In this study, we identified the phlebotomine sandfly vectors involved in the transmission of American Cutaneous Leishmaniasis (ACL) in Assis Brasil, Acre, Brazil, which is located on the Brazil-Peru-Bolivia frontier. The genotyping of Leishmania in phlebotomines was performed using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. A total of 6,850 sandflies comprising 67 species were captured by using CDC light traps in rural areas of the municipality. Three sandfly species were found in the state of Acre for the first time: Lutzomyia georgii, Lu. complexa and Lu. evangelistai. The predominant species was Lu. auraensis/Lu. ruifreitasi and Lu. davisi (total 59.27%). 32 of 368 pools were positive for the presence of Leishmania DNA (16 pools corresponding to Lu. davisi, and 16 corresponding to Lu. auraensis/Lu. ruifreitasi), with a minimal infection prevalence of 1.85% in Lu. davisi and 2.05% in Lu. auraensis/Lu. ruifreitasi. The Leishmania species found showed maximum identity with L. (Viannia) guyanensis and L. (V.) braziliensis in both phlebotomine species. Based on these results and similar scenarios previously described along the Brazil/Peru/Bolivia tri-border, the studied area must take into consideration the possibility of Lu. davisi and Lu. auraensis/Lu. ruifreitasi as probable vectors of ACL in this municipality.

51 years old (26.9% urban and 61.5% rural). High prevalence rates were observed in retired people (27.1% urban area), housewives and farmer (41.6% and 25%, respectively, in rural area). The main clinical symptoms were joint pains and sensation of leg coldness. Only Cerqueirellum argentiscutum (Simuliidae) transmits M. ozzardi in this municipality (PIR = 5.6% urban and 7.1% rural). M. ozzardi is a widely distributed parasitic disease in Coari. Thus, temporary residency in the region of people from other localities involved with the local gas exploitation might be a contributing factor in spreading the disease.]]>

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This study was undertaken to investigate the prevalence of Mansonella ozzardi infection and to estimate the parasitic infection rate (PIR) The filaria Mansonella ozzardi, one of the aetiological agents of mansonelliasis, is found on the American continent, as well as countries in the Caribbean. In South America, it has been reported in Panama, Colombia, Venezuela, Guyana, Suriname, Brazil, Argentina and Peru (Kozek et al. 1982). M. ozzardi is transmitted by Diptera insects of the families Ceratopogonidae in the Caribbean islands and Ceratopogonidae and Simuliidae in Central and South America (Shelley & Coscarón 2001).The pathogenicity of this filaria is not well defined. Several infected individuals show no symptoms; however, clinical manifestations that decrease the quality of life such as moderate fever, coldness in the legs, joint pains and headaches have been attributed to M. ozzardi infection (Batista et al. 1960b). Recently, the presence of ocular lesions has been reported as possibly associated with M. ozzardi infection (Branco et al. 1998, Cohen et al. 2008.The microfilaria M. ozzardi was detected in Brazil in the 1940s and 1950s (Deane 1949, Deane et al. 1954, Lacerda & Rachou 1956) and was described as a potentially extensive problem (Moraes 1958). Recently, some studies have shown that this filaria is still found with high prevalence (Medeiros et al. 2007(Medeiros et al. , 2008 and that simuliids are incriminated in the parasite's transmission in Brazil (Cerqueira 1959, Shelley & Shelley 1976, Shelley et al. 1980). Due to the absence of data and the importance of M. ozzardi for Amazonian populations, studies are still necessary to understand the geographical distribution of the cases, as well as the individual and cultural characteristics of the population in endemic areas that make them prone to infection. Indeed, eye lesions possibly associated with M. ozzardi have already been reported in the municipality of Pauini (Branco et al. 1998) and high prevalence rates were found in indigenous communities (Medeiros et al. 2007). Thus, our goal was to obtain data on human infection by M. ozzardi through comparison of prevalence rates between genders, as well as to examine the relationships between M. ozzardi infection and age and professional occupation. We also sought to identify the simuliid species involved in the transmission of M. ozzardi and to estimate the Parasitic Infection Rate (PIR) of the vectors. MATERIALs AND METHODsStudy area and population -This study was performed in the Purus and Pauini riverine communities in the municipality of Pauini (07º421'S 67º01'W), Amazonas (AM) (Fig. 1). The municipality of Pauini is located in southwest AM, about 900 km from Manaus. It has 17,092 inhabitants, with 6,970 in the urban zone and 10,122 in rural areas (IBGE 2000). The region is covered by native primary forest and presents long flood areas, accessible only by plane or boat. The rainy season is usually from November-March, with average annual temperatures between 24-26ºC, and a relative humidity bet...

