Community evaluation of the physical and insecticidal durability of DuraNet® Plus, an alpha-cypermethrin and piperonyl butoxide incorporated mosquito net: protocol for a multi-country study in West, Central and East Africa

BACKGROUND

Pyrethroid-PBO nets have demonstrated improved impact against clinical malaria transmitted by pyrethroid resistant mosquito vectors and are being scaled up across Africa. However very little is known about their physical and insecticidal durability under operational conditions. This study will investigate the attrition, fabric integrity, insecticide content and bioefficacy of DuraNet® Plus, a new WHO prequalified alphacypermethrin and PBO incorporated net developed by Shobikaa Impex Private Limited over 3 years of field use in communities in Benin, Cameroon and Tanzania.

METHODS

The study will be conducted in parallel in selected villages in Zakpota District in Benin, Mbalmayo, District in Cameroon and Muheza District in Tanzania. In each country, ~ 1800 households will be recruited and randomised to receive DuraNet® Plus or DuraNet® (a WHO prequalified alphacypermethrin-only ITN). Follow up surveys will be performed at 1 month post distribution to investigate adverse events and subsequently every 6-12 months to assess ITN attrition and fabric integrity following standard WHO procedures. A second cohort of nets will be withdrawn every 6-12 months and assessed for alpha-cypermethrin and PBO content and for entomological activity in laboratory bioassays (cone bioassays and tunnel tests). Alpha-cypermethrin bioefficacy will be monitored using the susceptible Anopheles gambiae Kisumu strain in cone bioassays while PBO bioefficacy will be monitored using pyrethroid resistant strains with overexpressed P450 enzymes in tunnel tests to determine the proportion of efficacious nets (≥ 95% knockdown, ≥ 80% mortality or ≥ 90% blood feeding inhibition in tunnels) at each time point. Nets withdrawn at 12, 24 and 36 months from each country will also be tested in experimental hut trials against wild free-flying pyrethroid resistant Anopheles gambiae sl in Côvè Benin to investigate the superiority of DuraNet® Plus over DuraNet® at each time point under semi field conditions.

CONCLUSION

This large-scale multi country trial will provide useful information on the durability of a pyrethroid-PBO net (DuraNet® Plus) in 3 different regions in sub-Saharan Africa. The methods proposed for bioefficacy testing could also contribute towards the development of new standardised guidelines for monitoring the insecticidal efficacy of pyrethroid-PBO nets under operational conditions.

Predictors of mosquito bed net use among children under-fives in Ghana: a multilevel analysis of the 2019 malaria indicator survey

BACKGROUND

Morbidities and mortalities due to malaria can be prevented by the use of insecticide-treated mosquito bed nets (ITN), which has been proven for malaria control and elimination. The purpose of this study was to assess the critical factors that predict the use of ITN among children under-fives in Ghana.

METHODS

The study utilized data from the 2019 Ghana Malaria Indicator Survey (GMIS). The outcome variable was mosquito bed net use among children under-fives. To determine critical factors that independently predict ITN use, multilevel multivariable logistic regression was employed using Stata version 16. Odds ratios and associated 95% confidence intervals and p-values were reported. A p < 0.05 was used to declare statistical significance.

RESULTS

The overall prevalence of ITN usage was 57.4%. Utilization of bed nets was 66.6% in the rural areas and 43.5% in the urban areas, was highest in the Upper West region (80.6%) even when stratified to rural (82.9%) and urban areas (70.3%) whilst Greater Accra region (30.5%, rural = 41.7%, urban = 28.9%) had the least. The community level multilevel analysis showed that bed net utilization was higher among children in rural areas [AOR = 1.99, 95% CI 1.32-3.01, p = 0.001] and in household with wooden wall materials [AOR = 3.29, 95% CI 1.15-9.40, p = 0.027]. Bed net utilization was however, less for households with 3 + children under-five [AOR = 0.29, 95% CI 0.19-0.46, p < 0.001), 4 years old (AOR = 0.66, 95% CI 00.48-00.92, p = 0.014], without universal access to bed net [AOR = 0.52, 95% CI 0.37-0.73, p < 0.001], those in the Greater Accra [AOR = 0.26, 95% CI 0.13-0.51, p < 0.001], Eastern [AOR = 0.47, 95% CI 0.23-0.95, p = 0.036], Northern [AOR = 0.42, 95% CI 0.20-0.88, p = 0.022], middle [AOR = 0.57, 95% CI 0.35-0.94, p = 0.026] and rich/richest [AOR = 0.51, 95% CI 0.29-0.92, p = 0.025] household wealth quintile. Substantial unobserved household and community level differences in bed net use were found.

