Seroprevalencia de marcadores de infecciones transmisibles por vía transfusional en banco de sangre de Colombia

OBJETIVO: Determinar la seroprevalencia de marcadores de infecciones transmisibles por vía transfusional. MÉTODOS: Estudio transversal con fuente de información secundaria, basada en los resultados de pruebas biológicas en los donantes de un banco de sangre de Medellín, Colombia, de 2007 a 2010. Se determinó la seroprevalencia de los marcadores de infección y se compararon según sexo y tipo de donante a través de análisis de frecuencias, chi cuadrado, Fisher y razones de prevalencia. RESULTADOS: La población de base estuvo conformada por 65.535 donantes de los cuales, 3,3% presentaran al menos una prueba biológica positiva. El marcador más prevalente en las pruebas del banco de sangre fue sífilis (1,2%), seguido de tripanosomiasis (1,0%), virus de la hepatitis C (VHC) (0,6%), virus de la inmunodeficiencia humana (VIH) (0,5%) y virus de la hepatitis B (VHB) (0,2%). Con base en el laboratorio de referencia se halló una prevalencia de 0,6% para sífilis, 0,1% para VHB y 0% para VHC, VIH y Chagas. Se hallaron diferencias estadísticas en la prevalencia de VHB y sífilis según sexo y tipo de donante. CONCLUSIONES: Los resultados son coherentes con las prevalencias dadas por la Organización Panamericana de la Salud (OPS) y se pueden correlacionar con la prevalencia mundial de las infecciones transmisibles por via transfusional. Los resultados hallados en las pruebas del banco de sangre posibilitan la disminución del riesgo transfusional pero limitan la optimización de recursos al excluir donantes clasificados como falsos positivos.

Malaria at Humaita county, Amazonas state, Brazil: XVII — immune response in patients with Plasmodium falciparum according to gametocytes

In August 1983 the Authors studied 36 patients with Plasmodium falciparum malaria and 14 normal individuals born in Humaita region who had never had malaria, had no spleen enlargement and had negative parasitemia as well as passive hemagglutination. Medical histories were obtained and complete physical examination were performed in all of them just as blood tests, parasite density and lymphocyte typing. The lymphocytes were separated and then frozen in liquid nitrogen for later typing by rosette formation. The patients were divided in two groups according to the presence (13 patients) or abscence (23 patients) of gametocytes before treatment. Severe malaria was predominant in the group without gametocytes. The results showed a decrease in the T-cell numbers in Plasmodium falciparum acute malaria patients both with or without gametocytes before the treatment, while B-cell numbers were normal only in the patients with gametocytes. These observations as like as those previously reported by the Authors, permit to associate the presence of gametocytes in peripheral blood and normal number of B-cells in patients with mild Plasmodium falciparum malaria.

Cryptosporidiosis among patients with acquired immunodeficiency syndrome (AIDS) in the county of São Paulo, Brazil

Stool samples of 157 patients with AIDS, living in the county of São Paulo, were submitted to several techniques in the search for Cryptosporidium sp.. Among the various techniques tested for slide preparation (direct smear, spontaneous sedimentation method, and formol-ether concentration), the latter, formol-ether concentration, offered the best results, clearly outdoing all the others. Nineteen samples out of 157 prepared by this technique, after dyeing by the Kinyoun method or by carbol fuchsin dimethyl sulfoxide, were found to be positive for Cryptosporidium sp..

Borrelia burgdorferi antibodies in dogs from Cotia county, São Paulo State, Brazil

Dogs sera samples collected from Cotia County, São Paulo were tested using indirect immunoenzymatic test (ELISA) in order to study Lyme disease serology in dogs. ELISA method was standardized and G39/40 North American strain of Borrelia burgdorferi was used as antigen. Positive results were confirmed employing the Western blotting technique. Because of the possibility of cross-reactions, sera were also tested for different serological strains of Leptospira interrogans and L. biflexa using microscopic sera agglutination test. Twenty-three of 237 (9.7%) serum samples were positive in the ELISA; 20 of them (86.9%) were confirmed by the Western blotting, what suggests that Cotia may be a risk area for Lyme disease. Although 4 samples (1.7%) were positive for Lyme disease and leptospirosis, no correlation was found between the results (X² = 0.725; p = 0.394) what suggests absence of serological cross reactivity.

