Thrombocytopenia as a surrogate marker of hepatosplenic schistosomiasis in endemic areas for Schistosomiasis mansoni

Introduction This study aimed to evaluate whether a low platelet count is a good surrogate marker of hepatosplenic schistosomiasis (HSS) in a rural area of Brazil. A small district in southeastern Brazil, with a population of 1,543 individuals and a 23% prevalence of schistosomiasis, was selected for this investigation. Methods In July 2012, 384 volunteers were subjected to clinical, ultrasonography (US), and laboratory examinations, including stool sample analysis. The HSS patients were classified into four groups: Group 1 consisted of patients with a spleen >13cm and liver fibrosis; Group 2 consisted of patients with a palpable spleen and spleen>13cm measured by US; Group 3 consisted of patients with a spleen >13cm measured by US; and Group 4 consisted of patients with a palpable spleen. Results Eight patients were in Group 1 (2.1%), twenty-one were in Group 2 (5.5%), eight were in Group 3 (2.1%), and eighteen were in Group 4 (4.7%). A significant difference in the mean platelet counts was observed between the patients with and without HSS (p<0.01). Based on the receiver operating characteristic (ROC) curve (platelet count <143,000/mm3), the sensitivity was greater than 92% in all groups, and the specificity varied from 44.4% to 75%. Conclusions We concluded that in endemic areas, thrombocytopenia demonstrates good sensitivity for detecting HSS and may be used as a screening tool to identify patients with HSS. .

Acute schistosomiasis diagnosis: a new tool for the diagnosis of schistosomiasis in a group of travelers recently infected in a new focus of Schistosoma mansoni

Introduction The diagnosis of schistosomiasis mansoni on early stages of infection is important to prevent late morbidity. A simple, cheap, sensitive and specific assay for routine diagnosis of schistosome infection based on the detection of specific IgG for schistosomula tegument antigens (ELISA-SmTeg) was developed by our group. Methods We describe here an acute outbreak involving a travel group of 80 individuals from a non-endemic area of the State of Minas Gerais, Brazil. These individuals were in contact with a freshwater pool where Biomphalaria glabrata was found. Results obtained from our new methodology were compared to IgG antibody titers against soluble worm antigenic preparation (SWAP) by ELISA and, also to parasitological examination, nuclear magnetic resonance and clinical findings. Results ELISA-SmTeg was capable of detecting 64 positive cases among the 80 individuals participating at the survey with a positivity ratio of 80% and a higher sensitivity than ELISA-SWAP that was only sensitive for 56% of positive cases. Besides, a significant correlation was found for the severity of the infection and the specific IgG titers against SmTeg. Conclusions Our data showed that ELISA-SmTeg might serve as the initial diagnostic tool for acute stages of the infection in community-based helminth control programs or for the surveillance of individuals from non-endemic areas. .

Schistosomiasis control program in the state of Minas Gerais in Brazil

The Schistosomiasis Control Program (PCE) was implemented in Minas Gerais (MG) in 1984. In 1999, the state started the investigation and control of schistosomiasis in 470 municipalities. The aim of the present paper is to report the evolution of this Program from 1984-2007. The program included a coproscopic survey carried out in the municipalities of known endemic areas using a quantitative method. Positives were treated with praziquantel and given a program of health education. The information for this study was obtained from data collected and stored by the Health State Department. From 2003-2007, 2,643,564 stool examinations resulted in 141,284 positive tests for Schistosoma mansoni (5.3 percent). In the first evaluation after treatment, a decrease in the number of municipalities with prevalence over 10 percent was documented. In one village, selected for a more detailed evaluation, the percentage of positive tests decreased from 14.9 percent in the baseline survey to 5.3 percent after treatment. A reference centre for patients with severe schistosomiasis was created in Belo Horizonte, MG. Based on our findings, we believe that the implementation of PCE in MG is on the right path and in due time these new initiatives will provide desirable results.

A geoprocessing approach for studying and controlling schistosomiasis in the state of Minas Gerais, Brazil

Geographical information systems (GIS) are tools that have been recently tested for improving our understanding of the spatial distribution of disease. The objective of this paper was to further develop the GIS technology to model and control schistosomiasis using environmental, social, biological and remote-sensing variables. A final regression model (R² = 0.39) was established, after a variable selection phase, with a set of spatial variables including the presence or absence of Biomphalaria glabrata, winter enhanced vegetation index, summer minimum temperature and percentage of houses with water coming from a spring or well. A regional model was also developed by splitting the state of Minas Gerais (MG) into four regions and establishing a linear regression model for each of the four regions: 1 (R² = 0.97), 2 (R² = 0.60), 3 (R² = 0.63) and 4 (R² = 0.76). Based on these models, a schistosomiasis risk map was built for MG. In this paper, geostatistics was also used to make inferences about the presence of Biomphalaria spp. The result was a map of species and risk areas. The obtained risk map permits the association of uncertainties, which can be used to qualify the inferences and it can be thought of as an auxiliary tool for public health strategies.

