Análise multivariada da esquistossomose no estado de Minas Gerais: análise de componentes principais / Multivariate analysis of schistosomiasis in the state of Minas Gerais: principal component analysis

INTRODUÇÃO: A esquistossomose mansônica é uma doença negligenciada no Brasil, logo, relacionada à pobreza e ausência de condições sanitárias. Ocorre na região litorânea do nordeste e se interioriza a partir do estado da Bahia, chegando a Minas Gerais. OBJETIVO: Agrupar, por meio da análise de componentes principais, as principais variáveis relacionadas à esquistossomose em fatores que possam explicar a variância dos dados. MÉTODOS: Foram avaliadas as notificações de esquistossomose entre os anos de 2007 a 2014, considerando a média por 100 mil habitantes. As variáveis: educação, saúde, economia, infraestrutura e saneamento, População, altimetria e Índice de Desenvolvimento Humano (IDH), foram obtidas no Atlas Brasil; os dados das notificações de esquistossomose foram obtidos no Sistema de Informação de Agravos e Notificação (SINAN). A análise estatística foi realizada a partir da análise de componentes principais, visando identificar os principais fatores que contribuem de forma mais significativa, com a variância dos dados. RESULTADOS: Considerando os critérios propostos, três fatores explicaram mais de 76% da variância, sendo o primeiro relacionado às variáveis: taxa de analfabetismo em 18 anos ou mais, sem ensino fundamental, mortalidade infantil, extremamente pobre, vulnerável a pobreza, esgotamento sanitário inadequado e população rural. O segundo foi relacionado à variável esgotamento sanitário e o terceiro fator à variável altitude. CONCLUSÃO: As variáveis associadas aos fatores, principalmente aquelas pautadas nos determinantes sociais de saúde, demonstram uma forte relação com a ocorrência da esquistossomose. A contribuição do estudo nos remete a possibilidade de agrupar variáveis em fatores que comportam de forma sinérgica e favorecem a incidência da parasitose.

INTRODUCTION: Schistosomiasis mansoni is a neglected disease in Brazil, therefore, related to poverty and lack of sanitary conditions. Occurs in the coastal region of the northeast and spreads inland from the state of Bahia, reaching Minas Gerais. OBJECTIVE: To group, through component analysis, the main variables related to schistosomiasis in factors that may explain data variance. METHODS: Reports of schistosomiasis between the years 2007 to 2014 were evaluated, considering averages per 100 thousand inhabitants. The variables: education, health, economy, infrastructure and sanitation, population, altimetry and Human Development Index (HDI), were obtained from Atlas Brazil; the schistosomiasis notification data were obtained from the injury and notification information system (SINAN). Statistical analysis was based on the analysis of main components, aiming to identify the key factors that contribute most significantly to data variance. RESULTS: Considering the proposed criteria, three factors explained more than 76% of the variance, the first one related to the following variables: illiteracy rate at 18 years of age or more, no elementary education, child mortality, extremely poor, vulnerable to poverty, inadequate sanitary sewage and rural population. The second was related to the sanitary sewage variable and the third factor to the altitude variable. CONCLUSION: The variables associated with factors, especially those based on the social determinants of health; show a strong relation with the occurrence of schistosomiasis. The contribution of the study reminds us of the possibility of grouping variables into factors that behave synergistically and favor the incidence of parasitosis.

Acute schistosomiasis in European students returning from fieldwork at Lake Tanganyika, Tanzania.

BACKGROUND: Schistosomiasis is common in many African regions and poses a risk for travelers and the local population. So far, schistosomiasis in travelers or expatriates returning from the Tanzanian bank of Lake Tanganyika has not been reported. METHODS: We report a group of students who sought treatment with signs of acute schistosomiasis after having returned from Lake Tanganyika, Tanzania. Information as to travel and exposure as well as clinical and laboratory data were collected. RESULTS: Schistosomiasis was diagnosed in 8 of 16 students from Berlin, Germany, who had returned from a 2- to 3-month stay of fieldwork in Kigoma District at Lake Tanganyika, Tanzania. All 16 students reported frequent freshwater exposure at the lake. Six patients showed signs of acute schistosomiasis and had fever, and some of them also had cough, weakness, headache, or abdominal pain. Eosinophilia was present in five of the six symptomatic individuals. Notably, two serologically enzyme-linked immunosorbent assay (ELISA)-positive individuals did not report or present with symptoms or abnormal laboratory parameters. Schistosoma mansoni eggs were found in one symptomatic and one asymptomatic individual each. Blood and stool samples from the other eight individuals who were equally exposed to freshwater yielded negative results. CONCLUSIONS: This is the first report of an outbreak of acute schistosomiasis imported from the Tanzanian shore of Lake Tanganyika and highlights the risk for travelers and the local population of acquiring the infection in that part of Tanzania. It provides arguments for routine serological screening for schistosomiasis in individuals who had prior freshwater contact in endemic areas, irrespective of symptoms or other laboratory findings.

