Global Zoonotic Diseases: Viral Diseases and Prion Disease
Disease in Humans | Causative Organism | Animals Involved | Geographic Distribution | Probable Means of Transmission to Humans | Clinical Manifestations in Humans |
|---|---|---|---|---|---|
Viral Diseases | |||||
Alkhurma (Alkhumra) hemorrhagic fever | Alkhurma (=Alkhumra) virus (family Flaviviirdae, genus Flavivirus); variant of Kyasanur Forest virus; member of tickborne encephalitis virus serocomplex | Sheep, goats, camels | Middle East | Ticks (Ornithodoros and Hyalomma spp); direct contact with animal meat via broken skin or ingestion of unpasteurized camel milk linked to some cases | Febrile illness, often with GI signs; encephalitic/neurologic and hemorrhagic signs in some; early reports suggested case fatality up to 25% but probably lower, recently < 1%; subclinical infections may be common |
Barmah Forest virus infection; epidemic polyarthritis | Barmah Forest virus (family Togaviridae, genus Alphavirus) | Natural hosts unknown; horses, brushtail possums, kangaroos might hosts | Australia, Papua New Guinea | Mosquito bites; Culex and Aedes spp implicated; also found in Culicoides midges | Resembles disease due to Ross River virus; fever, rash, and nonspecific clinical signs; myalgia and polyarthralgia can persist for months |
Buffalopox | Vaccinia virus, Buffalopox virus strain (family Poxviridae, genus Orthopoxvirus) | Water buffalo, cattle | Indian subcontinent (south Asia), Indonesia, parts of Middle East | Skin contact with infected animals, often when milking | Pox skin lesions mainly on hands, face, legs, buttocks; occasionally lymphadenopathy, fever, malaise |
California encephalitis virus serogroup (California serogroup) infections | California encephalitis virus serogroup (family Bunyaviridae, genus Orthobunyavirus); includes California, La Crosse, Tahyna, Inkoo, Jamestown Canyon, Morro Bay, Snowshoe hare, Guaroa, Lumbo, Chatanga, and other viruses | Many wild and domestic mammals; major reservoirs and amplifying hosts can differ between viruses | North and South America, Europe, Africa, Asia; possibly worldwide; distribution of each virus varies | Mosquito bites | Syndromes, severity vary with the virus; flu-like illness, meningitis, or encephalitis common with North American viruses |
—La Crosse encephalitis | La Crosse virus (California encephalitis virus serogroup) | Chipmunks, squirrels are major amplifying hosts; 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 < 1% in cases with encephalitis |
—Tahyna fever | Tahyna virus (California encephalitis virus serogroup) | Hares, rabbits, rodents, hedgehogs, and other mammals | Europe, Asia, Africa | Mosquito bites (culicine and anopheles) | Influenza-like illness, sometimes including GI signs; arthritis or respiratory signs, including bronchopneumonia in some; meningitis possible but appears uncommon; most often in children; does not appear to cause fatal disease |
Camelpox | Camelpox virus | Old World camelids, possibly other species | Middle East, Asia, Africa, possibly other areas; human cases recently described in India in camel handlers, rare unconfirmed cases suggested in other locations | Direct contact | Skin lesions similar to cowpox, variola virus infections |
Chikungunya | Chikungunya virus (family Togaviridae, genus Alphavirus) | Sylvatic cycle in nonhuman primates, possibly rodents in Africa; Asian lineage virus thought to be maintained in humans; however, sylvatic cycle may also exist in some locations | Asia, Africa, Europe, South America | Mosquito bites (especially Aedes spp) | Febrile illness, may have rash and/or GI signs; arthralgia, especially in small joints, and myalgia prominent, may persist for months; myocarditis, neurologic signs, hemorrhages reported in a few cases |
Colorado tick fever | Colorado tick fever virus (family Reoviridae, genus Coltivurus; Salmon River virus and California hare coltivirus may be variants | Rodents and small mammals and other mammals can also be infected | Some regions in western North America | Tick bites (primary vector is Dermacentor andersoni) | Nonspecific febrile illness; pharyngitis, rash, or GI signs possible; biphasic or triphasic in some; complications (eg, neurologic signs, hemorrhages, pericarditis, myocarditis, orchitis) uncommon but can occur in severe cases; deaths rare |
