During the last decade, malaria-endemic countries have witnessed a historic increase in the amount of resources dedicated to fight the disease [1–3]. Bilateral and multilateral institutions such as the Global Fund to fight AIDS, Tuberculosis and Malaria, the World Bank and the US President’s Malaria Initiative (PMI) have more than doubled funding to help ease the burden of malaria, especially in sub-Saharan Africa (SSA) [4–7]. Additionally, non-profit private sector initiatives, such as the Bill and Melinda Gates Foundation, have played an important role in changing the debate on financing, design and implementation of malaria control programmes.
Malaria researchers and policy makers have taken advantage of heightened global malaria awareness to shift their focus to a rapid expansion of effective malaria control programmes while downplaying issues related to sustainability of these programmes. Following the increased awareness, malaria control policies, such as implementation of large-scale indoor residual spraying with insecticides and universal free bed net coverage campaigns have seen increased financial support, especially in SSA [8–11]. Meanwhile, the last 10 years has seen complete overhaul of policies addressing malaria case management in endemic settings. Most countries with high malaria burden have changed their treatment algorithms by adopting more efficacious but expensive artemisinin-based drug combinations [12–14]. Countries have also been urged to improve malaria diagnostics through adoption of universal testing of all suspected malaria cases by use of either microscopy or rapid diagnostic tests (RDTs) . Support for preventive treatments in highly endemic areas through adoption of intermittent preventive treatments in pregnant women, infants and school-age children have also substantially increased [15–18]. The long-term health, economic and social impact of adopting these changes is not well understood [19, 20]. However, given the positive correlation of malaria and poverty , it is important to understand how the current large-scale malaria control policies are impacting different segments of populations, especially the very poor.
Although initial strategies to scale up insecticide-treated nets (ITNs) relied on cost-recovery, social marketing and targeted distribution strategies (focused on biological and socio-economically vulnerable groups), increased funding has allowed for universal free bed net distributions in many SSA countries. While some countries have welcomed the new financing mechanisms and aligned their policies accordingly, some have shifted largely to respond to donor mandates alone, and others have defied the call for universal free bed net distribution as they continue with implementation of targeted bed net distribution [22, 23]. Supporters of universal free bed net distribution have consistently favoured the strategy as the most feasible way to equitably reach the poor with the life-saving interventions [22, 24, 25]. They argue that cost sharing and targeted interventions dampen demand, enhance inequities and consequently exacerbate the malaria burden . Despite their arguments, there are potential pitfalls. First, the claim that free bed net distribution enhances equity is mainly based on limited case–control studies which may be unrepresentative of real-world conditions [10, 27]. As a result, such studies are not necessarily generalizable because of infrastructural and large-scale programme implementation challenges which may threaten the feasibility of reaching out to those most in need [28, 29]. Secondly, given the current global fiscal austerity measures sparked by the global economic recession and the concomitant over-reliance on international development assistance, the long-term consequences of this strategy in terms of its sustainability remain uncertain [30, 31]. Finally, there has been some scepticism about uniform solutions to a relatively diverse health problem and whether the disease can ever be eradicated [32–36]. Economists have also expressed concerns on the need for malaria interventions to do more by incorporating economic tenets on value for money as well as aspects of programme sustainability .
Therefore, any proposed solutions to African economic, socio-political and health, including those related to malaria, must first recognize and adapt to the continent’s diverse socio-economic and epidemiologic settings. Despite constituting the largest disease burden globally, malaria epidemiology in SSA varies widely [38–40]. The variations in malaria policies, strategies and epidemiology can be attributed to a number of factors, including weather and climate, altitude, physical infrastructure such as water drainage systems, level of economic development reflected in population incomes, household structures and investments in public health programmes. It is important to explore how large-scale malaria control programmes such as targeted free bed net distribution may impact malaria control efforts, especially among the poorest people. One study attempted to evaluate the health impact of a large-scale malaria control programme in Zambia . However, the study did not explore how such large-scale interventions benefited various groups of people with different socio-economic backgrounds. A recent study from Malawi reported that people living closest to the health facilities were most likely to have bed nets than those living far away from health clinics . Another study in Zambia reported households with a woman having attended antenatal clinic or with children under five years old were twice more likely to have bed nets than those without . In Angola, people residing more than 15 km outside the capital city of Luanda were almost six times more likely to test positive for malaria when screened at the health clinic than those living in the inner-city . Apart from these few studies, little is known about the impact of the large-scale implementation of malaria programmes, such as universal bed net campaigns, on household socio-economic disparities and malaria burden or access and use of effective malaria control tools.
This study aims to understand how implementation of targeted free bed net distribution has contributed to reduction of childhood malaria infection rates by their household socioeconomic disparities. The study is unique in the sense that it uses nationally representative malaria indicator survey data from three sub Saharan Africa countries of Angola, Tanzania and Uganda. It is the first study to use national data and compare inequalities in access of bed nets and their consequence in children under-five years of age malaria infection rates across the three countries with diverse malaria transmission settings and also their socioeconomic backgrounds. The study uses wealth measured as the proxy for household socio-economic status in exploring these relationships. A list of household assets including household construction materials, ownership of toilets, use of piped water at home or community sources of drinking water, furniture, and other assets like bicycles, television and sofa sets, vehicles etc. were used as detailed in MIS data collection tools . More specifically, a set of malaria control indicators in children under-five defined as RDT and microscopy-confirmed positive results on the day of interview, household ownership of bed nets and children’s use of nets, will be explored and compared across districts/provinces with and without targeted free bed net distribution programs.
