an STD
during their lifetime
At least 15% of infertile US women are caused by
untreated STD
Bacterial STDs are curable with antibiotics |
|
|
Term
|
Definition
Syphilis (Treponema pallidum)
Gonorrhea (Neisseria gonorrhoeae)
Chlamydia trachomatis
Mycoplasma genitalium
Ureaplasma urealyticum
Chancroid (Haemophilis ducreyi) |
|
|
Term
| Main Symptoms and Disease |
|
Definition
50-75% have no symptoms (lag time
between infection and complications)
Lower abdominal pain
Abnormal discharge
Genital Ulcers
Painful or frequent urination
If left untreated:
Pelvic Inflammatory Disease (PID)
Infertility |
|
|
Term
|
Definition
Microscopy
Gram stain
Culture of organism
Slow growth (2 days minimum)
Some pathogens do not grow
Molecular biology methods (quick)
Polymerase Chain Reaction (PCR)
DNA probe, DNA sequencing
NAAT (Nucleid Acid Amplification Test) |
|
|
Term
|
Definition
Cause of Syphilis
Gram-negative spiral-shaped
bacteria
Humans only reservoir
Diagnosis:
Never grown in culture
Presence of Syphilis antibodies in
blood sample
Treatment: Penicillin |
|
|
Term
|
Definition
Primary lesion or Chancre
(ulcerated lesion) at site of
infection
hard red nodule
filled with infectious
Treponema pallidum
usually painless
starts 10-90 days after
exposure, lasts 1-5 weeks
heal on their own
1/3 of untreated people
develop secondary syphilis |
|
|
Term
|
Definition
Dissemination and symptoms throughout
the body
malaise and fever
rashes involves all skin surfaces- palms, soles,
swollen lymph glands
0-10 weeks after chancre,
lasts 2-6 weeks
highly infectious
May reoccur in 25% of
untreated patients |
|
|
Term
|
Definition
Can last for several years, spontaneous cures
unusual
No symptoms but bacteria still there and
growing
usually in spleen and lymph nodes, but also heart, eyes,
nerves, bones, joints, liver, brain
usually relatively non-infectious
Eventually damage so serious that symptoms
occur
often fatal
usually starts an autoimmune response |
|
|
Term
|
Definition
Rarely seen today due to
effective and prevalent
antibiotica
Many forms, depending on
which organs are affected
Occurs in 1/3 of untreated
patients, 20-40 years after
onset infection
Almost any tissue can be the
target
Really, it is just which one
fails first |
|
|
Term
|
Definition
Clinical study conducted in Tuskegee
(Alabama) to observe natural progression of
disease when left untreated
Poor, mostly illiterate, African-American men
with syphilis were deliberately and
systematically denied effective treatment
Controversy over unethical research behavior
led to major changes in patient protection in
clinical studies |
|
|
Term
|
Definition
Clinical study conducted in Tuskegee
(Alabama) to observe natural progression of
disease when left untreated
Poor, mostly illiterate, African-American men
with syphilis were deliberately and
systematically denied effective treatment
Controversy over unethical research behavior
led to major changes in patient protection in
clinical studies |
|
|
Term
|
Definition
STD
Blood contact
Direct contact with open chancres
Oral sex - much more than HIV
Reportable disease
CANNOT be transmitted by toilet seats,
drinking cups, doorknobs, money, etc. |
|
|
Term
|
Definition
Organism cannot be grown in culture
Detection of organisms
microscopically from lesion
specimen
Detection of antibodies in blood from
patient
Molecular methods difficult - can’t
grow to make DNA |
|
|
Term
| Current Syphilis Treatment |
|
Definition
Single dose of penicillin for active,
multiple doses for latent
almost 100% effective
no resistance yet seen -- a real puzzle!
Contact notification and public health laws
Problems with late stage treatment
autoimmune responses |
|
|
Term
|
Definition
2-10 days after infection
10% of infected males and 80% of infected
females are asymptomatic
Urethritis -
urethral discharge
inflammation
Painful urination
Bleeding
Burning
Painful sex
Swollen testicles |
|
|
Term
|
Definition
Urine sample or vaginal swab
Gram stain of exudate (quick)
Best in males, poor in females
Culture of organism (2 days)
Fluorescent antibody
Molecular biology methods (quick)
Polymerase Chain Reaction
NAAT (Nucleid Acid Amplification
Test), based on amplification of DNA |
|
|
Term
|
Definition
Originally the organisms were highly susceptible to
penicillin and tetracyclines, but resistance
developed
Current therapy: Cephalosporins |
|
|
Term
| Principal agents Non-gonococcal urethritis (NGU) |
|
Definition
Chlamydia
• Mycoplasma genitalium
• Ureaplasma urealyticum |
|
|
Term
|
Definition
Most common STD in the US
25% males and 30% females have no
symptoms
If symptoms appear usually 1-3 after exposure
Transmission with gonorrhea and syphilis,
screen for all
Difficult to distinguish from gonorrhea
Only in 1963 identified as STD |
|
|
Term
|
Definition
Gram-negative, Originally, thought to be a virus,
because small round organisms 0.3 uM diameter
Obligate intracellular parasites (only lives inside human
cell)
Chlamydiae cannot synthesize adenosine triphosphate
(ATP)
Have two phases
RB = Reticulate body; intracellular replicative form
EB = Elementary body; extracellular infective form
with little metabolic activity |
|
|
Term
|
Definition
Microscopy
Culture is very slow
Molecular Methods: DNA probes, PCR, DNA
sequencing, NAAT (replaced culture) |
|
|
Term
|
Definition
Easily treated with antibiotics (azithromycin or
doxycycline) |
|
|
Term
| Syphilis Male to Female Ratio |
|
Definition
|
|
Term
| Gonorrhea Male to female ratio |
|
Definition
|
|
Term
| Chlamydia Male to Female Ratio |
|
Definition
|
|
Term
Mycoplasma genitalium and
Ureaplasma urealyticum |
|
Definition
Small bacteria 0.2 -0.5 uM without a cell wall
Originally isolated in 1980
Smallest genome (521 genes) known for free-living
organism
Grow on surface of animal cell
Mycoplasma genitalium is very difficult to grow.
