The alpaca, Lama pacos, does not have regular oestrous cycles, but oestrus lasts for 21 to 36 days during the breeding season. Ovulation is induced by coitus. Follicular ovulation rupture occurs spontaneously 26 hr after coital stimulation and can be induced by a single injection of hcg. The low fertility observed in this species is considered to be due to low sperm production in the males and a high incidence of pseudopregnancy in the females. The gestation period has been determined to be about 342 to 345 days.
BackgroundAn increasing number of reports are calling our attention to the worldwide spread of leishmaniasis. The urbanization of zoonotic visceral leishmaniasis (VL) has been observed in different South American countries, due to changes in demographic and ecological factors. In May 2006, VL was detected for the first time in the city of Posadas (Misiones, Argentina). This event encouraged us to conduct a clinical and parasitological pilot survey on domestic dogs from Posadas to identify their potential role as reservoirs for the disease.MethodsOne hundred and ten dogs from the city of Posadas were included in the study. They were selected based on convenience and availability. All dogs underwent clinical examination. Symptomatology related to canine leishmaniasis was recorded, and peripheral blood and lymph node aspirates were collected. Anti-Leishmania antibodies were detected using rK39-immunocromatographic tests and IFAT. Parasite detection was based on peripheral blood and lymph node aspirate PCR targeting the SSUrRNA gene. Molecular typing was addressed by DNA sequence analysis of the PCR products obtained by SSUrRNA and ITS-1 PCR.ResultsAccording to clinical examination, 69.1% (76/110) of the dogs presented symptoms compatible with canine leishmaniasis. Serological analyses were positive for 43.6% (48/110) of the dogs and parasite DNA was detected in 47.3% (52/110). A total of 63 dogs (57.3%) were positive by serology and/or PCR. Molecular typing identified Leishmania infantum (syn. Leishmania chagasi) as the causative agent.ConclusionsThis work confirms recent findings which revealed the presence of Lutzomyia longipalpis, the vector of L. infantum in this area of South America. This new VL focus could be well established, and further work is needed to ascertain its magnitude and to prevent further human VL cases.
The ZNS slides can be sent easily to reference laboratories for later molecular analysis that can be useful not only to improve the diagnosis, but also for the application of other molecular techniques.
The emergence of zoonotic visceral leishmaniasis (ZVL) in Latin America is a growing
public health problem. The urbanization of ZVL has been observed in different
countries around the world, and there are a growing number of reports drawing
attention to the emergence of this infection in new locations, as well as its
increase in previously established areas of endemicity. In the city of Posadas,
Misiones province, Northeastern Argentina, the transmission of ZVL associated with
canines and Lutzomyia longipalpis was first reported in 2006. In the
city of Puerto Iguazú, also in Misiones province, the first human case of ZVL was
reported in February 2014. From 209 surveyed dogs, 15 (7.17%) were identified as
positive by serological and/or parasitological methods. Amplification was observed in
14 samples and in all cases the species implicated was Leishmania
infantum. To the authors’ knowledge, this is the first molecular
characterization of L. infantum from dogs in this area.
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