Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon

INTRODUCTION: Deforestation, uncontrolled forest, human population migration from endemic areas, and the large number of reservoirs and wild vectors naturally infected by Trypanosoma cruzi promote the endemicity of Chagas disease in the Amazon region. METHODS: We conducted an initial serological survey (ELISA) in a sample of 1,263 persons; 1,095 (86.7%) were natives of the State of Amazonas, 666 (52.7%) were male, and 948 (75.1%) were over 20 years old. Serum samples that were found to be reactive, indeterminate, or inconclusive by indirect immunofluorescence (IFI) or positive with low titer by IFA were tested by Western blot (WB). Serologically confirmed patients (WB) were evaluated in terms of epidemiological, clinical, ECG, and echocardiography characteristics. RESULTS: Fifteen patients had serologically confirmed T. cruzi infection, and 12 of them were autochthonous to the state of Amazonas, for an overall seroprevalence of 1.2% and 0.9% for the state of Amazonas. Five of the 15 cases were males, and the average age was 47 years old; most were farmers with low education. One patient who was not autochthonous, having originated from Alagoas, showed right bundle branch block, bundle branch block, and anterosuperior left ventricular systolic dysfunction with an ejection fraction of 54%. CONCLUSIONS: The results of this study ratify the importance of monitoring CD cases in Amazonia, particularly in the state of Amazonas.

Active surveillance of American tegumentary leishmaniasis in endemic areas in rural Bolivia

INTRODUCTION: American tegumentary leishmaniasis (ATL), including mucocutaneous leishmaniasis (MCL) and localized cutaneous leishmaniasis (LCL), is endemic in Bolivia. We describe the results of active surveillance of ATL from 2001 to 2006 and assess demographic data related to ATL epidemiology in the Yungas valleys. METHODS: Community-based active ATL surveillance was performed by the institutions SERVIR, CÁRITAS, and the Health Services Department of La Paz, whose files were reviewed retrospectively. A cross-sectional survey was carried out to assess demographic data in two communities. RESULTS: Two thousand nine hundred nine cases of ATL were detected from 2001 to 2006: 2,488 (85.5%) corresponded to LCL and 421 (14.5%) to MCL. A reduction in the proportion of mucosal cases was observed between 2001 and 2006. The proportion of MCL cases increased with age and was higher among males (15.5% versus 12.1%, p=0.018). The rate of positivity via direct observation of the parasite in dermal scrapings and in parasite cultivation was significantly higher for LCL than for MCL (p<0.001 and p=0.009, respectively). The rate of reactivity in the leishmanin skin test was higher in the group with mucosal lesions (p=0.012). The cross-sectional survey showed that 40% of the families had emigrated from the Altiplano. CONCLUSIONS: It is necessary to undertake continuous case detection of ATL in the area, where the disease presents a high rate of mucosal cases. Increasing incidence seems to be associated with immigration and continuous deforestation to expand the crop-growing areas.

Sandfly frequency in a clean and well-organized rural environment in the state of Paraná, Brazil

INTRODUCTION: Sandflies caught in Santa Juliana Farm in Sarandi, State of Paraná, Brazil, were assessed in terms of their fauna, seasonality, and frequency in the homes and in shelters of domestic animals around the homes, as well as in the nearby forest. METHODS: In Santa Juliana Farm, there are no records of cases of ACL, differing from other relatively clean and organized areas where surveys of sandflies have been conducted in Paraná. Samples were collected with Falcão light traps, fortnightly from 22:00 to 02:00 hours, from November 2007 to November 2008. RESULTS: A total of 4,506 sandflies were captured, representing 13 species, predominantly Nyssomyia whitmani (71.8%). More sandflies were collected in the forest (52.6%) than outside the forest (residences and pigsty) (47.4%). However, Ny. whitmani was collected in greater numbers outside (38.3%) than inside the forest (33.5%). Most sandflies were collected in the warmer months and during periods with regular rainfall. CONCLUSIONS: The results suggest that cleaning and organization around the houses could reduce sandfly population in peridomicile. Constructing shelters for animal at a distance of approximately 100m from domiciles is recommended to prevent the invasion of sandflies, as this farm has an area of preserved forest, with wild animals and sandflies present to maintain the enzootic cycle of Leishmania.

Prevalence of serum antibodies to hantavirus in a rural population from the southern state of Santa Catarina, Brazil

INTRODUCTION: Rodent-borne hantaviruses cause severe human diseases. We completed a serological survey of hantavirus infection in rural inhabitants of Turvo County, in the southern State of Santa Catarina, Brazil, in which seropositivity for hantavirus was correlated to previous disease in the participants. METHODS: The levels of IgG antibodies to hantavirus Araraquara in the sera of 257 individuals were determined using an immunoenzymatic assay. RESULTS: IgG antibodies to hantavirus were found in 2.3% of the participants. All seropositive participants reported previous disease with symptoms suggestive of hantavirus cardiopulmonary syndrome. CONCLUSIONS: Human infections causing unreported cardiopulmonary syndrome probably occur in the southern State of Santa Catarina.

