Assessing reservoir host status in leishmaniasis with special reference to the infectiousness of Leishmania (Viannia) braziliensis infections in wild rodents

Molecular methods have been responsible for a notable increase in the detection of Leishmaniinae infections in wild animals. Determining their infectiousness is of paramount importance in evaluating their epidemiological significance. One of the most efficient ways of determining infectiousness for vector borne diseases is xenodiagnosis with the appropriate vector. However, this is logistically very difficult to accomplish in the field, and an ideal solution is to find a molecular surrogate for xenodiagnosis. In this review we discuss different approaches to the problem by focusing on the infectiousness of Leishmania (Viannia) braziliensis in rodents under laboratory and field conditions. Comparisons with similar studies for other Leishmania species emphasizes that there are pivotal differences in the infectiousness and the importance of asymptomatic infections in different hosts. Potentially the most promising surrogate is the real time quantitative PCR (qPCR). However, its success depends on choosing a tissue that relates to the vector’s feeding location and the parasite’s tissue tropism. This requires detailed knowledge of the infection of each species in its wild hosts. We conclude that for L. (V.) braziliensis infections in wild rodents the tissue of choice for a molecular xenodiagnostic test, based on the qPCR is blood, providing that a significant number of samples must be examined

Spatial and temporal patterns of occurrence of lutzomyia sand fly species in an endemic area for cutaneous leishmaniasis in the Atlantic forest region of northeast Brazil

Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly population's abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurence361Sand fly research and controlS71S76CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ410481/2006-

Incidence of human and free-ranging wild rodent infections with Leishmania (Viannia) braziliensis, aetiological agent of cutaneous Leishmaniasis

Background. Human and wild rodent infection rates with Leishmania (Viannia) braziliensis are needed to differentiate transmission pathways in anthropogenically altered habitats. Methods. Human participants in northeast Brazil were tested by the leishmanin skin test (LST) and inspected for lesions/scars characteristic of American clinical leishmaniasis (ACL). Molecular (PCR/qPCR) test records of free-ranging rodents were available from a concurrent capture–mark–recapture study. Force of Infection (λ) and recovery (ρ) rates were estimated from cross-sectional and longitudinal datasets. Results. Cumulative prevalences of human LST+ves and ACL scar+ves were 0.343–0.563 (n = 503 participants) and 0.122–0.475 (n = 503), respectively. Active ACL lesions were not detected. Annual rates of LST conversions were λ = 0.03–0.15 and ρ = 0.02–0.07. The probability of infection was independent of sex and associated with increasing age in addition to the period of exposure. Rodents (n = 596 individuals of 6 species) showed high rates of exclusively asymptomatic infection (λ = 0.222/month) and potential infectiousness to the sand fly vector. Spatially concurrent rodent and household human infection prevalences were correlated. Conclusions. Human exposure to L. (V.) braziliensis continues to be high despite the substantial drop in reported ACL cases in recent years. Spill-over transmission risk to humans from rodents in peridomestic habitats is likely supported by a rodent infection/transmission corridor linking houses, plantations, and the Atlantic Forest

El Instituto Aggeu Magalhães y su figura símbolo: Frederico Simões Barbosa

Submitted by Adagilson Silva ([email protected]) on 2017-05-15T18:19:55Z No. of bitstreams: 1 27557283 2016 cou-ins.pdf: 1222454 bytes, checksum: f1b1e657ff8373cf911a372f19dfa7ad (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-05-15T19:01:49Z (GMT) No. of bitstreams: 1 27557283 2016 cou-ins.pdf: 1222454 bytes, checksum: f1b1e657ff8373cf911a372f19dfa7ad (MD5)Made available in DSpace on 2017-05-15T19:01:49Z (GMT). No. of bitstreams: 1 27557283 2016 cou-ins.pdf: 1222454 bytes, checksum: f1b1e657ff8373cf911a372f19dfa7ad (MD5) Previous issue date: 2016-08Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, Brasil