Indoor residual spraying with a non-pyrethroid insecticide reduces the reservoir of Plasmodium falciparum in a high-transmission area in northern Ghana.

High-malaria burden countries in sub-Saharan Africa are shifting from malaria control towards elimination. Hence, there is need to gain a contemporary understanding of how indoor residual spraying (IRS) with non-pyrethroid insecticides when combined with long-lasting insecticidal nets (LLINs) impregnated with pyrethroid insecticides, contribute to the efforts of National Malaria Control Programmes to interrupt transmission and reduce the reservoir of Plasmodium falciparum infections across all ages. Using an interrupted time-series study design, four age-stratified malariometric surveys, each of ~2,000 participants, were undertaken pre- and post-IRS in Bongo District, Ghana. Following the application of three-rounds of IRS, P. falciparum transmission intensity declined, as measured by a >90% reduction in the monthly entomological inoculation rate. This decline was accompanied by reductions in parasitological parameters, with participants of all ages being significantly less likely to harbor P. falciparum infections at the end of the wet season post-IRS (aOR = 0.22 [95% CI: 0.19-0.26], p-value < 0.001). In addition, multiplicity of infection (MOI var ) was measured using a parasite fingerprinting tool, designed to capture within-host genome diversity. At the end of the wet season post-IRS, the prevalence of multi-genome infections declined from 75.6% to 54.1%. This study demonstrates that in areas characterized by high seasonal malaria transmission, IRS in combination with LLINs can significantly reduce the reservoir of P. falciparum infection. Nonetheless despite this success, 41.6% of the population, especially older children and adolescents, still harboured multi-genome infections. Given the persistence of this diverse reservoir across all ages, these data highlight the importance of sustaining vector control in combination with targeted chemotherapy to move high-transmission settings towards pre-elimination. This study also points to the benefits of molecular surveillance to ensure that incremental achievements are not lost and that the goals advocated for in the WHO's High Burden to High Impact strategy are realized.

The Role of the Private Sector in Supporting Malaria Control in Resource Development Settings.

Industrial operations of the private sector, such as extraction, agriculture, and construction, can bring large numbers of people into new settlement areas and cause environmental change that promotes the transmission of vector-borne diseases. Industry-related workers and communities unduly exposed to infection risk typically lack the knowledge and means to protect themselves. However, there is a strong business rationale for protecting local resident employees through integrated vector control programs, as well as an ethical responsibility to care for these individuals and the affected communities. We discuss the role and challenges of the private sector in developing malaria control programs, which can include extensive collaborations with the public sector that go on to form the basis of national vector control programs or more broadly support local healthcare systems.

Costs of insecticide-treated bed net distribution systems in sub-Saharan Africa.

BACKGROUND: Insecticide-treated nets (ITNs) are one of the most cost-effective measures for preventing malaria. The World Health Organization recommends both large-scale mass distribution campaigns and continuous distributions (CD) as part of a multifaceted strategy to achieve and sustain universal access to ITNs. A combination of these strategies has been effective for scaling up ITN access. For policy makers to make informed decisions on how to efficiently implement CD or combined strategies, information on the costs and cost-effectiveness of these delivery systems is necessary, but relatively few published studies of the cost continuous distribution systems exist. METHODS: To address the gap in continuous distribution cost data, four types of delivery systems-CD through antenatal care services (ANC) and the expanded programme on immunization (EPI) (Ghana, Mali, and mainland Tanzania), CD through schools (Ghana and mainland Tanzania), and a combined community/health facility-based distribution (Zanzibar, Tanzania), as well as mass distributions (Mali)-were costed. Data on costs were collected retrospectively from financial and operational records, stakeholder interviews, and resource use surveys. RESULTS: Overall, from a full provider perspective, mass distributions and continuous systems delivered ITNs at overlapping economic costs per net distributed (mass distributions: 4.37-4.61 USD, CD channels: 3.56-9.90 USD), with two of the school-based systems and the mass distributions at the lower end of this range. From the perspective of international donors, the costs of the CD systems were, for the most part, less costly than the mass distributions (mass distributions: 4.34-4.55 USD, Ghana and Tanzania 2017 school-based: 3.30-3.69 USD, health facility-based: 3.90-4.55 USD, combined community/health facility 4.55 USD). The 2015 school-based distribution (7.30 USD) and 2016 health facility-based distribution (6.52 USD) programmes in Tanzania were an exception. Mass distributions were more heavily financed by donors, while CD relied more extensively on domestic resource contributions. CONCLUSIONS: These results suggest that CD strategies can continue to deliver nets at a comparable cost to mass distributions, especially from the perspective of the donor.