[Radiological findings in patients with imported schistosomiasis]. / Hallazgos radiológicos en pacientes con esquistosomiasis importada.

INTRODUCTION: Imaging techniques, primarily ultrasound, are useful in the diagnosis and monitoring of patients with schistosomiasis in endemic areas. METHODS: Study of 219 patients treated in sub-Saharan Tropical Medicine Unit with a diagnosis of imported schistosomiasis by imaging techniques investigations including plain abdominal radiography and ultrasound. RESULTS: A total of 17.8% of patients who had an abdominal X-ray showed findings suggestive of schistosomiasis, in most cases bladder calcifications. In 73 patients (41%) ultrasound showed pathological findings, mainly diffuse or focal wall thickening (26 patients), nodular lesions (n=14), and pseudopolyps (n=8). One patient, who had a large bladder mass (9cm) and bilateral ureterohydronephrosis, was finally diagnosed with squamous cell carcinoma of the bladder. Ultrasound liver abnormalities were found in 10 patients, 4 with signs of portal hypertension, of which 3 had the characteristic periportal fibrosis in schistosomiasis. CONCLUSION: Imaging studies, especially abdominal and bladder ultrasound, are useful for diagnosis, the study of disease and monitoring of patients with schistosomiasis in non-endemic countries.

An outbreak of acute schistosomiasis following a church retreat to Mwanza, Tanzania, 2008.

Clinical and laboratory findings are described from 77 persons from Nairobi, Kenya, of whom 66 were diagnosed with acute Schistosoma mansoni infection following a trip to Mwanza, Tanzania. Unusual ocular symptoms were observed as a rare manifestation of acute schistosomiasis. The outbreak highlights the risk of swimming in Lake Victoria.

Evaluation of the role of angiogenic factors in the pathogenesis of schistosomiasis.

Schistosomiasis is one disease produced by helminths, which affect many people in tropical areas. Granuloma formation is the main mechanism involved in the pathogenesis of this disease. Experimental studies have demonstrated angiogenesis (blood vessels formation from pre-existing vessels) in the initial phase of granuloma formation. In the present work, VEGF (vascular endothelial growth factor) levels were analyzed in sera from people diagnosed with different helminthic infections. Patients with schistosomiasis and filariasis had significantly high VEGF levels in compared with healthy people and patients diagnosed with hookworms. In addition, the effects of angiogenesis inhibition using anti-angiogenic factors (endostatin) were evaluated in a schistosomiasis murine model. A lesion decrease was observed in mice infected with Schistosoma mansoni and treated with endostatin. Finally, mechanisms of angiogenesis induction were studied and observed that cercariae antigens stimulated the angiogenic factors by host alveolar macrophages.

Microgeographical and tribal variations in water contact and Schistosoma mansoni exposure within a Ugandan fishing community.

OBJECTIVE: To explore patterns of water contact and Schistosoma mansoni exposure by age, sex, tribe and space within a single village. METHODS: For 10 months, we systematically observed water contacts made by the 800 inhabitants of a small Ugandan fishing village. In order to estimate cercarial exposure, times spent in water were weighted by snail infection levels, time of day and degree of immersion. RESULTS: There were marked differences in water contact patterns between the two main tribes, which inhabited geographically distinct ends of the village resulting in geographically distinct spatial patterns of water contact. The distributions of the intermediate hosts, Biomphalaria sudanica and Biomphalaria stanleyi, also appeared to differ over small distances. This led to quite different exposure patterns between the two tribes, particularly amongst females. CONCLUSIONS: Schistosoma mansoni exposure can vary markedly within a single village. Such non-homogenous patterns of exposure are likely to have wider implications for schistosomiasis control programmes and research studies.

