Infection and exposure to vector-borne pathogens in rural dogs and their ticks, Uganda

Abstract

BackgroundIn rural parts of Africa, dogs live in close association with humans and livestock, roam freely, and usually do not receive prophylactic measures. Thus, they are a source of infectious disease for humans and for wildlife such as protected carnivores. In 2011, an epidemiological study was carried out around three conservation areas in Uganda to detect the presence and determine the prevalence of vector-borne pathogens in rural dogs and associated ticks to evaluate the risk that these pathogens pose to humans and wildlife.MethodsSerum samples (n = 105), blood smears (n = 43) and blood preserved on FTA cards (n = 38) and ticks (58 monospecific pools of Haemaphysalis leachi and Rhipicephalus praetextatus including 312 ticks from 52 dogs) were collected from dogs. Dog sera were tested by indirect immunofluorescence to detect the presence of antibodies against Rickettsia conorii and Ehrlichia canis. Antibodies against R. conorii were also examined by indirect enzyme immunoassay. Real time PCR for the detection of Rickettsia spp., Anaplasmataceae, Bartonella spp. and Babesia spp. was performed in DNA extracted from FTA cards and ticks.Results99 % of the dogs were seropositive to Rickettsia spp. and 29.5 % to Ehrlichia spp. Molecular analyses revealed that 7.8 % of the blood samples were infected with Babesia rossi, and all were negative for Rickettsia spp. and Ehrlichia spp. Ticks were infected with Rickettsia sp. (18.9 %), including R. conorii and R. massiliae; Ehrlichia sp. (18.9 %), including E. chaffeensis and Anaplasma platys; and B. rossi (1.7 %). Bartonella spp. was not detected in any of the blood or tick samples.ConclusionsThis study confirms the presence of previously undetected vector-borne pathogens of humans and animals in East Africa. We recommend that dog owners in rural Uganda be advised to protect their animals against ectoparasites to prevent the transmission of pathogens to humans and wildlife.

Canine vector-borne pathogens in rural dogs in Chile: molecular survey and co-infection patterns

“…The observed prevalence in our study can be considered high when compared with other studies in rural dogs. It is close to the prevalences reported by Brown et al [69] in free-roaming dogs associated with remote Aboriginal communities in Australia, but higher than other studies carried out in Brazil [62], Ivory Coast [70], Kenya [70] and Uganda [59]. The higher probability of A. platys infections in young dogs in our study was already been recorded in a previous study in Africa [70], most likely due to a primary exposure of juvenile individuals to the pathogen [71,72] and might be related to the lower levels CD8 T lymphocytes found in young dogs [73], which has a role in clearance of rickettsial infections [74].…”

“…We found a widespread occurrence of CVBP in rural, free-ranging dogs of central Chile, with three quarters of the dogs positive to at least one pathogen. Previous studies in other parts of the world showed that rural dogs are frequently exposed to or infected by different vector-borne pathogens [59,60]. The outdoor activity of these dogs exposes them to a range of vectors, which is, together with the absence of antiparasitic prophylactic management, the most likely reasons for our ndings.…”

Molecular investigation of tick-borne pathogens in dogs from Luanda, Angola

“…For example, B. rossi , which was not detected in this study, is known to be endemic in South Africa [ 13 ], Sudan [ 19 ], Nigeria [ 20 ] and Uganda [ 21 ]. In addition, the agent of human monocytic ehrlichiosis, Ehrlichia chaffeensis , was previously detected in dogs from Uganda [ 21 ] and in ticks collected from dogs in Cameroon [ 22 ]; and the agent of human granulocytic ehrlichiosis, Ehrlichia ewingii , was detected in dogs from Cameroon [ 23 ]. The species Babesia canis ( sensu stricto ), which is prevalent in Europe, where it is vectored by tick Dermacentor reticulatus , was found in a dog from Nigeria [ 24 ].…”

Bartonella infections in cats and dogs including zoonotic aspects

“…seroprevalence (%) PCR / culture prevalence (%) Confirmed Bartonella spp. and type Reference Africa East nf PCR: 0 nf [ 269 ] Central nf PCR: 2.3 B. clarridgeiae , B. henselae [ 27 ] North 19.5–47.4 PCR: 0.85–37.1 B. clarridgeiae , B. elizabethae , B. henselae , B. rochalimae , B. vinsonii berkhoffii [ 230 , 270 – 272 ] South 14 PCR: 0–9.0; Culture: 0 B. henselae [ 233 , 273 , 274 ] West nf PCR: 0 nf [ 275 ] Asia Middle East 6.6–47.4 Culture and PCR: 9.2–37.1 “ Candidatus Bartonella merieuxii”, B. vinsonii berkhoffii (type III in one study) [ 276 – 278 ] South Korea nf PCR: 0–29.6 B. clarridgeiae , B. henselae [ 241 , 279 , 280 ] Sri Lanka 5.1 PCR: 3.38 Bartonella strain HMD [ 281 ] Thailand 38 PCR: 1.8; Culture and PCR: 0.3–31.3 B. clarridgeiae , B. elizabethae , B. grahamii , B. quintana , B. taylorii , B. vinsonii arupensis [ 40 , 282 – …”