Esquistossomose em área de ecoturismo do Estado de Minas Gerais, Brasil / Schistosomiasis in an ecotourism area in Minas Gerais State, Brazil

Neste trabalho, são discutidos os modos de transmissão da esquistossomose na localidade de São José da Serra, com 500 habitantes, no Município de Jaboticatubas, Minas Gerais, Brasil. A região ao redor recebe, durante todo o ano, milhares de pessoas para a prática de ecoturismo. A ocorrência de esquistossomose aguda em um casal que viajou para essa área, no carnaval de 2007, motivou este estudo. Exames de fezes foram feitos em 268 moradores, 53,6 por cento da população total. Trinta e cinco (13 por cento) estavam eliminando ovos nas fezes. Comparando os resultados coproscópicos com os de um inquérito feito em 2005, observa-se um aumento da proporção de positivos de 9,6 por cento para 12,5 por cento, entre 56 pessoas que participaram em ambos os estudos. Foram coletados 65 exemplares de Biomphalaria glabrata, sendo 1 (1,5 por cento) positivo. No inquérito malacológico realizado em 2005, em 182 biomphalarias, nenhum exemplar foi encontrado positivo. Esses dados indicam a ocorrência de transmissão ativa de esquistossomose na área, revelando a necessidade de planejamento coordenado no desenvolvimento do setor turístico, incluindo a implantação de programas educativos integrados para a comunidade e, principalmente, para os turistas.

This paper discusses schistosomiasis transmission in São José da Serra, a village with a population of 500 in the county of Jaboticatubas, Minas Gerais State, Brazil. The area receives thousands of visitors a year for ecotourism. The study was motivated by a case of acute schistosomiasis involving a couple that spent the 2007 Carnival (Mardi Gras) holiday in the area. Stool tests from 268 local residents (53.6 percent of the population) showed that 35 (13 percent) were positive for the infection. A comparison with a previous survey (2005) in the same location showed an increase in the schistosomiasis-positive rate from 9.6 percent to 12.5 percent, among the 56 individuals who participated in both surveys. A malacological survey of 65 Biomphalaria glabrata snails showed one specimen (1.5 percent) eliminating cercariae. In a similar survey in 2005, no positive snail specimens were found. The study indicates that active schistosomiasis transmission is occurring in the area, and that integrated educational programs are needed for both the local community and tourists.

Morbidity of schistosomiasis mansoni in the state of Minas Gerais, Brazil

From 2002 to 2005, a program of active search for patients with hepatosplenic schistosomiasis and schistosomal myeloradiculopathy has been implemented in the state of Minas Gerais by the local Health Department. The state was divided in 28 regional health centers and the local representatives have been trained to identify and direct patients with hepatosplenic schistosomiasis and neuroschistosomiasis to a reference center in Belo Horizonte, the capital of the state of Minas Gerais. Seventy five patients with hepatosplenic schistosomiasis and 54 with schistosomal myeloradiculopathy have been referred and examined in the reference center in a period of time of 3 years. Schistosomal myeloradiculopathy should be emphasized because the number of cases reported is increasing rapidly and when timely diagnosed and treated, they respond promptly to treatment. Left untreated, they die or become invalid for life. In our view, the time has come for more active investigation of the different aspects of morbidity caused by schistosomiasis mansoni in Brazil.

Hepatosplenic schistosomiasis in field-based studies: a combined clinical and sonographic definition

A combined clinical and sonographic classification of hepatosplenic schistosomiasis mansoni to be used in field-based studies is proposed herein. Seven hundred forty one individuals out of 892 (83 percent), living in an area endemic for schistosomiasis in Brazil, have been ubmitted to clinical and ultrasound examinations. Based on two stool examinations the overall prevalence for schistosomiasis in this area was 73 percent. Abdominal palpation was performed with patients in dorsal decubit, during deep breath, by two experienced physicians and a portable ultrasound was used for the evaluation of liver fibrosis, portal collaterals and spleen size. Four groups of individuals were identified using data obtained by abdominal palpation and ultrasound examination: (1) palpable spleen and intense periportal thickening in 9 individuals (1.2 percent); (2) spleen not palpable and intense periportal thickening in 15 (2 percent); (3) palpable spleen with light to moderate periportal thickening in 32 (4.3 percent), and (4) palpable spleen with a normal liver on ultrasound in 30 (4 percent). The definition of hepatosplenic schistosomiasis in field-based studies as the finding of Schistosoma mansoni eggs in the stools in an individual with splenomegaly is not acceptable anymore. Abdominal ultrasound should be combined with clinical examination to accurately identify hepatosplenics in endemic areas for schistosomiasis

