A qualitative study of use of long-lasting insecticidal nets (LLINs) for intended and unintended purposes in Adami Tullu, East Shewa Zone, Ethiopia

The challenge of improving long-lasting insecticidal nets coverage on Bioko Island: using data to adapt distribution strategies

Background

Since 2015, malaria vector control on Bioko Island has relied heavily upon long-lasting insecticidal nets (LLIN) to complement other interventions. Despite significant resources utilised, however, achieving and maintaining high coverage has been elusive. Here, core LLIN indicators were used to assess and redefine distribution strategies.

Methods

LLIN indicators were estimated for Bioko Island between 2015 and 2022 using a 1×1 km grid of areas. The way these indicators interacted was used to critically assess coverage targets. Particular attention was paid to spatial heterogeneity and to differences between urban Malabo, the capital, and the rural periphery.

Results

LLIN coverage according to all indicators varied substantially across areas, decreased significantly soon after mass distribution campaigns (MDC) and, with few exceptions, remained consistently below the recommended target. Use was strongly correlated with population access, particularly in Malabo. After a change in strategy in Malabo from MDC to fixed distribution points, use-to-access showed significant improvement, indicating those who obtained their nets from these sources were more likely to keep them and use them. Moreover, their use rates were significantly higher than those of whom sourced their nets elsewhere.

Conclusions

Striking a better balance between LLIN distribution efficiency and coverage represents a major challenge as LLIN retention and use rates remain low despite high access resulting from MDC. The cost benefit of fixed distribution points in Malabo was deemed significant, providing a viable alternative for guaranteeing access to LLINs to those who use them.

Effectiveness of health education interventions to improve malaria knowledge and insecticide-treated nets usage among populations of sub-Saharan Africa: systematic review and meta-analysis

Introduction

Malaria health education intervention is a community-directed approach that has long been considered important in preventing malaria in sub-Saharan Africa. However, its effectiveness is being questioned due to a lack of strong evidence. We aim to synthesize the evidence of the impact of health education on malaria knowledge and insecticide-treated nets (ITN) usage. Specifically, we analyzed the odds of correctly answering malaria-related questions and the odds of using ITN between the intervention and control groups.

Methods

Experimental and observational studies conducted in sub-Saharan Africa between 2000 and 2021 which had quantitatively evaluated the impact of health education interventions on malaria knowledge and ITN usage were included in the review.

Results

A total of 11 studies (20,523 participants) were included. Four studies used educational interventions to teach appropriate ITN strategies and promote ITN usage. Two others focused on improving knowledge of malaria transmission, prevention, treatment, and its signs and symptoms. The remaining five studies assessed both ITN use and malaria knowledge. Of these, 10 were eligible for meta-analysis. On average, the odds of a person in the intervention group reporting better malaria knowledge (odds ratio 1.30, 95% CI: 1.00 to 1.70, p = 0.05) and higher ITN usage (odds ratio 1.53, 95% CI: 1.02 to 2.29, p = 0.004) increased significantly after receiving health education interventions compared to those in the control group. The odds of ITN usage also substantially increased when the interventions were based on a theory or model (odds ratio 5.27, 95% CI: 3.24 to 8.58, p = 0.05).

Discussion

Our review highlights sub-Saharan Africa's various health education strategies to curb malaria over the past two decades. Meta-analysis findings show that health education interventions are moderately effective in improving malaria knowledge and ITN usage and have contributed to the effort of global malaria strategy.

Association between Livestock Ownership and Malaria Incidence in South-Central Ethiopia: A Cohort Study

Zooprophylaxis is one of the possible environmental vector control strategies for malaria prevention. However, its effect on reducing malaria transmission has been questionable, requiring a detailed understanding of contextual factors. This study aims to evaluate the effect of keeping livestock on malaria incidence in south-central Ethiopia. A cohort of 34,548 people in a total of 6,071 households was followed for 121 weeks from October 2014 to January 2017. Baseline data were collected, including livestock ownership. Weekly home visits were done to actively search for malaria cases, and passive case detection was also carried out. Malaria was diagnosed with rapid diagnostic tests. Log binomial and parametric regression survival-time models were used to estimate effect measures. A total of 27,471 residents had complete follow-ups, and the majority (87.5%) lived in households owning livestock, including cattle, sheep, goats, and chickens. The overall incidence risk of malaria was 3.7%, and there was a 24% reduction in the risk of malaria among livestock owners. The total cohort contributed to 71,861.62 person-years of observation. The incidence rate of malaria was 14.7 cases per 1,000 person-years. There was a 17% reduction in the rate of malaria among livestock owners. Meanwhile, the protective effect of livestock ownership increased as the number of livestock or the livestock-to-human ratio increased. In conclusion, livestock owners had less malaria. In a setup where domestication of livestock is a common practice and the predominant malaria vector tends to feed more on livestock than humans, zooprophylaxis remains a promising strategy for malaria prevention.