Orf virus (family Poxviridae, genus Parapoxvirus) | Sheep, goats, camelids, wild ungulates; rare cases in dogs and cats | Worldwide | Occupational exposure via contact with broken skin (both live animals and meat processing) | Papule(s) that umbilicate and ulcerate, usually on hands; dissemination rare but has occurred in humans with atopic dermatitis; large lesions refractory to treatment can occur in immunosuppressed | |
Cowpox virus (family Poxviridae, genus Orthopoxvirus) | Rodents are usual reservoir host; also in domestic and wild cats, occasionally cattle, other mammals | Parts of Europe and Asia | Contact exposure via broken skin, bites, scratches | Papules, vesicles that become pustular, to ulcerative nodules, scars; single or multiple lesions, often on hands; regional adenopathy and malaise, flu-like symptoms in some; lesions remain localized in healthy humans; more extensive or generalized disease may occur in children, humans with eczema, immunocompromised; severe cases can involve respiratory mucosa; rare fatal cases (eg, complications of encephalitis) | |
Crimean-Congo hemorrhagic fever virus (family Bunyaviridae, genus Orthonairovirus) | Cattle, water buffalo, rodents, sheep, goats, hares, other mammals, rarely in birds (eg, ostriches) | Africa, Middle East, Asia, parts of Europe where Hyalomma ticks occur | Tick bites, especially Hyalomma but other genera may also transmit; skin, mucous membrane contact with blood or tissues of animals or crushed ticks; ingestion of unpasteurized milk and possibly uncooked animal tissues; rarely airborne; person-to-person transmission occurs, especially via hemorrhage and during close contact | Febrile flu-like signs, GI symptoms; hemorrhagic signs may begin with petechial rash; hepatitis, abortion, other organ involvement in some cases; asymptomatic or mild in some; case fatality rate usually 3%–30% but can be higher | |
Eastern equine encephalomyelitis virus (EEEV), Madariaga virus (former South American EEEV lineages) (family Togaviridae, genus Alphavirus) | Birds are principal reservoir hosts, small mammals might also amplify, snakes might have role in overwintering virus; small mammals (eg, rodents), marsupials might be reservoir hosts for Madariaga virus; clinical cases in equids and occasionally other mammals and birds but domestic animals are almost always dead-end hosts | Americas | Mosquito bites; Culiseta melanura important in EEEV maintenance cycle; Culex spp might be important for Madariaga virus; various mosquito species (Aedes, Coquillettidia, Culex) can transmit to humans | EEEV causes nonspecific febrile illness, which may be followed by severe encephalitis; neurologic sequelae common after encephalitis; case fatality rate 30%–70%;more severe in infants and elderly; Madariaga virus causes similar signs but seems less severe | |
Ebola hemorrhagic fever | Zaire ebolavirus, Sudan ebolavirus, Tai Forest ebolavirus (formerly Ivory Coast ebolavirus), Bundibugyo ebolavirus (family Filoviridae, genus Ebolavirus); Reston ebolavirus does not seem to affect humans | Bats are reservoir hosts for Zaire ebolavirus and suspected reservoir hosts for others; primates, duikers, pigs, possibly other mammals can be infected | Africa | Contact with infected tissues (especially nonhuman primates and duikers), blood; probable transmission from bats in caves; person-to-person transmission occurs | Initially nonspecific febrile illness; maculopapular rash with desquamation; various oral/ pharyngeal mucosal lesions possible; signs of increased vascular permeability, mild to severe bleeding tendency, various other signs (eg, neurologic signs, dyspnea, multiorgan dysfunction) develop a few days after onset; mortality rate 36%–90%, varies with isolate |
Encephalomyocarditis | Encephalomyocarditis virus (family Picornaviridae, genus Cardiovirus); implicated as zoonotic pathogen but few confirmed cases | Rodents, possibly wild boar, may be reservoir hosts; also found in wild and domestic mammals (including swine, nonhuman primates), and wild birds | Worldwide in animals | Probably ingestion of contaminated food or water | Nonspecific febrile illness, sometimes with GI signs, and/or decreased reflexes have been reported in adults, with recovery within several days; implicated in CNS signs, including paralysis in children; most infections may be asymptomatic or mild |