CONCLUSION

This study demonstrates the need to intensify promotion of ITN use to those in urban areas, Greater Accra, Eastern and Northern regions, houses without wooden wall materials, middle and rich/richest households. Interventions should be targeted at older children and households with more under-five children and to ensure full access and use of ITNs among all children under-fives in each household as part of the overall goal of achieving the health-related SDGs.

Associations between the use of insecticide-treated nets in early childhood and educational outcomes, marriage and child-bearing in early adulthood: evidence from a 22-year prospective cohort study in Tanzania

BACKGROUND

The effectiveness of insecticide-treated nets (ITNs) in preventing malaria in young children is well established. However, the long-term effects of early childhood ITN use on educational outcomes, fertility, and marriage in early adulthood are not well understood.

METHODS

This study uses 22 years of longitudinal data from rural Tanzania to investigate the associations between early life ITN use and educational attainment, fertility and marriage in early adulthood. Unadjusted and adjusted logistic regression models were used to estimate the associations between early life ITN use and early adult outcomes (education, childbearing, and marriage), controlling for potential confounders, such as parental education, household asset quintiles, and year of birth. Analyses were conducted separately for men and women.

RESULTS

A total of 6706 participants born between 1998 and 2000 were enrolled in the study between 1998 and 2003. By 2019 a total of 604 had died and a further 723 could not be found, leaving 5379 participants who were interviewed, among whom complete data were available for 5216. Among women, sleeping under a treated net at least half of the time during early childhood ["high ITN use"] was associated with a 13% increase in the odds of completing primary school (adjusted odds ratio (aOR) 1.13 [0.85, 1.50]) and with a 40% increase in the odds of completing secondary school (aOR 1.40 [1.11, 1.76]) compared with women sleeping less frequently under ITNs in early life (< age 5 years). Among men, high ITN use was associated with a 50% increase in the odds of completing primary school (aOR 1.50 [1.18, 1.92]) and a 56% increase in the odds of completing secondary school (aOR 1.56 [1.16, 2.08]) compared to men with low ITN use in early life. Weaker associations were found between ITN use in early life and both adolescent childbearing (aOR 0.91 [0.75, 1.10]) and early marriage (aOR 0.86 [0.69, 1.05]).

CONCLUSION

This study found that early life use of ITNs was strongly associated with increased school completion in both men and women. More marginal associations were found between early-life ITN use and both marriage and child-bearing in early adulthood. ITN use during early childhood may have long-term positive effects on educational attainment in Tanzania. However, further research is needed to understand the mechanisms behind these associations and to explore the broader impacts of ITN use on other aspects of early adult life.

Individual, community and societal correlates of insecticide treated net use among pregnant women in sub-Saharan Africa: a multi-level analysis

BACKGROUND

Malaria in pregnancy is a crucial public health concern due to the enormous risk it poses to maternal and newborn health. The World Health Organisation therefore recommends insecticide-treated net (ITN) for pregnant women. The world over, sub-Saharan Africa bears the highest prevalence of malaria and its associated complications. This study investigated the individual, community and society level factors associated with ITN use among pregnant women in sub-Saharan Africa.

METHODS

The study was conducted with Demographic and Health Survey data of 21 sub-Saharan African countries. A total of 17,731 pregnant women who possessed ITN participated in the study. Descriptive computation of ITN use by survey country and socio-demographic characteristics was conducted. Further, five multi-level binary logistic regression models were fitted with MLwiN 3.05 package in STATA. The Markov Chain Monte Carlo (MCMC) estimation procedure was used in estimating the parameters whilst the Bayesian Deviance Information Criterion was used for the model fitness test.

RESULTS

On average, 74.2% pregnant women in SSA used ITN. The highest prevalence of ITN use occurred in Mali (83.7%) whilst the least usage occurred in Namibia (7%). Women aged 30-34 were more likely to use ITN compared with those aged 45-49 [aOR = 1.14; Crl = 1.07-1.50]. Poorest women were less probable to use ITN relative to richest women [aOR = 0.79; Crl = 0.70-0.89]. Compared to women who did not want their pregnancies at all, women who wanted their pregnancies [aOR = 1.06; Crl = 1.04-1.19] were more probable to use ITN. Women in male-headed households had higher likelihood of ITN use compared to those from female-headed households [aOR = 1.28; Crl = 1.19-1.39]. On the whole, 38.1% variation in ITN use was attributable to societal level factors whilst 20.9% variation was attributable to community level factors.

