The role of private drug vendors as malaria treatment providers in selected malaria endemic areas of Sri Lanka.

BACKGROUND AND OBJECTIVES: The involvement of private drug vendors in malaria treatment is particularly high in developing countries and understanding their practices and knowledge about antimalarials and malaria treatment will aid in devising strategies to increase the correct use of antimalarials and improve adherence to the government's malaria drug policy. Results of a study on the knowledge and practices of the private drug vendors conducted in seven districts in Sri Lanka, mostly in malarious areas are presented. METHODS: Data on awareness of government's malaria drug policy, practice of issuing antimalarials, knowledge about malaria and antimalarial drugs were collected from the drug vendors using pre-tested questionnaire in vernacular language. Data were statistically analysed using Stata 8.2. Chi-square test was carried out for individual explanatory variables and a logistic regression model was applied taking all response variables as binary outcome. RESULTS: Vendors' knowledge on antimalarials was poor with 58% of the vendors being unaware of the government malaria drug policy in the country. Also, the advice provided to customers buying antimalarials was limited. However, the majority of the private vendors emphasised that they were aware of the importance of case confirmation before treatment as stressed in the national policy. Although, the vendors did not have a high awareness of national drug policies they were only found selling chloroquine and primaquine as recommended by the Ministry of Health. INTERPRETATION AND CONCLUSION: In recent years Sri Lanka, as a whole, has experienced very little malaria. The reduction in demand for antimalarials due to low incidence levels may have influenced the knowledge and awareness on antimalarials and government drug policies. However, since low levels of malaria do not guarantee that epidemics will not occur, attempts to educate private drug vendors as a part of an organised control programmes are of major importance.

Practice of using human excreta as fertilizer and implications for health in Nghean Province, Vietnam.

The ancient practice of applying latrine wastes to agricultural land has maintained soil fertility in Vietnam for several centuries but may be associated with health risks if the wastes are inadequately treated before usage. This study aimed at investigating the perceptions and handling practices using latrine wastes as fertilizers in a community in central Vietnam. Information was collected through structured questionnaire interviews administered to 75 farming households, focus group discussions, and key informant interviews. The majority (64%) of households had a single vault latrine, a possession that was associated with low income (chi2= 12.45; p < 0.05). Most households (85%) used latrine waste in agriculture that was composted before usage (98%). Households often mixed the composted excreta with kitchen ashes and powdered lime likely to increase pH and pathogen die-off. About 28% of households that were applying latrine waste as fertilizer composted three to six months, and only 11 (18%) households composted human excreta for more than the recommended six months. Households with double vault latrines were 7.8 (chi2= 9.4; p<0.05) times more likely to compost human excreta more than six months as compared with households having single vault latrine. Most farmers distributed the latrine wastes with bare hands (66%) because of convenience during application. Respondents with a high educational level used protective gloves more often when distributing latrine wastes in the fields compared to respondents with a low educational level (chi2 = 7.6; p<0.05). If any negative health impacts of latrine waste use in agriculture are to be reduced, then it is suggested that sustainable interventions should take into consideration farmers current excreta-use practices.

Physico-chemical characteristics of Anopheles culicifacies and Anopheles varuna breeding water in a dry zone stream in Sri Lanka.

BACKGROUND & OBJECTIVES: Selected physico-chemical characteristics of flowing and pooled water in a stream that generated two malaria vectors, Anopheles culicifacies s.l. Giles and Anopheles varuna Iyengar, were investigated during August-September 1997 and July 1998 at the Upper Yan Oya watershed in north-central Sri Lanka. METHODS: The physico-chemical parameters measured were: temperature, dissolved oxygen, pH, conductivity, total dissolved solids, alkalinity, ammonia nitrogen, nitrate nitrogen, calcium, magnesium, carbondioxide, ferrous iron, phosphate, colour and turbidity. In total, 75.5% of 151 samples analysed were mosquito-positive. Logistic regression was used for statistical analysis. RESULTS: Among physico-chemical parameters, An. culicifacies (the major malaria vector in the country) was positively related only to temperature, and An. varuna (a secondary malaria vector) to calcium. Among habitat characteristics, An. culicifacies was associated with light and vegetation, and negatively associated with the presence of potential predators. An. varuna was positively associated with other aquatic fauna. INTERPRETATION & CONCLUSION: Surprisingly this detailed study did not find an association between An. culicifacies and dissolved oxygen as previously found in the few studies that have looked at physico-chemical characteristics of malaria vector breeding habitats in south Asia. This study, along with existing information from other studies indicate that most of the physico-chemical parameters measured under natural conditions within the same habitat type is insufficient to explain the distribution of vectors within such habitats. However, it seems likely that both An. culicifacies and An. varuna follow a strategy whereby ovipositing females scatter their eggs over most of or all of a highly temporary and only transiently available stream bed pool habitat, in order to optimise breeding success.

Characteristics of malaria vector breeding habitats in Sri Lanka: relevance for environmental management.

In and around a village in the Anuradhapura District of Sri Lanka anopheline larvae were sampled from July 1994 to April 1996 in all surface water bodies. Samples positive for Anopheles culicifacies, the established vector of malaria in Sri Lanka, and for An. barbirostris, An. vagus, and An. varuna, potential secondary vectors, were characterized by site, exposure to sunlight, substratum, turbidity of the water, presence of vegetation, and presence of fauna. Availability of pools of stagnant water in the stream near the village and along the edge of the village tank was highly predictive for presence of An. culicifacies larvae, independent from the other characteristics that were included in the study. The biological and physical characteristics could not very well explain the preference for certain habitats, but it was of interest that An. culicifacies, generally considered to bread in sun exposed clear water pools, was able to exploit habitats that were shaded and contained turbid water. Environmental management interventions to control An. culicifacies breeding have to take into account that the secondary vectors of malaria exploit other habitats and would not be affected by the interventions.