Parasite contamination of sand and soil from daycare sandboxes and play areas

Ascaris and hookworm transmission in preschool children from rural Panama: role of yard environment, soil eggs/larvae and hygiene and play behaviours

This study explored whether the yard environment and child hygiene and play behaviours were associated with presence and intensity of Ascaris and hookworm in preschool children and with eggs and larvae in soil. Data were collected using questionnaires, a visual survey of the yard, soil samples and fecal samples collected at baseline and following re-infection. The presence of eggs/larvae in soil was associated negatively with water storage (eggs) but positively with dogs (eggs) and distance from home to latrine (larvae). Baseline and re-infection prevalences were: hookworm (28.0%, 3.4%); Ascaris (16.9%, 9.5%); Trichuris (0.9%, 0.7%). Zero-inflated negative binomial regression models revealed a higher baseline hookworm infection if yards had eggs or larvae, more vegetation or garbage, and if the child played with soil. Baseline Ascaris was associated with dirt floor, dogs, exposed soil in yard, open defecation and with less time playing outdoors, whereas Ascaris re-infection was associated with water storage, vegetation cover and garbage near the home and not playing with animals. Our results show complex interactions between infection, the yard environment and child behaviours, and indicate that transmission would be reduced if latrines were closer to the home, and if open defecation and water spillage were reduced.

Comparison of methods of sampling for Toxocara species and fecal coliforms in an outdoor day care environment

OBJECTIVE

To compare three sampling methods and to pretest methods for the determination of fecal coliform (FC) counts and Toxocara species from sand in the day care outdoor environment.

DESIGN

The sand samples were obtained from the play area and the sandbox of a day care centre and examined for the presence of FC and Toxocara species, the common roundworm of dogs and cats. The sampling methods included random selection and two types of judgement methods. The latter included one method where domestic animals were judged to be likely to defecate and the other where children would be likely to be playing. In addition, to obtain a global estimate of contamination, the entire areas of both the sandbox and the play area were sampled on the last day.

SETTING

Outdoor day care environment.

MAIN RESULTS

The most representative levels of bacterial contamination and Toxocara species originated from the combined sample of the entire surface areas rather than from any separate random or judgement method of sampling. FCs were found in all sampled areas of the sandbox (median 910 FCs/g of sand) and of the play area (median 350 FCs/g of sand). Toxocara species were recovered from a number of areas in both the sandbox and the play area.

CONCLUSIONS

Research on environmental microbial contamination of outdoor day care settings would benefit from the application of standardized and validated sampling and laboratory methods.

Impact of Mycobacterium avium complex prophylaxis on the incidence of mycobacterial infections and transfusion-requiring anemia in an HIV-positive population

Disseminated Mycobacterium avium complex (MAC) infection is common in persons with advanced HIV infection and can be prevented by prophylactic use of rifabutin; however, routine prophylaxis is costly and incompletely effective. Chronic anemia is a common manifestation of MAC infection. We conducted a retrospective population study of the annual incidence of MAC bacteremia and blood transfusion for anemia in a regional HIV-positive population before and after the introduction of rifabutin to determine the effect of MAC prophylaxis on the incidence of transfusion-requiring anemia. The HIV-infected patient populations in 1992 and 1993 were comparable in number, severity of immunodeficiency, and zidovudine (ZDV) use. The use of rifabutin for MAC prophylaxis for those with CD4 T-lymphocyte counts < 100/microl increased from 17.2% in 1992 to 33.7% in 1993 (p < 0.001), whereas diagnostic surveillance for MAC bacteremia was stable. In 1993, there was a decrease in the number of HIV-infected persons from whom MAC was isolated (10 vs. 26, p = 0.004), and a significant decrease in the number of patients transfused for anemia (15 vs. 35, p = 0.002), number of transfusion episodes, and numbers of units transfused, associated with significant cost and resource savings. Adoption of MAC prophylaxis was followed by a significant decrease in the number of diagnosed MAC infections and in transfusion requirements in an HIV-positive population with sustained surveillance and similar levels of immunodeficiency, which may represent a health and economic benefit of effective [correction of defective] MAC prophylaxis in a population at risk.