Ureaplasmas also have no cell wall and have a small
genome
Both are found frequently in the genital tract |
|
|
Term
Diagnosis of Mycoplasma genitalium and
Ureaplasma urealyticum |
|
Definition
PCR is only method available
Culture
rarely successful ; very slow; cross contamination
with lab strains - verified by DNA sequencing |
|
|
Term
Treatment of Mycoplasma genitalium and
Ureaplasma urealyticum |
|
Definition
Antibiotics; resistant to azithromycin and susceptible
to tetracyclines, but become resistant |
|
|
Term
|
Definition
Caused by a bacterium, Haemophilus ducreyi
Genital blisters and ulcers
Diagnosis by culture of organism (slow and only a few
laboratories do it)
Treatment: cephalosporins, azithromycin and
quinolones
Prevalence: Rare in USA, mainly in developing
countries (tropics)
Risk factor for HIV infection |
|
|
Term
| US and global Distribution of STDs |
|
Definition
~19 million new STD infections/year (USA)
~1 billion STI worldwide/year (1 every 3 adults)
~448 million new cases of curable STIs/year
Up to 80% of curable STIs occur in developing
countries
Half of them among ages 15-24
Costs ~$15,9 billion annually |
|
|
Term
|
Definition
Declining rates of curable STD in
industrialized Countries (Syphilis,
Chlamydia, Gonorrhea) |
|
|
Term
|
Definition
Viral STD remain a major problem in the US
US highest rates of curable STDs compared
to other industrialized countries
Emerging antimicrobial resistance |
|
|
Term
|
Definition
Identify and treat infected persons (very successful
in gonorrhea and syphilis)
Partner notification
Use of condoms
Development of bactericidal and viricidal
preparations for vaginal use
Vaccination against HPV
Education of youth
Success in HAART in HIV infections may have lead
to an increase in syphilis in men who have sex
with men. |
|
|
Term
|
Definition
- Resemble organisms (genes, self-reproduction), but no own
metabolism or cell division
- Consist of genetic material (DNA or RNA) surrounded by
protective coat of proteins
- Invade host cells and take over the machinery and
metabolism of host cells
- One single virus infected cell may yield as many as 10
6
viruses (“viral factories”)
- Viruses even smaller than bacteria (HIV has 9 genes)
- Antibiotic drugs only kill bacteria not viruses |
|
|
Term
| The Baltimore Classification of Viruses |
|
Definition
- DNA/RNA
- Double/single stranded
- positive(+)/negative(-) sense |
|
|
Term
|
Definition
- Herpes Simplex Virus
- Human Papilloma Virus
- HIV
- Hepatitis B |
|
|
Term
|
Definition
- Double-stranded linear DNA within
icosahedral capsid
- Wrapped in lipid bilayer (envelope)
- ~ 74-94 genes (HSV)
- Greek for “creep”
(spread on skin)
- Causes life-long infection where the
virus is latent (dormant/hiding)
- Very well adapted to host and
host immunity |
|
|
Term
|
Definition
Oral Herpes
Oral transmission, but can be sexual
Usually above the waist, increasing rate of genital infection |
|
|
Term
|
Definition
Genital herpes
Sexual Transmission
Genital infection |
|
|
Term
| Herpes Simplex Virus (HSV) |
|
Definition
- Infection often asymptomatic
asymptomatic persons can transmit |
|
|
Term
|
Definition
Viral latency: periodic recurrence of lesions
Initial lesion most painful w/ gradual lessening of severity over time
Reactivation triggers: sunburn, fever/illness,
“exam stress”
Transmission during reactivation of virus
least to most frequent: oral HSV2, genital HSV1, oral HSV1, genital HSV2 |
|
|
Term
|
Definition
- Worldwide rates of HSV between 60-90%
- HSV1 more common than HSV-2
- Prevalence of genital herpes
1 out of 4 or 5 persons
(20-25% of sexually active persons)
Only ~20% of HSV-2 seropositive are aware of infection
- Women have higher rates of infection than men
- Incidence of genital herpes:
500,000 new cases per year in the US (total 40-60M) |
|
|
Term
| HSV Diagnosis- Virologic tests (direct detection of virus) |
|
Definition
- Skin biopsy or scraping from active lesion
- Virus isolation in tissue culture
- PCR to test for viral DNA |
|
|
Term
| HSV Diagnosis- Serologic (blood) tests (indirect detection) |
|
Definition
- Antibody tests – past exposure
- New Ab test (Immunodot) can discriminate
between HSV-1 and HSV-2 |
|
|
Term
|
Definition
- Antiviral medication can shorten & prevent outbreaks
- Acyclovir and related ”cyclovirs” interfere with viral
replication and suppress symptoms
- Valacyclovir/Valtrex (late night TV ads) oral formulation
- Vaccines have been tried and are ongoing:
- No success at prevention
- No success for treatment of existing disease |
|
|
Term
|
Definition
Small double-stranded nonenveloped DNA virus
Several 100 genotypes
Infection mostly asymptomatic
Highly host- and tissue-tropic
HPV also known as “common
cold” of STI; Worldwide
prevalence is 10%
At least 50% of sexually active
men & women get it at some
point (CDC) |
|
|
Term
|
Definition
