Sergio de Almeida Basano

Leishmaniose tegumentar americana: histórico, epidemiologia e perspectivas de controle

A Leishmaniose Tegumentar Americana (LTA) e uma doenca causada por protozoarios do genero Leishmania, transmitida ao homem pela picada de mosquitos flebotomineos (Ordem Diptera; Familia Psychodidae; Sub-Familia Phlebotominae). No Brasil existem atualmente 6 especies de Leishmania responsaveis pela doenca humana, e mais de 200 especies de flebotomineos implicados em sua transmissao. Trata-se de uma doenca que acompanha o homem desde tempos remotos e que tem apresentado, nos ultimos 20 anos, um aumento do numero de casos e ampliacao de sua ocorrencia geografica, sendo encontrada atualmente em todos os Estados brasileiros, sob diferentes perfis epidemiologicos. Estima-se que, entre 1985 e 2003, ocorreram 523.975 casos autoctones, a sua maior parte nas regioes Nordeste e Norte do Brasil. Neste estudo, sao discutidos aspectos relacionados ao tratamento e ao controle dessa doenca, assim como tambem as dificuldades para a implementacao dessas medidas. Sao apontadas alternativas que passam pela estruturacao dos servicos de saude, com respeito ao diagnostico, no desenvolvimento de drogas de aplicacao topica ou por via oral, no desenvolvimento de vacinas, no controle diferenciado de vetores e no aprofundamento de estudos relacionados a biologia celular do parasita.

Epidemiological aspects of American cutaneous leishmaniasis and phlebotomine sandfly population, in the municipality of Monte Negro, State of Rondônia, Brazil

INTRODUCTION This work was carried out on the purpose of identifying the species of phlebotomine sandflies in the municipality of Monte Negro, state of Rondonia, Brazil, that may have been transmitting the American cutaneous leishmaniasis (ACL), and concisely describe epidemiological aspects of disease. METHODS The epidemiologic and socioeconomical indicators were obtained from government institutions and the local Municipal Secretary of Health. Phlebotomine sandflies were captured using CDC light traps between July 2006 to July 2008. The total of 1,240 of female sandflies were examined by PCR method directed to k-DNA. RESULTS There has been a significant decrease in the incidence of ACL of about 50% over the last ten years in the municipality. A total of 1,935 specimens of 53 sandfly species were captured, three of the genus Brumptomyia genus and 50 of the genus Lutzomyia. The predominant species was Lutzomyia acanthopharynx, Lutzomyia whitmani, Lutzomyia geniculata and Lutzomyia davisi. None were positive for Leishmania sp. CONCLUSIONS Four sandflies species were found in the State of Rondonia for the first time: Brumptomyia brumpti, Lutzomyia tarapacaensis, Lutzomyia melloi and Lutzomyia lenti. The presence of Lutzomyia longipalpis, was also captured. Socioeconomical improvement of Brazilian economy and the increase of environmental surveillance in the last 15 years collaborated in the decrease of people exposed to vectors, reducing the incidence of ACL.

Improvement of a PCR test to diagnose infection by Mansonella ozzardi

INTRODUCTION Mansonelliasis is caused by Mansonella ozzardi. It is widespread in the Amazon region, with a high prevalence. The common exam of thick blood smears stained with Giemsa shows low efficacy levels and has been an obstacle to diagnosing individuals with low blood parasitemia. METHODS In order to increase diagnosis efficacy, the PCR technique was improved. RESULTS AND CONCLUSIONS PCR demonstrated the best performance, with sensitivity and negative predictive values (NPV) of 100%, followed by blood filtration through membrane filters, which showed a sensitivity of 88.9% and a NPV of 84.6%, when compared to thick blood smears.

Sustained Clearance of Mansonella ozzardi Infection after Treatment with Ivermectin in the Brazilian Amazon

Therapy for mansonelliasis is challenging because there is no standard drug recommended for its treatment. This non-randomized study was conducted to evaluate the effectiveness of a single dose of 0.15 mg/kg of ivermectin to reduce Mansonella ozzardi microfilaraemia in infected persons. A total of 74 patients were studied within the municipality of Lábrea, which is located in Amazonas State, Brazil. The patients were treated with ivermectin after detection of the parasite by blood examination. Significant microfilaraemia reduction was observed and its residual effect was maintained for at least 12 months. There was no significant change in the laboratory blood count, hepatic metabolites, and nitrogen-bounding compound excreta dosage values that could compromise the use of this drug, demonstrating that ivermectin has a low toxicity level.

