Mortality in a seven-and-a-half-year follow-up of a trial of insecticide-treated mosquito nets in Ghana

A 17% efficacy in preventing all-cause mortality in children aged 6-59 months was previously reported from a cluster-randomized controlled trial of insecticide-treated mosquito nets (ITNs) carried out in the Kassena-Nankana District of northern Ghana from July 1993-June 1995. A follow-up until the end of 2000 found no indication in any age group of increased mortality in the ITN group after the end of the randomized intervention. These results should further encourage the use of ITNs as a malaria control tool in areas of high endemicity of Plasmodium falciparu

Part Two: Socio-cultural context of infant / child morbidity and mortality in Kasena-Nankana district (part two)

Infant and child mortality rates in Northern Ghana are among the highest in Africa, but the reasons remain uncertain. A population based case-control study was carried out to look at potential risk factors for mortality. Cases and controls were matched for age, sex and locality from the demographic database for the district. Mothers or guardians of each case and matched control were interviewed to obtain information on social, economic, demographic, environmental and other possible risk factors. Matched analyses were performed using discordant pairs and conditional logistic regression. The mortality rate of children aged 6 months to 4 years was estimated as 23.9/1000. An increased risk of death was observed when a child was not fed colostrum after birth (OR=l.8 95% CI 1.2-2.6), had a history of measles (OR= 2.4, 95% CI 1.0-5.8), the preceeding birth interval was less than 24 months, if the father beat the child's mother (OR=2.9, 95% CI 1.2-6.8), the compound was poor measured by the absence of corrugated zinc roof(OR=1.7, 955 CI, 1.2-2.6) or ifthe water source was poor (OR=l.4, 95% CI 1.0-1. 9). No association was found between perinatal factors, other feeding practices, parental education or any of the other socio-economic or compound sanitation variables considered. Malaria, Acute Gastroenteritis and acute respiratory infection accounted for 60% of deaths with agreed cause of death determined by verbal autopsy. Relatively few risk factors were identified and none which were very strong determinants of child death. This may have been because of the relative homogeneity of the study population. While child mortality rates may be reduced by targeted intervention such as improved and well managed primary health care delivery system, vitamin A supplementation, insecticide impregnated bednets, more general improvements in the socio-economic status in the region are essential

Species abundance and insecticide resistance of Anopheles gambiae in selected areas of Ghana and Burkina Faso

The Ghanaian National Malaria Control Programme has prioritized insecticide-treated materials as a key strategy for malaria control. We report on a survey of the distribution of the molecular forms of Anopheles gambiae Giles (Diptera: Culicidae) and insecticide resistance (the kdr mutation), carried out by sampling mosquitoes from 11 locations in Ghana and one additional site in Burkina Faso. The molecular M and S forms of An. gambiae were found to occur in sympatry in southern Ghana. The S form predominated throughout its distribution in the coastal savannah, except at one location in the strand and mangrove zone where rice was cultivated. The M form was the only form collected in northern Ghana and was the predominant form (97.5%) in Burkina Faso. No M/S hybrids were detected. The kdr mutation was observed at very high frequencies (98-100%) within the S form but reached a maximum of only 3.38% in the M form in one population at an irrigation scheme in the Ghanaian coastal savannah zone