- Transmission mostly skin contact (genital & genital/hand)
- In 90% of cases HPV is cleared by immune system
- Depending on immune system and HPV type can cause:
- Genital warts, rarely in throat
- Cervical cancer (take years
to develop) |
|
|
Term
| High risk vs. Low risk HPV |
|
Definition
Several 100 genotypes
types
of which >40 sexually
transmitted
15 are high-risk types
(cancer)
Infection mostly
asymptomatic |
|
|
Term
|
Definition
DNA from tissue
PCR
Sequencing |
|
|
Term
|
Definition
Topical Creams (Imiquimod)
Cryotherapy with liquid nitrogen
Trichloroacetic acid
Surgical removal |
|
|
Term
| Epidemiology of HPV& cervical cancer |
|
Definition
- 5
th
most common cancer in women worldwide (US 8
th
)
- More than 85% cases occur in developing countries,
where accounts 13% of all female cancers
- Annual cases in the US :
- 6.2 million new HPV infections (male & female)
- 12,000 women get cervical cancer, 3,900 fatal
- Other HPV-associated cancers: vulvar, vaginal,
penile, anal
- Factors associated with cervical cancer (& other STDs)
- Age at first intercourse
- Number of partners |
|
|
Term
|
Definition
- HPV access & infects basal cells via micro-abrasions
- HPV infects & replicates in epithelial cells
- Immune systems eliminate infection in 90% within 2 years
- Integrated viral DNA inactivate genes that suppress cancer |
|
|
Term
|
Definition
- detects small
pre-cancer (dysplasia) &
cancer cells from cervix
- Cervical cancer evolves
slowly through a number
of stages (20-40 years)
- Regular screen greatly reduced incidence of
cervical cancer rates (~80%)
- 90% of cervical cancer is curable |
|
|
Term
|
Definition
| there is currently NO treatment |
|
|
Term
| Cervical Cancer Treatment |
|
Definition
treatment depends on stage,
may include surgery, chemotherapy |
|
|
Term
| What types of HPV does the vaccine protect against? |
|
Definition
HPV 16 and 18 (cervical)
HPV 6 and 11 (genital warts) |
|
|
Term
|
Definition
| HPV vaccine for only 16&18 |
|
|
Term
| Viral hemorrhagic fevers VHF |
|
Definition
described multisystem organ dysfunction
accompanied by hemorrhage (bleeding)
- Bleeding itself rarely life-threatening, but shut-down of
organs (multi-organ failure)
- Death rate varies - 20 to 70%
- Incubation - two to three weeks
- Spread in health-care facilities where sterile materials
are at a premium is a major problem |
|
|
Term
|
Definition
All RNA viruses
Humans are not the natural
host
Zoonotic (animal born)
transmission
(animal/arthropod are hosts)
Diagnostic mostly by PCR on
virus isolate |
|
|
Term
|
Definition
- Fever, fatigue, dizziness, muscle aches,
loss of strength, exhaustion
- Severe cases:
bleeding under skin and internal
organs or mouth, eyes and ears
- Also, shock, nervous system
malfunction, coma, delirium and
seizures |
|
|
Term
|
Definition
No vaccines, with the exception of yellow
fever and Argentine hemorrhagic fever
No cure or established treatment
- Ribavirin, anti-viral drug
- Supportive Therapy: balancing fluids
and electrolytes, maintain oxygen levels
- Prevention by controlling rodent
populations and spread of insects and
arthropods |
|
|
Term
|
Definition
single-stranded
RNA virus
_____ first described in 1977,
_____ in 1967
Biosafety Level 4
Fatal in humans and nonhuman primates |
|
|
Term
|
Definition
- Natural reservoir unsure
(exact origin, location, habitat or host)
- Animal host is native in Africa
- People-to-people transmission via
direct contact with blood/secretions
- One of the most virulent viruses known – fatality
rate ~70%
- Currently, low potential to become epidemic due
to high fatality rate, quick demise (7-14 days)
and presence in remote areas |
|
|
Term
|
Definition
- Marburg virus
Marburg, Germany (Lab) 1967
Angola 2005
Congo 2007
(survival of gorillas threatened)
Uganda 2007
- The source of the virus in the Marburg Germany
outbreak was green monkeys imported from Uganda
(7/31 deaths/cases)
- Spread through body fluids
- Airplanes are a concern as a mode of transmission |
|
|
Term
|
Definition
- Incubation for 5-10 days
- Symptoms – multiorgan dysfunction
hemorrhaging rare
- Symptoms similar to other infectious diseases,
such as malaria and typhoid
- Mortality - 25-90%
- Treatment - supportive care, no drugs available
- Ebola/Marburg vaccine in development
- Barrier protection for Health care Workers |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Two single-stranded negativesense RNA
Infect rodents, occasionally
humans
Divided in Old World and New
World, depending on location
6 arenaviruses cause
hemorrhagic fever in humans
Focus: Lassa Virus |
|
|
Term
|
Definition
- First described - 1969 in Lassa, Nigeria
- Major cause of illness in West Africa
- Carried by rodents (feces, urine)
- Transmission via inhalation of rodent
excrement (respiratory or
gastrointestinal)
- Spread from one human to another
- 300,000 to 500,000 cases/year,
resulting in 5,000 deaths |