Quantifying the direct and indirect protection provided by insecticide treated bed nets against malaria

Long lasting insecticidal nets (LLINs) provide both direct and indirect protection against malaria. As pyrethroid resistance evolves in mosquito vectors, it will be useful to understand how the specific benefits LLINs afford individuals and communities may be affected. Here we use modelling to show that there is no minimum LLIN usage needed for users and non-users to benefit from community protection. Modelling results also indicate that pyrethroid resistance in local mosquitoes will likely diminish the direct and indirect benefits from insecticides, leaving the barrier effects intact, but LLINs are still expected to provide enhanced benefit over untreated nets even at high levels of pyrethroid resistance.

Increasing challenges of malaria control in sub-Saharan Africa: Priorities for public health research and policymakers

The ever-increasing cases and mortality due to malaria remains one of the most important public health threats, especially in sub-Saharan Africa-where this burden is considerably high. In 2020, sub-Saharan Africa accounted for about 95% of all cases and 96% of all malaria deaths with about 80% of these deaths reported in children under the age of 5. This review, adopting a public health focus, aimed to understand the challenges of malaria control in sub-Saharan Africa despite ongoing public health interventions. Our review highlights two important findings. First, the increasing resistance of malaria parasites to artemisinin-based combination therapy (ACT) and its partner drugs coupled with increased vector resistance to pyrethroids and insecticides is reversing the progress of public health interventions in keeping malaria under control. Second, the wanning for the efficacy of the WHO-approved vaccine i.e. RTS,S from 60 to 70% following 18 months of observation, and its short-term availability remains an impediment to achieving the WHO target of producing malaria vaccines with more than 75% efficacy by 2030. Our findings underline the need to reassess research priorities with a focus on vaccine production in sub-Saharan Africa. Furthermore, African governments and policymakers must be committed to invest both the political and financial capital in vaccine production and distribution.

Community knowledge, perceptions, and practices regarding malaria and its control in Jabi Tehnan district, Amhara Region, Northwest Ethiopia

Background

Use of long-lasting insecticidal nets (LLINs), indoor residual spraying (IRS), community-based malaria education, prompt diagnosis and treatment are key programme components of malaria prevention and control in Ethiopia. However, the effectiveness of these interventions is often undermined by various challenges, including insecticide and drug resistance, the plasticity of malaria vectors feeding and biting behaviour, and certain household factors that lead to misuse and poor utilization of LLINs. The primary objective of this study was to document households’ perceptions towards malaria and assess the prevalence of the disease and the constraints related to the ongoing interventions in Ethiopia (LLINs, IRS, community mobilization house screening).

Methods

The study was conducted in Jabi Tehnan district, Northwestern Ethiopia, from November 2019 to March 2020. A total of 3010 households from 38 villages were randomly selected for socio-economic and demographic survey. Focus group discussions (FGDs) were conducted in 11 different health clusters considering agro-ecological differences. A total of 1256 children under 10 years of age were screened for malaria parasites using microscopy to determine malaria prevalence. Furthermore, 5-year malaria trend analysis was undertaken based on data obtained from the district health office to understand the disease dynamics.

Results

Malaria knowledge in the area was high as all FGD participants correctly identified mosquito bites during the night as sources of malaria transmission. Delayed health-seeking behaviour remains a key behavioural challenge in malaria control as it took patients on average 4 days before reporting the case at the nearby health facility. On average, households lost 2.53 working days per person-per malaria episode and they spent US$ 18 per person per episode. Out of the 1256 randomly selected under 10 children tested for malaria parasites, 11 (0.89%) were found to be positive. Malaria disproportionately affected the adult segment of the population more, with 50% of the total cases reported from households being from among individuals who were 15 years or older. The second most affected group was the age group between 5 and 14 years followed by children aged under 5, with 31% and 14% burden, respectively.

Conclusion

Despite the achievement of universal coverage in terms of LLINs access, utilization of vector control interventions in the area remained low. Using bed nets for unintended purposes remained a major challenge. Therefore, continued community education and communication work should be prioritized in the study area to bring about the desired behavioural changes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03996-5.

Role of health extension workers in the relationship between vector control interventions and malaria in Ethiopia

BACKGROUND

Despite a tremendous decline in the burden of malaria through public health interventions, it is yet remains a critical parasitic health problem in Ethiopia. Insecticide-treated nets and indoor residual spray are considered as the most effective preventive interventions against malaria. This study intended to determine the role of health extension workers in influencing the relationship between vector control strategies and malaria prevalence in Ethiopia.

