Marcos Barbosa de Souza

Visceral leishmaniasis in Rio de Janeiro, Brazil: eco-epidemiological aspects and control

From 1977 (index case) to 2006, 87 cases of visceral leishmaniasis were confirmed in the municipality of Rio de Janeiro, Brazil, in periurban areas on the continental and coastal slopes of the Pedra Branca massif and the continental slopes of the Gericinó massif. The majority (65.5%) of the patients were more than five years old, predominantly males (61.5%), but without any difference between the sexes below the age of 14 years. The overall fatality rate was 10.4%. Two cases of visceral leishmaniasis/human immunodeficiency virus coinfection were detected. Leishmania chagasi was isolated from human and canine cases. The associations between the presence of phlebotomines and human and canine migrations, disorderly occupation involving degradation of environmental preservation areas and poor socioeconomic conditions may have created a favorable setting for the establishment and propagation of the disease. Close epidemiological surveillance associated with traditional control measures and others (active case researches, land clearing and health education), reduced the incidence of human cases from 2.8 per 100,000 inhabitants in 1981 to less than 0.01 per 100,000 since 1997. The canine infection rates decreased from 4.6% in 1984 to 1.6% in 2008. Lutzomyia longipalpis was not detected in some locations where human and canine cases occurred. In the years 2007 and 2008, no new human cases were reported, but there is a persistent and worrisome residual canine seroprevalence.

Absence of Lutzomyia longipalpis in some endemic visceral leishmaniasis areas in Rio de Janeiro municipality

The first autochthonous case of human visceral leishmaniasis (VL) in the Municipality of Rio de Janeiro was diagnosed in 1977. Since 1980, 54 autochthonous cases have been diagnosed in various locations, and since 1993 some 17 autochthonous human cases have been reported. Eight of these occurred in the neighborhood of Barra de Guaratiba and the others were distributed in the following neighborhoods: Camorim, Colônia, Grota Funda, Grumari, Ilha de Guaratiba, and Carapiá. From September 1996 to December 1999, phebotomine sandfly captures were performed at 18 sites on the mountainsides of the Pedra Branca Massif, in the Municipality, and a total of 18,303 specimens were collected, with a predominance of L. intermedia (87.33%), L. migonei (6.59%), L. longipalpis (3.10%), and L. firmatoi (1.90%). The species L. longipalpis predominated in Barra de Guaratiba (46.80%) and was absent from the other six locations where VL cases also occurred, suggesting the participation of other species like L. migonei and L. firmatoi, belonging to the same paraphyletic group of the vector species, in the VL transmission chain in the region.

Prevalência da infecção canina em áreas endêmicas de leishmaniose tegumentar americana, do município de Paracambi, Estado do Rio de Janeiro, no período entre 1992 e 1993

In the district of Paracambi, State of Rio de Janeiro an epidemiological survey for American tegumentary leishmaniasis in canine population was carried out in endemic localities. A total of 179 dogs was registered and 138 (77.1%) examined for their clinical aspects, development of delayed hypersensitivity (DHS) with Imunoleish® antigen and serological responses by indirect immunofluorescent reaction and enzyme-linked immunosorbent assay. In 9 (6.5%) dogs with active cutaneous lesions or suspect scars, 66.7% were caused by Leishmania sp; 44.4% produced infection in hamsters and showed growth in culture media, which was considered to be compatible with the species of Leishmania braziliensis complex. The molecular characterization (isoenzyme and KDNA restriction profiles) defined two strains with similar profiles for L. (Viannia) braziliensis. The prevalence of canine infection estimated by the cutaneous test, IFR and ELISA was 10.1%, 16.7% and 27.8%, respectively. The presence of clinical / sub-clinical form of ATL in canine population associated with human infections suggested that the dog can act as source of infection as well as for dissemination of the disease.

Flebotomíneos de áreas com notificações de casos autóctones de leishmaniose visceral canina e leishmaniose tegumentar americana em Angra dos Reis, Rio de Janeiro, Brasil

The city of Angra dos Reis presents human cases of American cutaneous leishmaniasis since 1945. Phlebotomine surveys in 1978 had disclosed the presence of Nyssomyia intermedia and the first notification of Lutzomyia longipalpis in Rio de Janeiro, Ilha Grande, Angra dos Reis. In August of 2002 the first canine case of visceral leishmaniasis in the Ilha Grande, Angra dos Reis was notified. Surveys of phlebotomines in the peridomiciliary areas, in the period of November, 2002, through May, 2003, in four localities of Angra dos Reis, resulted in 12,554 specimens belonging to nine species: Brumptomyia sp. Nyssomyia intermedia, Migonemyia migonei, Micropygomyia schreiberi, Pintomyia fischeri, Psychodopygus davisi, Psychodopygus ayrosai, Evandromyia tupinambay, Psathyromyia pelloni. Nyssomyia intermedia was predominant in all localities, followed by M. migonei. The main vector of the AVL, L. longipalpis, was not detected in the localities, including their surroundings, where an infected dog inhabited.

