https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(07)60325-0.pdf

Achieving child survival goals: potential contribution of community health workers

It is often argued that cost-sharing—charging a subsidized, positive price—for a health product is necessary to avoid wasting resources on those who will not use or do not need the product. We explore this argument through a field experiment in Kenya, in which we randomized the price at which prenatal clinics could sell long lasting anti-malarial insecticide-treated nets (ITNs) to pregnant women. We find no evidence that costsharing reduces wastage on those that will not use the product: women who received free ITNs are not less likely to use them than those who paid subsidized positive prices. We also find no evidence that costsharing induces selection of women who need the net more: those who pay higher prices appear no sicker than the average prenatal client in the area in terms of measured anemia (an important indicator of malaria). Cost-sharing does, however, considerably dampen demand. We find that uptake drops by 75 percent when the price of ITNs increases from zero to $0.75 (i.e. from 100 to 87.5 percent subsidy), the price at which ITNs are currently sold to pregnant women in Kenya. We combine our estimates in a cost-effectiveness analysis of ITN prices on child mortality that incorporates both private and social returns to ITN usage. Overall, our results suggest that free distribution of ITNs could save many more lives than cost-sharing programs have achieved so far, and, given the large positive externality associated with widespread usage of ITNs, it would likely do so at a lesser cost per life saved.

/pdf/free-distribution-or-cost-sharing-evidence-from-a-randomized-1hk9oc6jjf.pdf

Free Distribution or Cost-Sharing? Evidence from a Randomized Malaria Prevention Experiment

Background 
Malaria prevention in Africa merits particular attention as the world strives toward a better life for the poorest. Insecticide-treated nets (ITNs) represent a practical means to prevent malaria in Africa, so scaling up coverage to at least 80% of young children and pregnant women by 2010 is integral to the Millennium Development Goals (MDG). Targeting individual protection to vulnerable groups is an accepted priority, but community-level impacts of broader population coverage are largely ignored even though they may be just as important. We therefore estimated coverage thresholds for entire populations at which individual- and community-level protection are equivalent, representing rational targets for ITN coverage beyond vulnerable groups.


Methods and Findings 
Using field-parameterized malaria transmission models, we show that high (80% use) but exclusively targeted coverage of young children and pregnant women (representing <20% of the population) will deliver limited protection and equity for these vulnerable groups. In contrast, relatively modest coverage (35%–65% use, with this threshold depending on ecological scenario and net quality) of all adults and children, rather than just vulnerable groups, can achieve equitable community-wide benefits equivalent to or greater than personal protection.


Conclusions 
Coverage of entire populations will be required to accomplish large reductions of the malaria burden in Africa. While coverage of vulnerable groups should still be prioritized, the equitable and communal benefits of wide-scale ITN use by older children and adults should be explicitly promoted and evaluated by national malaria control programmes. ITN use by the majority of entire populations could protect all children in such communities, even those not actually covered by achieving existing personal protection targets of the MDG, Roll Back Malaria Partnership, or the US President's Malaria Initiative.

/pdf/preventing-childhood-malaria-in-africa-by-protecting-adults-3rzfk5jcoz.pdf

Preventing childhood malaria in Africa by protecting adults from mosquitoes with insecticide-treated nets.

Domestic and personal protection measures against malaria exposure either divert host-seeking vectors to other hosts or kill those attempting to feed. Here, we explicitly model mosquito host-seeking processes in the context of local host availability and elucidate the impacts and mechanisms of pyrethroid-treated bed nets in Africa. It has been suggested that excitorepellent insecticides could increase exposure of unprotected humans by concentrating mosquito biting activity on this vulnerable group. This worst-case scenario is confirmed as a possibility where vector populations lack alternative hosts, but an approximate 'break-even' scenario, with users experiencing little overall change in exposure, is more likely because of increased mosquito mortality while foraging for resources. Insecticidal nets are predicted to have epidemiologically significant impacts on transmission experienced by users and non-users at levels of coverage that can be achieved by sustainable net distribution systems, regardless of excitorepellency or the ecological setting. The results are consistent with the outcome of several randomised controlled trials, predicting enormous reductions in transmission at individual and community levels. As financial support, technology and distribution systems for insecticide-treated nets improve, massive reductions in malaria transmission could be realised.

https://doc.rero.ch/record/293445/files/101-9-867.pdf

Exploring the contributions of bed nets, cattle, insecticides and excitorepellency to malaria control: a deterministic model of mosquito host-seeking behaviour and mortality

Objective To evaluate the effects of intermittent preventive treatment for malaria in infants (IPTi) with sulfadoxine-pyrimethamine in an area of intense, seasonal transmission.

