Bacterial Diseases

Anthrax (see Anthrax)

Bacillus anthracis

Mainly in cattle, sheep, goats, horses, wild herbivorous animals; virtually all mammals and some birds are susceptible to high dose

Worldwide but distribution is focal; common in Africa, Asia, South America, Middle East, parts of Europe

Occupational contact exposure (abraded skin, mechanical transmission by biting flies, other routes); ingestion/foodborne, rarely airborne; early signs vary with route of inoculation

Ulcerative skin lesions; mild to severe gastroenteritis ± hematemesis, bloody diarrhea, ascites (abdominal GI form); sore throat, dysphagia, fever, neck swelling, mouth lesions (oropharyngeal GI form); pneumonia; all may progress to sepsis, meningitis; untreated cases fatal in 5–20% (cutaneous) to 100% (inhalation)

Bordetellosis (see Respiratory Diseases of Pigs, see Respiratory Diseases of Small Animals: Infectious Tracheobronchitis of Dogs)

Bordetella bronchiseptica

Dogs, rabbits, pigs, guinea pigs, other mammals

Worldwide; rare in humans

Exposure to saliva or sputum, aerosols

Sinusitis, bronchitis, pertussis-like illness; pneumonia and disseminated disease, usually in immunocompromised

—Lyme disease

Borrelia burgdorferi sensu lato complex (B burgdorferi sensu stricto, B garinii, B afzelii, B japonica)

Wild rodents, insectivores, hedgehogs, hares, deer, other mammals, birds

Worldwide where Ixodes ticks are found

Ixodes spp bites

Fever, headache, malaise and other nonspecific signs early; target skin lesions in many; may progress to arthritis, neurologic and/or cardiac signs

—Southern tick-associated rash illness

B lonestari implicated

Deer, birds implicated

USA; most cases in southeast

Tick (Amblyomma americanum) bite

Resembles Lyme disease

B melitensis

Goats, sheep; other mammalian spillover hosts

Asia, Africa, Middle East, Mexico, Central and South America, some parts of Europe

Ingestion (including unpasteurized dairy products), contact with mucous membranes and broken skin; rev-1 vaccine

As above; this species is highly pathogenic for humans

B canis

Dogs; evidence of infection in wild canids including coyotes

Worldwide; rare in humans

Probably via ingestion or contact with mucous membranes, broken skin; transmission occurs during close contact

As above

Campylobacter enteritis (see Enteric Campylobacteriosis)

Campylobacter jejuni, C coli, occasionally other species

Cattle, swine, poultry, dogs, cats, other mammals, wild birds

Worldwide

Foodborne (especially unpasteurized dairy products); waterborne; contact with animals including dogs, cats with diarrhea

Gastroenteritis, often with malaise, headache, myalgia, arthralgia; typically self-limiting; other syndromes including sepsis are uncommon

Capnocytophaga infection

Capnocytophaga canimorsus, C cynodegmi

Dogs, cats

Probably worldwide

Bites or scratches

Fever, localized infections to sepsis; often in immunocompromised or elderly

Chlamydiosis (see also Psittacosis below)

Chlamydophila abortus, C felis

C abortus sheep, goats, other mammals, green sea turtles, snakes; C felis in cats

C felis worldwide; C abortus in most sheep-raising areas but not Australia or New Zealand

Contact with animals; C abortus probably contact with pregnant or aborting ruminants

Abortions, septicemia (C abortus); keratoconjunctivitis, endocarditis, glomerulonephritis (C felis)

Clostridium perfringens, type A (most common), C, or D

Domestic and wild animals, humans

Worldwide

Foodborne (usually type A); nonfood-associated intestinal infection; wound contaminant, usually environmental; may be endogenous in debilitated from GI or urogenital tract

Foodborne gastroenteritis, usually brief, self-limited except in debilitated; nonfood-related intestinal infection with prolonged diarrhea, sometimes bloody, mainly in elderly after antibiotics; life-threatening necrotic enteritis, often in debilitated; gas gangrene, sepsis; necrotic enteritis, gas gangrene, sepsis are fatal if not treated

Dermatophilosis (see Dermatophilosis)

Dermatophilus congolensis

Cattle, horses, deer, sheep, goats, other mammals

Worldwide

Usually direct contact with lesions; mechanical transmission on arthropod vectors, fomites possible

Pustular desquamative dermatitis

Erysipeloid (see Erysipelothrix rhusiopathiae Infection)

Erysipelothrix rhusiopathiae

Swine, sheep, cattle, rodents, turkeys, pigeons, marine mammals; other domestic and wild mammals, birds, reptiles, fish, mollusks, crustaceans

Worldwide

Contact with animal products; via skin, usually after scratch or puncture wound; contaminated soil (survives for months)

Cellulitis, usually self-limiting, often on hands; arthritis in finger joints common; endocarditis; generalization with sepsis, other syndromes uncommon and often in immunocompromised

Helicobacter pullorum infection

Helicobacter pullorum

Poultry

Ingestion of undercooked poultry suspected

Gastroenteritis or diarrhea, liver disease

Leptospirosis (see Leptospirosis)

Leptospira spp

Domestic and wild animals; reservoir hosts include rodents, dogs, cattle, sheep, pigs, others

Worldwide

Occupational and recreational exposure; especially skin, mucous membrane contact with contaminated urine, infected fetuses or reproductive fluids; water- and foodborne

Asymptomatic to severe, sometimes biphasic; nonspecific febrile illness, rash in first stage; second stage with aseptic meningitis (anicteric form, which is rarely fatal) or pulmonary and cardiac signs, hemorrhages, jaundice/liver disease, renal failure (icteric form, with case fatality rate 5–15%)

Melioidosis (Pseudoglanders, see Melioidosis)

Burkholderia pseudomallei; (other species of soil-associated Burkholderia, such as B oklahomensis sp nov in North America, rarely linked to human infections)

Sheep, goats, swine; occasional cases in many other terrestrial and aquatic mammals; also reptiles, some birds including parrots, tropical fish

Asia, Africa, Australia, South America, Middle East, Caribbean

Wound infection, inhalation, and ingestion; organisms live in soil and surface water; most cases are acquired from the environment, but direct transmission from animals is possible

Mimics many other diseases; acute localized infections including skin lesions, cellulitis, abscesses, corneal ulcers; pulmonary disease, septicemia, internal organ abscesses; often occurs in immunocompromised; case fatality rate varies with form, >90% in untreated septicemia

Mycobacteriosis (see Tuberculosis and other Mycobacterial Infections)