Study sites and malaria control efforts
Despite its oil wealth and fast-growing economy, a third of Angola’s population is poor and relies on subsistence farming. Three decades of civil war ended in 2002 leaving its footprints marked by dilapidated health infrastructure, with nearly half of its total population lacking any access to health-care services . In 2006 the country had one of the world’s highest under-five mortality rates estimated at 250 deaths per 1,000 live births. According to Angola’s National Malaria Control Programme, 35% of under-five mortality is attributable to malaria with stable transmission in most of the northern part of the country . Following its launch in 2005, PMI embarked on supporting malaria control strategies identified by Angola’s National Malaria Control Programme. The ITN scale-up strategy in Angola consisted of both targeted free distribution and a market segmentation approach through social marketing. PMI, in collaboration with UNICEF Angola, supported targeted free ITN distribution in seven of Angola’s 18 administrative provinces. The strategy was focused on the highly malaria-endemic provinces of Cabinda, Zaire, Malanje, Moxico, Lunda Norte, Lunda Sul and Uige . A total of 813,000 long-lasting ITNs were distributed to households with children under-five years during the nationwide measles immunization campaign, which occurred from July to August 2006, and also included the delivery of oral polio vaccine, vitamin A, and an anthelminthic. In addition to free net distribution, a demonstration on the proper method to hang, care for and use the ITN was provided. At least one free net was provided to each child under-five presenting for immunization in each of the seven provinces. Prior to the targeted free bed net distribution campaign, Angola had one of the lowest rates of bed net use by children under-five, estimated at less than 11% .
Approximately 95% of the population is estimated to be at risk of malaria, which causes between 14 and 19 million clinical episodes annually. In 2005, malaria was estimated to cause up to 36% and 20% of all deaths among children under-five and pregnant women respectively . Following results from studies on efficacy and effectiveness of ITN use in Tanzania, a market-based national ITN voucher programme to scale up bed nets was adopted in 2004 [50–53]. With initial support of funding from the Global Fund, the strategy was part of nationwide malaria prevention, targeting vulnerable groups, i e, pregnant women and children under-five. Distribution of bed nets relied on the private market and existing public and private health facility infrastructure. Vouchers for ITNs were issued to women attending their first antenatal care visits at fixed price of less than US$3.00. These women used the vouchers to redeem bed nets from participating private sector bed net retailers. While overall ownership and use of bed nets through this programme improved, the coverage was generally below national and international targets. Therefore, Tanzania’s National Malaria Control Programme (NMCP) took advantage of increased international financing for malaria to implement an alternative targeted free ITN distribution strategy . The new strategy was piloted by UNICEF and International Federation of Red Cross, in selected areas with high malaria burden. Targeted free distribution of bed nets to pregnant women and children under-five was implemented in the 15 districts with the lowest ITN coverage (these were: Tanga Urban and Pangani Districts in Tanga Region; Rufiji District in Coastal Region, Lindi rural, Lindi Urban, Ruangwa, Liwale, Kilwa, Nachingwea Districts from Lindi Region, and, Tandahimba, Newala, Masasi, Nanyumbu, Mtwara Rural and Mtwara Urban Districts from Mtwara Region). Over 900,000 bed nets bundled with insecticide were made available for distribution in mainland Tanzania [49, 53–55].
Meanwhile in Zanzibar, a targeted free ITN distribution campaign was implemented in all 10 districts (five districts in each of the two islands of Pemba and Unguja) . The Global Fund and the PMI supported the implementation of this programme, from August 2005 to early 2006. As in mainland Tanzania, the programme covered all pregnant women and children under-five. Therefore, total districts receiving targeted mass free ITN distribution in Tanzania were 25 with an estimated population of over 2.8 million people.
Over 90% of the Ugandan population is at constant risk of contracting malaria. Malaria is responsible for 30-50% of all outpatient visits to health clinics and almost half of all inpatient deaths among children under-five. Annual direct malaria treatment cost for the year 2003 was estimated at $41.6 million . PMI pledged to support Uganda’s NMCP strategies including a large-scale ITN distribution in the conflict districts of northern Uganda [58, 59].
To improve ITN scale-up, the Ugandan NMCP adopted a mixed model approach which included: distribution of free ITN to vulnerable groups through ANC clinics and NGOs, large-scale campaigns to targeted populations and the sale of ITNs through the retail market. The strategy was complemented by annual net retreatment campaigns to ensure that ITNs maintained their effectiveness. PMI supported the distribution of ITNs to pregnant women through ANC clinics in 24 districts in northern Uganda (these were: Nebbi, Nyadri, Arua, Koboko, Yumbe, Moyo, Adjumani, Amuru, Gulu, Kitgum, Pader, Oyam, Apac, Lira, Dokolo, Amolorar, Amuria, Kaberamido, Katakwi, Abim, Kotido, Kaabong, Moroto and Nakapiripiri) . By the time data collection was completed in 2009 for the Malaria Indicator Survey (MIS), over 400,000 free ITNs had been distributed to over 1.5 million people in northern Uganda. Following the bed net distribution campaign, health workers at antenatal clinics were trained and urged to explain the need to use ITNs. Health workers were also asked to demonstrate proper hanging and use of nets [59, 60].