Flebótomos de áreas com ocorrências de casos humanos de leishmaniose tegumentar americana no Município de Seropédica, Estado do Rio de Janeiro

American cutaneous leishmaniasis is caused by protozoa of the genus Leishmania, which affects the skin and mucosa. It is primarily a zoonotic infection. Sandfly surveys were conducted in four areas with occurrences of human cases of American cutaneous leishmaniasis in the municipality of Seropédica. A manual method was used to catch specimens between 6:00 pm and 10:00 pm, for 12 consecutive months. From October 2004 to September 2005, we caught 2,390 individuals belonging to four species: Lutzomyia intermedia accounted for 97.1% of the total collected, followed by Lutzomyia whitmani (1.6%), Lutzomyia migonei (1.2%) and Lutzomyia oswaldoi (0.1%). The Valão das Louças had the highest density of sandflies, followed by the localities of Km 39, Km 40 and Caçador. The low diversity of species is due to significant changes in the ecotope of the region. It is suggested that American cutaneous leishmaniasis is being transmitted by Lutzomyia intermedia in the municipality of Seropédica.

Survey of sandfly vectors of leishmaniasis in Marambaia Island, municipality of Mangaratiba, State of Rio de Janeiro, Brazil

INTRODUCTION The influx and efflux of military personnel in the possible endemic areas of leishmaniasis provided the impetus for research on the sandflies on Marambaia Island. METHODS Sandflies were collected with light traps installed in the 3 ecotypes of 3 areas chosen for their particular landscape aspects. RESULTS In 2009, were collected 32,006 specimens of sandflies belonging to 13 species. The species that showed highest density were Nyssomyia intermedia and Migoneimyia migonei. CONCLUSIONS N. intermedia and M. migonei are the principal vectors of American tegumentary leishmaniasis (ATL) in Brazil; thus, extension studies related to the eco-epidemiology of these species of Marambaia Island are essential.

Occurrence of Anopheles (Nyssorhynchus) rangeli (Gabaldon et al) and Anopheles (Nyssorhynchus) evansae (Brethes) (Diptera: Culicidae) in an eutrophized dam.

This is the first record of immature stages of species belonging to the subgenus Nyssorhynchus (Blanchard) in eutrophized breeding habitats. Larvae of Anopheles (Nys.) evansae (Brethes), Anopheles (Nyssorhynchus) rangeli (Gabaldon et al), Culex nigripalpus (Theobald) and Culex quinquefasciatus (Say) (Diptera: Culicidae) were collected in a rural eutrophized dam in Rio de Janeiro State, in Southeastern Brazil. Eutrophication was substantiated by the low diversity of mosquitoes, the high incidence of Cx. quinquefasciatus (42%) and of Daphinia sp. and, the high levels of both organic nitrogen (0.28 mg/l) and total phosphorus (0.02 mg/l).

Natural breeding sites of phlebotomine sand flies (Diptera:Psychodidae) on Marambaia Island, Rio de Janeiro State, Brazil

Immature phlebotomine sand flies develop in soils with essential and ideal characteristics for their life cycle, such as organic matter, humidity, temperature and low levels of light. Information regarding the potential breeding places of these dipterans is fundamental to understand the epidemiology and ecology of leishmaniasis, in addition to its importance to control them. In the present study, we aimed to find natural breeding sites of sand flies on Marambaia Island with the aid of emergence traps and direct search of immature forms using the flotation technique with saturated sugar solution in organic substrates of the region. Both methods were effective, with a total of 42 specimens of six different species - including some species that participate in the transmission cycle of American Tegumentary Leishmaniasis - collected by the emergence traps, and five immature forms obtained by floatation technique. However, further studies are still necessary, mainly with respect to the ecology and biology of immature sandfly stages, so that control measures focused on breeding sites can produce positive sustainable results in natural environments.

CANINE VISCERAL LEISHMANIASIS CASE INVESTIGATION IN THE JACARE REGION OF NITEROI, RIO DE JANEIRO, BRAZIL

SUMMARY American visceral leishmaniasis is a vector-borne zoonosis in expansion in Brazil. Dogs are the main urban reservoir. Departing from a case of canine visceral leishmaniasis (CVL) in Jacaré, Niterói, Rio de Janeiro State, an epidemiological canine and entomological study was performed to assess the extension of the disease at the location. Sample was collected around the case and the dogs identified by serological tests (rapid double platform immunochromatographic exams, immunoenzymatic assay/ELISA, indirect immunofluorescence/IFAT). The parasitological diagnosis was performed in animals positive in at least one of these tests. The entomological study was carried out by using light traps and manual collection. The associations between canine variables and outcome (ELISA and IFAT reagents) were assessed by the chi-square test and adjusted by multivariate logistic regression for those associations with p < 0.1 in the bivariate analysis. Seventeen cases of CVL were detected among 110 evaluated dogs (prevalence of 15.5%). Presence of ectoparasites (OR 6.5; 95% CI 1.1-37.4), animals with clinical signs (OR 9.5; 95% CI 1.2-76.6), and previous cases of CVL in the same house (OR 17.9; 95% CI 2.2-147.1) were associated with the outcome. Lutzomyia longipalpiswas not detected. Our results are indicative of an ongoing transmission in the area.

Parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil: an approach in public health

This research aimed to describe the frequency of parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil. One hundred and five stool samples were collected and processed by the coproparasitological techniques ethyl acetate sedimentation and centrifuge-flotation using saturated sugar solution. Parasites were detected in 81.9% of the samples, hookworm being the most prevalent, followed by Trichuris vulpis. Ascaris sp. eggs were also found. A high level of evolutive forms of parasites with public health risk was found in stool samples of the environment studied. We propose that health education programs, allied to an improvement of human and animal health care, must be employed to reduce the environmental contamination.