Malaria risk factors in an endemic region of Sri Lanka, and the impact and cost implications of risk factor-based interventions.

Abstract

In an 18-month study of malaria in a population of 1,875 residents in 423 houses in an endemic area in southern Sri Lanka, the risk of malaria was found to be 2.5-fold higher in residents of poorly constructed houses than in those living in houses of good construction type. In residents of poorly constructed houses but not in others, the risk was even greater when the house was located near a source of water that could act as a potential breeding place for malaria vector mosquitoes (P ϭ 0.0001). Based on previous findings that confirmed that house construction type was itself a risk determinant, and not merely a marker of other behavioral factors, we have estimated the potential impact of two feasible interventions to reduce the risk of malaria: 1) the imposition of a buffer zone of 200 meters around bodies of water from which houses of poor construction were excluded, which was estimated to lead to a 21% reduction of the malaria incidence in the overall population and a 43% reduction in the relocated community; and 2) the conversion of houses of poor construction type located in the buffer zone to those of a good construction type, which was estimated to lead to a 36% reduction in the incidence rates in the whole population and a 76% reduction in the residents of houses whose construction type was improved. Taking into consideration the cost to the Government of malaria prevention, we estimated the worth of a Government's investment in improving house construction type. The investment in housing was estimated to be offset in 7.2 years by savings to the Government on malaria costs alone, and beyond this period, to bring a return on the Government's investment by way of savings to the malaria control program.

Quantifying genetic and nongenetic contributions to malarial infection in a Sri Lankan population

“…Most people in our study population have about one clinical attack per year, and generally 1-2% of the population are infected (at detectable levels) with either Plasmodium vivax or Plasmodium falciparum at any point in time (29). Epidemics of P. falciparum malaria used to occur at 7-to 10-year intervals (31), but since 1986, P. falciparum has persisted (32,33). Further details of the study site are given elsewhere (29,33).…”

“…Epidemics of P. falciparum malaria used to occur at 7-to 10-year intervals (31), but since 1986, P. falciparum has persisted (32,33). Further details of the study site are given elsewhere (29,33). information on age, sex, previous malarial infections, and various predisposing factors were recorded on the entire population since 1986 (33).…”

Climate change and mosquito-borne disease.

“…Malaria was almost eradicated from all of Sri Lanka in the 1960s, but in recent years it has returned as a major public health problem, with almost 0.3 million infections reported annually in its population of 17 million (108).…”

Optimizing the malaria data recording system through a study of case detection and treatment in Sri Lanka

“…Spatial analysis of health and related information, which can form a very important component of disease control strategies (de Savigny & Wijeyaratne 1994;Gunawardena et al 1997), depends on accurate information on the geographical origin of infections. Our findings show that the present data recording system does not support an accurate spatial database: Whereas at the level of the health care institution, all information on confirmed malaria patients is being collected and recorded with patients' residential addresses and village names, at the Regional Malaria Office this information is used for two purposes.…”