Fauna of Culicidae in rural areas of Porto Velho and the first record of Mansonia (Mansonia) flaveola (Coquillet, 1906), for the state of Rondônia, Brazil

INTRODUCTION: Knowledge concerning the fauna of Culicidae in the Brazilian Amazon States contributes to current understanding of the bionomics of the insects collected and makes it possible to observe changes in the fauna over time. METHODS: The Culicidae were captured with a BG-Sentinel® trap in extra-domiciliary area of two rural regions of Porto Velho in June and July of 2007 and 2008. RESULTS: A total of 10,695 Culicidae was collected, belonging to nine genera: Coquillettidia, Culex, Mansonia, Psorophora, Aedes, Aedeomyia, Anopheles, Uranotaenia and Wyeomyia. CONCLUSIONS: The presence of Mansonia (Mansonia) flaveola was recorded in the State of Rondônia for the first time.

Seroepidemiology of Trypanosoma cruzi infection in the semiarid rural zone of the State of Rio Grande do Norte, Brazil

INTRODUCTION: A seroepidemiological survey was carried out to evaluate Trypanosoma cruzi infection in an endemic area of the State of Rio Grande do Norte, Brazil, involving rural residents. METHODS: Sixteen municipalities were randomly selected, 15 from the west mesoregion and one from the central, with an estimated population of 83,852 individuals. A total of 1,950 blood samples were collected in the west mesoregion and 390 in Caicó. Anti-T. cruzi antibodies were detected using the Chagatest® ELISA HAI-hemagglutination kits and indirect immunofluorescence. As sera presented indeterminate results, TESAcruzi® western blot was performed to confirm reactivity. RESULTS: An estimated seroprevalence of 6.5% was determined for the west mesoregion and 3.3% for Caicó. Seropositivity rises progressively with the age of individuals, up to 40 years in Caicó and up to 50 years in the west mesoregion. Only educational level and knowledge regarding the triatomine were associated with seropositivity. No seroreactive individuals under 18 years of age were identified. CONCLUSIONS: Infection by T. cruzi remains high and is concentrated in municipalities in the central western area of the west mesoregion; however, evidence suggests a decline in vector transmission in this mesoregion and in Caicó. Epidemiological variables appear not to influence seropositivity, with the exception of education and knowledge concerning the triatomine, among seroreactive individuals from the west mesoregion.

Phlebotomine sandflies fauna (Diptera: Psychodidae) at rural settlements in the municipality of Cáceres, State of Mato Grosso, Brazil

INTRODUCTION: Leishmaniasis is expanding across Brazil, including the State of Mato Grosso (MT). The aim of this study was to characterize the phlebotomine sandfly fauna at threerural settlements located in the municipality of Cáceres, MT, from August 2010 to July 2011. METHODS: Sandfly captures were conducted at the forest border and in intra and peridomicile areas with automatic light traps, biweekly, from 5pm to 6am. RESULTS: Of the 630 sandflies collected, 348 were female, and 282 were male. Captured specimens were distributed across 11 genera - Brumptomyia, Evandromyia, Expapillata, Lutzomyia, Martinsmyia, Micropygomyia, Nyssomyia, Pintomyia, Psathyromyia, Psychodopygus, and Sciopemyia - and 28 species. Among these, six species had not been marked yet in MT (Brumptomyia avellari, Br. mangabeirai, Evandromyia aldafalcaoae, Micropygomyia echinatopharynx, Micropygomyia peresi, and Pa. campograndensis). Nyssomyia whitmani was the most abundant species across ecotopes at all settlements. Interestingly, Lutzomyia longipalpis and Lutzomyia cruzi were found in sympatry. CONCLUSIONS: The disorganized occupation of the environment that is happening at the rural settlements of Mata Comprida, Laranjeira I and II could provide opportunities for the domiciliation of wild populations of phlebotomine, including vectors of leishmaniasis. Therefore, more studies are needed to understand the epidemiology of the disease in these areas and its impact on the human population.