METHODS

The study adopted a descriptive study based on panel data collected from 10 regions of Ethiopia from 2010 to 2018. The data collected were analyzed using STATA version 13.0. Structural equation modelling was used to assess the mediating effect of health extension workers in the relationship. Further, the random effect model was employed to investigate the direct relationship among the study variables.

RESULTS

We observed a strong mediating role of health extension workers to the relationship between strategic interventions and malaria prevalence, where the direct path is (β = 0.64, p < 0.05), and the indirect path (β = 0.72, p < 0.001) and (β = 0.98, p < 0.001) confirming the mediation condition to appear. Our analysis revealed that, insecticide-treated nets and indoor residual spray significantly impacts the malaria prevalence (β = 0.20, p < 0.05) and (β = 0.70, p < 0.001) respectively. Further, our analysis suggests that the cumulative effect of indoor residual spray and insecticide-treated mosquito nets have helped better avert malaria prevalence (β = 81.3%, P < 0.05). Moreover, the finding demonstrates the incremental rate of 30.2%, which is the indirect effect of the research [(β = 0.813) - (β1 = 0.511)].

CONCLUSION

The findings are potentially useful for the health sector in charge of infectious disease prevention and control, particularly in developing countries explaining how these group provided support to reduce malaria ensuring the provision of proper health message about the program.

Comparing insecticide-treated nets access-use based on universal household and population indicators vis-a-vis measures adapted to sleeping spaces in Ethiopia

Background

Insecticide-treated nets (ITNs) access-use has been pivotal monitoring indicator for malaria prevention and control, particularly in resource limited settings. The objective of the study was to compare ITN access-use based on universal household and population indicators and measures adapted to sleeping spaces.

Methods

A cross-sectional study was conducted in five districts of Jimma Zone, Ethiopia, March, 2019. 762 HHs were sampled for the survey. Multi-stage followed by simple random sampling used. Monitoring and evaluation reference group’s (MERG’s) indicators were used for measuring ITN access-use. MERG’s indicators are each adapted ITN access-use to sleeping spaces. Household (ownership, saturation and sufficiency) and population access and household members’ status of last night sleeping under ITN compared based on the two models. Differences of estimates of ITN access-use based on the two methods reported as magnitude of over/under estimations, at p-value < 0.05.

Results

Based on MERG’s approach, the study revealed household (HH) based indicators as such: HH ownership of at least 1 ITN (92.6%), sufficiency of ITN for every two people in HH (50.3%), and saturation of ITN for every 2 people in HHs with any ITN (54.6%). Moreover, population based indicators were: population with ITN access (P3 = 78.6%), people who slept under ITN previous night (63.0%), people who slept under ITN among who accessed it (73.1%), ITN use-gap (26.9%). Equivalent indicators of HH ownership, sufficiency, saturation, and people accessed at where they actually slept, and people slept under ITN among those accessed at where they slept estimated at 71.3%, 49.4%, 69.3%, 66.3%, and 92.1%, respectively. MERG’s approach over-estimated ownership, people’s access, and behaviour-failures by 21.3%, 12.3%, 19.0%, respectively. Over-estimation occurred for reasons such as many sleeping spaces lack ITN and > 2 people actually slept per sleeping space.

Conclusions

MERG’s universal indicators over estimated households and populations ITN access-use as a result of absence of measures capturing access-use values at spaces where people actually slept. Consequently, measures adapted to sleeping contexts revealed potential misdistributions practiced when the existing indicators are in use. Insertion of sleeping spaces into existing approach will be worthwhile and needs to be promoted as it improves curiosity in ITN distribution, produces closer estimates and prevents malaria prevention and control programmes from overlooking access-use challenges.

Coverage, determinants of use and repurposing of long-lasting insecticidal nets two years after a mass distribution in Lihir Islands, Papua New Guinea: a cross-sectional study

BACKGROUND

Universal coverage with long-lasting insecticidal nets (LLINs) is an essential component of malaria control programmes. Three-yearly mass distribution of LLINs in Papua New Guinea (PNG) has been successful in reducing infection transmission since 2009, but malaria prevalence ramped up from 2015 onwards. Although LLIN universal coverage is mostly achieved during these campaigns, it may not be related with net use over time. Uses given to LLINs and non-compliance of this strategy were evaluated.

METHODS

A knowledge, attitude and practice (KAP) cross-sectional study was conducted in Lihir Islands, PNG, 2-2.5 years after the last LLIN mass distribution campaign. Data on bed net ownership, use and maintenance behaviour was collected using a household questionnaire administered by trained community volunteers. Logistic regression models were used to identify factors associated with owning at least one LLIN and sleeping under a LLIN the previous night.

