Joanna Armstrong Schellenberg

Intermittent preventive treatment of malaria in infants (IPTi) reduces the incidence of clinical malaria. However, before making decisions about implementation, it is essential to ensure that IPTi is acceptable, that it does not adversely affect attitudes to immunization or existing health seeking behaviour. This paper reports on the reception of IPTi during the first implementation study of IPTi in southern Tanzania.

The Tanzania National Voucher Scheme (TNVS) uses the public health system and the commercial sector to deliver subsidised insecticide-treated nets (ITNs) to pregnant women. The system began operation in October 2004 and by May 2006 was operating in all districts in the country. Evaluating complex public health interventions which operate at national level requires a multidisciplinary approach, novel methods, and collaboration with implementers to support the timely translation of findings into programme changes. This paper describes this novel approach to delivering ITNs and the design of the monitoring and evaluation (M&E).

Background: Survey data are traditionally collected using pen-and-paper, with double data entry, comparison of entries and reconciliation of discrepancies before data cleaning can commence. We used Personal Digital Assistants (PDAs) for data entry at the point of collection, to save time and enhance the quality of data in a survey of over 21,000 scattered rural households in southern Tanzania. Methods: Pendragon Forms 4.0 software was used to develop a modular questionnaire designed to record information on household residents, birth histories, child health and health-seeking behaviour. The questionnaire was loaded onto Palm m130 PDAs with 8 Mb RAM. One hundred and twenty interviewers, the vast majority with no more than four years of secondary education and very few with any prior computer experience, were trained to interview using the PDAs. The 13 survey teams, each with a supervisor, laptop and a four-wheel drive vehicle, were supported by two back-up vehicles during the two months of field activities. PDAs and laptop computers were charged using solar and in-car chargers. Logical checks were performed and skip patterns taken care of at the time of data entry. Data records could not be edited after leaving each household, to ensure the integrity of the data from each interview. Data were downloaded to the laptop computers and daily summary reports produced to evaluate the completeness of data collection. Data were backed up at three levels: (i) at the end of every module, data were backed up onto storage cards in the PDA; (ii) at the end of every day, data were downloaded to laptop computers; and (iii) a compact disc (CD) was made of each team's data each day. A small group of interviewees from the community, as well as supervisors and interviewers, were asked about their attitudes to the use of PDAs. Results: Following two weeks of training and piloting, data were collected from 21,600 households (83,346 individuals) over a seven-week period in July-August 2004. No PDA-related problems or data loss were encountered. Fieldwork ended on 26 August 2004, the full dataset was available on a CD within 24 hours and the results of initial analyses were presented to district authorities on 28 August. Data completeness was over 99%. The PDAs were well accepted by both interviewees and interviewers. Conclusion: The use of PDAs eliminated the usual time-consuming and error-prone process of data entry and validation. PDAs are a promising tool for field research in Africa.

Background: Efficient delivery strategies for health interventions are essential for high and sustainable coverage. We report impact of a change in programmatic delivery strategy from routine delivery through the Expanded Programme on Immunization (EPI+) approach to twice-yearly mass distribution campaigns on coverage of vitamin A supplementation in Tanzania Methods: We investigated disparities in age, sex, socio-economic status, nutritional status and maternal education within vitamin A coverage in children between 1 and 2 years of age from two independent household level child health surveys conducted (1) during a continuous universal targeting scheme based on routine EPI contacts for children aged 9, 15 and 21 months (1999); and (2) three years later after the introduction of twice-yearly vitamin A supplementation campaigns for children aged 6 months to 5 years, a 6-monthly universal targeting scheme (2002). A representative cluster sample of approximately 2,400 rural households was obtained from Rufiji, Morogoro Rural, Kilombero and Ulanga districts. A modular questionnaire about the health of all children under the age of five was administered to consenting heads of households and caretakers of children. Information on the use of child health interventions including vitamin A was asked. Results: Coverage of vitamin A supplementation among 1–2 year old children increased from 13% [95% CI 10–18%] in 1999 to 76% [95%CI 72–81%] in 2002. In 2002 knowledge of two or more child health danger signs was negatively associated with vitamin A supplementation coverage (80% versus 70%) (p = 0.04). Nevertheless, we did not find any disparities in coverage of vitamin A by district, gender, socio-economic status and DPT vaccinations. Conclusion: Change in programmatic delivery of vitamin A supplementation was associated with a major improvement in coverage in Tanzania that was been sustained by repeated campaigns for at least three years. There is a need to monitor the effect of such campaigns on the routine health system and on equity of coverage. Documentation of vitamin A supplementation campaign contacts on routine maternal and child health cards would be a simple step to facilitate this monitoring.

Since 1997, discount vouchers for insecticide-treated nets (ITNs) have been used in two rural districts of southern Tanzania as a way to target subsidies to children under 5 years and pregnant women. We assessed appropriate use and misuse of discount vouchers through a follow-up study of 104 randomly selected vouchers. We traced these vouchers from their original issue in mother-and-child health (MCH) clinics through to being redeemed at a sales agent. We found that all vouchers that reached the target population (100%, 56/56) were used to buy an ITN. Moreover, 94% of the ITNs bought with vouchers were used by those intended, women and children under 5 years. However, up to 48% (50/104) of the vouchers had been misused at the clinics that issued them. Nevertheless, large-scale misuse occurred only at three of 21 clinics. Although most women slept under a net while pregnant, the use of voucher-subsidized ITNs during pregnancy was low despite widespread knowledge of the scheme. Parents had apparently decided to buy the subsidized ITNs once the child was born and not during pregnancy. Importantly, in 20% of households the only existing net had been bought with a voucher. Our findings suggest that vouchers are properly used by the target population, and that to minimize voucher leakage, control measures are needed at MCH clinics and to a certain extent for commercial sales agents. Increased awareness among the whole community on the right to receive a discount voucher may also help to control misuse at health facilities.

