A survey of congenital Chagas’ disease, carried out at three Health Institutions in São Paulo City, Brazil

The congenital transmission of Chagas’ disease was evaluated in 57 pregnant women with Chagas’ disease and their 58 offspring. The patients were selected from three Health Institutions in São Paulo City. The maternal clinical forms of Chagas’ disease were: indeterminate (47.4%), cardiac (43.8%) and digestive (8.8%); 55 were born in endemic areas and two in São Paulo City. The transmission of Chagas’ disease at fetal level was confirmed in three (5.17%) of the 58 cases studied and one probably case of congenital Chagas’ disease. Two infected infants were born to chagasic women with HIV infection and were diagnosed by parasitolological assays (microhematocrit, quantitative buffy coat-QBC or artificial xenodiagnosis). In both cases the placenta revealed T. cruzi and HIV p24 antigens detected by immunohistochemistry. In one case, a 14-week old abortus, the diagnosis of congenital T. cruzi infection was confirmed by immunohistochemistry. The other probable infection, a 30-week old stillborn, the parasites were found in the placenta and umbilical cord. The Western blot method using trypomastigote excreted/secreted antigens of T. cruzi (TESA) was positive for IgG antibodies in 54/55 newborns and for IgM in 1/55 newborns. One of the two newborns with circulating parasites had no detectable IgG or IgM antibodies. The assessment of IgG antibodies in the sera of pregnant women and their newborns was performed by ELISA using two different T. cruzi antigens: an alkaline extract of epimastigotes (EAE) and trypomastigote excreted/secreted antigens (TESA). The analysis showed a linear correlation between maternal and newborn IgG antibody titers at birth.

Jorge Lobo’s disease: experimental inoculation in Swiss mice

Sixty-four isogenic Swiss mice were intradermically inoculated in both hind foot pads. The inocula, consisting of fungal suspensions from biopsies obtained from Jorge Lobo’s Disease patients, had the total number of fungi and the viability index determined using a Neubauer chamber and the fluorescein diacetate-ethidium bromide technique (FD-EB), respectively. The animals were sacrificed at times ranging from ten days to eighteen months after inoculation. The cellular infiltrate, mainly consisting of macrophages containing fungi, increased progressively up to end of the study; however, no macroscopic alterations were observed in the inoculated feet. After nine months, small numbers of Langhans’ giant cells started to appear in the infiltrate. A considerable number of fungi was observed at the end of the experimental period, but only a few were viable when stained by the FD-EB technique. This fact suggests that there is a multiplication of fungal cells, which are destroyed by the macrophages but remain in the tissue for a long time due perhaps to the difficulties in their elimination. These findings led us to conclude that in spite of the maintenance of the infection in these animals, Swiss mice cannot be considered an ideal model to study Jorge Lobo’s Disease. However, the authors call attention to the possibility of other mouse strains being more susceptible to Paracoccidioides loboi.

Persistent infections in chronic Chagas' disease patients treated with anti-Trypanosoma cruzi nitroderivatives

We used a molecular method and demonstrated that treatment of the chronic human Trypanosoma cruzi infections with nitroderivatives did not lead to parasitological cure. Seventeen treated and 17 untreated chronic Chagas' disease patients, with at least two out of three positive serologic assays for the infection, and 17 control subjects formed the study groups. PCR assays with nested sets of T. cruzi DNA primers monitored the efficacy of treatment. The amplification products were hybridized to their complementary internal sequences. Untreated and treated Chagas' disease patients yielded PCR amplification products with T. cruzi nuclear DNA primers. Competitive PCR was conducted to determine the quantity of parasites in the blood and revealed < 1 to 75 T. cruzi/ml in untreated (means 25.83 ± 26.32) and < 1 to 36 T. cruzi/ml in treated (means 6.45 ± 9.28) Chagas' disease patients. The difference between the means was not statistically significant. These findings reveal a need for precise definition of the role of treatment of chronic Chagas' disease patients with nitrofuran and nitroimidazole compounds.

