G- (weakly)

spirochete

microaerophilic

Causes Lyme disease

Vector: deer (hard) tick

Main reservoir: mice

1. Rashes, flu-like symptoms
2. increased heart rate, Bell's palsy, meningitis, encephalitis
3. Lyme arthritis

G- (weakly)

spirochetes

microaerophilic

Causes Relapsing Fever

Vector: soft tick

Main reservoir: mice

• high fever, jaundice, rose-colored skin
• three or four relapses may occur, each shorter and less severe
• Why? Different antigenic types of spirochete, evades existing immune cells

G-

aerobic

bacillus

intracellular

• Causes Rocky Mountain Spotted Fever
• Vector: hard (dog) tick
• transovarian transmission - pathogen passed on to eggs of tick

• Rickettsiae damage permeability of endothelium of blood capillaries by replicating in them
• abrupt onset: fever, headache, chills, macular rash
• Loss of plasma, shock
• often fatal if misdiagnosed

G-

aerobic

bacillus

intracellular

• Causes Epidemic Typhus
• Vector: human body louse
• Multiplies in gut of louse, excreted when feeding on skin --> pathogen enters skins through scratch --> spreads to vascular endothelium in skin, heart, muscle, CNS, etc.
• High mortality --> increases with age
• Anne Frank died of epidemic typhus

AKA West Nile, STL Encephalitis

Vector: mosquitoes

Pathogen: Flavivirus, flaviviridae

Vertebrate reservoirs: birds

SLE most common, WNV more severe, fatality increases with age for both

Most cases subclinical, some fatal

chills, headache, fever

can progress to:

mental confusion, coma, neurological problems

Vector: mosquito

Pathogen: Flavivirus, flaviviridae

Mortality rates high: 20%

Vector: mosquito

Pathogen: Flavivirus, flaviviridae

similar to yellow fever virus but milder

fever, body rash, joint pain

rarely fatal but hemorrhagic shock syndrome is more common in children

Vector: mosquito

Pathogen: Plasmodium spp, protozoan

• 4 forms of the disease
• some forms benign (lethargy) to severe (RBC destruction/death)
• Life cycle: with the release of merozoites, there is also the release of toxic compounds (recurring symptoms)

chills, fever, headache during 2 - 3 day intervals

Vector: snail

Pathogen: fluke (trematode)

• Female lives in groove of male --> continual supply of eggs --> eggs lodge in tissue, causes granulomas
• Most areas of US the suitable snail vector is not present --> people may be shedding eggs but the lack of a snail vector and proper sanitation prevents an epidemic

1 causes cystitis

2 cause enteritis

Adult worm can evade host immune system by coating with a layer that mimics host tissue

Vector: mosquito

Pathogen: roundworm (nematode)

Adult worms found in lymph nodes and lymphatic vessels

Asymptomatic to fever, rashes, lymphangitis, orchitis

If chronic obstruction, gross enlargement of breasts, scrotum, limbs