CONCLUSION

The study has revealed that in addition to individual level factors, community and society level factors affect ITN use in SSA. In as much as the study points towards the need to incorporate community and societal variations in ITN interventions, active involvement of men can yield better outcome for ITN utilisation interventions in SSA.

Rural-urban variation in insecticide-treated net utilization among pregnant women: evidence from 2018 Nigeria Demographic and Health Survey

Background

In 2018, Nigeria accounted for the highest prevalence of malaria worldwide. Pregnant women and children under five years bear the highest risk of malaria. Geographical factors affect utilization of insecticide-treated nets (ITN), yet existing literature have paid little attention to the rural–urban dimension of ITN utilization in Nigeria. This study aimed at investigating the rural–urban variation in ITN utilization among pregnant women in Nigeria using data from the 2018 Demographic and Health Survey.

Methods

A total of 2909 pregnant women were included in the study. The prevalence of ITN utilization for rural and urban pregnant women of Nigeria were presented with descriptive statistics. Chi-square test was employed to assess the association between residence, socio-demographic characteristics and ITN utilization at 95% level of significance. Subsequently, binary logistic regression was used to assess the influence of residence on ITN utilization.

Results

Eight out of ten of the rural residents utilized ITN (86.1%) compared with 74.1% among urban residents. Relative to urban pregnant women, those in rural Nigeria had higher odds of utilizing ITNs both in the crude [cOR = 2.17, CI = 1.66–2.84] and adjusted models [aOR = 1.18, CI = 1.05–1.24]. Pregnant women aged 40–44 had lower odds of ITN utilization compared to those aged 15–19 [aOR = 0.63, CI = 0.44–0.92]. Poorer pregnant women had higher odds of ITN utilization compared with poorest pregnant women [aOR = 1.09, CI = 1.04–1.32]. Across regions, those in the south [aOR = 0.26, CI = 0.14–0.49] and south-west [aOR = 0.29, CI = 0.16–0.54] had lower odds of ITN use compared to their counterparts in the north-west region.

Conclusion

The high use of ITNs among pregnant women in Nigeria may be due to the prioritization of rural communities by previous interventions. This is a dimension worth considering to enhance the attainment of the national anti-malarial initiatives. Since possession of ITN is not a guarantee for utilization, women in urban locations need constant reminder of ITN use through messages delivered at ANC and radio advertisements. Moreover, subsequent mass ITN campaigns ought to take cognizance of variations ITN use across regions and pragmatic steps be taken to increase the availability of ITN in households since there is a moderately high use in households with at least one ITN in Nigeria.

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.

Utilization of insecticide-treated bed nets and care-seeking for fever and its associated socio-demographic and geographical factors among under-five children in different regions: evidence from the Myanmar Demographic and Health Survey, 2015-2016

Background

Malaria is one of the top-five contributors to under-5 deaths in Myanmar. Use of insecticide-treated nets (ITN) and receiving early appropriate care in case of fever are the core interventions to prevent malaria and its complications and thereby deaths. This study aimed to assess among the under-five children, (a) utilization of ITNs and its associated factors, (b) care-seeking behaviour among their caregivers and its associated factors and uptake of malaria testing among those with fever in the last 2 weeks.

Methods

This was a cross sectional study using secondary analysis of Myanmar Demographic and Health Survey (MDHS) conducted in 2015–2016. Multivariable logistic regression was used to explore the factors associated with non-utilization of ITNs and not seeking care for fever. Effect sizes have been presented using odds ratios with 95% confidence intervals. Data analysis was done using svyset command in STATA to account for the multi-stage sampling design of the survey.

Results

Of 4597 alive under-five children, 80.5% did not sleep under an ITN last night. The factors significantly associated with non-utilization of ITNs were residing in malaria elimination regions (aOR = 2.0, 1.3–3.2), urban residence (aOR = 1.8, 1.2–2.9), staying in delta region (aOR = 8.7, 4.7–12.2), hilly region (aOR = 3.0, 2.0–4.6, and having highest wealth quintile (aOR = 1.8, 1.1–3.0). Around 16% had fever in the last 2 weeks, of whom 66.7% sought care for fever and 3% got tested for malaria. Nearly half (50.9%) of the caregivers sought care from a government health facility, followed by private hospital/doctor (27.8%), shop (8.0%), village health worker (4.4%) and pharmacy (3.1%). The factors associated with not seeking care for fever were residing in specific geographical locations (hilly, delta and central plains compared to coastal region) and having lowest wealth quintile (aOR = 2.3, 1.1–5.7).