RESULTS

Among 2694 households surveyed, 27.4 % (95 % CI: 25.8-29.2) owned at least one LLIN and 8.7 % (95 % CI: 7.6-9.8) had an adequate LLIN coverage (at least one LLIN for every two people). Out of 13,595 individuals in the surveyed households, 13.6 % (95 % CI: 13.0--4.2) reported having slept under a LLIN the preceding night. Determinants for sleeping under LLIN included living in a household with adequate LLIN coverage [adjusted OR (aOR) = 5.82 (95 % CI: 3.23-10.49)], household heads knowledge about LLINs [aOR = 16.44 (95 % CI: 8.29-32.58)], and female gender [aOR = 1.92 (95 % CI: 1.53-2.40)] (all p-values < 0.001). LLIN use decreased with older age [aOR = 0.29 (95 % CI: 0.21-0.40) for ≥ 15 year-olds, aOR = 0.38 (95 % CI: 0.27-0.55) for 5-14 year-olds] compared to < 5 year-olds (p-value < 0.001). Knowledge on the use of LLIN was good in 37.0 % of the household heads. Repurposed nets were reported serving as fishing nets (30.4 %), fruits and seedlings protection (26.6 %), covering up food (19.0 %) and bed linen (11.5 %).

CONCLUSIONS

Two years after mass distribution, LLIN coverage and use in Lihir Islands is extremely low. Three yearly distribution campaigns may not suffice to maintain an acceptable LLIN coverage unless knowledge on maintenance and use is promoted trough educational campaigns.

Ownership and utilization of bed nets and reasons for use or non-use of bed nets among community members at risk of malaria along the Thai-Myanmar border

Background

With the goal for malaria elimination in Thailand set for 2024, increased coverage and utilization of bed net, especially insecticide-treated net (ITN) or long-lasting insecticidal net (LLIN) is a key strategy. This study aims to provide the necessary information about bed net ownership and utilization among the population at risk of malaria living along the Thai-Myanmar border in Tak province.

Methods

A cross-sectional study was conducted using a mixed-method approach in 331 households from 5 hamlets in the villages of the Thai-Myanmar border. The research tools included a questionnaire, bed net inspection, and semi-structured interviews. Logistic regression was used to explore the sociodemographic factors associated with bed net utilization. The qualitative analysis employed a thematic analysis approach.

Results

This survey found that 98.5% of households had at least one bed net per household, and 74.3% had at least one ITN/LLIN. However, only 30.8% of households reached the standard policy set by the Minister of Public Health of one ITN/LLINs per two persons. Most residents used bed net (92.1% used in the previous night and 80.9% used every day). For those using bed nets, however, 61.9% used ITNs or LLINs the night before and 53.1% used them every day. Nonetheless, the usage rates of bed nets (any type) in the previous night among children and pregnant women were high, reaching 95.3% and 90.0%, respectively. Seven explanatory variables showed statistically significant associations with bed net use every day, including: “not staying overnight in the forest or the field”, “sleeping pattern based on gender”, “sufficient numbers of bed nets to cover all sleeping spaces”, “preference for free bed nets”, “age”, “gender”, and “SES score” showed statistically significant association with bed net use every day. The major reasons for the regular use of bed nets in both household and the forest were to prevent mosquito biting. The reasons for not using bednets in the household were discomfort feelings from heat, perception of unnecessity due to low mosquito density, whereas the reason for not using bed nets in the forest was inconvenience.

Conclusion

Despite that overall coverage and usage of bed nets was high, only one third reached the standard level specified by the policy. Overnight in the forest, the dissatisfaction with the quality of free bed nets, insufficient number of bed nets, sleeping alone, male gender, age more than 10 years, low socioeconomic status, discomfort from heat, perception of no benefits of bed nets due to low mosquito density, and inconvenience were factors influencing bed net use. Maintaining high coverage and utility rate of bed nets should be a priority for the malaria high-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-03837-5.

Malaria Infection is High at Transit and Destination Phases Among Seasonal Migrant Workers in Development Corridors of Northwest Ethiopia: A Repeated Cross-Sectional Study

Purpose

Malaria is a leading public health problem in Ethiopia. Every year, thousands of seasonal farm workers travel to farm corridors in Northwest Ethiopia and fall at risk of malaria infection. However, the magnitude of malaria infection and risk factors during harvest time were not well identified. This study aimed at estimating the prevalence and risk factors of malaria infection among seasonal migrant workers in Northwest Ethiopia.

Methods

A repeated cross-sectional study was conducted at transit and destination phases in Metema district from September 15, 2018 to October 30, 2019. Data were collected using a structured questionnaire. A capillary blood sample was collected to examine infection with malaria parasite using a microscope. A multivariate logistic regression technique was used to determine risk factors.