Mycobacterium avium- intracellulare complex

Many species of mammals, some birds

Worldwide

Environmental, from water and/or soil

Soft tissue and bone infections; lymphadenitis; pulmonary disease, often in immunocompromised or those with pre-existing lung conditions; disseminated in immunocompromised, especially AIDS patients

Mycobacteria other than tuberculosis (includes M simiae, M kansasii, M xenopi, M scrofulaceum, M szulgai, M fortuitum, M chelonae, M marinum, M ulcerans, others)

Cattle, other ruminants; swine, cats, dogs, koalas, other mammals, amphibians, reptiles, fish

Worldwide; distribution varies with the organism

Environmental, from water and/or soil

Same syndromes as M avium -intracellulare complex

Nocardiosis (see Nocardiosis)

Nocardia asteroides, N brasiliensis, N caviae, N otitidiscaviarum, N farcinica, N nova, and others

Cattle, dogs, cats, marine mammals, other domestic and wild mammals; fish

Worldwide; distribution of each species varies

Environmental exposure (inhalation or wound contamination); possibility of transmission in bites, scratches

Pneumonia; skin lesions, cellulitis, abscess, mycetoma; disseminated disease, including cerebral abscesses; many cases occur in immunocompromised

Plague (see Plague)

Yersinia pestis

Rodents including squirrels, prairie dogs, rats are main reservoir; cats, rabbits; > 200 species of mammals susceptible

Foci in North and South America, Asia, Middle East, and Africa

Flea bites, aerosols, handling infected animals (contact with broken skin or mucous membranes), bites or scratches

Febrile flu-like syndrome with swollen, very painful draining lymph node(s) (buboes); pneumonia; sepsis can occur in either bubonic or pneumonic form; case fatality rate in untreated 50–60% (bubonic) to 100% (pneumonic); < 5% mortality if treated early

Rat bite fever

Streptobacillus moniliformis

Rodents; also transmitted by dogs, cats, ferrets, which are probably infected from rodents

Worldwide

Bites and scratches; handling or kissing a rodent, exposure to rodent urine; can be waterborne or foodborne; aerosol transmission possible

Fever, severe myalgia and joint pain, headache, rash, sometimes GI signs; complications including polyarthritis, hepatitis, endocarditis, focal abscesses, sepsis possible if untreated; overall case fatality rate 10–13% if untreated

Salmonellosis (see Salmonellosis)

Salmonella enterica and S bongori, (> 2,500 serovars)

Poultry, swine, cattle, horses, dogs, cats, wild mammals and birds, reptiles, amphibians, crustaceans

Worldwide

Foodborne infection or fecal-oral; some cases of occupational and recreational exposure

Gastroenteritis to sepsis; focal infections possible; especially severe in the elderly, young children, or immunocompromised

Tetanus (see Clostridial Diseases: Tetanus)

Clostridium tetani

Principally herbivores, but all animals may be intestinal carriers

Worldwide

Wound infection and injections; most cases from soil but feces can also contain organism

Muscle spasms and contractions (especially facial), seizures, high mortality; can be localized before generalization; case fatality rate was 90% in USA in 1947, but effective treatment can greatly reduce mortality

Tularemia (see Tularemia)

Francisella tularensis Type A (F tularensis tularensis) virulent, type B (F tularensis holarctica) less virulent

Rabbits, rodents, cats, sheep, other mammals, birds, reptiles, fish; often in wild animals

Type A in North America; Type B in North America, Europe, Asia

Contact with mucous membranes, broken skin; insect bites; fomites; ingestion in food or water; inhalation

Fever, headache, malaise; ulcerative skin lesions, pharyngitis, adenitis, conjunctivitis, gastroenteritis, pneumonia, sepsis; case fatality rate 5% (localized disease, untreated) to 35% (untreated typhoidal form)

V vulnificus

Marine shellfish, shrimp, prawns, fish

Worldwide

Ingestion (often raw oysters); wound infection from water or handling hosts

Wound infections from mild, self-limited lesions, bullae to cellulitis, myositis; necrotizing fasciitis; gastroenteritis; sepsis, usually in immunocrompromised or those with liver disease, other debilitating illnesses (case fatality rate for sepsis >50%)

V cholerae Non-O1/O139 (non-epidemic strains)

Oysters, other seafood

Worldwide

Ingestion; wound infection

Gastroenteritis, usually mild and self-limited; wound infections; septicemia, usually in immunosuppressed or those with liver disease (case fatality rate for sepsis 47–60% or higher

Y enterocolitica; not all serotypes are pathogenic

Many domestic and wild mammals; some birds, reptiles, amphibians; zoonotic serotypes most common in pigs, dogs, cats

Worldwide

Ingestion

Gastroenteritis with watery diarrhea in young children, bloody stools uncommon; pseudoappendicitis in older children, adolescents; erythema nodosum in adults may follow gastroenteritis; arthritis, sepsis

Granulocytic ehrlichiosis

Ehrlichia ewingii

Dogs, possibly deer

Southeastern and south central USA

Ticks including Amblyomma americanum

Few cases described; fever, headache, malaise, myalgia, nausea, vomiting; many patients were immunosuppressed

Human granulocytic anaplasmosis (formerly human granulocytic ehrlichiosis)

Anaplasma phagocytophilum (formerly Ehrlichia phagocytophilum and E equi)

Deer, equids, dogs, cats, llamas, cattle, sheep, goats, non-human primates, rodents, rabbits, other mammals; birds

Worldwide

Tick (Ixodes spp) bites

Resembles human monocytic ehrlichiosis; often asymptomatic to mild in immunocompetent; rash uncommon; estimated case fatality rate <1%

Sennetsu fever

Neorickettsia sennetsu

Uncertain

Japan, Malaysia, possibly other Asian Countries

Relatively mild, resembles infectious mononucleosis; fever, lymphadenopathy, hepatosplenomegaly malaise, anorexia, sometimes chills, fatigue, myalgia

—African tick bite fever

Rickettsia africae

Cattle, goats

Sub-Saharan Africa, West Indies

Bite of infected tick (mainly Amblyomma hebraeum, A variegatum, also A lepidum, possibly Rhipicephalus decoloratus)

Painful regional lymphadenopathy in many; eschars often multiple; fever common; nuchal myalgia; sometimes sparse and/or vesicular rash; deaths do not seem to occur

—Fleaborne spotted fever; Cat flea typhus

R felis (synonym ELB agent)