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, typically in laboratories or other high concentrations of virus; broken skin or drinking virus-contaminated unpasteurized milk are recognized routes | Humans may become temporary nasal carriers after field exposure to virus but do not usually become ill; mild influenza-like disease and vesicular lesions (including lesions at site of skin entry) occur very rarely, mostly laboratory associated | |
Hantaviral diseases | |||||
—Hantaviral pulmonary syndrome | Sin Nombre, Black Creek Canal, Bayou, Andes, Choclo, Laguna Negra, and Cano Delgadito viruses, others (family Bunyaviridae, genus Hantavirus) | Reservoirs are rodents, insectivores; each virus tends to be associated with one to a few reservoir hosts; occasionally infect other hosts | North and South America | Aerosols from rodent excretions and secretions; contact with broken skin and mucous membranes; rodent bites; person-to-person transmission reported for Andes virus | Prodromal stage with nonspecific febrile illness; followed by respiratory failure, cardiac abnormalities; hemorrhagic signs possible, mainly with South American viruses; notable kidney disease uncommon; milder illnesses also possible; case fatality rate for most viruses approx. 25%–-40% in classical syndrome |
—Hemorrhagic fever with renal syndrome | Hantaan, Dobrava-Belgrade, Puumala, Seoul, and Amur-Soochong viruses, others (family Bunyaviridae, genus Hantavirus) | Reservoirs are rodents, insectivores; each virus tends to be associated with one to a few reservoir hosts; occasionally infect other hosts | Europe, Asia, Africa; Seoul virus is worldwide | Aerosols from rodent excretions and secretions; contact with broken skin and mucous membranes; rodent bites | Prodromal stage with nonspecific febrile illness; followed by hypotension, renal signs to renal failure with oliguria; hemorrhagic signs, other syndromes (including respiratory) in some; milder illnesses also possible; case fatality rate varies from < 1% (Puumala virus) to 5% (Hantaan virus), and up to 10%–-15% in the past |
Heartland virus disease | Heartland virus (family Bunyaviridae, genus Phlebovirus) | Not known | North America | Vector appears to be Amblyomma americanum tick | Febrile illness with headache, myalgia, arthralgia, diarrhea, thrombocytopenia; some cases fatal (may be associated with comorbidities) |
Hendra virus (family Paramyxoviridae, genus Henipavirus) | Fruit bats are normal reservoir host; horses can be infected | Australia | Direct contact with infected animals (all human cases have been linked with horses) or contaminated tissues | Respiratory infection, encephalitis (including recurrent encephalitis); few cases described but several were fatal | |
Hepatitis E | Hepatitis E virus, mammalian isolates (family Hepeviridae, genus Hepevirus); genotypes 3 and 6, possibly others, are zoonotic; genotypes 1 and 2 maintained in humans | Humans, swine, wild boar, deer, rabbits, ferrets, rats, mongoose, others; swine and probably other hosts are reservoirs for human infections | Worldwide; human and zoonotic genotypes may differ in prevalence between areas | Fecal-oral transmission; consumption of raw or undercooked meat and liver; waterborne, contact with animal reservoirs | Mild, self-limiting hepatitis to liver failure, more severe in pregnancy and can result in abortion, death of newborn, premature birth; usually acute, but can be chronic in organ-transplant patients; case fatality rate < 1% to 4% in general population, up to 20% in pregnant |
Herpes B virus disease | Cercopithecine herpesvirus 1 (McHV, Herpesvirus simiae, B virus) (family Herpesviridae, genus Simplexvirus) | Carried in genus Macaca (Old World macaques), with lifelong latency and potential for periodic shedding 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; very high mortality rate in untreated cases |
Influenza virus infections | |||||
—Avian influenza | Influenza A virus (family Orthomyxoviridae, genus Influenzavirus A); avian influenza viruses; many severe human cases linked to Asian lineage H5N1 highly pathogenic avian influenza (HPAI) or H7N9 LPAI viruses; however, other viruses also cause illness | Avian influenza viruses in wild and domestic birds, especially poultry; uncommon in mammals | Worldwide, distribution of strains varies | Usually by contact with infected poultry; avian viruses may be shed in respiratory secretions and 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 |