Results

The malaria prevalence at transit and destination phases among migrant workers was 13.5% (95% CI: 12.07–14.93%) and 18.7% (95% CI: 16.40–21.02%), respectively. The combined prevalence was 16.1% (95% CI: 14.67–17.63%). The odds of malaria infection among migrant workers at the destination phase was 1.5 (OR=1.5, 95% CI 1.167–1.846) times higher compared to the transit phase. Education (AOR=8.198; 95% CI: 4.318–15.564), knowledge of antimalarial drugs (AOR=2.4; 95% CI: 1.43–3.95), and use of long-lasting insecticidal nets (AOR=5.0; 95% CI: 3.34–4.43) were significantly associated with malaria infection at migration phases.

Conclusion

This study showed that the burden of malaria among seasonal migrant workers was high at transit and destination phases. Malaria prevalence was higher at the destination phase compared to the transit phase. A tailored malaria prevention intervention is needed including awareness creation, screening, treatment, repellent, and prophylaxis at both phases to reduce malaria infections.

Parents' perception on cause of malaria and their malaria prevention experience among school-aged children in Kutcha district, Southern Ethiopia; qualitative study

Introduction

School-aged children become a highly vulnerable group for malaria, yet they are less likely to use malaria prevention interventions. Previous studies exploring perception on cause of malaria mainly focused on pregnant mothers or parents of children under age five years. Exploring parent’s perception on cause of malaria and their experiences on the prevention of malaria and associated challenges among school-aged children is important to develop a malaria prevention education package for school-aged children to reduce malaria and malaria related morbidities among school-aged children.

Methods

A descriptive qualitative study is conducted in Kutcha district by recruiting 19 parents of school-aged children for semi-structured interviews, 6 key informants and 6 focus group discussion which consists of parents, health development army and health extension workers. A semi-structured interview guide is used to guide the interview process. The collected data is analyzed thematically with a focus on the three major areas of concern: perceived cause of malaria, experience of malaria prevention and challenges of bed net use for prevention of malaria.

Results

Five causes of malaria were identified, namely hunger, mosquito bite, exposure to hot sunshine, poor sanitation and hygiene and eating some sweet foods and unripe maize. Participants perceived that eating sweet foods and unripe maize lead to enlargement of the spleen that ends in malaria while poor hygiene and sanitation leads to either development of the ova of mosquito and the landing of the housefly to contaminate food for consumption. The experiences of malaria prevention were largely influenced by their perceived cause of malaria. The malaria prevention measures undertaken by parents were vectors control measures, homemade herbal remedies and restricting children from eating sweet foods. The challenges of malaria prevention by using bed nets were related to a negative attitude, sleeping behaviors of children; use of bed nets for unintended purposes, shortage of bed nets and delays in the distribution of bed nets.

Conclusion

There were misconceptions about the cause of malaria and associated experiences of malaria prevention. Control of malaria among school-aged children need health education targeting the challenges and correcting identified misconceptions by parents in Kutcha district and in other similar settings.

"After those nets are torn, most people use them for other purposes": an examination of alternative bed net use in western Kenya

BACKGROUND

Alternative long-lasting insecticidal net (LLIN) use for purposes other than sleeping protection from mosquitoes is widely debated as a limitation to successful malaria control efforts, yet rarely rigorously studied.

METHODS

A cross-sectional survey of 1217 households in an epidemic highland site and an endemic lowland site in western Kenya collected information on alternative use in three ways: direct observations, participant self-report, and participant reporting of community-level practices. LLIN misuse was defined as use of an intact net for alternative purposes and repurposing as alternatively using an old or damaged net. Associations between households with observed repurposed nets and universal access and household net use were examined.

RESULTS

Households describe repurposing nets when they are torn and/or old. Repurposed nets were observed in 8.1% (52/643) highlands households and 33.0% (184/574) lowlands households. Repurposed nets served as chicken coops (33% highlands, 20% lowlands), fences (37% highlands, 25% lowlands), tree covers (22% lowlands), curtains (3% highlands), covering bathrooms (1.5% highlands, 9% lowlands), and washing sponges (13% lowlands). No association was found between repurposing and universal access or household net use. Misuse was rare. Of 379 repurposed nets, 4 (1.06%) were in good condition with no holes. Of 1,758 active nets, 13 (0.74%) were misused.

CONCLUSIONS

Alternative net use in this study involved repurposing rather than misuse. Repurposing was not detrimental to malaria prevention efforts in these communities. Standardized measurement of alternative net use should be used to better understand the practice and its potential impact on the success of malaria interventions.

Health system, socio-cultural, economic, environmental and individual factors influencing bed net use in the prevention of malaria in pregnancy in two Ghanaian regions

Background

Improving maternal health remains a priority to the Ghanaian government. Consequently, it has implemented the World Health Organization recommendation of distributing free long-lasting insecticidal nets (LLINs) to pregnant women—one of the effective strategies to combating malaria in pregnancy. However, the burden of negative outcomes of malaria in pregnancy such as low birth weight and miscarriages is still high. This may be related to the health system, socio-cultural and economic dynamics that influence LLIN use, but their role is not well understood. This ethnographic study sought to understand health system, socio-cultural, economic and environmental dynamics in utilization of LLINs among pregnant women in two Ghanaian regions.