Unknown; emerging disease

North and South America, Europe, Asia, Africa, probably worldwide

Flea bites; has been associated with Ctenocephalides felis (cat flea), C canis (dog flea), Pulex irritans

Few clinical cases have been described but resembles other spotted fevers; eschar, febrile illness, rash; CNS involvement in some

—Rickettsial pox

R akari

Mice, rats

USA, Africa, Asia, Ukraine, Croatia, Turkey; possibly southern Europe, Central America; rare

Bite of infected rodent mites, Liponyssoides spp

Eschar, febrile illness; vesicular rash, resembles chickenpox; self-limiting

—Tickborne lymphadenopathy; Dermacentor-necrosis-erythema-lymphadenopathy

R slovaca

Uncertain; wild boar may be involved

Europe to Central Asia

Bites of infected ticks; especially Dermacentor marginatus, D reticulatus

Eschar, local lymphadenopathy; localized alopecia at bite site; fever and rash uncommon

Typhus group of Rickettsia

—Scrub typhus; Chigger-borne rickettsiosis

Orientia tsutsugamushi and related species

Rodents, insectivores

Asia, Australia, islands of southwestern Pacific Ocean; cases are usually concentrated regionally in “typhus islands”

Bite of infected larval trombiculid mites (chiggers)

Eschar in some; rash, headache, fever, painful lymphadenopathy, body aches, interstitial pneumonitis, pneumonia, neurologic signs or cardiac complications in some; mild to severe; convalescence prolonged; case fatality rate 35–50% if untreated

Fungal Diseases

Blastomycosis (see Fungal Infections: Blastomycosis)

Blastomyces dermatitidis

Dogs, cats, horses, sea mammals; other mammals

Worldwide; focal distribution

Environmental exposure most common (moist soil); infection common to humans and animals; also reported rarely by animal exposure

Acute to chronic pulmonary disease; skin or bone lesions; meningitis, other syndromes, disseminated disease possible; some cases fatal

Cryptococcosis (see Fungal Infections: Cryptococcosis)

Cryptococcus neoformans var grubii, C neoformans var neoformans, C neoformans var gattii

Birds including pigeons, psittacines; cats, other mammals

Worldwide

Principally environmental exposure, especially pigeon nests; via inhalation or through the skin; infection common to humans and animals, insignificant as zoonosis

Pulmonary granulomas, usually self-limiting in healthy host; skin lesions; CNS disease and dissemination most often in immunocompromised

H capsulatum var duboisii

As above

Africa

As above

Usually skin and subcutaneous lesions, osteolytic bone lesions, but can disseminate

Ringworm (Dermatophytosis, see Dermatophytosis)

Microsporum and Trichophyton spp

Dogs, cats, cattle, sheep, goats, horses, rodents, other animals

Worldwide

Direct skin/hair contact with infected animals, fomites

Skin and hair lesions, usually pruritic; rare skin dissemination in immunocompromised

Parasitic Diseases—Protozoans

B divergens

Cattle; B divergens or closely related organism in reindeer, other mammals

Europe, possibly North Africa

Tick (Ixodes ricinus) bites

Usually in splenectomized; acute, severe hemolysis; persistent high fever, headache, myalgia, abdominal pain, sometimes GI signs; shock and renal failure; cases progress rapidly; case fatality rate 40% with effective treatment, usually fatal if untreated

Balantidiasis

Balantidium coli and related species

Swine, rats, nonhuman primates, other animals

Worldwide; low incidence

Ingestion, especially of water contaminated with feces

Asymptomatic to mucoid, bloody stool; intestinal hemorrhage and perforation possible; rare extrain-testinal cases

Cryptosporidiosis (see Cryptosporidiosis)

Cryptosporidium parvum; less often C canis, C felis, C meleagridis, C muris, and other species; (C hominis is adapted mainly to humans)

Cattle and other ruminants (C parvum), other domestic and wild mammals, birds (C meleagridis), reptiles, fish

Worldwide

Fecal-oral; ingestion of contaminated food and water; inhalation

Self-limiting gastroenteritis in healthy; can be cholera-like and persistent in immunocompromised, with weight loss, wasting; cholecystitis; respiratory signs, mainly in immunosuppressed

Leishmaniosis

—Visceral (Kalaazar see Leishmaniosis)

Leishmania donovani, Leishmania infantum and other species

Wild canids and dogs, cats, horses, rodents; humans are main reservoir in India

Asia, South America, Caribbean, Africa, the Middle East, Mediterranean coast, North America

Bite of sand flies Phlebotomus and Lutzomyia spp

Undulating fever, hepatosplenomegaly; some have cough, diarrhea, lymphadenopathy, weight loss, petechiae or hemorrhages on mucous membranes, nodular lesions or darkening of skin; pancytopenia; almost always fatal if untreated; case fatality rate 10% or higher in treated

Malaria of nonhuman primates

At least 20 species of Plasmodium including P knowlesi; all may not be zoonotic

Old and New World monkeys, apes

Central and South America, Asia, Africa

Bite of Anopheline mosquitoes

Fever, chills; headache, myalgia, malaise, cough, nausea, vomiting and other symptoms in some; some cases fatal

Rhinosporidiosis (see Fungal Infections: Rhinosporidiosis)

Rhinosporidium seeberi; some strains may be host specific

Horses, cattle, mules, dogs, cats, and birds

Worldwide, endemic in South Asia and Africa

Environmental exposure (unidentified reservoirs)

Nasal and other mucous membrane masses and polyps; may cause obstruction; rare disseminated disease with osteolytic lesions or affecting viscera; rare skin and subcutaneous lesions

Sarcocystosis (continued)

S hominis

Humans, nonhuman primates are definitive hosts; cattle are intermediate host

Worldwide

Ingestion of raw beef

Gastroenteritis, usually mild or asymptomatic

Toxoplasmosis (see Toxoplasmosis)

Toxoplasma gondii

Felidae including domestic cat are definitive hosts; birds and mammals including sheep, goats, swine, and humans are intermediate hosts

Worldwide

Ingestion of oocysts shed in feces of infected cats (including contaminated soil, food, water) or ingestion of tissue cysts in undercooked meat or unpasteurized milk

Lymphadenopathy or mild, febrile, flu-like syndrome or uveitis in immunocompetent, nonpregnant host; often severe in immunocompromised, with neurologic disease, chorioretinitis, myocarditis, pneumonitis or disseminated disease; infection of fetus may result in CNS damage or generalized infection; abortions and stillbirths

Parasitic Diseases—Trematodes (Flukes)

Dicrocoeliasis

Dicrocoelium dendriticum, rarely D hospes (lancet flukes)

