Chagas' infection in university students of Santa Cruz de la Sierra, Bolivia. A serologic-electrocardiographic study

In order to learn the prevalence of Chagas' infection among students from Santa Cruz de la Sierra's universities, a random sample of 372 new students was drawn. All participants have had electrocardiograms (EKG) and serologic analysis (IHAT). 64/372 (17.2%) had serologic evidence of Chagas' infection, and from those, 10/64 (15.6%) had some EKG alterations. Among students presenting negative serologic test, 31/308 (10.1%) had EKG alterations. There was no statistical association between Chagas' infection and EKG alterations (X2=1.67, p=0.2). There was a positive association between Chagas' infection and intraventricular conduction defects and this association was higher among the students of 19 years of age or less (O.R. 10.4, p<0.05).

Prevalence of intestinal parasitic infection in five farms in Holambra, São Paulo, Brazil

A parasitological survey was carried out on 222 inhabitants of five farms in Holambra, located 30 km north of Campinas, São Paulo, Brazil, on October 1992. Approximately 70% of the inhabitants were found to be infected with at least one species of intestinal parasite. The positive rates of 6 helminths and 7 protozoan species detected are as follows: 5.4% Ascaris lumbricoides; 8.6% Trichuris trichiura; 19.8% Necator americanus; 10.4% Strongyloides stercoralis; 14% Enterobius vermicularis; 0.9% Hymenolepis nana; 3.2% Entamoeba histolytica; 2.7% E. hartmanni; 9.9% E. coli; 14.0% Endolimax nana; 2.3% Iodamoeba butschlii; 10.4% Giardia lamblia; 37.8% Blastocystis hominis. The positive rates of helminth infection were generaly higher in the younger-group under 16 years-old than those in the elder group aged 16 or more, whereas the infection rates of protozoan species were higher in the elder group. The infection rate of Strongyloides was found to be 10.4% by a newly developed sensitive method (an agarplate culture methods).

High prevalence of hepatitis C infection among Brazilian hemodialysis patients in Rio de Janeiro: a one-year follow-up study

Nearly 400 hemodialysis patients treated at 5 different hemodialysis units in Rio de Janeiro were tested for one year for the presence of hepatitis C and B markers. During the same period, samples were also obtained from 35 continuous ambulatory peritoneal dialysis (CAPD) patients and from 242 health care workers. Depending on the hemodialysis unit studied, anti-HCV prevalence rates ranging from 47% to 82% (mean 65%) were detected. CAPD patients showed a lower prevalence of 17%. The prevalence of antibodies against hepatitis C virus (anti-HCV) among health care workers was 2.9%. We observed a hepatitis C attack rate of 11.5% per year in the anti-HCV-negative hemodialysis patient population. An average of 9.4% of the hemodialysis patients were chronic carriers of hepatitis B virus (HBV) (range 1.8% - 20.4%), while 48.9% showed markers of previous HBV infection. The HBV attack rate was 4.5% per year (range 0% - 6%). These results indicate an alarming high prevalence of anti-HCV among hemodialysis patients of this studied region.

Evaluation of the enzyme-linked-immuno-electro-diffusion-assay (ELIEDA) for the diagnosis of Schistosoma mansoni infection with low worm burden

An immunoprecipitation technique, ELIEDA (enzyme-linked-immuno-electro-diffusion assay), was evaluated for the diagnosis of Schistosoma mansoni infection with low worm burden. One hundred of serum samples from patients excreting less than 600 eggs per gram of feces (epg), with unrelated diseases and clinically healthy subjects were studied. In patients with egg counts higher than 200 epg, the sensitivities of IgM and IgG ELIEDA were 1.000 and 0.923, respectively, not differing from other Serologic techniques, such as indirect hemaglutination (IHAT), immunofluorescence (IFT) tests and immuno-electrodiffusion assay (IEDA). However in patients with low egg counts (< 100 epg), the IgG ELIEDA provided better results (0.821) than IgM ELIEDA (0.679), showing sensitivity that did not differ from that of IgG IFT (0.929), but lower than that of IgM IFT (0.964). However, its sensivity was higher than that found with IHAT (0.607) and IEDA (0.536). The specificity of IgG ELIEDA was comparable to that of other techniques. The data indicate that IgG ELIEDA might be useful for the diagnosis of slight S. mansoni infections, and the cellulose acetate membrane strips can be stored for further retrospective studies.