Geographical distribution of Biomphalaria snails in the State of Minas Gerais, Brazil

Published and unpublished observations on geographical distribution of Biomphalaria snails in the State of Minas Gerais, Brazil, were compiled. This work is aimed at knowing the present occurrence of Biomphalaria species in this region, and at contributing to the elaboration of the planorbid chart of Minas Gerais. In malacological surveys, performed by several researchers, the presence of seven species of this genus was recorded. Those planorbids were found in 12 mesoregions, in 283 (33.1 percent) municipalities out of 853 with the following distribution: B. glabrata (185 municipalities), B. straminea (125), B. tenagophila (58), B. peregrina (57), B. schrammi (26), B. intermedia (20) and B. occidentalis (2). B. glabrata and B. tenagophila are found naturally infected by Schistosoma mansoni in Minas Gerais. In 24 municipalities the three snail hosts of S. mansoni in Brazil, B. glabrata, B. tenagophila and B. straminea, are present

Investigaçäo sobre a transmissäo da esquistossomose no complexo turístico da Serra do Cipó, MG / Investigation on transmission of schitosomiasis in the touristc complex of Serra do Cipó, MG, Brazil

Procede a levantamento malacológico, inquérito parasitológico e análise de água do Complexo Turístico da Serra do Cipó, MG, Brasil, objetivando detectar focos de transmissäo da esquistossomose e avaliar as condiçöes de balneabilidade das coleçöes hídricas. De fevereiro de 1997 a agosto de 1998, foram coletados 215 moluscos do gênero Drepanotrema lucidium (Pfeiffer, 1839), em 15 dentre 391 estaçöes pesquisadas nos municípios de Santana do Riacho e Jaboticatubas. As taxas de prevalência de esquistossomose nos moradores de Santana do Riacho de Jaboticatubas, foram de 3,9 por cento e 6,5 por cento, respectivamente. Dos 35 indivíduos infectados, 88,5 por cento relataram contato prévio com água em outras localidades endêmicas e foram tratados com oxamniquina. Camundongos sentinelas imersos em dois pontos do rio Cipó näo apresentaram vermes de Schistosoma mansoni no fígado e intestino após 50 dias. As condiçöes de balneabilidade das águas dos rios Cipó e Soberbo foram consideradas satisfatórias assim como as qualidades físico-químicas das mesmas. Nesse período, näo houve transmissäo de esquistossomose na regiäo graças à ausência de moluscos do gênero Biomphalaria, hospedeiros de S. mansoni, parasitados nas coleçöes hídricas. Medidas profiláticas foram recomendadas às autoridades em saúde para a manutençäo de condiçöes epidemiológicas satisfatórias no complexo

O Projeto Queixadinha: a morbidade e o controle da esquistossomose em área endêmica no nordeste de Minas Gerais, Brasil / Queixadinha project: morbidity and control of schistosomiasis in an endemic area in the northeast of State of Minas Gerais, Brazil

In an endemic area for schistosomiasis in the northeast of the state of Minas Gerais in Brazil 516 individuals have been submitted to clinical and laboratory examination, ultrasonography of the abdomen and dopplerecocardiography in order to define the morbidity of schistosomiasis before and after treatment. A high prevalence of schistosomiasis (66.3 per cent) and of severe disease (9.5per cent with palpable spleens) were recorded. Ultrasonography classified liver periportal fibrosis as light (19.4 per cent), moderate (27.6 per cent) and intense (6.8 per cent), and 46.0 per cent presented no periportal fibrosis. Twenty one out of the 53 individuals (39.6 per cent) with palpable spleens did not present liver fibrosis on ultrasound. Periportal lymph nodes were described in 33.8 per cent of the population and anti-KLH antibodies were found in the serum of 40.7 per cent. Urinary alterations compatible with the glomerulopathy of schistosomiasis were observed in 4.5 per cent of the population, and 11.7 per cent of the individuals examined by dopplerecocardiography had pulmonary hypertension. Twelve months after treatment for schistosomiasis the prevalence of the disease dropped from 66.3 per cent to 25.0 per cent. In Queixadinha, a profile of the morbidity of schistosomiasis has just been established.