Borelia spp

Bacteriology

• G-
• Spiral
• Outer membrane proteins encoded by plasmids:  UNIQUE:  gives 'em antigenic variability
• Nutritionallly fastideous, can be grown in axenic liquids Barbour-Steoenner-Kelly medium

Borelia spp.

clinical symptoms

Diagnosis

Treatment

• Abrupt onset of chills and fever   3-4d incubation
• INvades spleen, liver, kidneys, eyes, brain from blood
• cyclic attack
  
  • initial attack 3-7d
  • 3 follow-ons, shorter, less severe
    
• Dx: blood smear
• Tx: tetracylcline / chloramhenicol

Borelia burgdorferi

Vector, range, hosts, season

• SEASON - spring-summer  (tic nymphs active )
• VECTOR - ticks :deer and dog
• HOSTS - Deer, Deer mice, MAN
• RANGE - same as Ixodes ticks: N. hemisphere, 30-50

                     S. hemisphere: australia, NZ

LYME DISEASE

Symptoms

• FIRST STAGE
  • ECM Erythema Chronicum Migrans - target lesion at site of bite 3-14d
  • Red/brn/purple lesions on earlobes, nipples, scrotum, extremities
    
  • stiff neck, low fever, arthralgia: flu-like
    
• SECOND STAGE
  • May have more annular skin lesions
    
  • Arthritis+bursa+tendon pain
    
  • Atrophy and discoloration of the skin
  • CV, opthalmic, muscle
  • CNS symptoms

LYME DISEASE

diagnosis and treatment

DX

See B. burgdorferi in blood in FIRST STAGE ONLY Serology for later is unreliable

TX

Doxycycline or amoxacillin for early

Ceftriaxone or Cefotaxime (prolonged) for later

PREVENT

vaccines available !

LEPTOSPIROSIS

Bacteriology

• G-   spiral
• Hook on one or both ends
  
• Motile
• Sensitive to heat, drying, most chemicals
• Survives in water or soil for a couple of weeks
• Enters host by penetrating skin / mucus membrane

Leptospira interrogans

Resirvoir and Vector

RESIRVOIR

   wild animals (commensal), esp. rodents

   man is a dead-end host

VECTOR

   Animal urine--> water--> man via recreation/drink

Leptospirosis

Clinical aspects

• Incubation 8-12d
• EARLY Sx
• chills, headache, severe muscle pain, in thighs, calves, abdomen
  
• LATER
• Infectious jaundice or Weil's disease
• Severe hemmorhage  high mortality rate

Leptospirosis

diagnosis and treatment

• DX
  • Serodiagnosis - micro/macro agglutination
  • Culture takes TWO MONTHS - not practical
• TX
  • Penicillin, tetracycline, cephalosporin

Families of bacteria and viruses which cause

HEMMORHAGIC FEVERS

• BACTERIA:   Leptospirosis
• VIRUSES  (isolate via PCR for Dx)

1. Flavi
2. Arena
3. Bunya
4. Filo

no vaccines, TETRACYCLINE used,

FLAVIVIRUSES

Virology

• Flaviviriidae / flavivirus
• +ssRNA
• ARBOvirus except for Hep C
• All flaviviruses related:  cross-reacting antibodies
• INFECT MACROPHAGES
• CELL DAMAGE VIA MEDIATORS, T-CELL

FLAVIVIRUSES

PATHOGENESIS

• Infect MACROPHAGES
• Cell damage via cell mediators, tissue destroy by T's
• SHOCK SYNDROME
  • Virus/Ab complex enters monocites via Fc-R
  • Antibody enances infection
  • ↑ cytokines
  • severe illness, shock, hemorhages

FLAVIVIRUS

Diseases

1. DENGUE
   • fever/rash/hemorrhagic shock
   • Mosquitoes, resirvoir unkkonwn
   • India, SE asa, Pac, SA, Caribbean
     
   • no vaccine
   • Vector control 

1. YELLOW FEVER
   • Resirvoirs = monkeys
   • vecor = mosquitoes:  Ades aegypti
   • Severe hemorrhagic fever + liver fail+jaundice

ARENAVIRUSES

Virology

• Arenaviridae   Arenavirus
• -ssRNA  
• 2 segment (smaller is ambisense)
• Host ribosomes in virus particle: no function
• RAT resirvoir in many spp
• Spreads via RAT FECES and URINE
• Mortality 10-50%

ARENA VIRUS

LASSA FEVER

• Most common fever illness in Sierra Leone
• fever, diarrhea, hemorrhages, hemo-concentation and collapse
  
•  African bush RAT
• W. Africa
• no person-person spread
• 50% mortality
• Dx via CSF, blood

ARENAVIRUS

Bolivian hemmorhagic fever

Machupovirus

Machupovirus

• fever, myalgia, hemorrhage, shock, neuro illness
  
• bush MOUSE (callomys callosas)
• NE Bolivia
• 15% mortality

ARENAVIRUSES

Argentinean Hemorrhagic Fever

Junin virus

Juninvirus

• fever, myalgia, hemmorhages, collapse
  
• Callomys spp. of mice
  
• Argentina
• 10% fatal

BUNYAVIRUSES

Virology

• Bunyaviridae: bunyavirus, hantavirus, Niarovirus
• -ssRNA,  3 segments (S, M, L)
• Resirvoir in .....you guessed it....RATS and ticks
• Plasma and RBCs leak through vascular endothelium

BUNYAVIRUS

Korean Hemmorhagic Fever

(Hantaan virus)

• Hantavirus
  
• Hemorrhagic fever with renal syndrome
  
• Mice, rats
• Far East, Scandinavia, E. durope
• Severe pulmonary sndrome in SW USA (sin nombre)
• rodent control

BNYAVIRUS

Congo-crimean hemorrhagic fever

• Niarovirus
• Fever, hemmorhages
• Tick, resirvoir RODENTS
• Asia, AFrica,
• no vaccine, tick and rodent control

FILOVIRUS

Virology

• Filoviridae   filovirus
• -ssRNA, long, filamentous virus
• no known resirvoir
• Africa
• 10-20% fatal

FILOVIRUS

Marburg Hemorrhagic Fever

(MHF)

• Marburgvirus
• fever, rash, hemorhage, (DIC)
• ?? resirvoirs   ?? vector
• First appeared in Marburg: Ugandan monkeys
• 20% mortality
• Tissue necrosis in parenchyma of liver, spleen, lungs, lymph nodes
• edema and hypovolemic shock
• Angola outbreak 2005

FILOVIRUS

Ebola

• Ebolavirus
• Sudden febrile, vascular collapse, internal bleeding, death
  
• Sudan, Zaire (DR Congo)
• ??? vector    ??? resirvoir
• many epidemics
• 90% mortality

FILOVIRUS

Ebola

Pathogenesis and 4 strains

PATH

Glycoprotein peplomers cause destruction of vasc. endothelium--> massive hemorrhage

STRAINS

   1. Zaire (90%)

   2. Sudan (50%)

   3. Reston (nonpathogenic to humans)

   4. Cote d'Ivorie (20%)

Biosafety levels

Differences

• BSL-1............open bench
• BSL-2............splash and sharps protection
• BSL-3............aerosol protection
• BSL-4............sci-fi:  special building+full suits

Inhallation

Anthrax