An exanthematic disease epidemic associated with coxsackievirus B3 infection in a day care center

An epidemic of exanthematic illness in a day care center is described. Ten children aged 7 to 13 months were affected by the illness. The exanthem was characterized by nonconfluent macular or maculopapular lesions that appeared on the face, body and limbs. Fifty percent of the infected children had fever of up to 39ºC at the beginning of the disease. Coxsackievirus B3 (CB3) was isolated from the stool of one ill child. Paired serum samples were obtained from eight ill children and six of them presented seroconversion to CB3. Antibodies to CB3 were detected at titers higher than 16 in a single serum sample collected from the other two patients. Neutralizing antibodies to CB3 were detected in 71.0% of the contact children.

The relevance of laboratory diagnosis of human cryptosporidiosis and other coccidia

Human infection by Cryptosporidium spp and other coccidia are due to opportunist non-host specific microorganisms. In HIV seropositive patients, the gastrointestinal symptoms accompanying such infections may be serious and prolonged and may include nausea, low-grade fever, abdominal cramps, anorexia and watery diarrhoea. We studied 188 stool samples from 111 patients (84 men and 27 women) with diarrhoea. A modified Ziehl-Nielsen technique for the detection of Cryptosporidium spp and Isospora belli was employed. The mean age of the patients was 31 years. Cryptosporidium spp was seen in 18% (n=20) of the patients, 90% (n=18) of whom were HIV seropositive. Isospora belli was recorded only from HIV seropositive patients (5.4% of all the patients studied and 6.5% of those who were HIV seropositive). These data confirm the good results obtained with this technique for the identification of Cryptosporidium spp and other coccidia and also reaffirm the clinical importance of correctly diagnosing the cause of diarrhoea, particularly in HIV seropositive patients.

Association of human herpesvirus 6 infection with exanthem subitum in Belem, Brazil

Recent human herpesvirus 6 (HHV-6) infection was detected in cases of exanthem subitum (ES) involving four children, aged 10 to 24 months, between April and August 1994, in Belém, Brazil. By using the indirect immunofluorescence antibody assay (IFA), significant increases (at least eight times) in antibody concentrations were noted from the acute to the convalescent serum samples, with titers ranging from <1:10/1:80 to <1:10/1:640 (patients 3 and 2, respectively). All children had high fever (over 39ºC) for three days, followed by generalized, maculo-papular skin rash. A physical examination of the children also revealed concomitant, cervical lymph node swelling and tonsillar pharyngitis in two of them.

Secondary dengue infection in schoolchildren in a dengue endemic area in the State of Rio de Janeiro, Brazil

A seroepidemiologic survey was carried out in schoolchildren from public schools of the Niterói municipality, state of Rio de Janeiro, Brazil, after a period of sequential epidemics by dengue virus type 1 and 2 (DEN-1 and DEN-2). 450 blood samples were obtained by fingertip puncture and collected on filter paper discs. The hemagglutination inhibition (HAI) test was carried out using DEN-1 and DEN-2 antigens. HAI titres were demonstrated in 66% (297/450) of the sera and the geometric means of the titres were 1/182 and 1/71 for DEN-1 and DEN-2, respectively. Secondary infections were observed in 61% (181/297) of positive cases. Among these, 75% (135/181) were under fifteen years old. No dengue haemorrhagic fever (DHF) was reported in these children. Asymptomatic or oligosymptomatic infections were detected in 56% of the studied population. The absolute and relative frequencies of positive tests by age group and sex did not evidence statistically significant difference. The number of individuals infected probably produced a immunologic barrier responsible for the non occurrence of dengue epidemic in the latter years.

Acute primary cutaneous Nocardia asteroides infection in a patient with systemic lupus erythematosus. Case report

We report a case of acute primary cutaneous infection of traumatic origin caused by Nocardia asteroides, appeared as cellulitis in a patient with systemic lupus erythematosus. Diagnosis was established by direct examination and cultures from aspirate specimens. The clinical forms of Nocardia infections that affect the skin, reported in Rio Grande do Sul and Uruguay, are discussed.