Design Cluster randomised placebo controlled trial, with 96 clusters allocated randomly to sulfadoxine-pyrimethamine or placebo in blocks of eight.

Interventions Children received sulfadoxine-pyrimethamine or placebo and one month of iron supplementation when they received DPT-2, DPT-3, or measles vaccinations and at 12 months of age.

Main outcome measures Incidence of malaria and of anaemia determined through passive case detection.

Results 89% (1103/1242) of children in the placebo group and 88% (1088/1243) in the IPTi group completed follow-up to 24 months of age. The protective efficacy of IPTi against all episodes of malaria was 24.8% (95% confidence interval 14.3% to 34.0%) up to 15 months of age. IPTi had no protective effect against malaria between 16 and 24 months of age (protective efficacy -4.9%, -21.3% to 9.3%). The incidence of high parasite density malaria (≥ 5000 parasites/μl) was higher in the IPTi group than in the placebo group between 16 and 24 months of age (protective efficacy -19.5%, -39.8% to -2.2%). IPTi reduced hospital admissions with anaemia by 35.1% (10.5% to 52.9%) up to 15 months of age. IPTi had no significant effect on anaemia between 16 and 24 months of age (protective efficacy -6.4%, -76.8% to 35.9%). The relative risk of death up to 15 months of age in the IPTi group was 1.26 (95% confidence interval 0.81 to 1.96; P = 0.31), and from 16 to 24 months it was 1.28 (0.77 to 2.14; P = 0.35).

Conclusions Intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine can reduce malaria and anaemia in infants even in seasonal, high transmission areas, but concern exists about possible rebound in the incidence of malaria in the second year of life.

https://www.bmj.com/content/bmj/331/7519/727.full.pdf

Cluster randomised trial of intermittent preventive treatment for malaria in infants in area of high, seasonal transmission in Ghana

Objective To achieve high and equitable coverage of insecticide-treated bednets by integrating their distribution into a measles vaccination campaign. Methods In December 2002 in the Lawra district in Ghana, a measles vaccination campaign lasting 1 week targeted all children aged 9 months–15 years. Families with one or more children less than five years old were targeted to receive a free insecticide-treated bednet. The Ghana Health Service, with support from the Ghana Red Cross and UNICEF, provided logistical support, volunteer workers and social mobilization during the campaign. Volunteers visited homes to inform caregivers about the campaign and encourage them to participate. We assessed pre-campaign coverage of bednets by interviewing caregivers leaving vaccination and distribution sites. Five months after distribution, a two-stage cluster survey using population-proportional sampling assessed bednet coverage, retention and use. Both the pre-campaign and post-campaign survey assessed household wealth using an asset inventory. Findings At the campaign exit interview 636/776 (82.0%) caregivers reported that they had received a home visit by a Red Cross volunteer before the campaign and that 32/776 (4.1%) of the youngest children in each household who were less than 5 years of age slept under an insecticide-treated bednet. Five months after distribution caregivers reported that 204/219 (93.2%) of children aged 9 months to 5 years had been vaccinated during the campaign; 234/248 (94.4%) of households were observed to have an insecticide-treated bednet; and 170/249 (68.3%) were observed to have a net hung over a bed. Altogether 222/248 (89.5%) caregivers reported receiving at least one insecticide-treated bednet during the campaign, and 153/254 (60.2%) said that on the previous night their youngest child had slept under a bednet received during the campaign. For households in the poorest quintile, post-campaign coverage of insecticide-treated bednets was 10 times higher than pre-campaign coverage of households in the wealthiest quintile (46/51 (90.2%) versus 14/156 (9.0%)). The marginal operational cost was US$ 0.32 per insecticide-treated bednet delivered. Conclusion These findings suggest that linking bednet distribution to measles vaccination campaigns may provide an important opportunity for achieving high and equitable coverage of bednets.

/pdf/distributing-insecticide-treated-bednets-during-measles-5fecexhlxa.pdf

Holly Ladd

Papers

Distributing insecticide-treated bednets during measles vaccination: a low-cost means of achieving high and equitable coverage.