|
|
Term
|
Definition
- Humans show a broad spectrum of disease ranging
from subclinical infections to serious illness to death
(1% mortality)
- About 20% of infected people become sick
- Symptoms
fever, aches and pains, multi-organ failure
lungs, heart, GI tract, nerves
- Incubation - 1 to 3 weeks
- Drug - ribavirin (early), interferes with RNA
metabolism required for viral replication
- Treat symptoms
- No vaccine (yet)
- Limit exposure |
|
|
Term
|
Definition
Lusaka (Zambia),
Johannesburg |
|
|
Term
|
Definition
- Started in Lusaka, Zambia, 1 sick patient airlifted
to Johannesburg for medical treatment
- 5 people total in Fall 2008
- 1 travel agent (primary/index case)
- 4 HCW (hospital care worker)
- Ribavirin used to treat survivor (?)
- Distant to Lassa, more aggressive, highly
fatal (4 out of 5 = 80% case fatality)
- Rodent based |
|
|
Term
|
Definition
A eukaryotic organism that lives on or in
another host organism in a way that
harms or is of no advantage to the host |
|
|
Term
|
Definition
single cell
Sexual and asexual reproduction |
|
|
Term
|
Definition
multicelled
containing nervous tissue, muscle
fibers and reproductive tract
Sexual reproduction |
|
|
Term
| Tropical disease Risk factors |
|
Definition
Poverty
– Sanitation, clean water, vaccines, education
Drug resistance
War, refugee camps
– Lack of basic infrastructure
Movement to new areas - emergence
Population expansion (urbanization)
Emergence of new diseases
– Cryptococcus gattii
Climate changes
Global travel |
|
|
Term
|
Definition
• Organism in which a
parasite reproduces
sexually |
|
|
Term
|
Definition
• Organism in which
a parasite does NOT
reproduce sexually |
|
|
Term
|
Definition
• Non-human
organism which can
harbor parasites |
|
|
Term
|
Definition
Apicomplexans
Malaria
Toxoplasmosis
Cryptosporidiasis
Kinetoplastids
African Sleeping Sickness
Chagas Disease
Leishmaniasis
Amitochondriates
Giardiasis
Amebic Dysentery |
|
|
Term
|
Definition
Disease resembling ______ described over
4000 years ago in China
Transmitted by night-biting Anopheles
mosquitoes
Number one killer of children under 2 years
of age |
|
|
Term
|
Definition
parasite lives and
divides inside a liver cell; liver
cell bursts and releases
parasites into the blood stream |
|
|
Term
|
Definition
- parasites invade
Red Blood Cells (RBCs), divide
and invade new red blood cells
Blood cells infected with
Plasmodium falciparum
parasites are able to adhere to
the walls of blood vessels |
|
|
Term
| Childhood malaria- cerebral Malaria |
|
Definition
parasitized red blood cells bind
to the blood vessels of the brain
coma, convulsions death |
|
|
Term
|
Definition
Destruction of red blood cells
Children with severe malarial
anemia can be stunted
physically and intellectually
Can be fatal |
|
|
Term
|
Definition
Pregnant women are especially susceptible to malaria
Parasites attach to the placenta (not present in nonpregnant women
Maternal severe anemia
Maternal death
Low birthweight
Most severe in the first pregnancy; becomes less
severe with subsequent pregnancies as immunity
develops
75,000-200,000 infant deaths per year |
|
|
Term
|
Definition
mutation in the hemoglobin A
gene, called HbS
Individuals with two copies suffer
from Sickle Cell disease
Individuals with one copy of the
mutation are protected from
cerebral malaria
Highly prevalent in Sub-saharan
Africa |
|
|
Term
| Preventing Malaria Transmission |
|
Definition
Target the vector
Insecticides
Barriers (Bed nets)
Source reduction |
|
|
Term
| Current Malaria strategies |
|
Definition
ndoor Residual Spraying
DDT, other insecticides
Source reduction
Drainage
Oils, toxins, larva
predators (fish)
Bed nets
Insecticide-treated
Antimalarial drugs
Artemisinin Combination
Therapy (ACT) |
|
|
Term
| Problems with Malaria Eradication |
|
Definition
Resistance to DDT and other insecticides
Overspray leads to environmental
damage and resistance
Quantities used for vector control are
much smaller than agricultural use
Resistance to chloroquine and other
antimalarial drugs |
|
|
Term
|
Definition
African Sleeping Sickness
Chagas Disease
Leishmaniasis |
|
|
Term
| African sleeping Syndrome |
|
Definition
Trypanosoma brucei gambiense
Incubation period of days to weeks
Ulceration at the bite site
Winterbottom’s sign (nodules on neck)
Chronic disease if untreated
Trypanosoma brucei rhodesiense
Short incubation time
Acute disease progresses rapidly with damage to
CNS, kidneys, and heart |
|
|
Term
| Stages of African Sleeping Sickness |
|
Definition
Early stages, parasites in blood and
lymph
Swollen lymph nodes
Anemia
Later stages, parasite crosses the bloodbrain barrier
Confusion
Daytime sleepiness/night insomnia
Coma
Once the disease has crossed the
blood-brain barrier, the treatment
options are limited |
|
|
Term
| African sleeping Sickness Treatment |
|
Definition
All drugs used are highly toxic
Early phases of disease
