Donald A. P. Bundy

Hookworm-Related Anaemia among Pregnant Women: A Systematic Review.

Background and Objectives Hookworm infection is among the major causes of anaemia in poor communities, but its importance in causing maternal anaemia is poorly understood, and this has hampered effective lobbying for the inclusion of anthelmintic treatment in maternal health packages. We sought to review existing evidence on the role of hookworm as a risk factor for anaemia among pregnant women. We also estimate the number of hookworm infections in pregnant women in sub-Saharan Africa (SSA). Methods Structured searches using MEDLINE and EMBASE as well as manual searches of reference lists were conducted, and unpublished data were obtained by contacting authors. Papers were independently reviewed by two authors, and relevant data were extracted. We compared haemoglobin concentration (Hb) according to intensity of hookworm infection and calculated standardised mean differences and 95% confidence intervals. To estimate the number of pregnant women, we used population surfaces and a spatial model of hookworm prevalence. Findings One hundred and five reports were screened and 19 were eligible for inclusion: 13 cross-sectional studies, 2 randomised controlled trials, 2 non-randomised treatment trials and 2 observational studies. Comparing uninfected women and women lightly (1–1,999 eggs/gram [epg]) infected with hookworm, the standardised mean difference (SMD) was −0.24 (95% CI: −0.36 to −0.13). The SMD between women heavily (4000+ epg) infected and those lightly infected was −0.57 (95% CI: −0.87 to −0.26). All identified intervention studies showed a benefit of deworming for maternal or child health, but since a variety of outcomes measures were employed, quantitative evaluation was not possible. We estimate that 37.7 million women of reproductive age in SSA are infected with hookworm in 2005 and that approximately 6.9 million pregnant women are infected. Conclusions Evidence indicates that increasing hookworm infection intensity is associated with lower haemoglobin levels in pregnant women in poor countries. There are insufficient data to quantify the benefits of deworming, and further studies are warranted. Given that between a quarter and a third of pregnant women in SSA are infected with hookworm and at risk of preventable hookworm-related anaemia, efforts should be made to increase the coverage of anthelmintic treatment among pregnant women.

Unresolved issues in anthelmintic pharmacology for helminthiases of humans.

Helminth infections are an important constraint on the health and development of poor children and adults. Anthelmintic treatment programmes provide a safe and effective response, and increasing numbers of people are benefitting from these public health initiatives. Despite decades of clinical experience with anthelmintics for the treatment of human infections, relatively little is known about their clinical pharmacology. All of the drugs were developed initially in response to the considerable market for veterinary anthelmintics in high- and middle-income countries. In contrast, the greatest burden caused by these infections in humans is in resource-poor settings and as a result there has been insufficient commercial incentive to support studies on how these drugs work in humans, and how they should best be used in control programmes. The advent of mass drug administration programmes for the control of schistosomiasis, lymphatic filariasis, onchocerciasis and soil-transmitted helminthiases in humans increases the urgency to better understand and better monitor drug resistance, and to broaden the currently very narrow range of available anthelmintics. This provides fresh impetus for developing a comprehensive research platform designed to improve our understanding of these important drugs, in order to bring the scientific knowledge base supporting their use to a standard equivalent to that of drugs commonly used in developed countries. Furthermore, a better understanding of their clinical pharmacology will enable improved therapy and could contribute to the discovery of new products.

The co-distribution of Plasmodium falciparum and hookworm among African schoolchildren

BackgroundSurprisingly little is known about the geographical overlap between malaria and other tropical diseases, including helminth infections. This is despite the potential public health importance of co-infection and synergistic opportunities for control.MethodsStatistical models are presented that predict the large-scale distribution of hookworm in sub-Saharan Africa (SSA), based on the relationship between prevalence of infection among schoolchildren and remotely sensed environmental variables. Using a climate-based spatial model of the transmission potential for Plasmodium falciparum malaria, adjusted for urbanization, the spatial congruence of populations at coincident risk of infection is determined.ResultsThe model of hookworm indicates that the infection is widespread throughout Africa and that, of the 179.3 million school-aged children who live on the continent, 50.0 (95% CI: 48.9–51.1) million (27.9% of total population) are infected with hookworm and 45.1 (95% CI: 43.9–46) million are estimated to be at risk of coincident infection.ConclusionMalaria and hookworm infection are widespread throughout SSA and over a quarter of school-aged children in sub-Saharan Africa appear to be at risk of coincident infection and thus at enhanced risk of clinical disease. The results suggest that the control of parasitic helminths and of malaria in school children could be viewed as essential co-contributors to promoting the health of schoolchildren.

Rethinking school feeding social safety nets, child development, and the education sector

This review highlights three main findings. First, school feeding programs in low-income countries exhibit large variation in cost, with concomitant opportunities for cost containment. Second, as countries get richer, school feeding costs become a much smaller proportion of the investment in education. For example, in Zambia the cost of school feeding is about 50 percent of annual per capita costs for primary education; in Ireland it is only 10 percent. Further analysis is required to define these relationships, but supporting countries to maintain an investment in school feeding through this transition may emerge as a key role for development partners. Third, the main preconditions for the transition to sustainable national programs are mainstreaming school feeding in national policies and plans, especially education sector plans; identifying national sources of financing; and expanding national implementation capacity. Mainstreaming a development policy for school feeding into national education sector plans offers the added advantage of aligning support for school feeding with the processes already established to harmonize development partner support for the education for all-fast track initiative.