Understanding the gap between access and use: a qualitative study on barriers and facilitators to insecticide-treated net use in Ghana.

BACKGROUND: Mass and continuous distribution channels have significantly increased access to insecticide-treated nets (ITNs) in Ghana since 2000. Despite these gains, a large gap remains between ITN access and use. METHODS: A qualitative research study was carried out to explore the individual and contextual factors influencing ITN use among those with access in three sites in Ghana. Eighteen focus group discussions, and free listing and ranking activities were carried out with 174 participants; seven of those participants were selected for in-depth case study. Focus group discussions and case study interviews were audio-recorded, transcribed verbatim, and analysed thematically. RESULTS: ITN use, as described by study participants, was not binary; it varied throughout the night, across seasons, and over time. Heat was the most commonly cited barrier to consistent ITN use and contributed to low reported ITN use during the dry season. Barriers to ITN use throughout the year included skin irritation; lack of airflow in the sleeping space; and, in some cases, a lack of information on the connection between the use of ITNs and malaria prevention. Falling ill or losing a loved one to malaria was the most powerful motivator for consistent ITN use. Participants also discussed developing a habit of ITN use and the economic benefit of prevention over treatment as facilitating factors. Participants reported gender differences in ITN use, noting that men were more likely than women and children to stay outdoors late at night and more likely to sleep outdoors without an ITN. CONCLUSION: The study results suggest the greatest gains in ITN use among those with access could be made by promoting consistent use throughout the year among occasional and seasonal users. Opportunities for improving communication messages, such as increasing the time ITNs are aired before first use, as well as structural approaches to enhance the usability of ITNs in challenging contexts, such as promoting solutions for outdoor ITN use, were identified from this work. The information from this study can be used to inform social and behaviour change messaging and innovative approaches to closing the ITN use gap in Ghana.

The impact of industrial activities on vector-borne disease transmission.

Industrial activities have produced profound changes in the natural environment, including the mass removal of trees, fragmentation of habitats, and creation of larval mosquito breeding sites, that have allowed the vectors of disease pathogens to thrive. We conducted a review of the literature to assess the impact of industrial activities on vector-borne disease transmission. Our study shows that industrial activities may be coupled with significant changes to human demographics that can potentially increase contact between pathogens, vectors and hosts, and produce a shift of parasites and susceptible populations between low and high disease endemic areas. Indeed, where vector-borne diseases and industrial activities intersect, large numbers of potentially immunologically naïve people may be exposed to infection and lack the knowledge and means to protect themselves from infection. Such areas are typically associated with inadequate access to quality health care, thus allowing industrial development and production sites to become important foci of transmission. The altered local vector ecologies, and the changes in disease dynamics that changes affect, create challenges for under-resourced health care and vector-control systems.

Effect of anti-malarial interventions on trends of malaria cases, hospital admissions and deaths, 2005-2015, Ghana.