Conclusions

This study highlighted that ownership and utilization of ITNs was very poor among under-5children. Care-seeking behaviour of the caregivers of under-5 children in case of fever was dismal with two-thirds not seeking care. The programme should seriously consider addressing these barriers if Myanmar is to achieve zero malaria deaths by 2030.

Knowledge, motivation, self-efficacy, and their association with insecticidal net use among pregnant women in a secondary health centre in Maiduguri, Nigeria

BACKGROUND

Despite the high prevalence of malaria among pregnant women and its associated complications, the level of compliance with insecticide-treated nets (ITN) remains very low. Motivation and self-efficacy have been reported as important determinants of health behaviour, and may be important factors to consider in developing health intervention programmes. The aim of this study was to determine the knowledge, motivation and self-efficacy of ITN use, and their association with its practice, among pregnant women in a secondary health centre in Maiduguri.

METHODS

The study utilized a cross-sectional study design, using a structured and pre-tested questionnaire to obtain information from 380 respondents. Respondents were classified as ITN users if they slept under an ITN for at least 3 days in a week, while those who did not at all, or slept under it less frequently were classified as ITN non-users. Chi squared test was performed to test the bivariate association between ITN use and each of the items of the questionnaire. A further multivariate logistic regression was performed to determine the predictors of ITN use.

RESULTS

The respondents' ages ranged from 15 to 45 years, with median (interquartile range) age of 25 (8) years. Eighty percent of them were aware of ITN, but 50.5% believed ITNs could be dangerous. Only 5.5% and 0.8% respectively felt that sleeping under and ITN was either just bad or very bad for their health. Thirty-five percent of the respondents were ITN users. Not having a previous miscarriage (OR = 2.38; 95% CI 1.41-4.03, p = 0.001), knowledge that ITNs were not to be washed after every 1 month (OR = 3.60; 95% CI 1.18-11.06), significant others thinking they should sleep under an ITN (OR = 3.06; 95% CI 1.35-6.96), ability to effectively persuade others to sleep under an ITN (OR = 2.37; 95% CI 1.14-4.94) were significantly associated with ITN use.

CONCLUSIONS

A large proportion of pregnant women in this study were not sleeping under ITNs. The development of health promotion interventions aimed at boosting their self-efficacies for ITN use, and improving social support from their spouses are, therefore, recommended. Health education on ITN use should also be incorporated into post-abortal management.

Malaria prevalence, prevention and treatment seeking practices among nomadic pastoralists in northern Senegal

Background

Malaria transmission in Senegal is highly stratified, from low in the dry north to moderately high in the moist south. In northern Senegal, along the Senegal River Valley and in the Ferlo semi-desert region, annual incidence is less than five cases per 1000 inhabitants. Many nomadic pastoralists have permanent dwellings in the Ferlo Desert and Senegal River Valley, but spend dry season in the south with their herds, returning north when the rains start, leading to a concern that this population could contribute to ongoing transmission in the north.

Methods

A modified snowball sampling survey was conducted at six sites in northern Senegal to determine the malaria prevention and treatment seeking practices and parasite prevalence among nomadic pastoralists in the Senegal River Valley and the Ferlo Desert. Nomadic pastoralists aged 6 months and older were surveyed during September and October 2014, and data regarding demographics, access to care and preventive measures were collected. Parasite infection was detected using rapid diagnostic tests (RDTs), microscopy (thin and thick smears) and polymerase chain reaction (PCR). Molecular barcodes were determined by high resolution melting (HRM).

Results

Of 1800 participants, 61% were male. Sixty-four percent had at least one bed net in the household, and 53% reported using a net the night before. Only 29% had received a net from a mass distribution campaign. Of the 8% (142) who reported having had fever in the last month, 55% sought care, 20% of whom received a diagnostic test, one-third of which (n = 5) were reported to be positive. Parasite prevalence was 0.44% by thick smear and 0.50% by PCR. None of the molecular barcodes identified among the nomadic pastoralists had been previously identified in Senegal.