—Swine influenza | Influenza A virus (family Orthomyxoviridae, genus Influenzavirus A); swine influenza viruses | Usually in pigs; also turkeys; can infect mink, ferrets | Worldwide | Usually by contact with infected animals; swine influenza viruses occur in respiratory secretions | Seems to resemble human influenza; severity of disease varies; fatal cases have been reported uncommonly |
Japanese encephalitis (Japanese B encephalitis) | Japanese encephalitis virus (family Flaviviridae, genus Flavivirus) | Swine, wild birds are important maintenance and amplifying hosts; horses ill but epidemiologically unimportant in amplification; other mammals, reptiles, amphibians may be infected, usually subclinically | Asia, parts of western Pacific islands and Australia | Mosquito bites especially Culex; Culex tritaeniorhynchus important in maintenance cycle; also through broken skin or mucous membranes after direct contact with infected tissues | Nonspecific febrile flu-like illness can progress to severe encephalitis or less common neurological syndromes (eg, flaccid paralysis) in some; neurologic sequelae very common in survivors of encephalitis; reported case fatality rates < 5%–40% |
Kyasanur Forest disease | Kyasanur Forest virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis virus serocomplex | Rodents, shrews, other small mammals, ground-feeding birds thought to be reservoirs; affects monkeys; possible infections in other mammals, birds | India | Tick bites (especially Haemaphysalis spp, also others) | Nonspecific febrile illness; characteristic papulovesicular eruption on upper soft palate in some; course may be biphasic; hemorrhagic signs (eg, ecchymoses, purpura, petechiae, GI bleeding, epistaxis) and/or neurologic signs possible in second stage; prolonged convalescence in many; case fatality rate ~3% |
Lassa fever | Lassa virus (family Arenaviridae, genus Mammarenavirus) | Wild rodents, multimammate mouse is major host | West Africa | Contact with rodent excretions, secretions, or tissues; aerosols | 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 15%–20% among hospitalized patients |
Louping ill (Ovine encephalomyelitis) | Louping ill virus (family Flaviviridae, genus Flavivirus) | Sheep and red grouse are primary reservoirs; also reported in goats, South American camelids, cattle, horses, dogs, farmed cervids, other domestic and wild mammals; some birds related to grouse (eg, ptarmigan) are susceptible to experimental infection | UK, Northern Ireland; also reported in Norway, Denmark (island of Bornholm), part of eastern Russia; similar viruses in Spain, Greece, Turkey; historically in Bulgaria and possibly Japan | Usually tick bites (Ixodes ricinus) in animals but this route appears uncommon in humans; aerosol exposure in laboratory; contamination of skin wounds and mucous membranes after contact with cultures, infected animals or their tissues; possibly ingestion of milk; human illnesses seem to be rare and mostly laboratory associated | Biphasic influenza-like illness, sometimes followed by meningitis or meningoencephalitis, or polio-like paralytics, syndrome in second phase; case fatality rate appears low |
Lymphocytic choriomeningitis | Lymphocytic choriomeningitis virus (family Arenaviridae, genus Mammarenavirus) | Reservoir mainly house mouse; can be maintained in some other mice, hamster populations; also infects guinea pigs, chinchillas, rats, nonhuman primates, some other mammals | Worldwide | Direct or indirect contact with host excretions and secretions (via mucous membranes, broken skin, aerosols); bites; possibly ingestion | Ranges from mild flu-like illness to biphasic with meningitis in second phase; complications (eg, arthritis of hands, parotitis, orchitis) possible; can cause congenital defects (CNS defects, chorioretinitis, and other ocular lesions) or abortion; rarely fatal in immunocompetent (overall case fatality rate < 1%); serious and life-threatening multisystemic disease in transplant patients |