Summary: Randomized controlled trials have shown that insecticide‐treated nets (ITNs) have an impact on both malaria morbidity and mortality. Uniformly high coverage of ITNs characterized these trials and this resulted in some protection of nearby non‐users of ITNs. We have now assessed the coverage, distribution pattern and resultant spatial effects in one village in Tanzania where ITNs were distributed in a social marketing programme. The prevalence of parasitaemia, mild anaemia (Hb <11 g/dl) and moderate/severe anaemia (Hb <8 g/dl) in children under five was assessed cross‐sectionally. Data on ownership of ITNs were collected and inhabitants’ houses were mapped. One year after the start of the social marketing programme, 52% of the children were using a net which had been treated at least once. The ITNs were rather homogeneously distributed throughout the village at an average density of about 118 ITNs per thousand population. There was no evidence of a pattern in the distribution of parasitaemia and anaemia cases, but children living in areas of moderately high ITN coverage were about half as likely to have moderate/severe anaemia (OR 0.5, 95% CI: 0.2, 0.9) and had lower prevalence of splenomegaly, irrespective of their net use. No protective effects of coverage were found for prevalence of mild anaemia nor for parasitaemia. The use of untreated nets had neither coverage nor short distance effects. More efforts should be made to ensure high coverage in ITNs programmes to achieve maximum benefit.

Summary: Objective To review the impact of malaria control on haemoglobin (Hb) distributions and anaemia prevalences in children under 5 in malaria‐endemic Africa.Methods Literature review of community‐based studies of insecticide‐treated bednets, antimalarial chemoprophylaxis and insecticide residual spraying that reported the impact on childhood anaemia. Anaemia outcomes were standardized by conversion of packed cell volumes into Hb values assuming a fixed threefold difference, and by estimation of anaemia prevalences from mean Hb values by applying normal distributions. Determinants of impact were assessed in multivariate analysis.Results Across 29 studies, malaria control increased Hb among children by, on average, 0.76 g/dl [95% confidence interval (CI): 0.61–0.91], from a mean baseline level of 10.5 g/dl, after a mean of 1–2 years of intervention. This response corresponded to a relative risk for Hb < 11 g/dl of 0.73 (95% CI: 0.64–0.81) and for Hb < 8 g/dl of 0.40 (95% CI: 0.25–0.55). The anaemia response was positively correlated with the impact on parasitaemia (P = 0.005,P = 0.008 andP = 0.01 for the three outcome measures), but no relationship with the type or duration of malaria intervention was apparent. Impact on the prevalence of Hb < 11 g/dl was larger in sites with a higher baseline parasite prevalence. Although no age pattern in impact was apparent across the studies, some individual trials found larger impacts on anaemia in children aged 6–35 months than in older children.Conclusion In malaria‐endemic Africa, malaria control reduces childhood anaemia. Childhood anaemia may be a useful indicator of the burden of malaria and of the progress in malaria control.

Summary An entomological study on vectors of malaria and their relative contribution to Plasmodium falciparum transmission in the semi‐urban area of Ifakara, south‐eastern Tanzania, was conducted. A total of 32 houses were randomly sampled from the area and light trap catches (LTC) performed in one room in each house every 2 weeks for 1 year. A total of 147 448 mosquitoes were caught from 789 LTC; 26 134 Anopheles gambiae s.l., 615 A. funestus, 718 other anophelines and 119 981 culicines. More than 60% of the total A. gambiae s.l. were found in five (0.6%) LTCs, with a maximum of 5889 caught in a single trap. Of 505 A. gambiae s.l. speciated by polymerase chain reaction, 91.5% were found to be A. arabiensis. Plasmodium falciparum sporozoite enzyme‐linked immunosorbent assay tests were performed on 10 108 anopheles mosquitoes and 39 (0.38%) were positive. Entomological inoculation rate (EIR) estimates were generated using a standard method and an alternative method that allows the calculation of confidence intervals based on a negative binomial distribution of sporozoite positive mosquitoes. Overall EIR estimates were similar; 31 vs. 29 [95% confidence interval (CI): 19, 44] infectious bites per annum, respectively. The EIR ranged from 4 (95% CI: 1, 17) in the cool season to 108 (95% CI: 69, 170) in the wet season and from 54 (95% CI: 30, 97) in the east of the town to 15 (95% CI: 8, 30) in the town centre. These estimates show large variations over short distances in time and space. They are all markedly lower than those reported from nearby rural areas and for other parts of Tanzania.

Joanna Armstrong Schellenberg, Happiness Minja, Haji Mponda, Nassor Kikumbih, Adiel Mushi, Rose Nathan, Salim Abdulla, Oscar Mukasa, Tanya J. Marchant, Marcel T