Mass Distribution Of Long-lasting Insecticidal Nets Research Articles

Long-Lasting Insecticidal Net Ownership and Use in Mogode Health District, Cameroon.

Cameroon is a malaria-endemic country. Many control strategies including long-lasting insecticidal nets (LLIN) have been proposed to reduce the burden of malaria. The World Health Organization aims to achieve at least 80% of people sleeping under a LLIN. This study assessed the ownership and use of LLNs in the Mogode Health District (MHD). A community-based cross-sectional study was conducted in MHD in September 2021. Data on ownership and LLINs use were collected using structured questionnaires following the Roll Back Malaria guidelines. Univariate and multivariate analyses were performed to assess the determinants of ownership and failure to LLIN use. A total of 332 households were included from eight health areas. The proportion of households with at least one LLIN was 72.0% (238). However, 232 (70.0%) reported having used LLIN (sleeping under LLIN the previous night). Household heads with higher education were six times more likely to have owned LLINs than those with no education (adjusted odds ratio (AOR)=6.8; confidence interval (CI) 1.5, 31.0, p< 0.05). Additionally, household heads between the ages of 36-50 were 4.2 times (AOR= 4.2, CI 1.3-13.8, p< 0.05) likely to fail to use LLINs in households. However, households where heads had secondary education (AOR= 0.2, CI 0.1-0.6, p< 0.05), were negatively associated with failure to use LLINs. Ownership and use of LLINs in MHD remain challenging. Therefore, this finding will contribute to improving recommendations and updating strategies such as targeted messages aimed at raising awareness of malaria during mass LLIN distribution campaigns.

Prevalence and predictors of adverse events following exposure to long-lasting insecticidal nets used for malaria prevention: a community based cross-sectional study in the Democratic Republic of the Congo

BackgroundMalaria morbidity and mortality increase in the Democratic Republic of the Congo (DRC) may be the consequence of the low utilization rate of long-lasting insecticidal nets (LLINs) resulting from poor compliance due to adverse events (AEs). This study aimed at determining the prevalence and predictors of AEs following the mass distribution of LLINs in the Kisantu Health Zone (KHZ), a high malaria-endemic region in the DRC.MethodsA community-based cross-sectional study embedded was conducted within a randomized controlled trial (RCT) after the mass distribution of LLINs in 30 villages located in DRC KHZ. A three-stage sampling method was used without replacement to select 1790 children. Data was collected on adverse events (AEs) using a reporting form and information on demographics, nutritional status, and house characteristics. This was done using a structured questionnaire administered to household heads. Logistic regression models were used to identify predictors of AEs following the mass distribution of LLINs.ResultIn a total of 1790 children enrolled, 17.8% (95% CI 16.1–19.7) experienced AEs. The most common AEs were respiratory-related (61%). Around 60% of AEs occurred within 24 h of use, and 51% were resolved without treatment. Sleeping under deltamethrin LLINs (Adjusted OR, 95% CI 5.5 [3.8–8.0]) and zinc roofing (Adjusted OR, 95% CI 1.98 [1.1–3.57]) were associated with the risk of reporting an AE following the mass distribution of LLINs.ConclusionApproximately 1 out of 5 children had an AE within 24 h following LLIN use. These adverse events were often respiratory-related. LLINs and roofing types were associated with a higher risk of reporting AEs. However, further research using a robust study design is needed to confirm these findings. Future studies should design and implement interventions aiming to reduce AEs and improve compliance with LLINs.

Effect of Health Education through Community Leaders on Increase Utilization of Households Regarding LLINs in Intervention and Control Villages of New Halfa Locality-Kassala State (2017-2020)