Feeding sources and trypanosome infection index of Rhodnius pallescens in a Chagas disease endemic area of Amador County, Panama

The sylvatic triatomine Rhodnius pallescens is considered to be the most important and widespread vector of Trypanosoma cruzi and Trypanosoma rangeli in Panama. However, its behavior and biological characteristics have only been partially investigated. Thus, to achieve sustainable and efficient control over Chagas disease in Panama, a better understanding of the ecology and biology of R. pallescens is essential. In this study we evaluated R. pallescens host feeding sources using a dot-blot assay, and the trypanosome infection index by PCR analysis in a Chagas disease endemic area of central Panama. It was found that in peridomestic palm trees, 20.3% of the examined bugs had fed on opossums (Didelphis marsupialis). However, we observed an increased anthropophagy (25.4%) for those bugs collected inside houses. Considering the domestic and peridomestic habitats as a whole, the proportion of collected R. pallescens infected with trypanosomes was 87.4%. In the two habitats the predominant infection was with T. cruzi (80-90%). Between 47-51% of the analyzed triatomines were infected with T. rangeli. Mixed infections (40-51%) were also detected. These findings provide a better basis for the implementation of a rational control and surveillance program for Chagas disease in regions where R. pallescens is endemic.

Biology of Triatominae (Reduviidae Hemiptera) from North of Formosa County (Goiás-Brazil) I. Length of life cycle of Triatoma sordida (Stal. 1859)

In the present paper the life cycle of Triatoma sordida was studied. The mean length from egg to adult was 213 days. The mean length in days from each stage was: 24.3 (± 1.30) for the first. 32.8 (± 1.45) (2nd), 36.1 (± 1.50) (3rd), 44.6 (± 1.85) (4th) and 52.0 (± 1.92) (5th). The mean egg incubation períod was 23.2 (± 1.40). Overall mortality was 18.8% and egg viability was 82.5%.

Biology of Triatominae (Reduviidae, Hemiptera) from north of formosa county (Goiás - Brazil) II. Length of life cycle of Rhodnius Neglectus lent, 1954

In the present paper the life cycle of Rhodnius neglectus was studied. The mean length from egg to adult was 119 days. The mean length in day from each stage was: 17.4 (± 1.15) for first, 18.2 (± 1.28) for second, fourth and 29.8 (± 1.46) for fifth.

Biology of triatominae (Reduviidade, Hemiptera) from north of Formosa county (Goiás - Brazil). III: length of life cycle of Psammolestes tertius Lent and Jurberg 1965

In the present work the life cycle of Psammolestes tertius was studied. The mean length, in days, fromeach stage was: 26.3 (± 1.7) (1st), 28.6 (± 1.8) (2nd), 28.4 (± 1.8) (3rd), 32.2 (± 1.9) (4th) and 33.5 (± 5.8) (5th). The mean egg incubation period was 15.7 days (± 1.7). Overall mortality was 48.9% and egg viability was 65.7%.

Frequency of human leukocyte antigen (hla) in patients with malaria and in the general population of Humaitá county, Amazonas state, Brazil