Suramin (1916)
Pentamidine (1941)
Late stage of disease
Melarsoprol (1949)
causes death in 5% of patients
Tryparsamide (1919)
Eflornithine (hair growth inhibitor) |
|
|
Term
|
Definition
Caused by a related species of T. brucei
Does not cause disease in humans
Profound effect on settlement and economic
development in endemic regions |
|
|
Term
|
Definition
| intracellular to white blood cells |
|
|
Term
|
Definition
Infected reduviid bug takes blood meal
(Saliva not infected)
Bug defecates during feeding
(Feces contain parasites )
Host scratches bite wound
Parasites enter host |
|
|
Term
| Chagas disease related to reduviid range |
|
Definition
At risk: 100 million
Humans infected: 16-18 million
Deaths: 14,000/year |
|
|
Term
|
Definition
1%
Most severe in children under 5
Swelling and redness at bite site
Fever, chills, malaise
Death can occur within weeks |
|
|
Term
| Chagas Disease- chronic and asymptomatic |
|
Definition
20%
Organisms invade and multiply within host
tissues including heart, spleen, liver, and
brain
Chronic infections can last up to 20 years
Chronic Chagas disease is a common
cause for heart transplants |
|
|
Term
| leishmanisis disease range |
|
Definition
350 million at risk
2 million cases/year
60,000 deaths/year |
|
|
Term
|
Definition
Leishmania braziliensis
(new world species)
Mucosal localization
Severe disfigurement |
|
|
Term
Visceral Disease
Leishmania donovani |
|
Definition
Kala-azar
bone marrow
problem in HIV
enlargement of
spleen and liver
fatal if left untreated
Post Kala-azar
dermal leishmaniasis |
|
|
Term
| Treatments for Leishmaniasis |
|
Definition
Pentavalent antimonials (heavy metals)
toxic
resistance
Amphotericin
also toxic
Miltefosine
highly effective in patients co-infected with HIV
orphan drug
Liquid Nitrogen
cutaneous leishmaniasis |
|
|
Term
Challenges for
Kinetoplastid prevention |
|
Definition
Outdated drugs:
Arsenicals (1950s): African sleeping
sickness
Antimonials (1940s): Leishmaniasis
Nitroimidazoles (1960s): Chagas disease
Vaccines: we have no effective vaccines
Diagnostics: we need improved ways to
diagnose new cases and monitor
response to therapy |
|
|
Term
|
Definition
Major cause of diarrhea
Lack mitochondria (energy in most
eukaryotes)
Require reduced amounts of oxygen to live
Extracellular life cycle
Typically found in intestinal tract |
|
|
Term
|
Definition
Acute disease (1-3 weeks)
Nausea, vomiting, diarrhea
Chronic disease
Destruction of intestinal wall
Nutritional deficiency –
attachment to intestinal wall
Infectious dose as little as 10 cysts
Up to 1 billion cysts excreted per day
during acute stage
Cysts continue to be shed after
symptoms resolve |
|
|
Term
|
Definition
280 million annual infections
Most commonly identified intestinal parasite in the
U.S. (2.5 million cases per year)
Rocky Mt. waters
Day care centers |
|
|
Term
|
Definition
Mild to asymptomatic in 90% of infections
Bloody diarrhea, abdominal pain
Parasites can rapidly spread from the
intestine to liver, lungs, heart, and brain |
|
|
Term
Metazoan Parasites
(Helminths) |
|
Definition
Schistosomes
Schistosomiasis
Swimmer’s itch
Filariasis
River blindness
Lymphatic filariasis
Hookworm
Iron-deficiency anemia
Failure-to-thrive syndrome
Guinea worm |
|
|
Term
|
Definition
A single worm pair produces 2000 eggs per day
Most eggs get stuck in the body -- Strong immune response
Obstructions, liver cirrhosis, bladder cancer Hepatosplenic
enlargement
Chronic disease
carried by snails
cercariae pierce skin |
|
|
Term
|
Definition
|
|
Term
|
Definition
120 million at risk
18 million are infected
270,000 are blind |
|
|
Term
|
Definition
African river blindness
Nodules containing multiple male and female
worms form under the skin
Inflammation, itching, and swelling
Depigmentation
Worms migrate to the cornea
chronic inflammation leads to opaque cornea |
|
|
Term
|
Definition
developed by Merck in 1980s
Used to treat worm infections in animals
Found to be effective against Onchocerca
Merck partnered with WHO and others to
distribute Ivermectin freely to affected
populations
Profits from veterinary sales supported this
program
600,000 cases of river blindness have been
prevented |
|
|
Term
| Lymphatic filarisis Distribution |
|
Definition
1.2 billion at risk
120 million affected
15 million severe
lymphodema/leg elephantiasis |
|
|
Term
| Lymphatic Filarisis (elephantiasis) |
|
Definition
Adult worms live in lymphatic system
Obstruction of lymphatic system leading to
swelling
can only be managed, not cured |
|
|
Term
|
Definition
1909, John D Rockefeller donated
$1 million to eradicate hookworm |
|
|
Term
|
Definition
More than 1 billion people infected
feed on blood by
causing intestinal hemorrhages
Blood loss (Up to 0.3 mL per worm
per day)
Iron-deficiency anemia – intellectual
impairment
Stunted growth
Anti-helmetics are effective, BUT reinfection rates are high