Spatial distribution of schistosomiasis and geohelminthiasis cases in the rural areas of Pernambuco, Brazil

INTRODUCTION: The prevalence and intensity of geohelminth infections and schistosomiasis remain high in the rural areas of Zona da Mata, Pernambuco (ZMP), Brazil, where these parasites still represent a significant public health problem. The present study aimed to spatially assess the occurrences of schistosomiasis and geohelminthiasis in the ZMP. METHODS: The ZMP has a population of 1,132,544 inhabitants, formed by 43 municipalities. An ecological study was conducted, using secondary data relating to positive human cases and parasite loads of schistosomiasis and positive human cases of geohelminthiasis that were worked up in Excel 2007. We used the coordinates of the municipal headquarters to represent the cities which served as the unit of analysis of this study. The Kernel estimator was used to spatially analyze the data and identify distribution patterns and case densities, with analysis done in ArcGIS software. RESULTS: Spatial analysis from the Kernel intensity estimator made it possible to construct density maps showing that the northern ZMP was the region with the greatest number of children infected with parasites and the populations most intensely infected by Schistosoma mansoni. In relation to geohelminths, there was higher spatial distribution of cases of Ascaris lumbricoides and Trichuris trichiura in the southern ZMP, and greater occurrence of hookworms in the northern/central ZMP. CONCLUSIONS: Despite several surveys and studies showing occurrences of schistosomiasis and geohelminthiasis in the ZMP, no preventive measures that are known to have been effective in decreasing these health hazards have yet been implemented in the endemic area.

Ecology of phlebotomines (Diptera, Psychodidae) in rural foci of leishmaniasis in tropical Brazil

INTRODUCTION: This work aimed to study the community structure of sandflies, with regard to the richness, constancy, abundance, and monthly frequency of the species with a focus on the transmission of leishmaniasis. METHODS: The study was conducted in the rural villages of Bom Jardim and Santa Maria, situated on the edge of a tropical rain forest in the municipality of São Jose de Ribamar, Maranhão, Brazil. The phlebotomines were captured in the intradomiciles and peridomiciles of each village, with Centers for Disease Control (CDC) light traps set in 10 homes in each village, for 1 year, once a month, from 18h to 6h. RESULTS: We collected 1,378 individuals of 16 sandfly species. The capture success rate was higher in Bom Jardim (0.61 specimens/hour/trap) than that of Santa Maria (0.35/specimens/hour/trap). The sandflies were more abundant in the peridomiciles (86.1%) and in the rainy season (77%). Five species were considered constants (occurring in more than 50% of samples), 5 accessory (25%-50%), and 6 accidental (<25%). The most abundant species were Lutzomyia longipalpis (59.7%) and L whitmani (28%). The permutation analysis showed differences between the species composition of the villages and no separation between the intradomicile and peridomicile of each village. The species that most contributed to the dissimilarity between the light traps of the 2 villages were L. longipalpis, L. whitmani, and L. evandroi, contributing to 80.8% of the variation among groups. CONCLUSIONS: The high level of richness and abundance of species and the presence of competent vectors throughout the year and around houses justify the occurrence of leishmaniasis cases reported in the area.

Serologic survey of hantavirus in a rural population from the northern State of Mato Grosso, Brazil

INTRODUCTION: Hantavirus is a genus of ribonucleic acid (RNA) viruses included in the family Bunyaviridae. Hantaviruses are rodent-borne zoonoses that, in the last 18 years, became an emergent public health problem in the Americas, causing a severe cardiopulmonary syndrome. This disease has no specific treatment and has a high case fatality. The transmission of hantavirus to man occurs by inhaling aerosols of rodent excreta. The aim of this study was to determine the prevalence of antibodies to hantavirus in the population of the rural settlement of Tupã in the county of Marcelândia, state of Mato Grosso, Brazil. METHODS: The participants of the serologic survey were visited at their homes and selected randomly among the settlement population. Blood samples of the participants were collected by venopuncture. The serum samples were tested by an IgG-ELISA using an N recombinant protein of Araraquara hantavirus as antigen, using the protocol previously established by Figueiredo et al. RESULTS: IgG antibodies to hantavirus were detected in 7 (13%) of the 54 participants. The positivity was higher among men. It was observed that there was an association of seropositivity to hantavirus within the participants born in the south of Brazil. CONCLUSIONS: The results suggest that, in this rural area, everyone is exposed to the same risk of becoming infected with hantavirus, and, therefore, there is a need to intensify surveillance activities and education of the local people to prevent this viral infection.