In August 1983,85 inhabitants of the municipality of Humaitá, Amazonas State, Brazil were studied to determine the prevalence of antigens to HLA-A, -B, -C and DR. Thirty-eight were sick with malaria due to Plasmodium falciparum. All subjects were examined for splenomegaly, blood parasitaemia and antibodies to malaria. They constituted three groups: 1) 25 subjects native to the Amazon region who had never had malaria; 2) 38 Amazonian subjects who had malaria in the past or currently had an infection; 3) 22 patients with malaria who had acquired the infection in the Amazon Region but came from other regions of Brazil. Blood was taken from each person, the lymphocytes were separated and typed by the test of microlymphocytotoxicity. There was a high frequency of antigens that could not be identified in the groups studied which suggests the existence of a homozygote or phenotype not identified in the population. There was a high frequency of the phenotype Ag(W24) (44.7%) in group 2 when compared with group 1 (32%) or group 3 (9%). Also the individuals in group 2 showed an elevated frequency of antigen DR(4)80%) when compared with group 1 (36.6%) or group 3 (16.6%). These observations suggest the possibility of a genetic susceptibility to malaria among Amazonian residents and indicate a necessity for more extensive studies of the frequency of HLA antigens among inhabitants of this endemic malarial zone.

Malaria in humait a county, state of Amazonas, Brazil. XIX - evaluation of clindamycin for the treatment of patients with Plasmodium falciparum infection

A total of 207 patients with malaria caused by Plasmodium falciparum were submitted to 5 different treatment schedules with clindamycin from 1981 to 1984: A - 89 patients were treated intravenously and orally, or intramuscularly and orally with 20 mg/kg/day divided into two daily applications for 5 to 7 days; B-40 patients were treated orally with 20 mg/kg/day divided into two daily doses for 5 to 7 days; C-27 patients were treated with 20 mg/kg/day intravenously or orally divided into two daily applications for 3 days; D-16 patients were treated orally and/or intravenously with a single daily dose of 20 to 40 mg/kg/day for 5 to 7 days; E-35 patients were treated orally with 5 mg/kg/day divided into two doses for 5 days. Patients were examined daily during treatment and reexamined on the 7th, 24th, 21st, 28th and 35th day both clinically and parasitologically (blood test). Eighty three (40.1%) had moderate or severe malaria, and 97 (46.8%) had shown resistance to chloroquine or to the combination ofsulfadoxin and pyrimethamine. The proportion of cured patients was higher than 95% among patients submitted to schedules A and B. Side effects were only occasional and of low intensity. Three deaths occurred (1.4%), two of them involving patients whose signs and symptoms were already very severe when treatment was started. Thus, clindamycin proved to be very useful in the treatment of patients with malaria caused by Plasmodium falciparum and we recommend schedule A for moderate and severe cases and Bfor initial cases.

A retrospective serologic survey of hantavirus infections in the county of Cássia dos Coqueiros, State of São Paulo, Brazil

INTRODUCTION: In recent years, hantavirus infections producing severe diseases have obtained an increased attention from public health authorities from the countries of Eurasia to the Americas. Brazil has reported 1,300 cases of hantavirus cardiopulmonary syndrome (HCPS) from 1993 to 2010, with about 80 of them occurring in the northeast of the State of São Paulo, with 48% fatality rate. Araraquara virus was the causative agent of HCPS in the region. Considering that hantaviruses causing human disease in the Americas were unknown until 1993, we have looked for hantavirus infections in the population of Cássia dos Coqueiros county, northeast of the State of São Paulo, Brazil, before this time. This county has about 2,800 inhabitants and an economy based on agriculture, including cultivation of Brachiaria decumbens grass. The grass seeds are an important rodent attraction, facilitating transmission of hantavirus to man. Four HCPS cases were reported so far in the county. METHODS: In this study, 1,876 sera collected from 1987 to 1990 were tested for IgG to hantavirus by IgG-ELISA, using the N recombinant protein of Araraquara virus as antigen. RESULTS: Positive results were observed in 89 (4.7%) samples, which were all collected in 1987. The positivity among urban inhabitants was 5.3%, compared with 4.3% among those living in rural areas. CONCLUSIONS: Our results showed that hantavirus infections occurred in Cássia dos Coqueiros, completely unrecognized, even before hantaviruses were described in the Americas.