Marburg hemorrhagic fever | Marburg virus, Ravn virus (family Filoviridae, genus Marburgvirus) | Bats are reservoir hosts; primates can be infected | Africa | Contact with infected tissues (especially nonhuman primates); probable transmission from bats in caves | Initially nonspecific febrile illness; maculopapular rash with desquamation; hepatitis; signs of increased vascular permeability, mild to severe bleeding tendency, various organ dysfunctions develop a few days after onset; mortality rate 20%–88%, varies with isolate |
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 or blood of pigs reported in human cases | Severe illness with fever, severe headache, myalgia, lymphadenopathy, drenching sweats, macular rash |
Middle East respiratory syndrome (MERS) | MERS coronavirus | Dromedary camels source of virus for many cases in humans; bats might be a reservoir | Middle East; serologic evidence for virus in Africa | Contact with nasal secretions from camels; evidence for virus in unpasteurized camel milk, various tissues; possibly other virus sources | Asymptomatic or mild upper respiratory signs or flu-like illness to pneumonia; more severe in humans with coexisting illness or immunosuppression, elderly, but also in healthy; multiorgan failure possible; reported case fatality rates 20% or higher in confirmed cases but serologic evidence suggests milder cases probably missed |
Milker’s nodules (pseudocowpox) | Pseudocowpox virus (family Poxviridae, genus Parapoxvirus) | Cattle | Worldwide | Skin contact (especially broken skin) with lesions on cow’s udder or mouth of calf; also from fomites | Papular to nodular red skin lesions; self-limiting |
Monkeypox | Monkeypox virus (family Poxviridae, genus Orthopoxvirus); Congo Basin clade causes more severe illness than West African clade | Nonhuman primates, some wild and pet rodents, including Gambian rats, dormice, prairie dogs, African squirrels, dogs, some other mammals (eg, opossums); full host range uncertain | West and central Africa | Contact with lesions, blood or body fluids, fomites; bites; aerosols during close contact | 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%–17% or higher; milder in those vaccinated for smallpox |
Murray Valley encephalitis | Murray Valley encephalitis virus (family Flaviviridae, genus Flavivirus) | Wild water birds are reservoirs; rabbits, kangaroos may also amplify virus; some other mammals (eg, horses), dead-end hosts | Australia, New Guinea | Mosquito bites, especially Culex annulirostris | Asymptomatic or mild nonspecific febrile illness in majority; encephalitis, often with neurologic sequelae, or poliomyelitis-like flaccid paralysis in small number of patients; case fatality rate 15%–30% in encephalitic form |
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 found in Asia, the Middle East, Africa, Central and South America, parts of Mexico; also in cormorants in US | Occupational exposure, usually after contact with large amounts of virus | Highly virulent (velogenic) strains can cause self-limiting conjunctivitis, possibly other syndromes (eg, mild influenza-like disease); fatal pneumonia in a severely immunocompromised person |
New World hemorrhagic fever (Argentinean, Bolivian, Venezuelan and Brazilian hemorrhagic fevers) | Arenaviruses in Tacaribe complex (family Arenaviridae, genus M Ammarenavirus): Juin virus (Argentine hemorrhagic fever), Machupo virus (Bolivian hemorrhagic fever), Guanarito virus (Venezuelan hemorrhagic fever), Sabiá virus (Brazilian hemorrhagic fever), Chapare virus; possibly others | Rodents | South America | Viruses found in rodent excretions, secretions, tissues; inhalation of aerosolized virus or direct contact with mucous membranes or broken skin | Gradual onset of nonspecific clinical signs, including myalgia, headache, and fever; may develop petechial or ecchymotic hemorrhages, bleeding, CNS signs, hypotension/shock; case fatality rates differ between viruses |
Nipah virus (family Paramyxoviridae, genus Henipavirus) | Fruit bats of the genus Pteropus are normal reservoir; swine can be reservoir; occasionally in other mammals (spillover hosts) | Malaysia, Bangladesh, Northern India; apparent outbreak (or closely related virus) in Philippines; virus is probably endemic in southeast Asia; however, 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; outbreak in Philippines linked to contact with horses; person to person transmission occurs | Initial signs flu-like with fever, headache, myalgia, sometimes vomiting; encephalitis and meningitis; respiratory disease, including acute respiratory distress syndromes in some; septicemia; other complications in severely ill; case fatality rate 38%–75% | |