Schistosoma mansoni in migrants entering South Africa from Moçambique--a threat to public health in north-eastern KwaZulu-Natal?

OBJECTIVES: To identify possible public health consequences of Schistosoma mansoni infections in migrants entering north-eastern KwaZulu-Natal and Mpumalanga and Northern Province from southern Moçambique. DESIGN: (i) Intestinal parasite surveys, one sample per person, within a 4-month period; (ii) temperature recordings and snail collections in an irrigation system. SETTING: North-eastern KwaZulu-Natal and Kruger National Park, Mpumalanga and Northern Province. PARTICIPANTS: Ninety-seven migrants (1-68 years) from north-eastern KwaZulu-Natal and 47 from the Kruger Park (1 - 70 years). MAIN OUTCOME MEASURES: The relatively high S. mansoni prevalence may cause problems on the rice paddy scheme in north-eastern KwaZulu-Natal. Ranges and prevalence rates of other parasites were recorded. RESULTS: S. mansoni prevalence in Moçambicans entering north-eastern KwaZulu-Natal was 14.4%, seven times more than in local residents. S. mansoni is not endemic to this region because most bodies of water become too warm for either the parasite or its snail host, Biomphalaria pfeifferi, to develop. Recordings in paddies suggest, however, that the rice modifies the temperature pattern as it grows and provides a suitable habitat for transmission. Migrants entering the Transvaal lowveld where S. mansoni is endemic may become more severely infected. Thirteen other parasite species were recorded from migrants entering KwaZulu-Natal and 8 from those entering Mpumalanga and Northern Province. CONCLUSIONS: The relatively high S. mansoni prevalence among migrants entering north-eastern KwaZulu-Natal may have public health implications as it could encourage transmission in a non-endemic area. The range of parasites carried by migrants entering KwaZulu-Natal, Mpumalanga and Northern Province was similar to that harboured by local people but prevalence rates were generally lower.

Epidemiology of Schistosoma mansoni infection in a low-endemic area in Brazil: clinical and nutritional characteristics

A cross-sectional case-control study designed to evaluate the role of malnutrition in the association between the intensity of Schistosoma mansoni infection and clinical schistosomiasis, was conducted in an area with both low frequency of infection and low morbidity of schistosomiasis in Brazil. Cases (256) were patients with a positive stool examination for S. mansoni; their geometrical mean number of eggs/gram of feces was 90. Controls (256) were a random sample of the negative participants paired to the cases by age, sex and length of residence in the area. The clinical signs and symptoms found to be associated with S. mansoni infection, comparing cases and controls, were blood in stools and presence of a palpable liver. A linear trend in the relative odds of these signs and symptoms with increasing levels of infection was detected. Adjusting by the level of egg excretion, the existence of an interaction between palpable liver and ethnic group (white) was suggested. No differences in the nutritional status of infected and non-infected participants were found

Epidemiology of Schistosoma mansoni infection in a low-endemic area in Brazil: clinical and nutritional characteristics.

A cross-sectional case-control study designed to evaluate the role of malnutrition in the association between the intensity of Schistosoma mansoni infection and clinical schistosomiasis, was conducted in an area with both low frequency of infection and low morbidity of schistosomiasis in Brazil. Cases (256) were patients with a positive stool examination for S. mansoni; their geometrical mean number of eggs/gram of feces was 90. Controls (256) were a random sample of the negative participants paired to the cases by age, sex and length of residence in the area. The clinical signs and symptoms found to be associated with S. mansoni infection, comparing cases and controls, were blood in stools and presence of a palpable liver. A linear trend in the relative odds of these signs and symptoms with increasing levels of infection was detected. Adjusting by the level of egg excretion, the existence of an interaction between palpable liver and ethnic group (white) was suggested. No differences in the nutritional status of infected and non-infected participants were found.

Influence of the host related factors in the development of the hepatosplenic form of schistosomiasis mansoni.