Preventative “deworming”
correlates with improved outcomes |
|
|
Term
|
Definition
bat, rodent,
monkey, etc. |
|
|
Term
|
Definition
|
|
Term
|
Definition
air, blood, sexual,
fomite (inanimate
disease carrier) |
|
|
Term
Vector-borne
transmission: |
|
Definition
primarily
arthropod
(insect) bites |
|
|
Term
|
Definition
|
|
Term
|
Definition
Intermediate hosts, primarily insects
Do not cause disease themselves
Spread infection
Transmit pathogens from one human host to
another, or from an infected host to a reservoir
and then to another uninfected host.
Typically not susceptible to the pathogen
Can serve as a critical amplification and
physiological step in pathogen’s lifecycle |
|
|
Term
| Vector Borne Diseases- viruses (mosquitoes) |
|
Definition
West Nile
Dengue
Yellow Fever
Recent and Rare
Chikungunya
Nipah and Hendra (Viral diseases, NOT vector-borne) |
|
|
Term
| Vector Borne Diseases- bacteria |
|
Definition
Lyme Disease (Ticks)
Rocky Mountain Spotted Fever (Ticks)
Tularemia (Ticks and Deer Flies)
Bubonic Plague (Fleas) |
|
|
Term
|
Definition
NOT A VIRAL GROUPING
Arthropod (mosquitoes, ticks, other insects, arachnids)
Borne
Viruses |
|
|
Term
|
Definition
Many arboviruses
Enveloped
Single-stranded RNA viruses |
|
|
Term
|
Definition
Flavivirus
Enveloped
(+) ssRNA virus
Similar to:
Dengue
Japanese encephalitis (JE)
St. Louis encephalitis (SLE)
Yellow Fever Virus (YFV) |
|
|
Term
| West Nile Virus Life cycle |
|
Definition
Primary host and resevoir: birds
primary vector: mosquitoes
incidental hosts: humans and horses- end of the line |
|
|
Term
|
Definition
First identified in Uganda
(West Nile District), 1937
First epidemic in Israel in
1951-54
Now common in Africa, W.
Asia, Europe, Middle East
First case in W. hemisphere in
NYC in 1999 |
|
|
Term
|
Definition
Many infections are asymptomatic
West Nile Fever
Fever, headaches, aches, rash, and swollen lymph
nodes
3-14 days after infection (mosquito bite)
Severe West Nile Disease
Virus enters the brain or the spinal cord
Meningitis or encephalitis (neuroinvasive)
10% mortality
Current infections in the US
50% neuroinvasive disease |
|
|
Term
|
Definition
Outdoor lifestyle (i.e. exposed to mosquito bites)
Over 50 years old or weakened immune system for severe disease
Blood/organ donation (now screened – risk is low to nil)
Case reports of:
Mother-to-child transmission
Lab-worker infection |
|
|
Term
|
Definition
| NO specific treatment for WNV infection (only for symptoms) |
|
|
Term
|
Definition
Preventing mosquito bites is key
Licensed equine vaccine, but no human vaccine |
|
|
Term
| Public health against WNV |
|
Definition
Focus is on avoiding vector
Insect repellent - DEET
Covering up - long sleeves
Reduce mosquito
populations/remove standing
water
Comprehensive educational
outreach for awareness |
|
|
Term
|
Definition
Flavivirus
(+) ss RNA
4 virus serotypes
Vector:
Aedes mosquito (primarily female)
Mosquito can transmit the virus for it’s
whole life (1 month)
Host:
Human (transmitted via vector)
Virus can be vertically transmitted to the fetus in
utero or to an infant during childbirth
One of the most widespread arboviruses |
|
|
Term
|
Definition
| occur 4-7 days post infections |
|
|
Term
|
Definition
High fever and at least two of the following:
Severe headache
Severe eye pain (behind eyes)
Joint pain
Muscle and/or bone pain
Rash
Mild bleeding manifestation (e.g., nose or gum bleed or easy bruising)
Low white cell count
Young children and those with first dengue infection have a
milder illness than older children and adults. |
|
|
Term
|
Definition
(untreated ~20% mortality)
Dengue hemorrhagic fever (DHF)
Dengue shock syndrome (DSS) |
|
|
Term
| Global burden of Dengue and DHF |
|
Definition
• 50 million infections/year
• 500,000 cases of
DHF/year
• 22,000 deaths (mostly in
children)
• Increased travel
• Geographical expansion
of the mosquito
• Breakdown of vector
control |
|
|
Term
| Dengue fever and immune response |
|
Definition
4 virus stereotypes
If infected with serotype 1:
Immunity to 1 and
Temporary immunity to 2, 3, 4 (~3 months)
Increased likelihood of DHF/DSS in subsequent dengue virus
infection of a different serotype (1 then 3, or 4 then 2, etc)
Non-protective antibodies cause severe disease via immune
system-enhancement
Implications for vaccine development |
|
|
Term
|
Definition
Treat with fluids
supportive care
no effective antivirals available |
|
|
Term
|
Definition
No current vaccine
Experimental vaccine(s) in development
Problem with non-protective antibodies and
increased DHF risk |
|
|
Term
|
Definition
Similar to West Nile and other vector-borne
diseases
Mosquito control
Surveillance |
|
|
Term
| Dengue vaccine in clinical trials |
|
Definition
Circulating serotype 2 virus
Vaccine effective against serotypes 1, 3 and 4
Overall effectiveness ~30%
No enhancement of disease (this was highly
important)!