Omsk hemorrhagic fever | Omsk hemorrhagic fever virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis virus serocomplex | Voles, muskrats; also found in other animals | Siberia | Tick bites (Dermacentor spp); direct contact with body fluids or carcasses of muskrats and possibly other animal hosts | Biphasic febrile illness with headache, GI signs, ± hemorrhages (nose, gums, lungs, uterus); CNS signs in minority of patients; mortality rate < 3% |
Powassan virus encephalitis | Powassan virus (family Flaviviridae, genus Flavivirus); member of tickborne encephalitis serocomplex | Rodents and other small mammals thought to be reservoirs; evidence for infection in many other mammals, some birds | North America, eastern Russia | Tick bites, especially Ixodes spp, possibly other routes of transmission | Nonspecific febrile illness; may progress to neurologic signs, which can sometimes be severe; some cases fatal |
Rabies and rabies-related infections | Lyssaviruses:rabies virus (family Rhabdoviridae, genus Lyssavirus) and related lyssaviruses, Duvenhage virus, Mokola virus, Australian bat lyssavirus, European bat lyssaviruses 1 and 2, Irkut virus, possibly others | Wild and domestic canids, Mustelidae, Viverridae, Procyonidae, and order Chiroptera (bats) are important reservoir hosts for rabies; bats are reservoir hosts for the rabies-related viruses except Mokola virus, which might be carried in rodents and shrews; probably all mammals are susceptible | Rabies is worldwide with a few exceptions: rabies-related lyssaviruses are found only in eastern hemisphere (distribution varies) | Exposure to saliva of diseased animals through broken skin or mucous membranes, often in bites; 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 in clinical cases thought to be very rare |
Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus) | Sheep, goats, cattle, water buffalo, African buffalo, camels, nonhuman primates; squirrels and other rodents; puppies and kittens | Africa | Mosquito bites; contact with animal tissues, aerosolized virus in laboratories or animal slaughter | Influenza-like febrile illness in most; complications can include renal disease, meningoencephalitis, ocular disease or hemorrhagic syndrome with liver involvement; death uncommon except with hemorrhagic syndrome | |
Ross River virus infection, Ross River fever; epidemic polyarthritis | Ross River virus (family Togaviridae, genus Alphavirus) | Marsupials, important amplifying hosts; possibly also amplified by horses, other mammals during epizootics | Australia, South Pacific Islands | Mosquito bites (especially Culex annulirostris and Aedes spp) | Mild fever, arthralgia ± arthritis, headache, rash; small joints most affected but large joints can also be involved; arthralgia, myalgia, lethargy may persist for months |
St. Louis encephalitis | St. Louis encephalitis virus (family Flaviviridae, genus Flavivirus) | Wild birds are major hosts; mammals (eg, rodents, bats) might also be involved in some locations | Western hemisphere | Mosquito bites, especially Culex spp | Flu-like illness sometimes followed by meningitis or encephalitis, focal neurologic signs; more severe in elderly and those with debilitating diseases; case fatality rate of 5%–20% reported in epidemics |
Severe acute respiratory syndrome (SARS) | SARS coronavirus (family Coronaviridae, genus Coronavirus) | Bats are thought to be reservoir hosts; can also infect palm civets, raccoon dogs, cats, pigs, ferrets, rodents, nonhuman primates, other mammals; palm civets might have role in transmission to humans but uncertain | China, southeast Asia | Contamination of mucous membranes with respiratory droplets or virus on fomites; possibly aerosol transmission | Mild upper respiratory or flu-like illness (sometimes with diarrhea) to severe pneumonia; generally more severe in people with comorbidities, elderly or immunocompromised, but also severe in some healthy people; multiorgan failure possible; fatality rate among known cases ranged from 6%– 17% in different areas |