Methods

An ethnographic study design was used. In-depth interviews and conversations were conducted among health workers, pregnant women and opinion leaders. Observations were conducted in 12 communities and eight health facilities. Ethical clearance was obtained from the University of Health and Allied Sciences’ Research Ethics Committee. Nvivo 11 was used to support data coding. Data were triangulated and analysed using a thematic approach.

Results

Findings suggest health system, socio-cultural, economic, environmental and individual factors influenced LLIN use. Health facility readiness in stocking LLINs influenced ownership and use. Receiving appropriate information from health providers and encouragement from public officials improved LLIN use. Women with a history of LLIN use prior to becoming pregnant and women who had young children remained consistent users. Experiencing irritating effects of LLINs and preference for traditional methods to wade off mosquitoes, reduced LLIN use. Pregnant women whose household and family members used LLINs were influenced positively to use them. Gender power relations between husbands and wives influenced women’s use of LLINs. The type of housing and weather conditions contributed to inconsistent use. Staying out late for business purposes and to converse, exposed pregnant women to mosquito bites.

Conclusion

Giving out LLINs at facility level should be accompanied with comprehensive information, which is relevant to the socio-cultural context that women live in. Mass distribution should factor in individual and public information to promote community acceptance and proper use of ITNs. Facilities should be encouraged to constantly maintain LLINs stock in order to ensure that ANC registrants receive LLINs for use.

Barriers of persistent long-lasting insecticidal nets utilization in villages around Lake Tana, Northwest Ethiopia: a qualitative study

Background

Malaria remains a major public health problem in Ethiopia. The use of LLINs is an effective approach to reducing transmission. Persistent use of LLINs is determined by numerous factors. Quantitative studies have assessed LLIN ownership and utilization, but the behavioral, socio-cultural, socioeconomic and net distribution contexts that impact their use have not been examined in depth. This study aimed to explore barriers of persistent LLIN use among communities around Lake Tana.

Methods

Twenty-three community residents who owned LLINs (15) or not (8) during the study period and 38 key informants were interviewed from April to June 2017. Phenomenological study was employed to explore the local contexts and factors that influence persistent use of LLINs. Individuals were purposefully selected to capture different views. Community residents were selected based on their permanent residence and LLIN use experience. Key informants were health extension workers, local leaders, students, and health professionals. The data were managed using QSR International NVivo Version 10 software and coded, and themes were identified.

Results

Killing ability of nets against arthropods other than mosquitoes reportedly made use of LLINs a favored malaria prevention method despite their ineffectiveness after 3 months. Conical nets were preferred due to their compatibility with varied sleeping structures. Numerous factors influenced persistent use, notably erroneous perceptions about LLINs, malaria and mosquitoes; bedbug infestation; inconvenience; unintended uses; distribution problem of nets; and socio-cultural and economic factors. Unintended uses were often associated with local needs and seldom linked with social issues and deficiencies in information about malaria and LLINs. Collateral benefits were considered important, principally in terms of disinfestation of bedbugs.

Conclusions

Non-persistent LLIN use was associated with inconvenient bed net design and early damage; non-potency of the insecticide against other arthropods; facilitation of bedbug infestation; unintended uses; wrong perceptions about malaria, mosquitoes, and LLINs; and inadequate follow-up regarding LLINs utilization. Distribution of conical nets and provision of adequate information on LLINs and malaria may promote persistent use. Using an insecticide that also kills arthropods other than mosquitoes may reduce unintended uses and increase persistent use.

Spatiotemporal clustering of malaria in southern-central Ethiopia: A community-based cohort study

Introduction

Understanding the spatiotemporal clustering of malaria transmission would help target interventions in settings of low malaria transmission. The aim of this study was to assess whether malaria infections were clustered in areas with long-lasting insecticidal nets (LLINs) alone, indoor residual spraying (IRS) alone, or a combination of LLINs and IRS interventions, and to determine the risk factors for the observed malaria clustering in southern-central Ethiopia.

Methods

A cohort of 34,548 individuals residing in 6,071 households was followed for 121 weeks, from October 2014 to January 2017. Both active and passive case detection mechanisms were used to identify clinical malaria episodes, and there were no geographic heterogeneity in data collection methods. Using SaTScan software v 9.4.4, a discrete Poisson model was used to identify high rates of spatial, temporal, and spatiotemporal malaria clustering. A multilevel logistic regression model was fitted to identify predictors of spatial malaria clustering.

