Clinical-epidemiologic study of schistosomiasis mansoni in Ponte do Pasmado, a village in the municipality of Itinga, State of Minas Gerais, Brazil, 1992

A clinical-epidemiologic study of schistosomiasis mansoni was conducted in the population of Ponte do Pasmado, a village in the municipality of Itinga, state of Minas Gerais, Brazil. Faecal Parasitology by the Kato-Katz method and clinical examination were performed in 93.8% and 82.8% of the local population, respectively. A socioeconomic survey was also made and the signs and symptoms presented by the patients were recorded, as well as their contacts with natural waters. The rate of Schistosoma mansoni infection was 50.3%; the peak of infection occurred during the second decade of life; there was a predominance of low egg counts in faeces (85.89% of positive patients eliminated less than 500 eggs per gram of faeces); the splenomegaly rate was 1.23%. When the risk factors for S. mansoni infection were studied, significant risks were detected in activities such as fetching water, washing dishes, bathing, and crossing streams.

Chagas' disease in the Brazilian Amazon: II. A serological survey

A serological survey, involving indirect immunofluorescence testing of blood sera samples, was carried out on the residents of one in every five dwellings in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 Km from Manaus by river) and on the rural populations of the villages of Piloto and Marará (also on the right bank of the Rio Negro, 30 minutes by boat from Barcelos). A total of 710 sera samples were tested, 628 from the resident population in the town of Barcelos, 35 from Piloto and 47 from Marará. The tests were carried out using human anti-gammaglobulin type IgG (Biolab) and antigen from formolized culture of T.cruzi Y strain. The sera were serially diluted from 1:40 to 1:320 in PBS 7.2. Of the 710 samples examined 89(12.5%) were positive for anti-T.cruzi antibodies: 2 of these (2.2%) at a dilution of 1:320; 12(13.4%) at 1:160; 38 (42.6%) at 1:80; and the remainder at 1:40, giving a median serological dilution of 1:80. The following questions are discussed: the high serological prevalence for Chagas'infection found in our survey; the possibility of serological cross-reactions; the need for confirmatory tests for the positives reactions; and the strong correlation between our results and preliminary epidemiological data (such as the level of human contact with wild triatominae, know locally as "Piacava's lice". We draw attention to the isolation by xenodiagnosis of one strain of T.cruzi from a patient with positive serology for Chagas' infection.

Enzyme linked immunosorbent assay for rubella antibodies: a simple method of antigen production. A preliminary report

A simple method of rubella antigen production by treatment with sodium desoxycholate for use in enzyme immunoassay (IMT-ELISA) is presented. When this assay was compared with a commercial test (Enzygnost-Rubella, Behring), in the study of 108 sera and 118 filter paper blood samples, 96.9% (219/226) overall agreement and correlation coefficient of 0.90 between absorbances were observed. Seven samples showed discordant results, negative by the commercial kit and positive by our test. Four of those 7 samples were available, being 3 positive by HI.

A simple and inexprensive method to generate a microaerophilic atmosphere for the isolation of Campylobacter sp

Faeces of 138 chickens were inoculated on Blaser agar plates. One set of plates was incubated in jars with CampyPak envelopes. The others were incubated in "Zip-lock" plastic bags (7 x X in.) and a microaerophilic atmosphere was generated exhaling into the "Zip-lock" plastic bag, after holding the breath for 20 sec. Then, the bag was pressed to evacuate its atmosphere, inflated again, and pressed (4 times), and finally sealed. Campylobacter was isolated from 127 (96.2%) of samples incubated in jars with gas generator envelopes and from 129 (98%) of the specimens incubated into the bags. The proposed methodology offers good savings for cost-conscious laboratories.

Studies on prevalence of Strongyloides infection in Holambra and Maceió, Brazil, by the agar plate faecal culture method

Prevalence of Strongyloides stercoralis infection in three areas of Brazil was surveyed by a recently developed faecal culture method (an agar plate culture). The Strongyloides infection was confirmed in 11.3% of 432 subjects examined. The diagnostic efficacy of the agar plate culture was as high as 93.9% compared to only 28.5% and 26.5% by the Harada-Mori filter paper culture and faecal concentration methods, when faecal samples were examined simultaneously by these three methods. Among the 49 positive samples, about 60% were confirmed to be positive only by the agar plate culture. These results indicate that the agar plate culture is a sensitive new tool for the correct diagnosis of chronic Strongyloides infection.