Severe fever with thrombocytopenia syndrome (SFTS) | SFTS virus (family Bunyaviridae, genus Phlebovirus); agent appears related to heartland disease virus | Reservoir host unknown; antibodies or viral RNA found in various domestic and wild mammals | Asia | Tick bites (Haemaphysalis longicornis and members of other genera) | Febrile illness with GI signs; thrombocytopenia; multiple organ failure possible; some cases fatal |
Sindbis virus disease | Sindbis virus (family Togaviridae, genus Alphavirus) | Birds (passeriformes are main reservoirs or amplifying hosts); occasionally found in other vertebrates | Virus widespread in Eastern hemisphere; outbreaks tend to occur in limited locations but sporadic cases can occur anywhere | Mosquito bites; Culex and Culiseta, also others (eg, Aedes that act as bridge vectors) | Fever, arthritis, rash, prominent myalgia; nausea, vomiting, mild jaundice in some; joint pain can persist for months; seems to be mild or asymptomatic in most children; fatalities appear absent or very rare |
Tanapox | Tanapox virus (family Poxviridae, genus Yatapoxvirus); Yaba-like disease virus may be a variant of tanapox virus | Nonhuman primates | Africa, and in monkey colonies | Direct contact through broken skin; mosquitoes suspected to be vector in Africa | Nonspecific febrile illness followed by self- limited papulovesicular or nodular lesions (may be pruritic or tender), often on extremities; number of lesions varies but often 1–2 |
Tickborne encephalitis (far eastern tickborne encephalitis, Russian spring-summer encephalitis, central European tickborne encephalitis) | Tickborne encephalitis virus (TBEV) (family Flaviviridae, genus Flavivirus); three major subtypes: European (TBEV-Eu [least virulent]), Siberian (TBEV-Sib), Far Eastern (TBEV-FE) | Small mammals especially rodents; important in maintaining virus; ruminants, dogs, horses, and other mammals; birds can be infected | Eurasia; TBEV-Eu mainly Europe to former USSR; TBEV-FE mainly Asia to former USSR; TBEV-Sib mainly in Siberia | Tick bites (mainly Ixodes ricinus and I persculatus; also other species); may be ingested in unpasteurized milk and milk products | Often biphasic, with flu-like febrile illness in initial stage; neurologic signs from mild meningitis to severe encephalitis in some; myelitis or flaccid poliomyelitis-like paralysis (usually arms, shoulders, levator muscles of head); possibility of chronic and progressive forms; cases with hemorrhagic signs reported in parts of Russia; case fatality rate in Europe (mainly TBEV-Eu) < 1% but some subtypes seem to have higher mortality |
Usutu virus infections | Usutu virus (family Flaviviridae, genus Flavivirus) | Birds are reservoir hosts; infections also occur in various mammals including horses, dogs, suids, rodents | Africa, Europe, Middle East | Mosquito bites, mainly Culex spp | Febrile flu-like illness, sometimes with rash; jaundice possible; encephalitis or meningoencephalitis in some; neurologic complications might occur mainly in people with comorbidities or immunosuppression; many cases might be mild/asymptomatic |
Vaccinia-related poxviruses | Vaccinia or vaccinia-like viruses (family Poxviridae, genus Orthopoxvirus) of uncertain origin | Reservoir uncertain; found in wild rodents, cattle, horses, nonhuman primates | Appear to be endemic in Brazil | Direct contact | Pox skin lesions (papules, pustules, ulcerative nodules), may be accompanied by fever, lymphadenopathy |
Venezuelan equine encephalomyelitis | Venezuelan equine encephalitis virus (VEEV) complex (family Togaviridae, genus Alphavirus) | Enzootic VEEV maintained in rodents, other small mammals, bats, not amplified in equids; epizootic viruses amplified in equids; occasionally in other mammals and birds | Western Hemisphere; enzootic strains probably Florida to South America; epizootic strains emerge in South America, spread, including to North America | Mosquito bites (epizootic VEEV mainly Culex; enzootic VEEV by multiple genera); epizootic viruses possibly also by mechanical vectors including blackflies; exposure to aerosolized debris from infected laboratory rodents; laboratory accidents | Most have nonspecific febrile illness, can be followed by neurologic signs in a small percentage of cases, especially children and to a lesser extent the elderly; encephalitis has case fatality rate of 10%–35% with highest rates in children < 5 yr old; fetal losses in some pregnant women |