BACKGROUND: Since 2005, the Government of Ghana and its partners, in concerted efforts to control malaria, scaled up the use of artemisinin-based combination therapy (ACT) and insecticide-treated nets (ITNs). Beginning in 2011, a mass campaign of long-lasting insecticidal nets (LLINs) was implemented, targeting all the population. The impact of these interventions on malaria cases, admissions and deaths was assessed using data from district hospitals. METHODS: Records of malaria cases and deaths and availability of ACT in 88 hospitals, as well as at district level, ITN distribution, and indoor residual spraying were reviewed. Annual proportion of the population potentially protected by ITNs was estimated with the assumption that each LLIN covered 1.8 persons for 3 years. Changes in trends of cases and deaths in 2015 were estimated by segmented log-linear regression, comparing trends in post-scale-up (2011-2015) with that of pre-scale-up (2005-2010) period. Trends of mortality in children under 5 years old from population-based household surveys were also compared with the trends observed in hospitals for the same time period. RESULTS: Among all ages, the number of outpatient malaria cases (confirmed and presumed) declined by 57% (95% confidence interval [CI], 47-66%) by first half of 2015 (during the post-scale-up) compared to the pre-scale-up (2005-2010) period. The number of microscopically confirmed cases decreased by 53% (28-69%) while microscopic testing was stable. Test positivity rate (TPR) decreased by 41% (19-57%). The change in malaria admissions was insignificant while malaria deaths fell significantly by 65% (52-75%). In children under 5 years old, total malaria outpatient cases, admissions and deaths decreased by 50% (32-63%), 46% (19-75%) and 70% (49-82%), respectively. The proportion of outpatient malaria cases, admissions and deaths of all-cause conditions in both all ages and children under five also fell significantly by >30%. Similar decreases in the main malaria indicators were observed in the three epidemiological strata (coastal, forest, savannah). All-cause admissions increased significantly in patients covered by the National Health Insurance Scheme (NHIS) compared to the non-insured. The non-malaria cases and non-malaria deaths increased or remained unchanged during the same period. All-cause mortality for children under 5 years old in household surveys, similar to those observed in the hospitals, declined by 43% between 2008 and 2014. CONCLUSIONS: The data provide compelling evidence of impact following LLIN mass campaigns targeting all ages since 2011, while maintaining other anti-malarial interventions. Malaria cases and deaths decreased by over 50 and 65%, respectively. The declines were stronger in children under five. Test positivity rate in all ages decreased by >40%. The decrease in malaria deaths was against a backdrop of increased admissions owing to free access to hospitalization through the NHIS. The study demonstrated that retrospective health facility-based data minimize reporting biases to assess effect of interventions. Malaria control in Ghana is dependent on sustained coverage of effective interventions and strengthened surveillance is vital to monitor progress of these investments.

Glucose-6-Phosphate Dehydrogenase Deficiency and Haemoglobin Drop after Sulphadoxine-Pyrimethamine Use for Intermittent Preventive Treatment of Malaria during Pregnancy in Ghana - A Cohort Study.

BACKGROUND: Sulphadoxine-Pyrimethamine (SP) is still the only recommended antimalarial for use in intermittent preventive treatment of malaria during pregnancy (IPTp) in some malaria endemic countries including Ghana. SP has the potential to cause acute haemolysis in G6PD deficient people resulting in significant haemoglobin (Hb) drop but there is limited data on post SP-IPTp Hb drop. This study determined the difference, if any in proportions of women with significant acute haemoglobin drop between G6PD normal, partial deficient and full deficient women after SP-IPTp. METHODS AND FINDINGS: Prospectively, 1518 pregnant women who received SP for IPTp as part of their normal antenatal care were enrolled. Their G6PD status were determined at enrollment followed by assessments on days 3, 7,14 and 28 to document any adverse effects and changes in post-IPTp haemoglobin (Hb) levels. The three groups were comparable at baseline except for their mean Hb (10.3 g/dL for G6PD normal, 10.8 g/dL for G6PD partial deficient and 10.8 g/dL for G6PD full defect women).The prevalence of G6PD full defect was 2.3% and 17.0% for G6PD partial defect. There was no difference in the proportions with fractional Hb drop ≥ 20% as compared to their baseline value post SP-IPTp among the 3 groups on days 3, 7, 14. The G6PD full defect group had the highest median fractional drop at day 7. There was a weak negative correlation between G6PD activity and fractional Hb drop. There was no statistical difference between the three groups in the proportions of those who started the study with Hb ≥ 8g/dl whose Hb level subsequently fell below 8g/dl post-SP IPTp. No study participant required transfusion or hospitalization for severe anaemia. CONCLUSIONS: There was no significant difference between G6PD normal and deficient women in proportions with significant acute haemoglobin drop post SP-IPTp and lower G6PD enzyme activity was not strongly associated with significant acute drug-induced haemoglobin drop post SP-IPTp but a larger study is required to confirm consistency of findings.

Prevalence of malaria parasitaemia in school children from two districts of Ghana earmarked for indoor residual spraying: a cross-sectional study.