Serologic assessment of yellow fever immunity in the rural population of a yellow fever-endemic area in Central Brazil

IntroductionThe yellow fever epidemic that occurred in 1972/73 in Central Brazil surprised the majority of the population unprotected. A clinical-epidemiological survey conducted at that time in the rural area of 19 municipalities found that the highest (13.8%) number of disease cases were present in the municipality of Luziânia, State of Goiás.MethodsThirty-eight years later, a new seroepidemiological survey was conducted with the aim of assessing the degree of immune protection of the rural population of Luziânia, following the continuous attempts of public health services to obtain vaccination coverage in the region. A total of 383 volunteers, aged between 5 and 89 years and with predominant rural labor activities (75.5%), were interviewed. The presence of antibodies against the yellow fever was also investigated in these individuals, by using plaque reduction neutralization test, and correlated to information regarding residency, occupation, epidemiological data and immunity against the yellow fever virus.ResultsWe found a high (97.6%) frequency of protective titers (>1:10) of neutralizing antibodies against the yellow fever virus; the frequency of titers of 1:640 or higher was 23.2%, indicating wide immune protection against the disease in the study population. The presence of protective immunity was correlated to increasing age.ConclusionsThis study reinforces the importance of surveys to address the immune state of a population at risk for yellow fever infection and to the surveillance of actions to control the disease in endemic areas.

Phlebotomine sandfly fauna and natural Leishmania infection rates in a rural area of Cerrado (tropical savannah) in Nova Mutum, State of Mato Grosso in Brazil

Introduction American cutaneous leishmaniasis (ACL) has been reported in every municipality of the State of Mato Grosso, Brazil, but the transmission epidemiology remains poorly understood. Our study was developed in a rural area of the Nova Mutum municipality where four autochthonous cases of ACL were reported in 2009. Our aims were to describe the local phlebotomine sandfly fauna and to investigate the infection rates and infecting Leishmania species in the captured sandflies. Methods Entomological captures were performed bimonthly at 10 fixed sites close to the edge of a forested area between June 2011 and April 2012. Results A total of 3,743 phlebotomine sandflies belonging to 31 distinct species were captured. Approximately 75% of the specimens were females. The most abundant species (45.4%) was Lutzomyia antunesi, which was consistently captured at every site. Species that are epidemiologically important for ACL, such as L. flaviscutellata, L. whitmani and L. umbratilis, were also captured. L. antunesi and L. ubiquitalis were naturally infected by Leishmania braziliensis or Le. guyanensis, with minimum infection rates of 0.88% and 6.67%, respectively. Surprisingly, L. antunesi was infected by Le. infantum (synonym chagasi). Conclusions The natural infection of L. antunesi and L. ubiquitalis by Leishmania sp. suggests that these species might play a role in the zoonotic cycle of ACL in Nova Mutum. The presence of Le. infantum in L. antunesi suggests that there may be a risk of an outbreak of visceral leishmaniasis (VL) in Nova Mutum.

Epidemiological aspects of schistosomiasis in workers of the Movement of Landless Rural Workers

Introduction Schistosomiasis is endemic in 74 countries and is considered a serious public health problem in some locations. Methods A transverse study was performed of 13 landless settlements in southern Sergipe from February to December 2009. The study included 822 settlers, of whom 601 underwent stool testing. Results The prevalence of schistosomiasis in landless workers was 4.3%. The population has a low education level, and basic sanitation services are not available to all residents. Conclusions The prevalence of schistosomiasis was low in the population and among different settlements, possibly because of different forms of water use by the settlers.

The exotic palm Roystonea oleracea(Jacq.) O.F. Cook as a rural biotype for Rhodnius neglectus Lent, 1954, in Caçu, State of Goiás

IntroductionRhodnius neglectus is a triatomine that colonizes different palm species. In this study, we aimed to describe the presence of this triatomine bug in the royal palms (Roystonea oleracea) in a rural region of the State of Goiás.MethodsPalm infestation was investigated by dissecting the palms or by using live-bait traps.ResultsTwo palm trees were infested by R. neglectusnegative for Trypanosoma cruzi, the etiological agent for Chagas disease. In the study area, R. neglectus is frequently found in households.ConclusionsThe adaptation of this species to palm trees introduced in Brazil for landscaping purposes poses another challenge for controlling the vectors of Chagas disease.

An atypical Toxoplasma gondii genotype in a rural Brazilian dog co-infected with Leishmania (Viannia) braziliensis

Toxoplasmosis and leishmaniasis are two worldwide zoonoses caused by the protozoan parasites Toxoplasma gondii and Leishmania spp., respectively. This report describes the clinical and laboratorial findings of a co-infection with both parasites in a 4-year-old female dog suspected of ehrlichiosis that presented anemia, thrombocytopenia, hypoalbuminemia, hyperglobulinemia, tachyzoite-like structures to the lung imprints, and polymerase chain reaction (PCR) results positive for T. gondii (kidney, lung, and liver) and Leishmania spp. Co-infection with Toxoplasma gondii and Leishmania braziliensis was confirmed by sequencing; restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) confirmed an atypical T. gondii genotype circulating in dogs that has been reported to cause human congenital toxoplasmosis.