Vesicular stomatitis | Vesicular stomatitis Indiana virus, vesicular stomatitis New Jersey virus, vesicular stomatitis Alagoas virus, and Cocal virus (family Rhadboviridae, genus Vesiculovirus) | Equids, swine, cattle; occasionally in South American camelids, sheep, and goats; also rodents; serologic evidence of infection in many wild mammals | North and South America; most likely not endemic north of Mexico but sporadic outbreaks | Contact with animals (lesions, secretions) or in laboratory, probably also from insect bites, including mosquitoes and biting flies (Lutzomyia spp, Culicoides midges, and blackflies) | Usually asymptomatic; may develop acute, self-limited, febrile flu-like illness; vesicles sometimes found in mouth, pharynx, or inoculation site (eg, hands); one case of encephalitis in young child attributed to VSV |
Wesselsbron fever | Wesselsbron virus (family Flaviviridae, genus Flavivirus) | Ruminants, especially sheep, goats; also evidence of infection in other mammals, including rodents; lemurs; can infect birds | Africa | Mosquito bites (mainly Aedes spp, possibly others); also by contact with contaminated material especially in the laboratory | Nonspecific febrile illness ± maculopapular rash or ocular signs in some; few cases described but seems to be self-limiting; one case of encephalitis after accidental laboratory exposure of eye |
West Nile virus (family Flaviviridae, genus Flavivirus); lineage 1 and lineage 2 viruses are both pathogenic | Birds are primary reservoir hosts; also affects horses, other mammals, alligators, possibly other reptiles and amphibians | Eastern and western hemisphere | Mosquito bites (primarily , Culex spp); also by handling infected birds or reptiles or their tissues | Nonspecific febrile illness, occasionally with rash; some cases progress to encephalitis, meningitis, and/or acute flaccid paralysis that resembles poliomyelitis; occasionally other syndromes; < 1% develop neurologic disease but case fatality rate ~10% in all patients with this form and higher in the elderly | |
Western equine encephalomyelitis virus (family Togaviridae, genus Alphavirus) | Birds are reservoir hosts, may also cycle in jackrabbits; equids and other mammals are dead-end (incidental) hosts and do not amplify; reptiles might help overwinter | Americas | Mosquito bites; Culex tarsalis important in maintenance cycle in birds in North America; also transmitted by other genera especially Aedes | Nonspecific febrile illness may be followed by encephalitis in infants and children, uncommonly in healthy adults; case fatality rate 3%–4% | |
Yellow fever | Yellow fever virus (family Flaviviridae, genus Flavivirus); only sylvatic cycle is zoonotic (humans are reservoir for urban cycle) | Nonhuman primates | South America, Africa | Mosquito bites (Haemagogus spp and Sabethes spp in sylvatic cycles in South America, Aedes spp in sylvatic cycles in Africa) | Nonspecific, mild to severe febrile illness followed by liver and renal failure in some; hemorrhages (eg, epistaxis, hematemesis, melena, uterine hemorrhage) and often jaundice in severe cases; can be fatal |
Zika virus infection | Zika virus (family Flaviviridae) | Nonhuman and human primates are likely the main reservoirs of the virus | Africa, the Americas, Southern Asia, Western Pacific | Mosquito bites (infected Aedes mosquitoes [A aegypti and A albopictus]) | Many people are asymptomatic; acute onset of fever with maculopapular rash, arthralgia, conjunctivitis, myalgia, headache; there have been cases of Guillain-Barré syndrome reported in patients following suspected Zika virus infection; infection during pregnancy is a cause of microcephaly and other severe fetal brain defects |
Prion Disease | |||||
Variant Creutzfeldt-Jakob disease | Bovine spongiform encephalopathy prion | Cattle are most important host; also infects other ruminants, cats and other felids, lemurs | Most cases in the UK but also in many other countries | Ingestion of bovine products, especially those contaminated with CNS tissues | Neurodegenerative disorder similar to sporadic Creutzfeldt-Jakob disease but often in younger patients and progresses more rapidly; always fatal |