BACKGROUND: Indoor residual spraying (IRS) is considered a valuable transmission control measure against malaria but exact efficacy data are not available for many epidemiological settings. This study was conducted to determine indicators for malaria epidemiology and transmission among school children as baseline assessment before IRS implementation in Ghana. METHODS: A cross-sectional study was conducted in Adansi South District of the Ashanti Region and Wa West District of the Upper West Region of Ghana. Malarial parasitaemia and anaemia were determined in pupils between the ages of 2 and 14 years from Early Childhood Development Centres and primary schools. Plasmodium falciparum parasitaemia was detected by light microscopy. RESULTS: Out of 1,649 pupils who were enrolled at participating schools, 684 were positive for plasmodia resulting in a baseline parasitaemia prevalence of 41.5%. Parasite rate was similar in the two districts (42.0% in Adansi South and 40.7% in Wa West), but differed across the nine sentinel schools ranging from 21 to 63% (p < 0.001). The mean haemoglobin concentration was 11.3 g/dl [standard deviation (SD) ±2.1]. Pupils who had moderate to mild anaemia (7.0-10.9 g/dl) constituted 41.7% of the study sample. CONCLUSION: The burden of parasitaemia, malaria and anaemia is a major public health problem among school children in rural Ghana with extensive heterogeneity between schools and warrants further investment in intervention measures.

Implementation of the Affordable Medicines for Malaria Facility (AMFm) in Ghana: processes, challenges and achievements.

In 2004, Ghana adopted Artemisinin-based Combination Therapy (ACT) for the treatment of uncomplicated malaria. The use of ACTs had been low, especially in the private sector, because of higher prices of ACTs. The Affordable Medicine Facility for Malaria Initiative, in which international organizations subsidize ACTs to make them affordable locally, is being implemented in Ghana. We document the processes, challenges, and achievements of this initiative in Ghana based on a review of policies, guidelines, reports, meeting minutes, and an internet search. The review spanned activities from July 2009 to December 2011. Ghana was the first country to receive these subsidized ACTs (called 'co-paid'), and availability of ACTs increased from 31 per cent to 83 per cent nationwide. The price of ACTs dropped from about US$7 to $0.75 for adults and from $5 to $0.5 for children. Misuse of anti-malarials so that they fail to improve health and can spread resistance may occur if the initiative is not well managed. Collaboration with stakeholders, especially the private sector, and implementation of appropriate supportive activities is important with this initiative.

Community perceptions of malaria and malaria treatment behaviour in a rural district of Ghana: implications for artemisinin combination therapy.

BACKGROUND: Artesunate-amodiaquine (AS-AQ) was introduced in Ghana as the first line drug for treatment of uncomplicated malaria in 2004. We report the perceptions of malaria and malaria treatment behaviour, the community awareness of and perceptions about AS-AQ two years after the introduction of this ACT treatment for malaria. METHODS: Two surveys were conducted; a cross-sectional survey of 729 randomly selected household heads (urban-362, rural-367) and 282 women with children < 5 years (urban-121, rural-161) was conducted in 2006. A district wide survey was conducted in 2007 to assess awareness of AS-AQ. These were complemented with twenty-eight focus group discussions (FGDs) and 16 key informant interviews (KII) among community members and major stakeholders in the health care delivery services. All nine (9) health facilities and five (5) purposively selected drug stores were audited in order to identify commonly used anti-malarials in the study area at the time of the survey. RESULTS: Majority of respondents ( > 75%) in the sampled survey mentioned mosquito bites as the cause of malaria. Other causes mentioned include environmental factors (e.g. dirty surroundings) and standing in the sun. Close to 60% of the household heads and 40% of the care-givers interviewed did not know about AS-AQ. The community respondents who knew about and had ever taken AS-AQ perceived it to be a good drug; although they mentioned they had experienced some side effects including headaches and body weakness. Co-blistered AS-AQ was available in all the government health facilities in the study area. Different formulations of ACTs were however found in urban chemical shops but not in rural chemical stores where monotherapy antimalarials were predominant. CONCLUSION: The knowledge of fever as a symptom of malaria is high among the study population. The awareness of AS-AQ therapy and its side-effect was low in the study area. Community education and sensitization, targeting all categories of the population, has to be intensified to ensure an efficient implementation process.