Ruminants especially sheep, goats, cattle, occasionally other mammals are definitive hosts; land snails (1st) and ants (2nd) are intermediate hosts

D dendriticum worldwide; D hospes in Africa south of Sahara desert

Ingestion of infected ants

Abdominal discomfort, flatulent indigestion; occasionally alternating diarrhea/constipation, vomiting, pain

Fascioliasis

Fasciola hepatica

Cattle, sheep, water buffalo, horses, rabbits, other herbivores are definitive hosts; snails are intermediate hosts

Worldwide or nearly worldwide; in temperate areas

Ingestion of contaminated greens, eg, watercress, or water that contains metacercariae

Gastroenteritis, hepatomegaly, fever, urticaria possible acutely; biliary colic and obstructive jaundice in chronic cases; aberrant migration with extrahepatic signs (pulmonary infiltrates, meningitis, lymphadenopathy, skin lesions or subcutaneous swelling) in some

Fasciolopsiasis

Fasciolopsis buski

Swine, humans are definitive hosts; snails are intermediate hosts

Asian pig-raising regions

Ingestion of aquatic vegetables or contaminated drinking water containing metacercariae

Often asymptomatic; gastroenteritis; intestinal obstruction possible; facial, abdominal, extremity edema may occur

Heterophyiasis

Heterophyes spp and other heterophids

Cats, dogs, foxes, wolves, fish-eating birds are definitive hosts; fish (and snails) are intermediate hosts

Middle East (especially Nile delta), Turkey, Asia

Ingestion of undercooked fish containing encysted larvae

Diarrhea with mucus, colicky pain; heart or CNS involvement possible

Metorchiasis

Metorchis conjunctus, Canadian liver fluke

Dogs, foxes and other canids, cats, raccoons, muskrats, mink, other fish-eating mammals are definitive hosts; fish (and snails) are intermediate hosts

North America; human infection rare

Ingestion of undercooked freshwater fish containing encysted larvae

Fever, abdominal pain (mainly epigastric), anorexia during acute stage; effects of chronic infection uncertain

Opisthorchiasis

Opisthorchis felineus (cat liver fluke)

Cats, dogs, foxes, swine, seals, other fish-eating mammals are definitive hosts; fish (and snails) are intermediate hosts

Europe, Asia, Siberia

Ingestion of undercooked freshwater fish containing encysted larvae

Acute febrile illness with arthralgia, lymphadenopathy, skin rash; suppurative cholangitis and liver abscess in subacute, chronic stages; possible increased risk of cholangiocarcinoma

Amphimerus pseudofelineus

Dogs, cats, coyotes, opossums are definitive hosts; fish suspected as intermediate hosts

North and South America

Undetermined, but probably ingestion of intermediate host

Schistosomiasis, intestinal and hepatic

Schistosoma japonicum

Many mammals including cattle, water buffalo, swine, dogs, cats, deer, rodents are definitive hosts; snails are intermediate hosts

China, Indonesia, Philippines

Penetration of unbroken skin by cercariae from infected snails in water

Acute disease (Katayama fever), especially after first infection; febrile illness, sometimes with cough, diarrhea, abdominal pain, hepatosplenomegaly and/or rash/urticaria; apparent clinical recovery may be followed by chronic intestinal schistosomiasis with abdominal pain/discomfort, diarrhea with or without blood; chronic hepatic schistosomiasis with hepatosplenomegaly followed by liver fibrosis, ascites, portal hypertension with hematemesis and/or melena, portocaval shunting with pulmonary signs; ectopic parasites can cause seizures, paralysis, meningoencephalitis; intestinal and hepatic lesions tend to progress rapidly; death can occur

S mattheei

Cattle, sheep, goats, waterbuck, wildebeest, antelope, buffalo, other mammals are definitive hosts; snails are intermediate hosts

Southern Africa

Penetration of unbroken skin by cercariae from infected snails in water

Intestinal and hepatic schistosomiasis; death can occur

S intercalatum

Cattle, sheep, antelope, goats, primates, rats are definitive hosts; snails are intermediate hosts

Central Africa

Penetration of unbroken skin by cercariae from infected snails in water

Intestinal schistosomiasis only, often mild or asymptomatic; occasionally bloody feces, diarrhea

Swimmer's itch (Cercarial dermatitis)

Schistosome cercariae from Schistosoma spp (mammals); Gigantobilharzia, Trichobilharzia, and Austrobilharzia spp (birds)

Birds, mammals are definitive hosts; snails are intermediate hosts

Worldwide

Penetration of unbroken skin by cercariae from infected snails in fresh- and saltwater

Self-limiting urticaria, pruritus, rash

Bertielliasis

Bertiella studeri, B mucronata

Nonhuman primates are usual hosts; other mammals including dogs, humans can be infected

Asia, South America, Africa; can occur in imported primates in other areas

Ingestion of infected oribatid mites in food

Most cases asymptomatic; abdominal pain, vomiting, diarrhea, constipation, weight loss

T serialis

Definitive hosts are canids; intermediate hosts are lagomorphs, occasionally other mammals

Africa, Europe, North America; rare in humans

As above

Painless skin swelling; also in muscles and retroperitoneally; CNS involvement possible

Cysticercosis

Taenia solium (see also Taeniasis)

Humans are definitive hosts; swine, other mammals are intermediate hosts; (humans can be both definitive and intermediate hosts)

Worldwide where swine are reared; most cases occur in Africa, Asia, Central and South America

Ingestion of eggs (including autoinfection from adult parasite in human intestine)

Inflammation in CNS caused by death of larva (years after infection) can cause seizures, other CNS signs; less often in eye or heart

Diphyllobothriasis (Fish tapeworm infection)

Diphyllobothrium latum (Dibothriocephalus latus), D pacificum, D dendriticum, and other Diphyllobothrium spp

Dogs, bears, seals, sea lions, gulls, and other fish-eating mammals and birds are definitive hosts; freshwater or marine fish (and copepods) are intermediate hosts

Worldwide

Ingestion of undercooked infected fish

Usually asymptomatic; may cause mild abdominal distress; rare megaloblastic anemia

Echinococcosis

Echinococcus granulosus

Dogs, hyenas, and other canids are definitive hosts; sheep, cattle, swine, rodents, deer, moose, other mammals are either intermediate or aberrant hosts

Worldwide

Ingestion of tapeworm eggs in food, water; to mouth on hands; eggs stick to fur and hands