Results

The overall incidence of malaria was 16.5 per 1,000 person-year observations. Spatial, temporal, and spatiotemporal clustering of malaria was detected in all types of malaria infection (P. falciparum, P. vivax, or mixed). Spatial clustering was identified in all study arms: for LLIN + IRS arm, a most likely cluster size of 169 cases in 305 households [relative risk (RR) = 4.54, P<0.001]; for LLIN alone arm a cluster size of 88 cases in 103 households (RR = 5.58, P<0.001); for IRS alone arm a cluster size of 58 cases in 50 households (RR = 7.15, P<0.001), and for control arm a cluster size of 147 cases in 377 households (RR = 2.78, P<0.001). Living 1 km closer to potential vector breeding sites increased the odds of being in spatial clusters by 41.32 fold (adjusted OR = 41.32, 95% CI = 3.79–138.89).

Conclusions

The risk of malaria infection varied significantly between kebeles, within kebeles, and even among households in areas targeted for different types of malaria control interventions in low malaria transmission setting. The results of this study can be used in planning and implementation of malaria control strategies at micro-geographic scale.

Trial registration

PACT R2014 11000 882128 (8 September 2014).

Impact of combining indoor residual spraying and long-lasting insecticidal nets on Anopheles arabiensis in Ethiopia: results from a cluster randomized controlled trial

BACKGROUND

Indoor residual house spraying (IRS) and long-lasting insecticidal nets (LLINs) are the key front-line malaria vector interventions against Anopheles arabiensis, the sole primary malaria vector in Ethiopia. Universal coverage of both interventions has been promoted and there is a growing demand in combinations of interventions for malaria control and elimination. This study compared the impact on entomological outcomes of combining IRS and LLINs with either intervention alone in Adami Tullu district, south-central Ethiopia. The epidemiological outcomes were recently published on a separate paper.

METHODS

This factorial, cluster-randomized, controlled trial randomized villages to four study arms: IRS + LLIN, IRS, LLIN, and control. LLINs (PermaNet 2.0) were provided free of charge. IRS with propoxur was applied before the main malaria transmission season in 2014, 2015 and 2016. Adult mosquitoes were collected in randomly selected villages in each arm using CDC light trap catch (LTC) set close to a sleeping person, pyrethrum spray catch (PSC), and artificial pit shelter (PIT), for measuring mosquito host-seeking density (HSD), indoor resting density (IRD), and outdoor resting density (ORD), respectively. Human landing catch (HLC) was performed in a sub-set of villages to monitor An. arabiensis human biting rates (HBR). Mean vector densities and HBR were compared among study arms using incidence rate ratio (IRR) calculated by negative binomial regression.

RESULTS

There were no significant differences in mean densities (HSD, IRD, ORD) and HBR of An. arabiensis between the IRS + LLIN arm and the IRS arm (p > 0.05). However, mean HSD, IRD, ORD, and HBR were significantly lower in the IRS + LLIN arm than in the LLIN alone arm (p < 0.05). All An. arabiensis tested for malaria infection were negative for Plasmodium species. For this reason, the entomological inoculation rate could not be determined.

CONCLUSIONS

The IRS + LLIN were as effective as IRS alone in reducing densities and HBR of An. arabiensis. However, the effectiveness of the two interventions combined was higher than LLINs alone in reducing densities and HBR of the vector. Added impact of the combination intervention against malaria infectivity rates of An. arabiensis compared to either intervention alone remains unknown and warrants further research. Trial registration PACTR201411000882128. Registered 8 September 2014, https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-016-1154-2.

Long-lasting insecticidal nets and indoor residual spraying may not be sufficient to eliminate malaria in a low malaria incidence area: results from a cluster randomized controlled trial in Ethiopia

Background

Conflicting results exist on the added benefit of combining long-lasting insecticidal nets (LLINs) with indoor residual spraying (IRS) to control malaria infection. The main study objective was to evaluate whether the combined use of LLINs and IRS with propoxur provides additional protection against Plasmodium falciparum and/or Plasmodium vivax among all age groups compared to LLINs or IRS alone.

Methods

This cluster-randomized, controlled trial was conducted in the Rift Valley area of Ethiopia from September 2014 to January 2017 (121 weeks); 44 villages were allocated to each of four study arms: LLIN + IRS, IRS, LLIN, and control. Each week, 6071 households with 34,548 persons were surveyed by active and passive case detection for clinical malaria. Primary endpoints were the incidence of clinical malaria and anaemia prevalence.

Results

During the study, 1183 malaria episodes were identified, of which 55.1% were P. falciparum and 25.3% were P. vivax, and 19.6% were mixed infections of P. falciparum and P. vivax. The overall malaria incidence was 16.5 per 1000 person-years of observation time (PYO), and similar in the four arms with 17.2 per 1000 PYO in the LLIN + IRS arm, 16.1 in LLIN, 17.0 in IRS, and 15.6 in the control arm. There was no significant difference in risk of anaemia among the trial arms.