By end of 2014, results of large clinical trials will be
completed |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| Yellow fever transmission |
|
Definition
Vector-borne (human-vector)
-human or monkey-vector-human) |
|
|
Term
|
Definition
Aedes mosquito
Vertical transmission (virus passed from
mother to mosquito eggs) |
|
|
Term
|
Definition
3-6 days after infection
Asymptomatic infection is common |
|
|
Term
| Yellow fever symptoms- mild case |
|
Definition
Fever, headache, malaise
Patient recovers in 3-4 days |
|
|
Term
| Yellow Fever- Toxic Phase (severe cases) |
|
Definition
(~15% of infection)
“Yellow” - jaundice
Abdominal pain with vomiting
Severe hemorrhages
20-50% mortality in 10-14 days |
|
|
Term
|
Definition
| NO specific treatment (only for symptoms) |
|
|
Term
|
Definition
Effective vaccine for 50 years
BUT lack a vaccination program to distribute it
Vaccination requirement for travelers from/to
endemic countries
Mosquito control |
|
|
Term
| Epidemiologic Surveillance Yellow Fever |
|
Definition
Generally low level of infections
Years or decades between epidemics
West Africa:
1-2 infections / 1000 people
0.2-0.5 deaths / 1000 people
Monkey to human transmission (via mosquito vector)
contributes to recent outbreaks
South America – lower risk
Monkeys do not play a large role in transmission |
|
|
Term
| Yellow Fever Distribution |
|
Definition
Recent cases restricted
to Africa and the Americas
No outbreak in North
America since 1905 (New
Orleans)
No reports from
Asia…yet
BUT appropriate vectors
are present in Asia – high
outbreak potential
US mosquitoes can carry
yellow fever, but mosquito
control helps |
|
|
Term
|
Definition
First outbreak in 1952 (Tanzania)
Virus identified in 1955
Alpha virus (Togaviridae) – (+) ssRNA
VECTOR: Aedes mosquito
HOST: Humans
SYMPTOMS (2-12 days after infection):
Viral fever, muscle pain, rash
“That which bends up” in Makonde (Tanzania)
Arthritic symptoms, rarely fatal |
|
|
Term
|
Definition
| NO current vaccine or treatment currently |
|
|
Term
|
Definition
Recently emerging viral disease – NOT vector-borne
Paramyxoviruses
(-) ssRNA viruses
Hendra – discovered in 1994 (Australia) – 3 cases
Nipah - discovered in 1999 (Malaysia)
RESERVOIR: fruit eating flying fox bats
HOSTS: humans, pigs (Nipah), horses (Hendra |
|
|
Term
| Nipah and Hendra Transmission |
|
Definition
Intermediate hosts (pigs, horses) to humans: close contact
Bats to intermediate hosts or to humans: ?
