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Background In 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. Methods Serum 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. Results 99 % 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. Conclusions This 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.

Fleas are known vectors of zoonotic agents. Thirty-five fleas, including 28 Ctenocephalides felis (Bouché), four Pulex irritans (L.), and three Echidnophaga gallinacea (Westwood) from 19 rural dogs from southwestern Uganda were analyzed for the presence of Rickettsia spp. (ompB, gltA, and 17 kDa fragment genes) and Bartonella spp. (rpoB and ITS genes) by PCR. Rickettsial DNA was detected in 27 out of 28 of Ct. felis and in two out of four P. irritans. None of the E. gallinacea specimens harbored Rickettsia DNA. Rickettsia felis was confirmed in 12 Ct. felis and in the two P. irritans specimens with positive PCR-results. In addition, the presence of Candidatus Rickettsia asemboensis was evidenced in 15 Ct. felis. Bartonella spp. was not amplified in any sample. Our survey indicates that R. felis, the agent of the flea-borne spotted fever, is present in the study area. Besides, this is the first description of Ca. R. asemboensis in Uganda.

Hundreds of southern right whale calves Eubalaena australis died on their calving ground at Península Valdés, Argentina from 2003 through 2011. During this period, the number of dead calves increased at a much greater rate than that of living calves over the preceding 32 yr, and with greater inter-annual variation. High mortality events occurred late in the calving seasons of 2005 and 2007, early in the seasons of 2008 and 2009, and were equally divided between early and late in 2010 and 2011. Calves that died late in the seasons of 2005 and 2007 were at least a meter longer (mean 7.3 m) than newborns, indicating that they had grown and presumably were healthy before dying. An unusual number of large calves (>6 m) died early in the seasons of 2008 and 2009, suggesting that a population-wide process (e.g. nutritional stress) affected many mothers including older, larger mothers that tend to give birth to larger calves early in the season. Many tissue samples have been collected and analyzed, but no consistent lesions, pathologic processes or elevated levels of algal biotoxins have been identified to explain these recent mortality events. Here, we document the high mortality events, place them in historical context and describe ongoing efforts to identify their causes. As of 2010, the southern right whale sub-population that calves off Península Valdés was estimated to be less than 20% of its initial size before whaling; the ongoing high mortality of calves will significantly affect its recovery.

Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color. The cellular and developmental bases of grey morphism are not understood. Here we describe cellular and ultrastructural features of grey-morph skin in relation to that of normal, wild-type skin. Melanocytes were identified histologically and counted, and melanosomes were measured using transmission electron microscopy. Grey-morph skin had fewer melanocytes when compared to wild-type skin, suggesting reduced melanocyte survival, migration, or proliferation in these whales. Grey-morph melanocytes had smaller melanosomes relative to wild-type skin, normal transport of melanosomes to surrounding keratinocytes, and normal localization of melanin granules above the keratinocyte nuclei. These findings indicate that SRW grey-morph pigmentation patterns are caused by reduced numbers of melanocytes in the skin, as well as by reduced amounts of melanin production and/or reduced sizes of mature melanosomes. Grey morphism is distinct from piebaldism and albinism found in other species, which are genetic pigmentation conditions resulting from the local absence of melanocytes, or the inability to synthesize melanin, respectively.