The frequency of hepatosplenomegaly in endemic areas is not proportional to the fecal ova count. This may be explained by epidemiological genetic. The occurrence of two or more cases of schistosomal hepatosplenomegaly in nuclear family is much higher than expected. The concentration is higher among siblings than it is among mothers and children of father and children. It is not significant between father and mother. If the mother, instead of the father, has hepatosplenic schistosomiasis the relative risk for the child to acquire hepatosplenomegaly is at least five times (the maternal affect). The inbreeding is higher in the hepatosplenic than in the hepato-intestinal patients. In some areas in Brazil the hepatosplenic form of the schistosomiasis mansoni occurs with much higher frequency in whites than in blacks. After treatment, reversion of hepatosplenic schistosomiasis occurs more frequently in non-whites. It seems that the resistance of blacks to the hepatosplenic form of schistosomiasis may be related to the glyoxalase system, perhaps associated to another genetic marker. The hepatosplenic schistosomiasis is less frequent in longilineal individuals. In some areas the hepatosplenic form of schistosomiasis is more frequent in A blood group of ABO system. The family heredograms do not suggest a single mendelian inheritance, but probably a multifactorial and possibly polygenic one.

Esquistossomose mansônica, raça e tipos de sobrenomes na regiäo de Catolândia, Bahia / Shistosomiasis mansoni, race and surnames types in Catolândia region, Bahia

A associaçäo entre hepatoesplenomegalia esquistossomótica e raça branca mantém-se consistente através da associaçäo secundária entre nomes de família näo-religiosos, principalmente os de origem em planta/animal, previamente correlacionados aos brancos e descendentes de índio. Esses nomes foram significantemente (p < 0,00001) mais freqüentes nos hepatosplênicos (46,7%) do que nos hepatointestinais (15,5)

Persistent Schistosoma mansoni infection in Yemeni immigrants to Israel.

Following sporadic reports on persistent Schistosoma mansoni (S.m) infections in Israelis of Yemeni origin, we systematically surveyed a group of 129 individuals who immigrated to Israel 38 years ago. Physical examination was uneventful in all members of the study group. A single stool examination revealed S.m eggs in 15 of 129 subjects (12%). Specific anti-S.m. IgE was detected in the sera of 48 individuals (37%). Among the 15 egg-positives, 14 had specific IgE (sensitivity 93.3%), but only 80 of the 114 egg-negatives were also negative for specific IgE (specificity 70%). This specific IgE positivity among egg-negatives in the study group (34/114) and its complete absence from two control groups, one of them comprising Yemenites born in Israel, suggest either an S.m infection with low egg output stemming from a low worm burden or low fecundity of senescent worms, or occult infections. Since the S.m infections could not have been contracted in Israel, our findings point to inordinately persistent infections in the members of our study group, and incidentally also to the diagnostic usefulness of specific IgE testing in such cases.

Serological studies on schistosomiasis mansoni in the northeast Brazil. I

Soros de pacientes com esquistosomiase mansonica do Hospital das Clinicas da Universidade Federal de Pernambuco (N = 10), de residentes da cidade do Cabo (PE) - 51 casos ovo-positivo e 452 casos ovo-negativo -, de pacientes do Hospital Instituto Materno Infantil de Pernambuco (IMIP) (N = 37), de imigrantes japoneses residentes na cidade de Petrolina (PE) (N = 127), assim como de japoneses supostamente saudaveis (N = 30) foram examinados sorologicamente atraves de testes como ELISA; os antigenos utilizados foram preparados a partir de ovos (ELISA-ovo) e de vermes adultos de Schistosoma mansoni (ELISA-adulto). Em 100 por cento dos soros de individuos nao infectados residentes em areas nao endemicas, tanto na ELISA-ovo como na ELISA-adulto os resultados foram negativos. No tocante a reacoes cruzadas, em 78 soros provenientes de individuos portadores de diferentes parasitas intestinais, apenas um apresentou reatividade frente aos antigenos de vermes adultos e ovos. O ELISA-ovo realizado com o soro de 51 individuos portadores de ovos de S. mansoni revelou uma alta sensibilidade (98 por cento de casos ovo-positivos); contudo grande numero de resultados falso-negativos foi observado em reacoes como ELISA-adulto, Ouchterlony usando antigeno de verme adulto, reacao periovular e intradermo-reacao. Em casos de jovens portadores

Forma hepatosplênica da esquistossomose mansônica, em relaçäo à composiçäo racial e ao nível sócio-econômico, em Catolândia-Bahia / Hepatosplenic form of schistosomiasis mansoni, in relation to race and socioeconomic level, in Catolândia-Bahia

