Rickettsial Diseases

Animals Involved
Ungulates

Known Distributions
Sub­Saharan Africa, eastern Caribbean

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

Clinical Manifestations in People
Nonspecific febrile illness; painful regional lymphadenopathy in many; eschars often multiple; nuchal myalgia; sometimes sparse maculopapular and/or vesicular rash; deaths do not seem to occur

Animals Involved
Dogs, deer proposed

Known Distributions
Southeastern and south central USA; has been detected in South America

Probable Means of Spreading
Ticks, including Amblyomma americanum

Clinical Manifestations in People
Few cases described; fever, headache, malaise, myalgia, nausea, vomiting; many patients were immunosuppressed

Animals Involved
Wild rodents, deer may be reservoirs in North America; livestock, wild ungulates, wild rodents may be reservoirs in Europe; many other animals (eg, equids, ruminants, dogs, cats, birds) can also be infected

Known Distributions
Worldwide

Probable Means of Spreading
Tick bites (Ixodes spp)

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

Animals Involved
Deer are probably major reservoir in North America, dogs and other canids, lemurs, other mammals can also be infected

Known Distributions
North America; also reported in South America, Asia, and Africa

Probable Means of Spreading
Ticks, including Amblyomma americanum

Clinical Manifestations in People
Asymptomatic to nonspecific febrile illness; rash in many pediatric cases, some adults; may progress to prolonged fever, renal failure, respiratory distress, hemorrhages,
cardiomyopathy, neurologic signs, multiorgan failure; more severe in immunosuppressed, elderly; estimated case fatality rate 2%–3%

Animals Involved
Dogs and other canids thought to be reservoirs for E canis, might also occur in felids; rodents may be reservoirs for E muris

Known Distributions
E canis worldwide; E muris Eastern Europe to Asia; E muris–like organism in North America

Probable Means of Spreading
Ticks (E canis transmitted by Rhipicephalus sanguineus, E muris by Haemaphysalis flava and Ixodes persulcatus complex)

Clinical Manifestations in People
Rare cases of febrile illness, in both healthy and immunosuppressed

Animals Involved
Dogs, rabbits implicated as reservoirs; other animals can be infected

Known Distributions
Europe, especially Mediterranean; cases reported in sub­Saharan Africa

Probable Means of Spreading
Bite of infected ticks (mainly Rhipicephalus sanguineus, also others), crushing tick

Clinical Manifestations in People
Nonspecific febrile illness; eschar (typically single) may or may not be present; rash, often maculopapular, in most; life­threatening disseminated disease or neurologic signs possible but uncommon; case fatality rate 1%–3% if untreated

Animals Involved
Rats are major reservoir; cats, opossums, possibly dogs, other species in peridomestic cycle

Known Distributions
Worldwide, especially warmer regions

Probable Means of Spreading
Infected rodent fleas, usually via flea feces; cat fleas seem to be involved in some cycles

Clinical Manifestations in People
Fever, severe headache, central rash (not always observed); other signs, including arthralgia, cough, nausea/vomiting in some; mortality rate 4% without treatment

Animals Involved
http://www.merckvetmanual.com/generalized-conditions/coxiellosis

Known Distributions
Worldwide

Probable Means of Spreading
Mainly airborne; exposure to placenta, birth tissues, animal excreta; occasionally ingestion (including unpasteurized milk); tickborne infections probably rare or nonexistent in people

Clinical Manifestations in People
Febrile influenza­like illness; atypical pneumonia, hepatitis, endocarditis in some; possible pregnancy complications; overall case fatality rate 1%–2% if untreated

Animals Involved
Rodents, insectivores

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

Probable Means of Spreading
Bite of infected larval trombiculid mites (chiggers)

Clinical Manifestations in People
Eschar in some; rash, headache, fever, painful lymphadenopathy, body aches, interstitial pneumonitis, GI signs; pneumonia,
neurologic signs or cardiac complications in some; mild to severe; convalescence prolonged; case fatality rate up to 30%–50% if untreated

Animals Involved
Uncertain, possibly fish

Known Distributions
Japan, Malaysia, Laos, possibly other Asian countries

Probable Means of Spreading
Thought to be ingestion of raw fish

Clinical Manifestations in People
Relatively mild, nonspecific, febrile illness, resembles infectious mononucleosis

Animals Involved
Flying squirrels

Known Distributions
Eastern USA

Probable Means of Spreading
Squirrel lice or fleas suspected

Clinical Manifestations in People
Nonspecific febrile illness, rash; GI signs in some; sepsis possible; appears to be somewhat milder than non­zoonotic typhus, which has a mortality rate of 20%–60% if untreated