How far is the journey before malaria is knocked out in Zimbabwe: results of the malaria indicator survey 2016

There are 60 rural districts in the country of which 51 are malarious with varying transmission intensity. Of the malarious districts, 45 are in the low-lying areas of the country characterized by high temperatures (up to 39 C). During the peak malaria transmission season, sporadic epidemics are reported in the high burdened districts. The population affected varies from year to year depending on the performance and coverage of the various malaria prevention and control interventions carried out by the National Malaria Control Programme. Apart from the routine health information system, Zimbabwe conducts regular surveys to measure some indicators whose data may not be sufficiently collected in routine health information. Zimbabwe Demographic and Health Surveys (ZDHS) and Multiple Indicator Cluster Surveys (MICS) collect information on some malaria indicators. The first malaria indicator survey was carried out in 2008 and the second was carried out in 2012 on a national scale following the approach of the MICS and the ZDHS. The ZDHS 2011/2012 indicated significant progress in the coverage of LLINs and high IRS coverage.

The NMCP in collaboration with multiple partners sets high targets for coverage of interventions and reduction in malaria burden as outlined in the National Malaria Strategy 2008–2015. The major anti-malaria strategies focus on malaria prevention, case management, detection and control of epidemics, social and behavior change communication (SBCC) and surveillance, monitoring and evaluation, and operational research [1]. IRS with insecticide and the distribution of LLINs are the major malaria prevention measures targeted at areas with ongoing malaria transmission. SP/Fansidar is given to all eligible pregnant women residing in high-burden areas, starting as soon as possible after the first trimester and continuing every four weeks thereafter until delivery [2, 3]. Case management is offered at all health facilities in the country. Treatment of uncomplicated malaria is based on artemisinin-based combination therapy (ACT); the first-line treatment is artemether-lumefantrine (Coartem®), while the second line is artesunate–amodiaquine. An alternative second line treatment is oral quinine in combination with either doxycycline or clindamycin, or oral quinine alone in children under 8 years of age.

The data collection for these surveys does not necessarily consider the peak transmission season, hence the need for the country to carry out the malaria indicator survey to focus on the malaria transmission areas and collect relevant data on coverage of key malaria interventions and related results during the peak transmission season. The nationwide malaria indicator survey set to have malaria baseline data for the next 5-year Malaria Strategic Plan after the expiration of the current one. It also had an objective to collect data that will be used for the re-stratification of the country’s malaria transmission zones.

Table 2 shows that information was collected for just over 33,700 people in the selected households. About 47.8% of the de facto population is male and 52.2% female. The size of the de facto population in the high transmission areas was 1.9 times that found in the moderate transmission areas, reflecting the greater number of high transmission districts in the survey. In general, the proportion of the household population in each age group declines as age increases, reflecting the relatively young average age structure of the population; 44% of the total population was under age 15.

IRS is the spraying of the interior walls of a dwelling with an insecticide and has been a mainstay of malaria vector control in Zimbabwe for many years. It reduces the transmission of malaria by killing adult female mosquitoes when they rest on the walls of the dwelling after feeding [6]. Households are considered to be covered by a vector control intervention if they own at least one LLIN and/or they have been sprayed by IRS at any time in the past 12 months. Malaria Indicator Survey 2016 found that 62% of households possessed a mosquito net, with 58% owning an LLIN. Slightly more households in the moderate malaria transmission areas owned an LLIN (62%) compared to those in the high malaria transmission areas (56%). Just under two-thirds of households had received IRS in the 12 months preceding the survey, with slightly more households sprayed in the high malaria transmission areas compared to in the moderate transmission areas—64% and 60%, respectively. Eighty-three percent of households had at least one LLIN per sleeping space, and/or had received IRS over the last 12 months.

There appears to be a general improvement in the overall ownership of LLINs from 2012 (46%) to 2016 (58%), although these figures are still below the target of universal access to nets [7, 8]. Similarly, there was a 55% increase in IRS coverage over the reporting period (2012, 49%; 2016, 62%) as shown in Table 7. The overall protection coverage by at least one major vector control measure, IRS and/or LLINs, was high 58%. Fifty-four percent of the sampled population had slept under a net the night before the survey. Only a third of children aged under 5 years had slept under an LLIN the night before the survey. However, protection by at least one vector control intervention was significantly higher, as 74% had either slept under an LLIN the previous night or slept in a dwelling that had received IRS in the past 12 months. About a third of women aged 15–49 years had slept under an LLIN the previous night, compared to only a quarter of pregnant women.

Malaria prevalence was assessed in all age groups. Among children under 5 years of age, 0.5% were found positive for malaria by rapid diagnostic test (RDT) and 0.2% by microscopy; for children aged 5–14 years the prevalence rate was 0.8% by RDT and 0.2% by microscopy; while among those aged 15 years and above, 0.5% were positive for malaria by RDT and 0.3% tested malaria slide-positive. There was a notable decline in exposure to malaria messages despite relatively high ownership, among the households sampled, of radios, TVs, and mobile phones. This also correlates with a decline in knowledge of the symptoms and danger signs of malaria compared to respondents’ reports in the 2012 MIS. The 2016 Malaria Indicator Survey seems to suggest that there are still challenges in seeking treatment as less than half of the households sampled were within a 5-km radius of a health facility. Furthermore, the other concern is that some women still report needing permission from some other person to bring a child with fever to a health facility for treatment. Only a quarter of the women interviewed reported that they would stop treatment for malaria when the child had taken the full dose prescribed by the health worker. There is need for continued mobilization and advocacy to the communities to ensure that malaria is put as priority at family level, eliminating a need for permission which may continue to co complicate malaria symptoms [9, 10].

Prevalence of malaria declined from 0.4% in 2012 to 0.2% in 2016 for children below 5 years which shows good direction towards malaria elimination targets. The prevalence for the age group 5 years and above was 0.2% although no comparative figure was available for 2012. There has been a general improvement in the overall ownership of LLINs from 2012 to 2016, although these figures are still below the target of universal access to nets. This therefore pose a challenge in view of the investment in these interventions and the malaria elimination goals [10]. On the other hand, there was a notable increase in IRS coverage over the reporting period. This could account for the fact that protection by at least one vector control method, IRS and/or LLIN, surpassed the programme target in 2016. Of concern though is the reported low net utilisation among high-risk groups such as children under 5 and pregnant women, despite the general increase in net ownership. Moreover, IPTp coverage has remained almost unchanged since the 2012 MIS with only a third of pregnant women receiving at least 2 doses of IPTp.

There is a need to expand continuous net distribution so that nets are replaced between the mass LLIN distribution campaigns. This will cover the attrition gap and ensure sustained universal coverage of nets across the communities. There should be strengthened SBCC campaigns, especially for delivering messages that foster mosquito net use in high-risk populations such as young children and pregnant women. It is important to undertake regular, local assessments of net use and take necessary remedial actions to increase and maintain net use. Information, education, and communication on malaria and its prevention needs to be strengthened [11]. With the high mobile phone penetration of the country, the NMCP should consider using this cost-effective platform more often to increase dissemination of malaria messages. These messages should focus on the danger signs of malaria; the importance of seeking treatment early, as well as compliance with the full course of malaria treatment; and the importance of using an LLIN at all times, even in what is not supposed to be the malaria transmission season [12].