De 1125 indivíduos, residentes em área hiperendêmica de esquistosomose mansônica, estudou-se a apresentaçäo clínica, relacionada aos grupos raciais (mestiço de índio, branco, mulato-claro, mulato-médio, mulato-escuro e negro) e ao nível sócioeconômico, conforme o somatório de 16 variáveis. Em 229 indivíduos brancos havia 24 (10,5%) com a forma hepatosplênica, significantemente superior, em comparaçäo com 32 (3,6%) dos 896 näo-brancos; entre os grupos raciais negróides ocorreram freqüentemente semelhantes. Os hepatosplênicos apresentaram nível sócio-econômico mais alto e quando, também, brancos, o risco relativo (2,78) foi marcadamente superior

[Hepatosplenic form of schistosomiasis mansoni, in relation to race and socioeconomic level, in Catolândia-Bahia]. / Forma hepatosplênica da esquistossomose mansônica, em relação à composição racial e ao nível sócio-econômico, em Catolândia-Bahia.

Of 1,125 individuals, residents in an area where mansonic schistosomiasis is hyperendemic, were studied regarding the clinical forms correlated to the racial groups (indian mestizo, white, light mullato, medium mullato, dark mullato and negro) and to their socio-economic level according to a set of 16 variables. The white individuals (10.5%) showed a significantly higher incidence of the hepatosplenic forms; in the other racial groups there were similar frequencies, altogether 3.6%. Those with hepatosplenomegaly had a higher socio-economic level and when they also belonged to the white race the relative risk (2.78) was significantly higher.

Epidemiology of schistosomiasis in the riverine population of Lagdo Lake, northern Cameroon: mixed infections and ethnic factors.

The distribution of S. mansoni and S. haematobium was evaluated using a cluster sampling technique in 15 fishing villages around Lagdo lake and 2 inland villages in northern Cameroon. The overall prevalence of S. haematobium infection was 26% and of S. mansoni was 15%, while 7% of the population sampled had mixed infections. The highest prevalences were observed in larger villages (greater than 200 persons) where sanitary conditions were poor. The intensity of S. haematobium infection in those also infected with S. mansoni was two to three times greater than in those with S. haematobium alone. Differences in prevalence among ethnic groups was attributed to occupational and cultural habits. The factors leading to the diversity of the distribution of schistosomiasis within a man-made lake are discussed.

Coeficiente de endocruzamento em portadores de esquistossomose mansônica / Imbreeding coefficient in carries of Schistosoma mansoni

O coeficiente de endocruzamento (f ou de Wright) foi calculado em 1123 indivíduos de Catolândia, Bahia, área hiperendêmica da esquistossomose mansônica: 148 (13,2%) tinham o coeficiente f > 0. A forma hepatosplênica foi significantemente maior nos indivíduos com f > 0 (26,8%). Nos brancos com f > 0 o risco relativo foi de 14,1; enquanto, nos brancos com f = 0, a freqüência da hepatosplenomegalia näo diferiu dos näo-brancos com f = ou f > 0. Com este coeficiente estimou-se a probabilidade de genes aléticos iguais, com origem em ancestral comum; os resultados reforçam a hipótese da regulaçäo genética na susceptibilidade à forma hepatosplênica da esquistossomose mansônica

[Inbreeding coefficient in carriers of Schistosoma mansoni]. / Coeficiente de endocruzamento em portadores de esquistossomose mansônica.

The coefficient of inbreeding (for Wright) was studied in Catolândia, in the state of Bahia, Brazil, an area considered hyperendemic for manson schistosomiasis in a population of 1,130 inhabitants. The coefficient of inbreeding was estimated for 1,123 individuals it was classified as f greater than 0 in 13.2% (n = 148). In the hepatosplenic group the frequency of f greater than 0 was 26.8%, and in the hepatointestinal group the frequency was 12.5%. The frequency of the hepatosplenic diagnosis in whites who were f = 0 did not differ from that which was observed in the negroid group. These verifications were confirmed by the Woolf's test; the relative risk of the whites, f greater than 0 in acquiring hepatosplenic schistosomiasis was 14.1. These observations reinforce the influence of the genetic component in the development of the hepatosplenic form of the mansons schistosomiasis.