Drug resistance of M. Tuberculosis isolated from patients with HIV infection seen at an AIDS Reference Center in São Paulo, Brazil

M. tuberculosis-positive cultures were obtained from 228 patients seen in our service and drug sensitivity assays were carried out from January 1992 to December 1994. A survey of the medical records of these patients showed resistance to one or more drugs in 47 (20.6%), 25 of whom (10.9%), who reported previous treatment, were considered to have acquired resistance. Among the antecedents investigated, only previous treatment and alcoholism were the factors independently associated with the occurrence of resistance. The survival of patients with resistant strains was lower than that of patients attacked by non-resistant M. tuberculosis. We conclude that in the present series M. tuberculosis resistance to tuberculostatic agents was predominantly of the acquired type.

Etiological drug treatment of human infection by Trypanosoma cruzi

Forty-nine American Trypanosomiasis (Chagas' disease) patients, with xenodiagnosis proven parasitemia were treated by the authors. Forty-one of these patients were given benznidazole, at dosages ranging from 5mg/kg/day to 8mg/kg/day, during a pre-established period of 60 days. In this group, 17 patients had an undetermined form of the disease, whereas 22 had cardiologic disease and 4 had digestive disease (two patients had a mixed form of the disease). Side effects were frequent, and led to the discontinuation of treatment in 17 patients. The follow-up period ranged from 1 to 20 years (mean follow-up period of 6 yrs. 7 mo). 26 (63.4%) of the patients became parasitemia-negative. The other eight patients were treated with nifurtimox, during 120 days, following a variable dose regime of 5mg/kg/day (initial dose) to 17 mg/kg/day (final dose). Six of them had severe side effects, and only one patient remained parasitemia-negative throughout the observation period (ranging from 1 to 18 years). Benznidazole proved to be better tolerated and more effective in the management of parasitemia when compared to nifurtimox, although more effective and less toxic drugs are still desirable.

Some hematimetric findings in human Giardia lambia infection

Up to now few reports about haematological alterations induced by Giardia lamblia infection have been described. Because there are questions on this matter still not answered, we carried out a study to evaluate some erythrometric and leucometric parameters in a sample that consisted of 55 patients exclusively infected with G. lamblia and of 55 sex and age matched parasite-free individuals. The haematological parameters evaluated were: mean corpuscular volume (MCV), hemoglobin concentration, and relative and absolute number of eosinophils and lymphocytes. No significant differences in the mean values of MCV, hemoglobin levels and absolute relative lymphocyte numbers between the two groups could be detected. When the giardiasis and control groups were separated by pediatric (0-18 years old) and adult (older than 18 years) classes, a very significant difference in both relative and absolute number of eosinophils in the adult class was observed. With respect of the pediatric class, no differences, either in relative and absolute number of eosinophils, could be observed. Our findings suggest that, during G. lamblia infection, some kind of parasite allergen(s) could be secreted and be responsible for the increasing of eosinophil counts in peripheral blood of adults.

Human enterovirus infection in stray dogs. Some aspects of interest to public health

To investigate the possible role of domestic animals as reservoirs of human enteroviruses, we studied 212 stray dogs captured in different areas of the municipality of São Paulo. The captured animals were divided into 19 groups of 10 to 20 dogs each; faeces of 126 of the 212 dogs were processed for enterovirus isolation. The following viruses were isolated from 12 dogs: poliovirus type 1 (2 dogs), poliovirus type 3 (1 dog), echovirus type 7 (8 dogs) and echovirus type 15 (1 dog). Of the 12 infected animals, four had specific homotypic neutralizing antibody titres > 16. All 212 animals were tested for the presence of neutralizing antibodies to human enteroviruses. The frequency of neutralizing antibodies present in titres of > 16 was 10.3%, 3,8% and 4.3% for vaccinal prototypes of polioviruses 1, 2 and 3 respectively; 1,9%, 1.4% and 1.5% for wild prototypes of the same viruses, 11.3% for echovirus 7, and 2.4% for echovirus 15. The proportion of dogs with neutralizing antibodies varied with the virus studied. Some indication of the susceptibility of dogs to infection with human enteroviruses was demonstrated, and the importance of this fact for the Plan for Global Eradication of the Wild Poliovirus is discussed.