Communicable Diseases
1. typhoid fever
agent: Salmonella typhi
reservoir: human
transmission: indirect, vectorborne (flies)
symptoms: can be asymptomatic
fever, gastroenteritis, nosebleeds
rose spots (red patches on abdomen)
2. paratyphoid
fever
agent: 3 main groups of Salmonella paratyphi
reservoir: primarily human
transmission: same as typhoid fever
symptoms: similar to typhoid, but much less virulent
3. Cholera
agent: Vibrio cholera
reservoir: human; perhaps environmental reservoirs
transmission: fecal (or vomitus)
[direct, indirect (food, water, flies)]
symptoms: sudden and severe diarrhea
vomiting, dehydration, death
4. Shigellosis (bacillary dysentary)
(dysentary) = acute colitis with diarrhea
agent: 4 groups of genus Shigella (bacteria)
reservoir: humans; primates
transmission: fecal [direct, indirect (food, water, flies)]
symptoms: diarrhea, fever, nausea
stools contain blood, mucus, and pus
5. Amebiasis (amebic dysentary)
agent: Entamoeba histolytica (a protozoon)
reservoir: human; usually a chronically ill
or asymptomatic carrier
transmission: fecal [direct, indirect (food, water, flies)]
acute patients pose limited danger
(absence of cysts)
symptoms: often asymptomatic; fever, chills, diarrhea
stools contain blood, mucus
6. Giardiasis
agent: Giardia lamblia (protozoan)
reservoir: human; possibly other animals
transmission: fecal (water or food) (cysts resist treatment)
symptoms: often asymptomatic; diarrhea, cramps, fatigue
1. Trichinosis
agent: Trichanella spiralis
reservoir: pigs, wild boar, bears, foxes, wolves, rats
transmission: eating infected animals
symptoms: nausea, gastroenteritis
(must thoroughly cook pork >150 deg. F)
2. Ascariasis (roundworms)
agent: primarily Ascaris lumbricoides
reservoir: humans, infected soils
transmission: not person to person
ingestion of infective eggs (soil)
symptoms: live worms in stool
varied: coughing, fever, nutrition
3. Schistosomiasis (blood flukes)
agent: Schistosoma (4 species)
reservoir: humans (and various animals)
transmission: vectors (biological)
larvae from snail infested waters
symptoms: varied
4. Other helminthic diseases
a. beef tapeworm Taenia saginata
b. pork tapeworm Taenia solium
c. fish tapeworm Diphyllobothrium latum
d. dracunculiasis
(dracontiasis) Dracunculus medinensis
e. ancylostomiasis
(hookworm) Ancylostoma
f. enterobiasis
(pinworm) Enterobias
Selected Miscellaneous Diseases
1. Ringworm
agent: Microsporum, Trichophyton, others (fungi)
reservoir: infected human or animal
transmission: physical contact
symptoms: dermatitis (athlete's foot,jock itch, etc.)
control: cleaning floors, showers, clothing
2. Tetanus
agent: Clostridium tetani
reservoir: soil, street dust, animal feces
transmission: entrance in a wound
symptoms: muscular contractions, spasms
case fatality can be high
control: immunization, cleansing wounds
3. Anthrax
agent: Bacillus anthracis
reservoir: cattle, sheep, goats, horses, swine
transmission: contact with hides or meat, flies
symptoms: itchy skin; complications if untreated
control: vaccine, sanitation, dust control
4. Leprosy
agent: Mycobacterium leprae
reservoir: humans
transmission: not clearly established
prolonged contact is important
symptoms: disease of skin, nerves, nasal musosa
symptoms vary
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