Parasitic infections in villagers from three districts of the Brazilian Amazon.
Eve E. Ferraz E. Thatcher VE.
Institute of Latin American Studies, University of London, U.K. email@example.com
A survey of intestinal parasites among 827 rural villagers in the Brazilian Amazon revealed that the prevalences of infection with Necator americanus, Trichuris trichiura and/or Ascaris lumbricoides were high. However, the intensities of infection with the two parasites for which there were enough data on intensity for further analysis, N. americanus and T. trichiura, were only low or moderate in each of the three districts studied. Possible reasons for the unusual (but not unique) absence of high intensities include moderately good sanitation, low population densities, the way in which work activities are located geographically, the use of indigenous anthelmintics and the geographical isolation of the communities which provided the subjects. Whether the light to moderate levels of infection observed require intervention is discussed.
Prevalence of infection with hepatitis G virus among various groups in Thailand.
Poovorawan Y. Theamboonlers A. Chongsrisawat V. Jantaradsamee P.
Paediatric Department, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand. firstname.lastname@example.org
Two research groups recently and independently, isolated a hepatotropic flavivirus from human sera. The two viruses, named GB virus C and hepatitis G virus (HGV), were subsequently discovered to represent the same virus, which was associated with acute and chronic hepatitis of the non-A-E type. The prevalences of infection with HGV have now been investigated in various groups of the Thai population, some of which [e.g. thalassaemic children, patients with chronic liver disease, carriers of antibodies to hepatitis B virus and/or hepatitis C virus (HCV), prostitutes and intravenous-drug users (IVDU)] were assumed to be at high risk. Samples of sera were investigated by reverse-transcriptase PCR, using four primers created from the 5' untranslated region of HGV. The prevalence of HGV infection among the healthy controls (1%-5%) was found to be much less than that among thalassaemic children (32.6%), asymptomatic carriers of anti-HCV (20.4%), IVDU (18.2%), aplastic anaemia patients (14.3%) and prostitutes (10%), although similar to that in patients with chronic liver disorders. These results confirm a parenteral route of transmission for HGV and emphasise the need for further research to determine the clinical significance of this virus.
Norwalk virus infection in Venezuela.
Pujol FH. Vasquez G. Rojas AM. Fuenmayor ME. Loureiro CL. Perez-Schael I. Estes MK. Liprandi F.
Laboratorio de Biologia de Virus, Centro de Microbiologia y Biologia Celular, Instituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela.
The presence of antibodies against Norwalk virus (NV) was studied in sera from different Venezuelan populations, using an enzyme immuno-assay (EIA) based on recombinant NV protein. Antibodies to NV were found in 47%-53% of urban subjects from Caracas, 83% of rural subjects from the west of the country, and 73%-93% of Amerindian subjects. The prevalences found in the rural and Amerindian groups were significantly higher than that in the urban group. Although about 50% of the children studied were seropositive for NV by the age of 5 years, only four (0.4%) of 1120 faecal samples from children with diarrhoea which were tested for the presence of NV antigen by sandwich EIA were found positive. An increase of at least 4-fold in the titre of anti-NV IgA was found in three (5%) of 61 pairs of sera taken during and 1 month after an acute episode of diarrhoea not due to rotavirus. NV was therefore not a predominant aetiological cause of gastro-enteritis in young children in Venezuela between 1993 and 1995, although it can be the cause of diarrhoea in infants.