BACKGROUND The state of Rondônia (RO) is a hot spot for human cases of cutaneous leishmaniasis. Many sandfly species in RO are putative vectors of leishmaniasis. OBJECTIVES This study examines the diversity patterns and the presence of Leishmania DNA and blood meal sources of sandflies in RO. METHODS A sandfly survey was performed between 2016 and 2018 in 10 municipalities categorised into three different environment types: (i) Conservation Unit (CUN)-comprised of preserved ombrophilous forests; (ii) Forest Edge (FE)-small forest fragments; and (iii) Peridomicile (PE)-areas around dwellings. FINDINGS A total of 73 species were identified from 9,535 sandflies. The most abundant species were Psychodopygus davisi (1,741 individuals), Nyssomyia antunesi (1,397), Trichophoromyia auraensis (1,295) and Trichophoromyia ubiquitalis (1,043). Diversity was the highest in CUN, followed by the FE and PE environments. One pool of Ps. davisi tested positive for Leishmania braziliensis, reinforcing the possibility that Ps. davisi acts as a vector. The cytochrome b (cytb) sequences were used to identify three blood meal sources: Bos taurus, Homo sapiens and Tamandua tetradactyla. MAIN CONCLUSIONS Our results demonstrated that sandflies can switch between blood meal sources in differing environments. This study enhances the knowledge of the vector life cycle in RO and provides information relevant to leishmaniasis surveillance.

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Sand flies (Diptera: Psychodidae) are responsible for the transmission of protozoan parasites that cause leishmaniases. They are found predominantly in forests, but some species exploit environments that have been subject to deforestation and subsequent human colonization. Studies conducted in Brazil over the past 30 years show that some species are adapting to peri-urban and urban settings. We evaluated sand fly diversity and abundance in the rural settlement of Rio Pardo, Presidente Figueiredo Municipality, Amazonas State, Brazil. Settlement households were divided into four categories. These categories were determined by the human population density and the degree of deforestation in the immediate area. We used CDC light traps to sample the area surrounding 24 households (6 households in each category). Samples were taken on six occasions during September-November 2009 and June-August 2010. A total of 3074 sand fly specimens were collected, including 1163 females and 1911 males. These were classified into 13 genera and 52 species. The greatest abundance of sand flies and the greatest richness of species were observed in areas where human population density was highest. Our results show that changes in the human occupancy and vegetation management in rural settlements may affect the population dynamics and distribution of sand fly species, thereby affecting the local transmission of cutaneous leishmaniases.

Introduction: Estimate the prevalence of Mansonella ozzardi infection and calculate the parasitic infection rate (PIR) in simuliid black flies in the municipality of Lábrea, State of Amazonas, Brazil. Methods: Prevalence was measured using the thick blood smear method collected from the fingers and was related to age, sex and occupation. Simuliidae were collected with a suction apparatus, then stained with hematoxylin and dissected to verify the PIR. Results:The average prevalence rate of M. ozzardi among the 694 individuals examined was 20.7%. Infection was higher in men (27.6%) than in women (14.3%) (p < 0.001) and occurred in most age groups, with the highest prevalence in the following age groups: 38-47 (40%), 48-57 (53.1%) and >58 (60.5%). The highest prevalence rates were observed in the retired (64%), followed by farm workers (47.1%). Infection by M. ozzardi was only identified in Cerqueirellum amazonicum (Simuliidae) with a PIR of 0.6%. Conclusions: This study showed a high prevalence of M. ozzardi in the riverine communities of Lábrea due to the lack of policies regarding the treatment of microfilaremic individuals in the region and an abundance of competent vectors for M. ozzardi. Keywords:Mansonelliasis. Mansonella ozzardi. Simuliidae. Municipality of Lábrea. Amazonas. RESUMOIntrodução: Estimar as prevalências de Mansonella ozzardi, e calcular a taxa de infecção parasitária nos simulídeos no município de Lábrea, Estado do Amazonas. Métodos: As prevalências foram obtidas através do método de gota espessa a partir do sangue coletado da polpa digital e foram relacionadas com a idade, sexo e ocupação. Os simulídeos foram coletados com capturador de sucção, posteriormente foram corados com hematoxilina e dissecados para se obter a taxa de infecção parasitária. Resultados: A prevalência de M. ozzardi entre as 694 pessoas examinadas foi de 20,7%. A infecção foi maior nos homens (27,6%) do que nas mulheres (14,3%) (p < 0,001) e ocorreu na maioria das faixas etárias com maiores prevalências nos indivíduos entre 38-47 (40%), 48-57 (53,1%) e >58 (60,5%) anos. As maiores prevalências foram observadas nos aposentados (64%) e agricultores (47,1%). Somente Cerqueirellum amazonicum (Simuliidae) foi encontrado infectado com M. ozzardi com uma taxa de infecção parasitária de 0,6%. Conclusões: Este trabalho mostra elevadas prevalências de M. ozzardi nas comunidades ribeirinhas de Lábrea devido à ausência de políticas de tratamento dos microfilarêmicos na região e a abundância de vetores competentes. Palavras-chaves:Mansonelose. Mansonella ozzardi. Simuliidae. Município de Lábrea. Amazonas.