Cause space-occupying lesions of organs, especially lung, liver, also other organs, rarely CNS; cyst grows slowly, can cause death if untreated

Echinococcosis

E oligarthrus

Wild felids are definitive hosts; agouti, pacas, spiny rats are intermediate hosts

Central and South America; rare in humans

Ingestion of tapeworm eggs in food, water; to mouth on hands; eggs stick to fur and hands

Has occurred in a variety of internal organs, eyes

Hymenolepiasis

Hymenolepis nana (dwarf tapeworm); most human infections probably from strains adapted to humans, but zoonoses possible

Humans, nonhuman primates, rodents are definitive hosts; insects including fleas, flour beetles, cereal beetles are intermediate hosts

Worldwide

Accidental ingestion of tapeworm eggs or infected insects; autoinfection possible

Mainly in children; mild abdominal distress, decreased appetite, irritability are most common; weight loss, flatulence, diarrhea possible

Inermicapsifer infection

Inermicapsifer madagascariensis

Rodents, humans are definitive hosts in Africa; humans may be exclusive host outside Africa

Africa, southeast Asia, tropical America

Probably ingestion of infected arthropods

Mild abdominal symptoms, if any

Sparganosis

Spirometra spp (pseudophyllidean tapeworms, second larval stage)

Dogs, cats, wild canids and felids are definitive hosts; copepods are first intermediate host; primates, pigs, weasels, rodents, insectivores, other mammals, birds, reptiles, amphibians, fish are second intermediate hosts

Worldwide; human cases mainly in Thailand

Ingestion of infected cyclops (in water) or undercooked intermediate host; application of contaminated tissues to skin (eg, as poultice)

Nodular, itchy skin lesions that can migrate; conjunctival and eyelid lesions; urticaria, painful edema; other organ involvement including CNS

—Asian taeniasis

Taenia taiwanensis, Taenia asiatica or T saginata asiatica

Domestic and wild pigs, occasionally cattle, goats, monkeys are intermediate hosts; humans are definitive hosts

East and southeast Asia, Africa

Ingestion of undercooked animal products, usually visceral organs such as liver and lung

Vague abdominal complaints and proglottid passage; anal pruritus; ingestion of eggs followed by larval migration and disseminated disease appears unlikely but has not been ruled out

—Pork tapeworm disease; Cysticercosis and neurocysticercosis

T solium

Humans are definitive host; swine, occasionally other mammals including humans are intermediate hosts

Worldwide where swine are reared; most cases occur in Africa, Asia, Central and South America

Ingestion of undercooked pork containing larvae causes taeniasis; ingestion of eggs (including autoinfection from adult worm in intestine) causes cysticercosis

Adult stage in intestine (taeniasis) mild or asymptomatic; cysticercosis usually asymptomatic for years until death of cysticerci result in inflammation in CNS (seizures, other CNS signs) or less often in eye or heart

Angiostrongyliasis

Parastrongylus costaricensis

Cotton rats and other rodents are definitive hosts; slugs are intermediate hosts

North and South America, Caribbean

Accidental ingestion of slugs or plants contaminated by their secretions

Abdominal angiostrongyliasis; resembles appendicitis, especially in children

Anisakiasis

Anisakis and Pseudoterranova spp

Marine mammals (cetaceans and pinnipeds) and fish-eating birds are definitive hosts; fish, crustaceans, and cephalopod mollusks are intermediate or paratenic hosts

Worldwide, but many cases in northern Asia and western Europe

Ingestion of undercooked marine fish, squid, octopus

Gastroenteritis with upper quadrant pain; rarely in sites other than stomach; oropharyngeal worm can cause hematemesis, cough; urticaria and other allergic signs after ingestion of live or dead worms

—Hepatic capillariasis

Capillaria hepatica, (synonym Calodium hepaticum)

Rodents, other wild and domestic mammals

Worldwide in scattered foci

Ingestion of embryonated eggs in soil

Acute or subacute hepatitis with marked eosinophilia; subclinical to fatal

—Pulmonary capillariasis

C aerophila, (synonym Eucoleus aerophilus)

Dogs, cats, other carnivores

Worldwide; rare in humans

Accidental ingestion of infective eggs in soil or contaminated food

Fever, cough, bronchospasm, bronchitis, dyspnea; can mimic bronchial carcinoma

Dracunculiasis (Guinea worm infection)

Dracunculus medinensis

Humans, nonhuman primates, domestic and wild carnivores, horses, cattle are definitive hosts; copepods are intermediate hosts

Asia (mainly Indian subcontinent) and Africa

Ingestion of infected cyclops in water

No symptoms until just before larviposition (~1 yr); papule to vesicular skin lesion to ulcer that opens in water to reveal worm; allergic reaction common at this time and secondary infection may occur

—Dirofilariasis

Dirofilaria immitis

Dogs, cats, wild mammals especially carnivores, mustelids, primates are definitive hosts; mosquitoes are intermediate hosts

Worldwide

Bite of infected mosquitoes

Fever, cough acutely, resulting in infarct or coin lesion in the lungs; often asymptomatic; rarely involves eye

—Malayan filariasis

Brugia malayi; subperiodic form is zoonotic; periodic form is exclusive to humans

Cats, wild felids, pangolins, other carnivores, nonhuman primates

Asia; subperiodic form is limited to peninsular Malaysia, Thailand, and parts of Indonesia, Vietnam, and the Philippines in swamp-forest environments

Bite of infected mosquitoes, mainly Brugia malayi, Mansonia spp

Recurrent painful lymphadenitis, lymphangitis, often preceded by prodromal illness with malaise or urticaria; may progress to elephantiasis, usually of legs; hypersensitivity syndrome with cough, chest pain, asthmatic attacks especially at night

Gongylonemiasis

Gongylonema pulchrum

Ruminants, domestic and wild swine, other mammals are definitive hosts; beetles, cockroaches are intermediate hosts

Worldwide; rare in humans

Ingestion of infected beetles, probably on vegetables; possible inhalation of small beetles

Movement of parasite in submucosa of mouth is sensed; local irritation; pharyngitis, stomatitis possible

Bunostomum phlebotomum

Cattle

Temperate regions

As above

As above

Larva migrans, visceral (See also angiostrongyliasis and anisakiasis, above)

Toxocara canis, T cati, possibly others

Dogs and wild canids (T canis), cats (T cati) are definitive hosts; many species can be paratenic hosts

Worldwide

Ingestion of embryonated eggs shed in feces of dogs and cats; via soil, water, food, fomites