Characterization and optimization of bovine Echinococcus granulosus cyst fluid to be used in immunodiagnosis of hydatid disease by ELISA

The aim of this work was to assess the influence in the diagnostic value for human hydatid disease of the composition of bovine hydatid cyst fluid (BHCF) obtained from fertile (FC) and non-fertile cysts (NFC). Eight batches from FC and 5 from NFC were prepared and analysed with respect to chemical composition: total protein, host-derived protein, carbohydrate and lipid contents. No differences were observed in the first two parameters but carbohydrate and lipid contents were shown to be higher in batches from FC than in those from NFC. Bands of 38 and 116 kD in SDS-PAGE profiles were observed to be present in BHCF from FC only. Two pools were prepared from BHCF batches obtained from FC (PFC) and NFC (PNFC), respectively. Antigen recognition patterns were analysed by immunoblot. Physicochemical conditions for adsorption of antigens to the polystyrene surface (ELISA plates) were optimized. The diagnostic value of both types of BHCF as well as the diagnostic relevance of oxidation of their carbohydrate moieties with periodate were assessed by ELISA using 42 serum samples from hydatid patients, 41 from patients with other disorders, and 15 from healthy donors. Reactivity of all sera against native antigen were tested with and without free phosphorylcholine. The best diagnostic efficiency was observed using BHCF from periodate-treated PFC using glycine buffer with strong ionic strength to coat ELISA plates.

Interrupting Chagas disease transmission in Venezuela

The interruption of vectorial transmission of Chagas disease in Venezuela is attributed to the combined effects of ongoing entomoepidemiological surveillance, ongoing house spraying with residual insecticides and the concurrent building and modification of rural houses in endemic areas during almost five decades. The original endemic areas which totaled 750,000 km², have been reduced to 365,000 km². During 1958-1968, initial entomological evaluations carried out showed that the house infestation index ranged between 60-80%, the house infection index at 8-11% and a house density index of 30-50 triatomine bugs per house. By 1990-98, these indexes were further reduced to 1.6-4.0%, 0.01-0.6% and 3-4 bugs per house respectively. The overall rural population seroprevalence has declined from 44.5% (95% C.I.: 43.4-45.3%) to 9.2% (95% C.I.: 9.0-9.4%) for successive grouped periods from 1958 to 1998. The annual blood donor prevalence is firmly established below 1%. The population at risk of infection has been estimated to be less than four million. Given that prevalence rates are stable and appropriate for public health programmes, consideration has been given to potential biases that may distort results such as: a) geographical differences in illness or longevity of patients; b) variations in levels of ascertainment; c) variations in diagnostic criteria; and d) variations in population structure, mainly due to appreciable population migration. The endemic areas with continuous transmission are now mainly confined to piedmonts, as well as patchy foci in higher mountainous ranges, where the exclusive vector is Rhodnius prolixus. There is also an unstable area, of which landscapes are made up of grasslands with scattered broad-leaved evergreen trees and costal plains, where transmission is very low and occasional outbreaks are reported.

Whipple's disease. Report of five cases with different clinical features

Whipple's disease (WD) is a rare systemic disease of infectious etiology which involves the small intestine but can virtually affect any organ. We present here five cases (four males and one female) ranging in age from 20 to 59 years. All patients had intestinal involvement associated or not with clinical manifestations linked to this organ. Vegetation in the tricuspid valve was observed in one patient, suggesting endocarditis caused by Tropheryma whippelii, with disappearance of the echocardiographic alterations after treatment. In one of the male patients the initial clinical manifestation was serologically negative spondylitis, with no diarrhea occurring at any time during follow-up. Ocular involvement associated with intestinal malabsorption and significant weight loss were observed in one case. In the other two cases, diarrhea was the major clinical manifestation. All patients were diagnosed by histological examination of the jejunal mucosa and, when indicated, of extraintestinal tissues by light and electron microscopy. After antibiotic treatment, full remission of symptoms occurred in all cases. A control examination of the intestinal mucosa performed after twelve months of treatment with sulfamethoxazole-trimethoprim revealed the disappearance of T. whippelii in four patients. The remaining patient was lost to follow-up.

