Entrez-PubMed

Premanath M

Eighty-five villages out of nearly 300 villages of Tiptur taluka covering a population of 47,271 where the incidence of Plasmodium falciparum (PF) malaria was very high, were selected for a programme during Aug 93 which lasted for 29 months until the end of Dec 95. Ten days of fever radical treatment (FRT) and 54 weekly and 29 fortnightly rapid fever surveillance (RFS) programmes were conducted. 64,142 blood smears were examined out of which 21,542 were positive for malaria and 14,291 were of PF type. There were 9858 PF cases during the last 5 months of 1993, which came down to 349 by the end of 1995. Fever morbidity which was nearly 1000 new cases per day during FRT came down to 120, 78, and 30 new cases per day during 1993, 1994 and 1995, respectively. Parasite index (PI) for PF Malaria was 140-321 during 1993, came down to 0.6-15 at the end of the study. Four rounds of DDT, two rounds of Ikon and one round of Delta-methrin were sprayed in four and two PHC areas, respectively during this period. Asymptomatic carriers for PF malaria were detected in the children under 14 years of age (3.1%). This programme did prove very effective in bringing down morbidity and mortality due to PF Malaria in the community.

PMID: 11229184

Incidence and management of malaria in two communities of different socio-economic level, in Accra, Ghana.

Biritwum RB, Welbeck J, Barnish G

Department of Community Health, Ghana Medical School, Korle Bu, Accra, Ghana. [email protected]

Two adjacent communities of differing socio-economic levels were selected, in Accra, Ghana, for the study of the home management of malaria. The youngest child in each selected household, each of which had a child aged < 5 years, was recruited for weekly follow-up, following informed consent. Malaria was the most common condition reported by the ‘caregivers’ (mothers of the subjects and others caring for the subjects) in each community, with 2.0 episodes of clinical malaria/child during the 9-month study. Most (89%) of the caregivers in the better-off community had been educated beyond primary-school level, but 55% of the caregivers in the poorer community had either received no formal education or only primary-school education. This difference was also reflected by the educational facilities provided to the children studied: 52% of the those in the better-off community attended nurseries, kindergartens or creches, compared with 8% of the children investigated in the poorer community. The proportion of caregivers who purchased drugs without prescription or used left-over drugs to treat clinical malaria in the children was higher in the poorer community (82% v. 53%), and a child from the poorer community was less likely to have been taken to a clinic or hospital to be treated for malaria than a child from the better-off community (27% v. 42%). During the follow-up period two children died, one from each community. Treatment of malaria in young children is likely to be less effective in the poorer community, where a lack of economic access to health services was demonstrated.

PMID: 11214095

Mosquito distribution and entomological inoculation rates in three malaria-endemic areas in Gabon.

Sylla EH, Kun JF, Kremsner PG

Department of Parasitology, Institute of Tropical Medicine, University of Tubingen, Wilhelmstrasse 27, D-72074 Tubingen, Germany.

Mosquitoes were collected during 3 separate periods in 3 areas of different malaria transmission rates in the province of Moyen Ogooue, Gabon, within 1 year (July 1996-May 1997). The campus of the Albert Schweitzer Hospital (HAS) and 2 villages, Bellevue and Tchad, were investigated. A total of 19,836 specimens were collected: 13,122 Mansonia, 3944 Anopheles, 2755 Culex and 15 Aedes were captured. The number of mosquitoes was 7896 and 7995 in July to August and from April to May respectively, and dropped to approximately half in November to December. The individual species showed a different distribution pattern in the 3 study areas. In Tchad we found the lowest number of mosquitoes and also the fewest Anopheles, but when we investigated the number of Plasmodium falciparum-infected Anopheles sp. we observed the highest entomological inoculation rate (EIR) there. The EIRs were 23 in HAS, 53 in Bellevue and 61 in Tchad. The method used to determine the number of infected mosquitoes was an enzyme-linked immunosorbent assay (ELISA), confirmed by a polymerase chain reaction-based approach. The ELISA alone revealed too many false-positive mosquitoes.

PMID: 11198649

Using a geographical information system to plan a malaria control programme in South Africa.

Booman M, Durrheim DN, La Grange K, Martin C, Mabuza AM, Zitha A, Mbokazi FM, Fraser C, Sharp BL

Malaria Control Programme, Mpumalanga Department of Health, Nelspruit, South Africa.

INTRODUCTION: Sustainable control of malaria in sub-Saharan Africa is jeopardized by dwindling public health resources resulting from competing health priorities that include an overwhelming acquired immunodeficiency syndrome (AIDS) epidemic. In Mpumalanga province, South Africa, rational planning has historically been hampered by a case surveillance system for malaria that only provided estimates of risk at the magisterial district level (a subdivision of a province). METHODS: To better map control programme activities to their geographical location, the malaria notification system was overhauled and a geographical information system implemented. The introduction of a simplified notification form used only for malaria and a carefully monitored notification system provided the good quality data necessary to support an effective geographical information system. RESULTS: The geographical information system displays data on malaria cases at a village or town level and has proved valuable in stratifying malaria risk within those magisterial districts at highest risk, Barberton and Nkomazi. The conspicuous west-to-east gradient, in which the risk rises sharply towards the Mozambican border (relative risk = 4.12, 95% confidence interval = 3.88-4.46 when the malaria risk within 5 km of the border was compared with the remaining areas in these two districts), allowed development of a targeted approach to control. DISCUSSION: The geographical information system for malaria was enormously valuable in enabling malaria risk at town and village level to be shown. Matching malaria control measures to specific strata of endemic malaria has provided the opportunity for more efficient malaria control in Mpumalanga province.