Conclusions

While access to and utilization of malaria control interventions among nomadic pastoralists was lower than the general population, parasite prevalence was lower than expected and sheds doubt on the perception that they are a source of ongoing transmission in the north. The National Malaria Control Program is making efforts to improve access to malaria prevention and case management for nomadic populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-2055-x) contains supplementary material, which is available to authorized users.

The effect of small solar powered 'Bͻkͻͻ' net fans on mosquito net use: results from a randomized controlled cross-over trial in southern Ghana

BACKGROUND

Long-lasting insecticidal nets (LLINs) are ineffective malaria transmission prevention tools if they are unused. Discomfort due to heat is the most commonly reported reason for not using nets, but this problem is largely unaddressed. With increasing rural electrification and the dropping price of solar power, fans could improve comfort inside nets and be affordable to populations in malaria endemic areas. Here, results are presented from a pilot randomized controlled cross-over study testing the effect of fans on LLIN use.

METHODS

Eighty-three households from two rural communities in Greater Accra, Ghana, randomized into three groups, participated in a 10-month cross-over trial. After a screening survey to identify eligible households, all households received new LLINs. Bͻkͻͻ net fan systems (one fan per member) were given to households in Group 1 and water filters were given to households in Group 2. At mid-point, Group 1 and 2 crossed over interventions. Households in Group 1 and 2 participated in fortnightly surveys on households' practices related to nets, fans and water filters, while households in Group 3 were surveyed only at screening, mid-point and study end. Entomological and weather data were collected throughout the study. Analysis took both 'per protocol' (PP) and 'intention to treat' (ITT) approaches. The mid- and end-point survey data from Group 1 and 2 were analysed using Firth logistic regressions. Fortnightly survey data from all groups were analysed using logistic regressions with random effects.

RESULTS

Provision of fans to households appeared to increase net use in this study. Although the increase in net use explained by fans was not significant in the primary analyses (ITT odds ratio 3.24, p > 0.01; PP odds ratio = 1.17, p > 0.01), it was significant in secondary PP analysis (odds ratio = 1.95, p < 0.01). Net use was high at screening and even higher after provision of new LLINs and with follow up. Fan use was 90-100% depending on the fortnightly visit.

CONCLUSIONS

This pilot study could not provide definitive evidence that fans increase net use. A larger study with additional statistical power is needed to assess this association across communities with diverse environmental and socio-demographic characteristics.

Knowledge of malaria prevention among pregnant women and female caregivers of under-five children in rural southwest Nigeria

Introduction. The morbidity and mortality from malaria are still unacceptably high in the developing countries, especially among the vulnerable groups like pregnant women and under-five children, despite all control efforts. The knowledge about the preventive measures of malaria is an important preceding factor for the acceptance and use of malaria preventive measures like Insecticide Treated Nets (ITN) by community members. Therefore, this study assessed the knowledge of malaria prevention among caregivers of under-five children and pregnant women in a rural community in Southwest Nigeria.

Methodology. This is part of a larger malaria prevention study in rural Southwest Nigeria. A descriptive cross-sectional survey was conducted among pregnant women and caregivers of under-five children in Igbo-Ora, a rural town in Southwest Nigeria using a semi-structured, interviewer-administered questionnaire. Information was obtained on knowledge of malaria prevention, and overall composite scores were computed for knowledge of malaria prevention and ITN use. Data were analyzed using SPSS version 16. Associations between variables were tested using a Chi-square with the level of statistical significance set at 5%.

Results. Of the 631 respondents, 84.9% were caregivers of under-five children and 67.7% were married. Mean age was 27.7 ± 6.3 years with 53.4% aged between 20 and 29 years. Majority (91.1%) had at least primary school education and 60.2% were traders. Overall, 57.7% had poor knowledge of malaria prevention. A good proportion (83.5%) were aware of the use of ITN for malaria prevention while 30.6% had poor knowledge of its use. Respondents who were younger (<30 years), had at least primary education and earn <10,000/per month had significantly poor knowledge of ITN use in malaria prevention. Majority (60.0%) respondents had poor attitude regarding use of ITNs.

Conclusion. This study showed that the knowledge of malaria prevention is still low among under-five caregivers and pregnant women in rural Southwest Nigeria despite current control measures. There is a need for concerted health education intervention to improve the knowledge of rural dwellers regarding malaria prevention, including the use of ITN. This will go a long way to improving the reported low level of ownership and utilization of ITN in the rural areas.