A single method to stain Malassezia furfur and Corynebacterium minutissimum in scales

A single and practical method to slain Malassezia furfur and Corynebacterium minutissimum in lesions' scales is described. The scales are collected by pressing small pieces of scotch tape (about 4 cm lenght and 2 cm width) onto the lesions and following withdrawl the furfuraceous scales will remain on the glue side. These pieces are then immersed for some minutes in lactophenol-cotton blue stain. Following absorption of the stain the scales are washed in current water to remove the excess of blue stain, dried with filter paper, dehydrated via passage in two bottles containing absolute alcohol and then placed in xylene in a centrifugation tube. The xylene dissolves the scotch tape glue and the scales fall free in the tube. After centrifugation and decantation the scales concentrated on the bottom of the tube are collected with a platinum-loop, placed in Canada balsam on a microscopy slide and closed with a cover slip. The preparations are then ready to be submitted to microscopic examination. Other stains may also be used instead of lactophenol-cotton blue. This method is simple, easily performed, and offers good conditions to study these fungi as well as being useful for the diagnosis of the diseases that they cause.

Epidemiological aspects of the Brazilian spotted fever: serological survey of dogs and horses in an endemic area in the State of São Paulo, Brazil

In order to obtain information on Brazilian spotted fever, a study in domestic animals was performed in the County of Pedreira, State of São Paulo, Brazil, where 17 human cases had been notified. Serum samples obtained from animals were tested by indirect immunofluorescence for detectable antibodies to spotted fever-group rickettsiae. Seropositivity was revealed in 12 (36.4%) of 33 dogs and seven (77.8%) of nine horses from the endemic area. For comparison, blood samples from dogs and horses from non endemic area were tested and four (12.9%) of 31 dogs and three (27.3%) of 11 horses were positive. The highest titers of antibodies by IFA (IgG > 1:1024) were found only in three dogs and six horses from endemic area. The results suggest that dogs as horses may serve as environmental sentinels for estabilishing the prevalence of foci of spotted fever in Brazil.

Detection and identification of dengue virus isolates from Brazil by a simplified reverse transcription - polymerase chain reaction (RT-PCR) method

We show here a simplified RT-PCR for identification of dengue virus types 1 and 2. Five dengue virus strains, isolated from Brazilian patients, and yellow fever vaccine 17DD as a negative control, were used in this study. C6/36 cells were infected and supernatants were collected after 7 days. The RT-PCR, done in a single reaction vessel, was carried out following a 1/10 dilution of virus in distilled water or in a detergent mixture containing Nonidet P40. The 50 µl assay reaction mixture included 50 pmol of specific primers amplifying a 482 base pair sequence for dengue type 1 and 210 base pair sequence for dengue type 2. In other assays, we used dengue virus consensus primers having maximum sequence similarity to the four serotypes, amplifying a 511 base pair sequence. The reaction mixture also contained 0.1 mM of the four deoxynucleoside triphosphates, 7.5 U of reverse transcriptase, 1U of thermostable Taq DNA polymerase. The mixture was incubated for 5 minutes at 37ºC for reverse transcription followed by 30 cycles of two-step PCR amplification (92ºC for 60 seconds, 53ºC for 60 seconds) with slow temperature increment. The PCR products were subjected to 1.7% agarose gel electrophoresis and visualized by UV light after staining with ethidium bromide solution. Low virus titer around 10 3, 6 TCID50/ml was detected by RT-PCR for dengue type 1. Specific DNA amplification was observed with all the Brazilian dengue strains by using dengue virus consensus primers. As compared to other RT-PCRs, this assay is less laborious, done in a shorter time, and has reduced risk of contamination

Human infection with Trypanosoma cruzi in Nasca, Peru: A seroepidemiological survey (1)