Tinea capitis: study of asymptomatic carriers and sick adolescents, adults and elderly who live with children with the disease

Tinea capitis is a dermatophyte infection that occurs mainly in childhood; there are few reports, in Brazil, in adolescents and adults. The detection of asymptomatic carriers is of great importance in the disease control. From February 1998 to February 1999, a study was performed at the outpatient Dermatologic Unit of Instituto de Puericultura e Pediatria Martagão Gesteira (Universidade Federal do Rio de Janeiro, Brasil) to verify the frequency of asymptomatic carriers and tinea capitis between 79 adolescents, adults and elderly who lived in the same household of 56 children (0-12 years) with tinea capitis. Of these, one female and one male adults (2.5%) were asymptomatic carriers and the cultures revealed Trichophyton tonsurans and Microsporum canis respectively. One female adolescent and two female adults (3.8%) had tinea capitis and all cultures revealed Trichophyton tonsurans. The study has shown that adolescents and adults who live in the same household of children with tinea capitis may be sick or asymptomatic carriers.

Pasteurization of human milk to prevent transmission of Chagas disease

Although admittedly transmission of Trypanosoma cruzi infection through breastfeeding is a rare event, it involves serious risks. To test the effectiveness of pasteurization in preventing this mode of infection, three sets of samples of human milk were tested: a - contaminated with T. cruzi and pasteurized; b - contaminated with T. cruzi and non-pasteurized; c - non-contaminated and pasteurized. Samples from all sets were orally and intraperitoneally administered to 90 BALB/c mice. The animals inoculated with contaminated, non-pasteurized samples, got the infection. Controls and the animals inoculated with contaminated and pasteurized milk were not infected. The hypothesis was accepted that pasteurization inactivates T. cruzi trypomastigotes.

The epidemiology of acute viral gastroenteritis in hospitalized children in Cordoba city, Argentina: an insight of disease burden

Information concerning the disease burden of viral gastroenteritis has important implications for the use and monitoring the impact of public health policies. The present study, carried out in Córdoba city, Argentina, documents the epidemiology of severe viral diarrhea as well as the burden of viral gastrointestinal disease in the hospital children admission. A total of 133 stools were collected from hospitalized children (Town Childhood Hospital) suffering from acute diarrhea and studied for the presence of Group A rotavirus, astrovirus and adenovirus 40/41 by enzyme-immuno assay, between November 1997 and October 1998. Enteric viruses accounted for 42.1% of the total diarrheal cases analyzed. Group A rotaviruses, astroviruses, adenoviruses 40/41 and mixed infections were found in 35.3, 4.5, 1.5, and 0.8% studied specimens respectively. We estimated that 1 in 27 children in the 0-35 month-old cohort/range would be annually hospitalized for a viral gastroenteritis illness. The major impact on viral diarrhea lies on rotaviral infection, accouting for 84.0% of the viral diarrheal cases analyzed and for approximately one third of severe diarrheas requiring hospital admission in Córdoba City, Argentina.

Congenital Chagas disease of second generation in Santiago, Chile. Report of two cases

Congenital Chagas disease (CChD) has been reported in different countries, mostly in Latin America. In 1987 a fatal case of CChD of second generation (CChDSG) was published. Within a period of six months - 1989-1990 - two cases of CChDSG were diagnosed and studied in the city of Santiago. Two premature newborns, sons of two sisters, with moderate liver and spleen enlargement, were found to have positive serology for Chagas disease and xenodiagnoses. The mothers, urban residents all their lives, without antecedents of triatomine bugs contact or blood transfusions, showed positive serology and xenodiagnoses. Their mother (grandmother of the infants), lived 20 years in a Northern rural Chagas disease endemic locality, in a triatomine infested house. Afterwards, she moved to Santiago, where she married and has resided up to now. Serology and xenodiagnoses were also positive. All the Trypanosoma cruzi infected individuals were successfully treated with nifurtimox.