INSECTICIDE-TREATED BED NETS IN RONDÔNIA, BRAZIL: EVALUATION OF THEIR IMPACT ON MALARIA CONTROL

Mosquito nets treated with long-lasting insecticide (LLINs), when used in compliance with guidelines of the World Health Organization, may be effective for malaria vector control. In 2012, approximately 150,000 LLINs were installed in nine municipalities in the state of Rondônia. However, no studies have assessed their impact on the reduction of malaria incidence. This study analyzed secondary data of malaria incidence, in order to assess the impact of LLINs on the annual parasite incidence (API). The results showed no statistically significant differences in API one year after LLIN installation when compared to municipalities without LLINs. The adoption of measures for malaria vector control should be associated with epidemiological studies and evaluations of their use and efficiency, with the aim of offering convincing advantages that justify their implementation and limit malaria infection in the Amazon Region.

Occurrence of Mansonella ozzardi diagnosed using a polycarbonate membrane in a riverside population of Lábrea in the Western Brazilian Amazon

INTRODUCTION Mansonella ozzardi is a widely distributed filaria worm in the Amazon region. This study aimed to determine the prevalence of M. ozzardi infection in riverine communities of Lábrea municipality, Amazonas State, Brazil. METHODS A diagnostic blood filtration method in a polycarbonate membrane was used. RESULTS M. ozzardi was found in 50.3% of the sample, with the highest prevalence in farmers/fishermen (69.4%; χ 2 = -19.14, p<0.001). The prevalence was higher in longer-term residents (≥11 years; 60.2%). CONCLUSIONS M. ozzardi infection rates are high near the Purus River, much greater than those previously reported based on diagnosis using thick blood smears.

STUDY OF THE PREVALENCE OF Capillaria hepatica IN HUMANS AND RODENTS IN AN URBAN AREA OF THE CITY OF PORTO VELHO, RONDÔNIA, BRAZIL

Introduction: Hepatic capillariosis, caused by Capillaria hepatica (Calodium hepaticum) (Bancroft, 1893), Travassos, 1915 (Nematoda, Trichinelloidea, Capillariidae), is a common zoonosis in rodents but is rare in humans. Seventy-two cases in humans have been reported worldwide since the first case was described by MACARTHUR in 192417,27. This study aimed to determine the prevalence of Capillaria hepatica in humans and rodents in an urban area of Porto Velho, the capital of Rondônia, in Brazil. Methods: After conducting a census of the area, 490 residents were randomly selected, and, after signing a term of consent, provided blood samples that were screened for anti-Capillaria hepatica antibodies. Simultaneously, rats were captured to assess the prevalence of this parasite in rodents by histopathological examination in liver sections. Results: A prevalence of 1.8% was found among residents who had specific antibodies at a dilution of 1:150, indicating exposure to parasite eggs; 0.8% of the subjects also had positive titers at a dilution of 1:400, indicating true infection. The prevalence in rats was 2%. Conclusions: The prevalence of infection with this parasite among humans and rats was low. While the prevalence encountered among humans was within the limits reported in the literature, the prevalence among rodents was much lower.

Transition of the morbidity and mortality profile in a municipality in the interior of the Brazilian Amazon

INTRODUCTION The morbidity and mortality profile in a given region reflects its quality of life and provides tools for improving public health policies in that region. METHODS A cross-sectional epidemiological study was performed using secondary mortality data collected from the Monte Negro municipality of the Brazilian Western Amazon from 2000 to 2011. These data were compared with data from similar municipalities in other Brazilian macro-regions. Data were obtained through the Departamento de Informática do Sistema Único de Saúde (DATASUS) information system. RESULTS The number of deaths reported over the study period was 606. The most common cause of death was external causes of morbidity and mortality [International Classification of Diseases (ICD)-10 chapter 20], followed by diseases of the circulatory system (ICD-10 chapter 9). Among the causes of death according to age group, infectious and parasitic diseases were the most common for 2- to 9-year-old children; external causes of disease were the most prevalent for 10- to 59-year-old people; and circulatory diseases prevailed in individuals over 60 years of age. Eleven percent of deaths were due to unknown causes. CONCLUSIONS These results point to a fragility in the public policies for prevention and awareness of this problem. Infectious and parasitic diseases contribute only 4.5% of deaths, but had the third highest Disability-Adjusted Life Year score (1,190 days). Improving support to the Estratégia Saúde da Família (Family Health Strategy) program and implementing a death verification service would significantly aid in reducing the occurrence of non-transmissible chronic diseases and clarifying unknown causes of death.