Conclusions

The clinical malaria incidence and anaemia prevalence were similar in the four study groups. In areas with low malaria incidence, using LLINs and IRS in combination or alone may not eliminate malaria. Complementary interventions that reduce residual malaria transmission should be explored in addition to LLINs and IRS to further reduce malaria transmission in such settings.

Trial registration PACTR201411000882128 (08 September 2014)

Electronic supplementary material

The online version of this article (10.1186/s12936-019-2775-1) contains supplementary material, which is available to authorized users.

Low use of long-lasting insecticidal nets for malaria prevention in south-central Ethiopia: A community-based cohort study

Introduction

A decline in malaria morbidity and mortality has been documented in Ethiopia since 2005 following a scale-up of the distribution of long-lasting insecticidal nets (LLINs). However, universal access to LLINs ownership and use has not yet been achieved. This study aimed to determine ownership and use of LLINs over time in south-central Ethiopia.

Methods

A cohort of 17,142 individuals residing in 3,006 households was followed-up from October 2014 to January 2017 (121 weeks). New PermaNet2.0 LLINs were given to households in October 2014. Once per week, the LLIN use status was documented for each individual. A survey was conducted after 110 weeks of LLIN distribution to determine LLIN ownership. A multilevel negative binomial regression model was fitted to identify significant predictors of LLIN use.

Results

At baseline, the LLIN ownership was 100%. After 110 weeks only 233 (8%) of the households owned at least one LLIN. The median proportion of LLIN use per individuals during the study period was only 14%. During the first year (week 1–52) the average LLIN use per individuals was 36% and during the second year (week 53–104) it was 4.6%. More frequent LLIN use was reported among age group [5–14 years (adjusted IRR = 1.13, 95% CI 1.04–1.22), 15–24 years (adjusted IRR = 1.33, 95% CI 1.23–1.45), ≥25 years (adjusted IRR = 1.99, 95% CI 1.83–2.17)] compared to <5 years, and household head educational status [read and write (adjusted IRR = 1.17, 95% CI 1.09–1.26), primary (adjusted IRR = 1.20, 95% CI 1.12–1.27), secondary or above (adjusted IRR = 1.20, 95% CI (1.11–1.30)] compared to illiterate. Having a family size of over five persons (adjusted IRR = 0.78, 95% CI 0.73–0.84) was associated with less frequent use of LLINs compared to a family size of ≤5 persons.

Conclusions

The study showed a low LLIN ownership after 110 weeks and a low LLIN use during 121 weeks of follow-up, despite 100% LLIN coverage at baseline. The study highlights the need to design strategies to increase LLIN ownership and use for setting similar to those studied here.

Bed nets used to protect against malaria do not last long in a semi-arid area of Ethiopia: a cohort study

Background

Long-lasting insecticidal nets (LLINs) are a key tool for malaria prevention and control. Currently, the recommended serviceable life of an LLIN is 3 years under field conditions. However, field studies show considerable variation in LLIN lifespan, from less than 2 years to more than 4 years. This study aimed to determine the attrition, physical integrity, functional survival, and bio-efficacy of LLINs under field conditions in south-central Ethiopia.

Methods

In October 2014, 7740 LLINs (PermaNet^® 2.0) were distributed to 3006 households. Among the distributed LLINs, a cohort study involving 1532 LLINs in 659 households was carried out from October 2014 to November 2016. Data were collected every 6 months by observation, and through interviews with the heads of households. The proportional hole index was used to categorize LLINs as either serviceable or torn. In addition, 120 randomly selected LLINs were tested for bio-efficacy.

Results

The overall attrition of LLINs was 96% (n = 993) during the study period. The nets’ attrition was mainly due to disposal (64.2%; n = 638). The proportion of LLINs with a hole size 0.5 cm or larger was 79.5% after 24 months. The use of the net on the previous night and having a clean net were associated with a good physical integrity. However, living in a household more than 1 km away from the mosquitoes’ breeding site was associated with poor physical integrity. By the 24th month, only 4% of the nets met the criteria for functional survival. The median functional survival time of the nets was 12 months. A longer functional survival was associated with having a clean net, and shorter survival was associated with living in a household more than 1 km away from the mosquitoes’ breeding site. The PermaNet^® 2.0 met the criteria of effective bio-efficacy up to month 24 after distribution.

Conclusions

The study showed that the median serviceable life of LLINs is only 12 months. However, the bio-efficacy of the LLINs is acceptable for at least 24 months. Therefore, stronger and more efficient LLINs need to be developed for conditions similar to those studied here.