Characterization of pesticide consumption in the county of Santarém, Pará, Brazil

Many potentially harmful pesticides for both human health and the environment are used in Brazilian Amazon. However, no scientific datum on pesticide usage is presently available for this region. Consequently, it is difficult to assess which substances arc used and in which quantities. As an important premise for future work on pesticide contamination in the county of Santarém (State of Pará, Brazil), a survey was conducted in order to qualify and quantify the use of some pesticides in this region. This investigation was made between January and March 1997 and August and October 1998 and revealed use of several organophosphates, synthetic pyrethroids and carbamates insecticides. Furthermore, many herbicides and fungicides were listed. These pesticides are used for agriculture, domestic, and sanitary programs. This paper also provides a first estimation of quantities of some insecticides commonly used in agriculture (chlorpyrifos, malathion, metamidophos and methyl-parathion). The annual consumption for these four compounds is estimated at ca. 1 910 kg. Organophosphate insecticide consumption in the county of Santarém seems to be lower than the Brazilian average in terms of «per capita» and «per agricultural area» consumptions. Nevertheless, this county uses toxic substances on sensitive environments such as floodplains (várzeas), making relevant a thorough study on the potential contamination of this environment and its biota.

Variação espaço-temporal na atividade forrageira da Saúva (Atta laevigata)

Na Amazônia, a regeneração natural da floresta em pastos e cultivos abandonados pode ser afetada pelas saúvas, pois estas são importantes predadoras das plântulas e das sementes das espécies arbóreas que eventualmente ali se estabelecem. Entretanto, pouco se sabe sobre como as chances de uma dada planta ser atacada ou de uma semente ser removida pelas saúvas varia no tempo e no espaço. Com este intuito, estabeleci uma parcela de 80 χ 120 m, subdividida em quadrantes de 10 χ 10m, em um campo abandonado próximo a Manaus. Na periferia desta parcela haviam 3 ninhos da saúva Atta laevigata. Ao longo de 1 ano, determinei quais plantas (das espécies arbóreas somente) foram atacadas pelas formigas. Determinei também como variou a atividade de coleta de sementes por A. laevigata. Para isto utilizei grãos de feijão (Phaseolus vulgaris). Iscas, com cerca de 20 feijões cada, foram distribuídas pela parcela ao longo do ano. Finalmente, determinei se plantas (mudas de Bellucia imperialis) estabelecidas em solo desnudo tinham uma maior chance de serem atacadas do que aquelas estabelecidas em solo com cobertura de gramíneas. Os resultados mostram que a atividade de coleta de sementes foi espacialmente agregada. A maior atividade foi observada nas regiões sudeste e noroeste da parcela, em geral, próximo aos ninhos. Forte variação temporal na coleta de sementes também foi observada. O pico máximo de atividade ocorreu em meados de julho e o de menor atividade em meados de janeiro. A atividade de corte seguiu um padrão similar. Houve uma clara diminuição no número de plantas atacadas entre novembro e janeiro. A proporção de plantas atacadas por parcela variou entre 6 e 89%. A incidência de ataques por saúvas sobre mudas de B. imperialis não variou em função da cobertura vegetal (com ou sem gramíneas). Isto possivelmente em função da forte heterogeneidade espacial na atividade de A. laevigata, que encobriu qualquer efeito devido a cobertura vegetal.

Philophthalmus gralli (Digenea: Philophthalmidae) parasite of Anas bahamensis and Amazonetta brasiliensis, from Lagoons of Maricá county, Rio de Janeiro, Brazil

Forty ducks, 18 Anas bahamensis (white-cheecked pintail) and 22 Amaxonetta brasiliensis (Brazilian duck) from Maricá and Guarapina lagoons, Maricá, RJ, Brazil, were examined. The prevalence of Philophthalmus gralli in A. bahamensis was 22.2% ans in A. brasiliensis was 27.27%. This is the first record of P. gralli in the Neotropical region, and A. bahamensis and A. brasiliensis are new host records for P. gralli.