We estimated the proportion of seropositivity for infection with Trypanosoma cruzi (Chagas’ disease) in a sample of the rural population of the Province of Nasca, Department of Ica, southwestern Peru. Although Triatoma infestans, the only vector species identified in the Department of Ica, is often found in domestic environments, data of the extent of human infection with T. cruzi are scant. This study comprised 446 houses, known to be infested with triatomines, distributed in 19 rural localities. While visiting those houses we collected filter paper bloodspots from 864 occupants (of both sexes, aged one year or over). By means of the indirect fluorescent antibody test (IFAT), we detected anti-T. cruzi IgG antibodies in samples from 178 individuals (20.6%). Seropositivity was significantly more frequent in females (23.8%) than in males (17.5%). Among the 410 individuals in the 1- to 10-year-old age group (47.5% of the population sample), 85 (20.7%) were found seropositive, which is indicative of an early acquisition of the infection. Within this group no significant differences in seropositivity were associated with sex

Hepatocellular carcinoma in Brazil: report of a national survey (Florianópolis, SC, 1995)

In order to investigate epidemiological aspects of hepatocellular carcinoma (HCC) in Brazil, basic informations about cases diagnosed from January 1992 to December 1994 were requested to several medical centers of different Brazilian States. A simple questionnaire included age, sex, alcohol abuse (over 80g/day), associated liver cirrhosis, persistent HBV infection (HBsAg), HCV infection (anti-HCV) and serum levels of alpha fetoprotein. 287 cases, over 16 years old, from 19 medical centers of 8 States (Pará, Bahia, Minas Gerais, Espirito Santo, Rio de Janeiro, São Paulo, Paraná and Rio Grande do Sul) were analysed. The results showed: (a) Mean age was 56.3 ± 14.4 for men and 54.7 ± 16.8 yr for women and the male/female ratio was 3.4:1. (b) 69.6% were caucasians, 21.8% mullatoes, 4.8% orientals and 3.7% blacks. (c) HBsAg (+) in 77/236 cases (41.6%) without differences between males and females. (d) Anti-HCV (+) in 52/193 cases (26.9%). (e) 7/180 cases were positive both for HBsAg and anti-HCV (3.8%). (f) There was chronic alcoholism in 88/235 cases (37%). (g) HCC was found in cirrhotic livers in 71.2% of 202 cases in which the presence or absence of cirrhosis was reported. (h) Alpha-fetoprotein above 20 ng/ml was found in 124/172 cases (72%) and above 500 ng/ml only in 40 cases (23.2%). These results showed that the HCC in Brazil has an intermediate epidemiological pattern as compared to those from areas of low and high incidence of the tumor. In spite of the high frequency of the association of HCC with the HBV and/or HCV infections, 42% of 180 cases were negative both for HBsAg and anti-HCV, indicating the possible role of other etiological factors. The comparison of data from different States showed some regional differences: higher frequency of associated HBsAg in Pará, Bahia, Minas Gerais and Espírito Santo, higher frequency of associated HCV infection in Rio de Janeiro, São Paulo and States of the Southern region and low frequency of associated liver cirrhosis in Salvador and Rio de Janeiro (55.5 and 50% respectively). Further investigation will be necessary to study the presence of other possible etiological factors as aflatoxins, suggested by the favourable climatic conditions for food contamination by fungi in the majority Brazilian regions

EPIDEMIOLOGICAL SURVEY ON CANINE POPULATION WITH THE USE OF IMMUNOLEISH SKIN TEST IN ENDEMIC AREAS OF HUMAN AMERICAN CUTANEOUS LEISHMANIASIS IN THE STATE OF RIO DE JANEIRO, BRAZIL