Fever, wheezing cough, upper abdominal discomfort; nodular rash on trunk and extremities; may wax and wane for months; eye involvement (ocular migrans) may resemble retinoblastoma

Oesophagostomiasis, Ternidensiasis

Oesophagostomum spp, Ternidens deminutus

Primates, including humans

Africa, Asia, South America (Brazil)

Ingestion of infective larvae in soil, often in food or water

Abdominal pain (may be right lower quadrant) and one or more masses ± mild fever; intestinal obstruction or abscessation possible; multinodular form (less common) with abdominal pain, persistent diarrhea, weight loss; rarely ectopic in omentum, liver, or skin

Strongyloidiasis (continued)

S fuelleborni

Primates including humans

Africa, Asia, and in captive primates in other areas

As above

Associated with abdominal pain, occasional diarrhea, not well studied

Trichinosis (Trichinellosis)

Trichinella spiralis and subspecies, T nativa, T britovi, T nelsoni, T pseudospiralis, possibly others

Main reservoir may be wild carnivores (foxes, badgers, wolves, lynx), omnivores (bears, boars); also in any mammal that eats (or is fed) meat including domestic swine, rodents, cats, dogs, horses, marine mammals; also birds (T pseudospiralis)

Worldwide, especially subarctic region; some species are limited in their distribution

Ingestion of undercooked pork, horse meat, game, and other tissues containing viable cysts

Gastroenteritis in some; followed by fever, headache, severe myalgia, facial swelling (especially eyelids); ocular pain, rashes, or pruritus possible; pneumonitis, CNS, or myocardial involvement can occur; inapparent to fatal

Trichuriasis (Whipworm infection)

Trichuris vulpis, T suis, and possibly other species; T spp, T trichiura occurs mainly in humans and zoonotic infections are unusual

T vulpis in canids; T suis in domestic and wild swine

Worldwide, especially warm, humid climates

Ingestion of embryonated eggs on plant foods, water, or in soil

Asymptomatic or mild to moderate gastroenteritis; bloody diarrhea possible; rarely, larva migrans from T trichiura , T vulpis

Acanthocephaliasis, Macracanthorhynchosis

Macracanthorhynchus hirudinaceus and other species

Hosts vary with parasite species; definitive hosts include domestic and wild pigs, rodents, muskrats, arctic foxes, dogs, sea otters, other terrestrial and marine mammals; intermediate hosts are beetles, cockroaches, crustaceans; fish are paratenic hosts

Worldwide

Ingestion of infected beetles, other intermediate hosts, or fish

Gastroenteritis, may lead to gut perforation or intestinal obstruction; some cases asymptomatic

Hirudiniasis (internal)

Limnatis nilotica and other aquatic leeches

Cattle, buffalo, other domestic and wild mammals, probably frogs

Africa, Asia, southern Europe, Middle East

Drinking unfiltered water (leech enters nares or mouth), wading in deep water (enters genitourinary tract)

Attaches to nasopharynx, pharynx, esophagus, occasionally deeper in respiratory tract, or in genitourinary tract; pressure and/or pain at attachment site; bleeding (eg, hemoptysis, hematemesis, epistaxis, vaginal bleeding), anemia (can be severe); other signs depend on location, may include persistent headache, cough, dyspnea, chest pain

Acariasis (Mange)

Mites of Sarcoptes, Cheyletiella, Dermanyssus, and Ornithonyssus spp

Mammals and birds

Worldwide

Contact with infected animals, fomites

Itchy skin lesions

Cordylobia anthropophaga, rarely C rodhaini(Tumbu flies)

Mammals

Africa, Saudi Arabia

Larvae from environment invade unbroken skin

Furuncular swelling at site of invasion, often feet

Dermatobia hominis (human bot fly)

Mammals, some birds

South and Central America, Mexico

Eggs carried by other insects; larvae hatch and penetrate skin of mammalian host when insect lands

Nonmigratory larvae in furuncles; pain, intense pruritus, sometimes with lymphangitis or lymphadenitis; can invade eyelids, eye sockets, mouth, especially in children

Myiasis

Hypoderma lineatum, H bovis (warbles), and other Hypoderma spp

H bovis and H lineatum in cattle, sometimes other mammals; other species primarily parasites of deer, caribou, or yaks

North America, Europe, Asia; species distribution varies

Eggs laid on host, larvae invade skin

Usually subcutaneous (slowly moving furuncles that can appear and disappear) or similar to cutaneous larva migrans; endophthalmia uncommon; H lineatum may also cause fever, muscle pain, eosinophilia, sometimes respiratory, cardiac, or neurologic signs

Wohlfahrtia spp, Wohlfahrtia vigil, W magnifica

W vigil in rabbits, mink, foxes, dogs, and other carnivores; W magnifica in sheep, cattle, other mammals, some birds, especially geese

W vigil in North America; W magnifica in Europe (mainly Mediterranean), north Africa, Asia

Larvae deposited on host or nearby, penetrate lesions (both agents) or intact skin (W vigil) and natural orifices

W vigil causes subcutaneous abscesses, furuncles; W magnifica has been reported from skin, eye, vulva, ear, orotracheal region

Linguatula serrata

Definitive hosts are dogs and other canids, felids; intermediate hosts are herbivores, especially sheep, goats, lagomorphs, and including humans

Worldwide

Ingestion of water or vegetables contaminated with eggs (from feces, saliva, or nasal discharge of definitive host); ingestion of larvae in undercooked liver or lymph nodes from intermediate hosts

Ingestion of eggs—usually asymptomatic; ocular or pulmonary signs, abdominal pain, icterus, and other symptoms possible from invasion of internal organs

Ingestion of larvae—throat irritation, pain; edema, congestion of nasopharynx may cause dyspnea, difficulty swallowing; most severe cases are probably in people who have been sensitized

Tunga infections

Tunga penetrans (sand fleas, jiggers)

Humans, dogs, pigs, other mammals

Africa, Central and South America, Caribbean, south Asia

Skin contact with contaminated soil

Penetration of skin and burrowing result in pain and itching around discrete sores, often on feet; may be secondarily infected

Alkhurma virus infection

Alkhurma virus; may be a variant or strain of Kyasanur Forest virus

Sheep, goats, camels

Mainly in Saudi Arabia; virus may exist throughout Arabian peninsula

Direct contact including transmission via broken skin, ingestion of unpasteurized camel milk, mosquito bites

Fever, headache, myalgia, anorexia, vomiting; encephalitic and hemorrhagic signs; case fatality rate 25%