Schistosomiasis and soil-transmitted helminth infections: forging control efforts

et al., 1992). After gradual intensification of efforts over the ensuing 10 years, the WHO and its member states and partners are implementing a combined strategy for the control of schistosomiasis and soil-transmitted helminths, integrated into ongoing health and education initiatives (WHO, in nrenaration, a). This strategy is summarized-in the World Health Assemblv (WHA) resolution of Mav 2001 KVHA. 200 1). ~l?re resolution urges member .states to ‘ensure access to essential drugs against schistosomiasis and soil-transmitted helminthiasis in all health services in endemic areas for the treatment of clinical cases and groups at high risk of morbidity such as women and children, with the goal of attaining a minimum target of regular administration of chemotherapy to at least 75% and up to 100% of all school-age children at risk of morbidity by 20 10. This policy is based on the evidence that morbidity can be controlled by periodical treatment of high-risk groups with anthelminthics. The burden of disease

An updated atlas of human helminth infections: the example of East Africa

BackgroundReliable and updated maps of helminth (worm) infection distributions are essential to target control strategies to those populations in greatest need. Although many surveys have been conducted in endemic countries, the data are rarely available in a form that is accessible to policy makers and the managers of public health programmes. This is especially true in sub-Saharan Africa, where empirical data are seldom in the public domain. In an attempt to address the paucity of geographical information on helminth risk, this article describes the development of an updated global atlas of human helminth infection, showing the example of East Africa.MethodsEmpirical, cross-sectional estimates of infection prevalence conducted since 1980 were identified using electronic and manual search strategies of published and unpublished sources. A number of inclusion criteria were imposed for identified information, which was extracted into a standardized database. Details of survey population, diagnostic methods, sample size and numbers infected with schistosomes and soil-transmitted helminths were recorded. A unique identifier linked each record to an electronic copy of the source document, in portable document format. An attempt was made to identify the geographical location of each record using standardized geolocation procedures and the assembled data were incorporated into a geographical information system.ResultsAt the time of writing, over 2,748 prevalence surveys were identified through multiple search strategies. Of these, 2,612 were able to be geolocated and mapped. More than half (58%) of included surveys were from grey literature or unpublished sources, underlining the importance of reviewing in-country sources. 66% of all surveys were conducted since 2000. Comprehensive, countrywide data are available for Burundi, Rwanda and Uganda. In contrast, information for Kenya and Tanzania is typically clustered in specific regions of the country, with few records from areas with very low population density and/or environmental conditions which are unfavourable for helminth transmission. Information is presented on the prevalence and geographical distribution for the major helminth species.ConclusionFor all five countries, the information assembled in the current atlas provides the most reliable, up-to-date and comprehensive source of data on the distribution of common helminth infections to guide the rational implementation of control efforts.

The Global Atlas of Helminth Infection: Mapping the Way Forward in Neglected Tropical Disease Control

The recent commitment of the Obama administration to establish the Global Health Initiative, which is expected to increase to over US

African Programme for Onchocerciasis Control 1995–2015: Model-Estimated Health Impact and Cost

100 million annually for neglected tropical disease (NTD) control, provides the most significant investment and opportunity for the global control of NTDs to date [1], [2]. These investments, together with commitments by the British Department for International Development, the World Bank, and several key private philanthropies, including the Bill & Melinda Gates Foundation, must be guided by a strong evidence-based approach. First, the problem, and the resources required to tackle it, need to be clearly quantified. Second, mass drug administration (MDA) should be optimally targeted to communities with the highest prevalence of infection and presumed greatest morbidity [3], [4]. Furthermore, for diseases targeted for elimination, including lymphatic filariasis (LF) and onchocerciasis, it will become increasingly important to determine whether MDA can be stopped, and, if so, when and where. In the case of schistosomiasis, as control is scaled up, there is the additional requirement of determining when and where to shift praziquantel treatment from once per year to less frequent intervals.

Multiple helminth infections in children: impact and control

Background Onchocerciasis causes a considerable disease burden in Africa, mainly through skin and eye disease. Since 1995, the African Programme for Onchocerciasis Control (APOC) has coordinated annual mass treatment with ivermectin in 16 countries. In this study, we estimate the health impact of APOC and the associated costs from a program perspective up to 2010 and provide expected trends up to 2015. Methods and Findings With data on pre-control prevalence of infection and population coverage of mass treatment, we simulated trends in infection, blindness, visual impairment, and severe itch using the micro-simulation model ONCHOSIM, and estimated disability-adjusted life years (DALYs) lost due to onchocerciasis. We assessed financial costs for APOC, beneficiary governments, and non-governmental development organizations, excluding cost of donated drugs. We estimated that between 1995 and 2010, mass treatment with ivermectin averted 8.2 million DALYs due to onchocerciasis in APOC areas, at a nominal cost of about US

Vitamin A supplementation every 6 months with retinol in 1 million pre-school children in north India: DEVTA, a cluster-randomised trial

257 million. We expect that APOC will avert another 9.2 million DALYs between 2011 and 2015, at a nominal cost of US