A survey for canine tegumentary leishmaniasis (CTL) has been carried out between 1986 and 1993 in seven endemic localities for American cutaneous leishmaniasis in the State of Rio de Janeiro. 270 dogs have been examined for their clinical aspects, the development of delayed hypersensitivity (DHS) with Immunoleish antigen and with immunofluorescent antibody research of IgG (IF). 28.2% of them had ulcer lesions and 3.3% had scars. The lesions consisted of single (39.5%) and mucocutaneous lesions (31.6%), multiple cutaneous (25.0%) and mucocutaneous lesions associated with cutaneous ulcers (4.0%). Twelve (15.8%) isolates from biopsies were analyzed by zimodeme and schizodeme and identified as L. (V.) braziliensis. The overall prevalence of canine infection that was evaluated with the skin test was of 40.5% and with IF it was of 25.5%. Both tests showed a high positive rate with relation to the animals with mucosal lesions, as in the case of human mucocutaneous leishmaniasis. The comparison of the two tests showed the skin test to have a better performance although there was no statistical difference (p>0.05) between them. The proportional sensitivity and specificity was of 84.0% and 74.0%, respectively. The Immunoleish skin test and IF are useful tools to be employed in CTL field epidemiological surveys.

SCHISTOSOMIASIS MANSONI IN THE "BAIXADA OCIDENTAL MARANHENSE", STATE OF MARANHÃO, BRAZIL: CROSS-SECTIONAL STUDIES PERFORMED IN 1987 AND 1993

A cross-sectional study on the prevalence of schistosomiasis mansoni in three sites of the "Baixada Ocidental Maranhense" was carried out in 1993 in: Alegre (in the municipality of São Bento), Aliança (in Cururupu) and Coroatá II (in the municipality of São João Batista). Results were compared to those of another study performed at the same sites and in similar conditions, in 1987. The entire population of the three sites, with few exceptions, was submitted to fecal tests using the Kato-Katz method and immediate intradermal tests for schistosomiasis in both studies. Subjects with positive results in one of these tests were clinically evaluated by a physical examination. In 1993, the total of 827 subjects were submitted to fecal examination and 826 to intradermal test. Schistosoma mansoni eggs were found in the feces of 154 (18.6%) subjects, while 478 (57.9%) subjects presented a positive intradermal test. Stool examination was carried out in 367 subjects in Alegre with a positivity rate of 14.9%; the intradermal test, performed in 366 subjects, was positive in 47.5% of the cases. In Aliança, 277 subjects had their feces examined and were submitted to an intradermal test, with a positivity rate of 34.4% and 70.7%, respectively. Finally in Coroatá II, 183 inhabitants submitted to fecal and intradermal tests had positivity rates of 2.2% and 59.0%, respectively. When the present data were compared to those obtained in the survey performed in 1987, a significant decrease in the prevalence of infection by S. mansoni was observed in Alegre and Coroatá II, and a prevalence increase in Aliança.

RE-EVALUATION OF SCHISTOSOMIASIS MANSONI IN MINAS GERAIS, BRAZIL. III. "NOROESTE DE MINAS" MESOREGION

This study was conducted to assess the presence of schistosomiasis mansoni in the "Noroeste de Minas" mesoregion, an area considered non-endemic. A malacologic survey and parasitologic stool examinations were undertaken in 13 municipalities of the mesoregion. A sample of 3,283 primary school students was submitted to fecal examination by the Kato-Katz method. A total of 3,627 planorbids was collected and examined. The molluscs were identified as Biomphalaria straminea in seven municipalities (Unaí, Bonfinópolis de Minas, Paracatu, João Pinheiro, Vazante, Lagamar and Lagoa Grande) and as Biomphalaria peregrina in one (Presidente Olegário). All planorbids were negative for Schistosoma mansoni. Four students were diagnosed with schistosomiasis in the municipalities of Buritis, Formoso, Paracatu and Unaí, but none of these cases was considered autochthonous. The data obtained indicate that the "Noroeste de Minas" mesoregion continues to be non-endemic for schistosomiasis mansoni, although the presence of intermediate hosts associated with parasitized individuals emphasizes the need for epidemiological surveillance of schistosomiasis in this mesoregion.

A TEN-YEAR SURVEY OF Tinea pedis IN THE CENTRAL REGION OF THE RIO GRANDE DO SUL, BRAZIL

Tinea pedis is the most common type of dermatophytosis, but can mimic many cutaneous diseases and tend to be chronic. We present a study of the frequency, epidemiology and clinical aspects of tinea pedis in the central region of Rio Grande do Sul during the period 1988-1997.