Buffalopox virus infection

Vaccinia virus, Buffalopox virus strain (Family Poxviridae, genus Orthopoxvirus)

Water buffalo, cattle

Indian subcontinent (south Asia), Egypt, Indonesia

Skin contact with infected animals, often when milking

Pox skin lesions mainly on hands, face, legs, buttocks; occasionally lymphadenopathy

—La Crosse encephalitis

La Crosse strain of California encephalitis virus (La Crosse virus)

Chipmunks, squirrels are major amplifying hosts; rabbits, foxes, and other mammals can be infected

North America

Mosquito bites

Many cases mild and flu-like; meningitis or encephalitis with seizures, paralysis, and focal neurologic signs possible; most cases in children; estimated case fatality rate in cases with encephalitis is 0.3%

Chikungunya virus infection

Chikungunya virus (Family Togaviridae, genus Alphavirus)

Sylvatic cycle in nonhuman primates in Africa; virus thought to be maintained in humans in Asia

Southeast Asia, Africa

Mosquito (especially Aedes spp) bites

Febrile illness, may have rash; arthralgia, especially in small joints, is prominent, may persist for months; myocarditis, neurologic signs, hemorrhages reported in a few cases

Contagious ecthyma (Orf, see Contagious Ecthyma)

Orf virus (Family Poxviridae, genus Parapoxvirus)

Sheep, goats, camelids, reindeer, wild ungulates; rare cases in dogs

Worldwide

Occupational exposure via contact with broken skin

Papule(s) that umbilicate and ulcerate, usually on hands; dissemination rare; large lesions refractory to treatment can occur in immunosuppressed

Crimean-Congo hemorrhagic fever (see Crimean-Congo Hemorrhagic Fever)

Crimean-Congo hemorrhagic fever virus (Family Bunyaviridae, genus Nairovirus)

Cattle, rodents, sheep, goats, hares, other mammals, some birds

Africa, Middle East, central Asia, eastern Europe

Tick bites, especially Hyalomma but also -Rhipicephalus, Dermacentor, other species; skin contact with animal or human blood or tissues or crushed ticks; ingestion of unpasteurized milk

Fever, headache, pharyngitis, abdominal symptoms, petechial rash, hemorrhage, hepatitis; very severe in pregnant women; case fatality rate 30–50%

Ebola hemorrhagic fever

Zaire ebolavirus, Sudan ebolavirus, Ivory Coast ebolavirus, Bundibugyo ebolavirus (Family Filoviridae, genus Ebolavirus)

Bats are reservoir hosts for Zaire ebolavirus and suspected reservoir hosts for others; primates, duikers, possibly other mammals can be infected

Africa

Contact with infected tissues (especially nonhuman primates and duikers); probable transmission from bats in caves

Initially nonspecific febrile illness; maculopapular rash with desquamation; mild to severe bleeding tendency develops a few days after onset; mortality rate 36–90%, varies with the isolate

Foot-and-mouth disease (see Foot-and-Mouth Disease)

Foot-and-mouth disease virus (Family Picornaviridae, genus Aphthovirus, types A, O, C, SAT 1, SAT 2, SAT 3, and Asia 1)

Cattle, swine, sheep, goats, other cloven-hoofed animals (Artiodactyla), a few mammals in other orders

Asia, Africa, Middle East, South America

Contact exposure

Humans can carry virus but do not usually become ill; mild influenza-like disease with vesicular lesions occurs very rarely

—Hantaviral pulmonary syndrome

Sin Nombre, Black Creek Canal, Muleshoe, Bayou, Andes, Bermejo, Choclo, Araraquara, Juquitiba, Maciel and Castelo dos Sonhos viruses, others (Family Bunyaviridae, genus Hantavirus)

Rodents; each virus tends to be associated with a single reservoir host

North and South America

Aerosols from rodent excretions and secretions; contact with broken skin and mucous membranes; rodent bites

Prodromal stage with nonspecific febrile illness; followed by respiratory failure, cardiac abnormalities; hemorrhagic signs possible with South American viruses; significant kidney disease uncommon; mortality rate varies with the virus, but can reach 40–60%

Hendra virus infection (see Hendra Virus Infection)

Hendra virus (Family Paramyxoviridae, genus Henipavirus)

Fruit bats are normal reservoir host; horses can be infected

Australia

Direct contact with infected animals or contaminated tissue

Respiratory infection, encephalitis; few cases described

Herpes B virus disease

Cercopithecine herpesvirus 1 (Herpesvirus simiae, B virus) (Family Herpesviridae, genus Simplexvirus)

Carried in genus Macaca (Old World macaques), with lifelong latency after infection; other nonhuman primates susceptible; cell cultures

Worldwide, can be common, especially in closed groups of macaques; human cases rare

Monkey bites and scratches, contamination of mucous membranes with infected saliva, secretions

Influenza-like symptoms; vesicular skin lesions, pain, or itching around wound; followed by severe encephalitis with seizures, paralysis, coma; 85% mortality rate

—Avian influenza

Influenza A virus (Family Orthomyxoviridae, genus Influenzavirus A); avian influenza viruses; avian viruses that cause severe zoonotic disease are usually high pathogenicity (HPAI) strains

Avian influenza viruses in wild and domestic birds; avian HPAI viruses generally found in poultry and rarely in wild birds; uncommon in mammals

Worldwide; HPAI avian influenza viruses eradicated from domestic poultry in many developed countries

Usually by contact with infected animals; avian viruses also in feces

Avian influenza viruses can cause conjunctivitis, human influenza-like illness, or severe disease with multiorgan dysfunction, death; severity of disease varies with influenza strain

Japanese encephalitis (Japanese B encephalitis)

Japanese encephalitis virus (Family Flaviviridae, genus Flavivirus)

Swine, horses; wild birds are subclinical maintenance hosts; other mammals, reptiles, amphibians may be infected asymptomatically

Asia, Pacific islands from Japan to the Philippines

Mosquito (Culex tritaeniorhynchus, other Culex spp) bites; also through broken skin or mucous membranes after direct contact with infected tissues

Fever, chills, myalgia, severe headache, GI symptoms; can progress to severe encephalitis; neurologic sequelae very common in survivors of encephalitis; case fatality rate 15–30%

Lassa fever

Lassa virus (Family Arenaviridae, genus Arenavirus)

Wild rodents, usually multimammate mouse

Africa

Contact with rodent excretions, secretions, or tissues

Gradual onset of nonspecific febrile illness, may be followed by chest pain, cough, GI signs, hepatitis; severe swelling of head and neck, hypotension/shock can develop; pleural/pericardial effusions; hemorrhagic syndrome less common; overall mortality rate 1% in endemic areas; case fatality rate can be up to 50% during epidemics