NO direct human to human spread |
|
|
Term
| Nipah and Hendra SYMPTOMS (4-18 days after infection): |
|
Definition
| Flu-like symptoms Lung and brain infections (~50% mortality) |
|
|
Term
|
Definition
Lyme Disease
Rocky Mountain Spotted Fever
Tularemia
Bubonic Plague |
|
|
Term
|
Definition
First identified in 1975
Named for Lyme, CT
Caused by bacterial species
Borrelia burgdorferi
Extracellular
Most common tick-borne disease in
Northern Hemisphere
Transmitted by blacklegged deer-tick
Ixodes scapularis
Hosts: rodents, humans, etc |
|
|
Term
| Lyme Disease Transmission |
|
Definition
Rural areas
Nature walks
Ticks found on tips of
grasses
Animals (wild, pets) |
|
|
Term
| Tick Life cycle and Lyme Disease |
|
Definition
Ticks live for two years
Three feeding stages
Larvae - in rodents
(natural host)
Nymph stage – most
human transmission
(small size)
Adults - male and female
*24 to 36 hours needed to transmit* |
|
|
Term
|
Definition
Erythema migrans (outwardly expanding rash)
3 to 30 days after bite in 70-80% of cases
Characteristic ‘bull’s-eye’ around bite (up to 12”)
Days-Weeks: fever, chills, pain, rash
Weeks-Months:
Loss of facial muscle tone/paralysis
Severe headaches
Heart palpitations
Joint pain
Years (in ~60% of cases)
Arthritis bouts
Joint swelling
Neurological complaints (shooting pains, numbness, tingling of the hands
and feet, short term memory loss) |
|
|
Term
| Treatment for Lyme disease |
|
Definition
| no vaccine, antibiotics available |
|
|
Term
| Lyme disease public health measures |
|
Definition
Vector control
Avoidance
Pesticide
Landscaping
Risk recognition
Area of tick encounter
Length of tick bite
Symptom recognition
Early diagnosis and
treatment
High-visibility public
health programs in
New England, esp. |
|
|
Term
| Rocky Mountain Spotted fever |
|
Definition
Most severe rickettsial infection in US
Rickettsia rickettsii
Gram-negative bacteria
Intracellular
Ticks - reservoirs and vectors
American dog tick (eastern US)
Rocky mountain wood tick (western US)
Throughout US, almost every state
seasonal- april-september |
|
|
Term
| Rocky Mountain Spotted Fever symptoms |
|
Definition
5-10 days post infection
Fever
Nausea
Vomiting
Muscle pain
Lack of appetite
Severe headache
Rash |
|
|
Term
| Rocky mountain spotted fever treatment |
|
Definition
tetracycline
effective if treated early |
|
|
Term
|
Definition
Discovered in 1911 in a rabbit
and ground squirrel outbreak in CA
“Rabbit fever”
Bacteria: Francisella tularensis
Intracellular
Infects white blood cells
Evades immune system
Invades many organ systems (lungs, liver, spleen,
lymphatic system) |
|
|
Term
| Tularemia transmit and stuffs |
|
Definition
Endemic in North America, Europe, Asia
Extremely rare outbreaks
~120 reported cases/year in the US
VECTOR: ticks and deer flies
RESERVOIRS: rabbits, rodents
TRANSMISSION TO HUMANS:
via vector
direct contact with infected animals
ingestion of contaminated food
inhalation of contaminated dusts or aerosols
(NOT direct person to person) |
|
|
Term
|
Definition
(3-5 days after exposure)
Headache, fatigue, dizziness, pain,
Ulcer at site of bacterial entry
Inflammation of lymph nodes
High fever
7% mortality in untreated cases |
|
|
Term
|
Definition
Used as a weapon by the Russians during World War II
(controversial)
Potential bioterrorism agent:
Easy to aerosolize
Highly infective
Highly incapacitating
Easy to decontaminate
Low lethality
Monitored in US with BioWatch system |
|
|
Term
|
Definition
| antibiotics (streptomycin, gentamicin) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Bacteria - Yersinia pestis
Intracellular
Infects white blood cells
Vector: rodent fleas
Reservoirs: rodents (rats, squirrels, etc)
Hosts: humans
Bacteria grows in flea
Blocks stomach, flea starves
Biting increases
Vomits blood at bite
Blood contaminated with bacteria
Enters host |
|
|
Term
| Plague transmission also occurs... |
|
Definition
Bite of an infected flea (most common)
Handling infected animals (prairie dogs, squirrels, rats, etc)
Inhaling droplets from the cough of an infected person or animal |
|
|
Term
|
Definition
(2-6 days after infection)
Many buboes
Die within a week (50%, 4-7 days) |
|
|
Term
| Plague symptoms Septicemic |
|
Definition
Bleeding in skin and organs
Black patches
Die same day as symptoms |
|
|
Term
| Plague symptoms pnuemonic |
|
Definition
Bacteria infect lungs
Can result from direct person to person (e.g.
coughing)
Fatal within a week if untreated |
|
|
Term
| 21st century plague cases |
|
Definition
| 1,000-3,000 cases every year globally |
|
|
Term
|
Definition
a. DNA stores almost all information for life on Earth
c. A single nucleic acid strand has a backbone composed of chain of sugars and phosphates
d. Native DNA is a double helix bound together by the base-pairing of A with T and C with G.
e. RNA is less stable than DNA |
|
|
Term
|
Definition
a. The usual order of information transfer is: DNA RNA protein
b. The promoter and terminator regions are important in regulating the expression of a gene.
c. Translation is done by the ribosome.
d. Messenger RNA (mRNA) contains information from DNA, encoded in a 3-nucleotide genetic code called codons. |
|
|
Term
| true or false: The nucleotides in protein match the nucleotides in DNA |
|
Definition
|
|
Term
| Involved in the translation of mRNA to protein |
|
Definition
amino acids
transfer RNA
messenger RNA
ribosomal RNA |
|
|
Term
| disease caused by eukaryotic pathogen |
|
Definition
|
|
Term
|
Definition
a. Its causative agent is an RNA virus
b. It has relatively low mortality (<10%) worldwide
c. It can be transmitted from person to person in air, body fluid, or contact
d. Its first known occurrence is in China |
|
|
Term
| T or F? SARS continues to increase around the world |
|
Definition
|
|