PMID: 11196490

Spatial targeting of interventions against malaria.

Carter R, Mendis KN, Roberts D

University of Edinburgh, Division of Biological Sciences, ICAPB, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, Scotland. [email protected]

Malaria transmission is strongly associated with location. This association has two main features. First, the disease is focused around specific mosquito breeding sites and can normally be transmitted only within certain distances from them: in Africa these are typically between a few hundred metres and a kilometre and rarely exceed 2-3 kilometres. Second, there is a marked clustering of persons with malaria parasites and clinical symptoms at particular sites, usually households. In localities of low endemicity the level of malaria risk or case incidence may vary widely between households because the specific characteristics of houses and their locations affect contact between humans and vectors. Where endemicity is high, differences in human/vector contact rates between different households may have less effect on malaria case incidences. This is because superinfection and exposure-acquired immunity blur the proportional relationship between inoculation rates and case incidences. Accurate information on the distribution of malaria on the ground permits interventions to be targeted towards the foci of transmission and the locations and households of high malaria risk within them. Such targeting greatly increases the effectiveness of control measures. On the other hand, the inadvertent exclusion of these locations causes potentially effective control measures to fail. The computerized mapping and management of location data in geographical information systems should greatly assist the targeting of interventions against malaria at the focal and household levels, leading to improved effectiveness and cost-effectiveness of control.

PMID: 11196487

Malaria in the United Republic of Tanzania: cultural considerations and health-seeking behaviour.

Oberlander L, Elverdan B

Department of General Practice, Institute of Public Health, University of Southern Denmark, Odense, Winslowparken 19, DK-5000 Odense C, Denmark.

Malaria is one of the biggest health problems in sub-Saharan Africa. Large amounts of resources have been invested to control and treat it. Few studies have recognized that local explanations for the symptoms of malaria may lead to the attribution of different causes for the disease and thus to the seeking of different treatments. This article illustrates the local nosology of Bondei society in the north-eastern part of the United Republic of Tanzania and shows how sociocultural context affects health-seeking behaviour. It shows how in this context therapy is best viewed as a process in which beliefs and actions are continuously debated and evaluated throughout the course of treatment.

PMID: 11143196

Estimates of the infectious reservoir of Plasmodium falciparum malaria in The Gambia and in Tanzania.

Drakeley CJ, Akim NI, Sauerwein RW, Greenwood BM, Targett GA

MRC Laboratories, PO Box 273 Fajara, The Gambia. [email protected]

Separate studies carried out in Farafenni, The Gambia and Ifakara, Tanzania in 1990-94 provided comparative data on population age structure, population gametocyte prevalences and gametocyte carrier infectivity. The percentage of the population estimated to be infective to mosquitoes was 5.5% and 3.8% in The Gambia and Tanzania, respectively. The age groups 1-4 years, 5-9 years, 10-19 years and 20 years or more comprised 17.5%, 21.7%, 22.2% and 37.9%, respectively, of the infectious population in The Gambia; the corresponding figures for Tanzania were 30.9%, 25.2%, 15.7% and 28.1%. These figures are in broad agreement with those from other published studies which estimated the infectious reservoir directly and suggest that adults contribute significantly to the infectious reservoir of malaria, particularly in areas of intense seasonal transmission. Control measures aimed at reduction of transmission may have only a limited effect in areas of moderate seasonal transmission if directed only at children.

PMID: 11132369

Risk factors associated with malaria infection in an urban setting.

Mendez F, Carrasquilla G, Munoz A

Instituto de Salud del Pacifico (INSALPA), Buenaventura, Colombia.

Incidence of malaria in urban settings is a growing concern in many regions of the world and individual risk factors need to be identified to appropriately adjust control strategies. We carried out a cross-sectional study in 1993/94 in an urban area of the largest port of the Pacific Coast of Colombia, where transmission has had an upward trend over the past 5 years. Prevalence of malaria infection was estimated in areas of the city with the highest incidence of disease, and the association between some characteristics of the population and the risk of malaria infection was assessed. Prevalence of malaria infection was 4.4% among the 1380 studied people and we found that it decreased with older age, and with knowledge of disease and preventive measures directed to elimination of breeding sites. In addition, the infection was positively associated with exposure to the forest (P < 0.05), although most of the cases (57/61, 93%) were likely to have been acquired in the urban area. We also found that individuals receiving antimalarial treatment in the previous month had around twice the risk of being infected as compared with those without treatment. In addition, our results suggest that use of bednets could not be a very effective protective measure in settings such as that of our study, and that environmental interventions may be needed to decrease the risk of infection.

PMID: 11127234