Lymphocytic choriomeningitis

Lymphocytic choriomeningitis virus (Family Arenaviridae, genus Arenavirus)

Reservoir mainly house mice; can be maintained in hamster populations; also infects guinea pigs, chinchillas, rats, nonhuman primates, some other mammals

Worldwide

Contact with host excretions and secretions; bites

Ranges from mild flu-like illness to biphasic with meningitis in second phase; arthritis, parotitis, and orchitis may occur; can be teratogenic (CNS) or cause abortion; rarely fatal in immunocompetent

Menangle virus infection

Menangle virus (Family Paramyxoviridae)

Fruit bats are normal reservoir host; pigs can also be reservoir

Australia

Close direct contact with tissues, amniotic fluid, blood reported in human cases

Severe illness with fever, severe headache, myalgia, lymphadenopathy, drenching sweats, macular rash

Monkeypox

Monkeypox virus (Family Poxviridae, genus Orthopoxvirus)

Nonhuman primates; Gambian rats, other African rodents; prairie dogs, other pet rodents, squirrels

West and central Africa

Contact with lesions, blood or body fluids, fomites; bites; aerosols

Smallpox-like disease; flu-like symptoms followed by maculopapular rash, which develops into vesicles, pustules, scabs; lymphadenopathy prominent; respiratory signs, encephalitis possible; case fatality rate varies with strain, <1% to 10%; milder in those vaccinated for smallpox

Newcastle disease

Newcastle disease virus/Avian paramyxovirus 1 (Family Paramyxoviridae, genus Avulavirus)

Domestic and wild birds

Mildly virulent (lentogenic, mesogenic strains) are found worldwide; highly virulent (velogenic) strains occur in Asia, the Middle East, Africa, Central and South America, parts of Mexico; also in cormorants in USA

Occupational exposure, usually after contact with large amounts of virus

Highly virulent (velogenic) strains can cause self-limiting conjunctivitis, possibly other syndromes

Nipah virus infection (see Nipah Virus Infection)

Nipah virus (Family Paramyxoviridae, genus Henipavirus)

Fruit bats are normal reservoir; swine can be reservoir; occasionally in other mammals (spillover hosts)

Malaysia, Bangladesh and Northern India; virus is probably endemic in southeast Asia, but outbreaks seem to cluster in certain geographic areas

Direct contact with infected pigs or contaminated tissue; direct or indirect (eg, contaminated fruit juice) bat-to-human transmission

Initial signs flu-like with fever, headache, myalgia, sometimes vomiting; encephalitis; respiratory disease including acute respiratory distress syndromes in some; septicemia; other complications in severely ill; case fatality rate 33–75%

Rabies and rabies-related infections (see Rabies)

Rabies virus (Family Rhabdoviridae, genus Lyssavirus) and the related lyssaviruses, Duvenhage virus, Mokola virus, Australian bat lyssa-virus, European bat lyssa-viruses; possibly others

Wild and domestic canids, Mustelidae, Viverridae, Procyonidae, and order Chiroptera (bats) are important reservoir hosts; all mammals are susceptible; bats are reservoir hosts for Duvenhage virus, Australian bat lyssavirus, and European bat lyssaviruses; Mokola virus carried in rodents and shrews

Rabies is worldwide except Australia, New Zealand, UK, Ireland, Scandinavia, Iceland, Japan, Taiwan; many smaller islands, including Hawaii, are free of infection

Bites of diseased animals; aerosols in closed environments

Paresthesias or pain at bite site; nonspecific prodromal signs such as fever, myalgia, malaise; mood changes progress to paresthesias, paresis, seizures, and many other neurologic signs; survival is extremely rare

Ross River virus infection, Ross River fever

Ross River virus (Family Togaviridae, genus Alphavirus)

Wallaby and dusky rats proposed as natural hosts; humans, horses may also be a source of virus during epidemics

Australia, South Pacific Islands

Mosquito (Culex annulirostris and Aedes spp) bites

Mild fever, arthralgia +/– arthritis, headache, rash; small joints most affected; arthralgia, myalgia, lethargy may persist for months

Severe acute respiratory syndrome (SARS)

SARS coronavirus (Family Coronaviridae, genus Coronavirus)

Bats are probable reservoir hosts; can also infect palm civets, raccoon dogs, cats, pigs, ferrets, rodents, nonhuman primates, other mammals

China, southeast Asia

Contamination of mucous membranes with respiratory droplets or virus on fomites; possibly aerosol transmission

Fever, myalgia, headache, diarrhea, cough; viral pneumonia with rapid deterioration; case fatality rate 15%

Tanapox

Tanapox virus (Family Poxviridae, genus Yatapoxvirus); Yaba-like disease virus may be a variant of tanapox virus

Nonhuman primates

Asia, Africa, and in monkey colonies

Direct contact through broken skin; mosquitoes suspected to be vector in Africa

Fever, severe backache, lymphadenopathy, and papulovesicular, pruritic lesions, often on extremities; rarely more than 1–2 skin lesions

Venezuelan equine encephalomyelitis

Venezuelan equine encephalitis virus (Family Togaviridae, genus Alphavirus)

Rodents, birds, equids, occasionally in other mammals

Western hemisphere

Mosquito (Mansonia, Aedes, Culex spp) bites; exposure to aerosolized debris from infected laboratory rodents; laboratory accidents

Most have nonspecific febrile illness; <5% progress to encephalitis with case fatality rate of 10% (adults) to 35% (children)

Wesselsbron fever

Wesselsbron virus (Family Flaviviridae, genus Flavivirus)

Sheep; also cattle, lemurs, other mammals, and birds

Southern Africa, southeast Asia

Mosquito (Aedes spp and possibly others) bites; also by contact with contaminated material

Fever, headache, myalgia, arthralgia; hyperesthesia of skin ± maculopapular rash in some; self-limiting

Western equine encephalomyelitis (see Equine Viral Encephalomyelitis)

Western equine encephalomyelitis virus (Family Togaviridae, genus Alphavirus)

Birds are reservoir hosts, also cycles in jackrabbits; equids, other mammals are incidental hosts; virus is also found in reptiles, amphibians

Western and Central USA, Canada, South America

Mosquito (Aedes spp, Culex spp) bites

Nonspecific febrile illness may be followed by encephalitis in infants and children, uncommonly in adults; case fatality rate 3–4%

Prion Diseases