Efficacy of permethrin-impregnated bed nets on malaria control in a hyperendemic area in Irian Jaya, Indonesia III. Antibodies to circumsporozoite protein and ring-infected erythrocyte surface antigen.

A two years intervention study was carried out using permethrin impregnated bed nets in a hyperendemic area, in Irian Jaya, Indonesia. To assess the influence of this intervention on natural immunity, concurrent immunological studies to determine levels of antibodies to the circumsporozoite (CS) and ring-infected erythrocyte surface antigen (RESA) proteins were conducted. Prevalence and titers of immunoglobulins (Ig)G and IgG subclasses were periodically measured in 138 individuals (30 children under the age of ten and 108 villagers ten years old and older). In the younger group, seropositivity of total IgG against CS fluctuated according to the parasite infection rates; however, IgG seropositive reaction against RESA gradually increased. In the older age group, seropositivity of both kinds of antibodies was stable during the whole study period. Nevertheless, the geometric mean titers of total IgG against CS and RESA were significantly reduced in this latter group in individuals who contained these antibodies before and after intervention. The geometric mean titer of IgG3 subclass against RESA was decreased at a highly significant level (p = 0.0005), and that of IgG4 against the same antigen was also decreased although to a lesser extent (p = 0.02).

Parasitological and nutritional situation of school children in the Sukaraja district, West Java, Indonesia.

A parasitological survey of children aged 8 to 10 years from ten schools located in the rural district Sukaraja, West Java, Indonesia was conducted in December 1995. A total of 348 fecal samples were examined by using modified Kato-Katz thick smear techniques, 365 blood samples for the measurement of hemoglobin concentration, and anthropometric data were obtained from 404 participants. Four nematode (hookworm taken as one species), two cestode and nine protozoan species were detected, but no trematode infection was observed. Among helminths, soil-transmitted nematode infections were predominant, Trichuris trichiura with a prevalence of 76% being the most common infection, followed by Ascaris lumbricoides (44%). Hookworm and Enterobius vermicularis were found in 9% and 3% of the children examined, respectively. Among protozoa, Blastocystis hominis was by far the most common species, detected in 60% of volunteers cases. For the helminths A. lumbricoides, T. trichiura and hookworm, school to school differences in parasite prevalence and infection intensity were observed; these were probably due to different socioeconomic and sanitary-environmental conditions. Intensity of Ascaris and hookworm infection tended to be highly over-dispersed; 85% of the worms identified were harbored by 15% and 7% of the children, respectively. Nutritional status was characterized by an average anemia rate of 13% and a prevalence of 51% stunting. All nutritional indicators differed significantly from school to school. Intensity of geohelminths infection could not be associated to the observed nutritional indicators. Thus, there must be additional factors contributing to the studied nutritional indicators of the school children which overlay a possible influence of moderate to heavy worm burden.

Anthelminthic treatment raises plasma iron levels but does not decrease the acute-phase response in Jakarta school children.

The study was conducted to investigate the impact of intestinal helminthiasis and treatment on iron status and acute phase response (APR) among urban Indonesian primary school children, aged 8-11 years old. The prevalence of helminthiasis among these children was; Ascaris lumbricoides, 81.6%; Trichuris trichiura, 88.3%; and mixed infection of A. lumbricoides and T. trichiura, 70.0%. Of 120 children enrolled in the investigation, 59 received a single 400 mg dose of albendazole, and 61 received a placebo. Ten days following treatment, the prevalence of ascariasis and trichuriasis in the treatment group diminished to 0% and 27%, respectively, and in the placebo group to 63.9% and 68.9%. Plasma iron, hemoglobin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell (WBC), interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor (TNF) concentrations were determined prior to the intervention and 10 days after. Plasma iron concentrations and WBC count rose in the treatment group (p=< or =0.05) when compared to baseline status. Increases in hemoglobin concentrations observed in the treatment group 10 days post-treatment were not statistically significant. CRP, IL-1, IL-6 and TNF were found to be within normal limits for both groups both before and after treatment. ESR increased significantly in both treatment and placebo groups when compared the rates measured before treatment. These findings show that treatment with albendazole is associated not only with a decreased worm burden in school children, but also a rise in plasma iron.

A non-invasive assessment of hepatitis B virus carrier status using saliva samples.

A non-invasive testing method to determine hepatitis B virus (HBV) carrier status in pregnant women was evaluated. Paired serum and saliva samples were collected and assessment of hepatitis B markers were performed. Of the 502 women enrolled, 5.6% (28/502) of their sera were found to be positive for HBV surface antigen (HBsAg). Assessment of 28 HBsAg seroreactive and 200 HBsAg sero-non-reactive paired saliva samples showed that 17 saliva contained HBsAg. Fourteen of the saliva reactive samples were matched to the serum reactive samples (50% sensitivity); and 3 saliva samples were positive for HBsAg among 200 subjects seronegative for HBsAg (98.5% specificity). Seven of the 28 HBsAg positive sera were found to be reactive for HBV envelope antigen (HBeAg) (25%). One of seven HBeAg seroreactive and 16 HBeAg seronegative paired saliva samples tested were non-reactive for HBeAg. This report found a non-invasive saliva testing method to be a possible alternative approach for determining chronic HBV carrier status if the sensitivity of the test can be improved.