The long-lasting insecticidal nets (LLIN) are effective against prevention of malaria and its utilization has been proven to save lives. Despite the mass distribution of LLIN, Nigeria remains the country with the highest malaria burden in Africa. . The current study aimed to assess the effect of Health Education through Community leaders on increased knowledge of Households Regarding malaria control, treatment and prevention in intervention and control villages of New Halfa Locality-Kassala State (2017-2020). Randomized community trials (Controlled intervention study) in New Halfa locality among two communities were randomly assigned to intervention group which receive health education messages regarding the use of LLINs and control group where there is no health education. Standard Questionnaire was use to collect data from the head of household at each village. The information collected should include the owner and using LLINs, distributed to household. The observation the conditions of LLINs. This Questionnaire was done with committee for integrated vector management - Federal Ministry of Health and WHO. The major source of information was TV in control (23.2%) and intervention villages (22.8%) with no significant difference, p&gt; 0.05. There was no significant difference between intervention and control regarding sleeping under net last night (p=.87). The proportion of households slept under nets was not significantly slightly increased in intervention villages (51.9%) compared to control villages (48.1%). The most reasons for not sleeping under nets in control and intervention villages was significantly were no mosquito, no need, hot weather, bad feeling, owner absence and other reasons not mentioned. The frequency distribution of number of bed nets per household. The number of bed nets per household in control villages was found to be 3.7(1.9%) during survey I , 3.1 (1.5%) during survey П and 3.2 (1.6%) during the survey Ш with mean of 3.2 (1.6%). However, the number of bed nets in intervention villages during surveyI , survey П, survey were found 3.7 (1.9%), 3.2 (1.4%) and 2.9 (1.4%) respectively with mean of 3.3 (1.7%). The number of households in control group during survey I was 2541 (44.8%), survey П 1838 (32.4%) and during survey Ш 1300 (22.9%). While the number of households in intervention villages during survey I 2526 (41.8%), survey П 1997 (33.1%) and during survey Ш was 1514 (25.1%). The ownership of bed nets was 100% in control village during surveyI, survey П and survey Ш, but the ownership was slightly decreased in intervention villages during survey I (99.4%) and during survey Ш (99.6%). Regarding use of nets, the use of bed nets during survey I in control villages was found high 70.8% compared to intervention villages (64.1%) while remarkable increased in bed nets use during survey П (82%) and survey Ш ( 55.8%) in intervention villages compared to control villages (74.8%), (47%) respectively. This may be due to health education packages. It can be concluded that the overall knowledge was fair in the present study. This could be attributed to the media campaign sessions during net distribution and to the role of community leaders in these campaigns. Also in other words this study has demonstrated the effectiveness of health education as vital tool for improving the knowledge of malaria and utilization of LLINs.

Effect of Health Education through Community Leaders on Increase Utilization of Households Regarding LLINs in Intervention and Control Villages of New Halfa Locality-Kassala State (2017-2020)

The long-lasting insecticidal nets (LLIN) are effective against prevention of malaria and its utilization has been proven to save lives. Despite the mass distribution of LLIN, Nigeria remains the country with the highest malaria burden in Africa. . The current study aimed to assess the effect of Health Education through Community leaders on increased knowledge of Households Regarding malaria control, treatment and prevention in intervention and control villages of New Halfa Locality-Kassala State (2017-2020). Randomized community trials (Controlled intervention study) in New Halfa locality among two communities were randomly assigned to intervention group which receive health education messages regarding the use of LLINs and control group where there is no health education. Standard Questionnaire was use to collect data from the head of household at each village. The information collected should include the owner and using LLINs, distributed to household. The observation the conditions of LLINs. This Questionnaire was done with committee for integrated vector management - Federal Ministry of Health and WHO. The major source of information was TV in control (23.2%) and intervention villages (22.8%) with no significant difference, p&gt; 0.05. There was no significant difference between intervention and control regarding sleeping under net last night (p=.87). The proportion of households slept under nets was not significantly slightly increased in intervention villages (51.9%) compared to control villages (48.1%). The most reasons for not sleeping under nets in control and intervention villages was significantly were no mosquito, no need, hot weather, bad feeling, owner absence and other reasons not mentioned. The frequency distribution of number of bed nets per household. The number of bed nets per household in control villages was found to be 3.7(1.9%) during survey I , 3.1 (1.5%) during survey П and 3.2 (1.6%) during the survey Ш with mean of 3.2 (1.6%). However, the number of bed nets in intervention villages during surveyI , survey П, survey were found 3.7 (1.9%), 3.2 (1.4%) and 2.9 (1.4%) respectively with mean of 3.3 (1.7%). The number of households in control group during survey I was 2541 (44.8%), survey П 1838 (32.4%) and during survey Ш 1300 (22.9%). While the number of households in intervention villages during survey I 2526 (41.8%), survey П 1997 (33.1%) and during survey Ш was 1514 (25.1%). The ownership of bed nets was 100% in control village during surveyI, survey П and survey Ш, but the ownership was slightly decreased in intervention villages during survey I (99.4%) and during survey Ш (99.6%). Regarding use of nets, the use of bed nets during survey I in control villages was found high 70.8% compared to intervention villages (64.1%) while remarkable increased in bed nets use during survey П (82%) and survey Ш ( 55.8%) in intervention villages compared to control villages (74.8%), (47%) respectively. This may be due to health education packages. It can be concluded that the overall knowledge was fair in the present study. This could be attributed to the media campaign sessions during net distribution and to the role of community leaders in these campaigns. Also in other words this study has demonstrated the effectiveness of health education as vital tool for improving the knowledge of malaria and utilization of LLINs.

Insecticide resistance and behavioural adaptation as a response to long-lasting insecticidal net deployment in malaria vectors in the Cascades region of Burkina Faso

The decline in malaria across Africa has been largely attributed to vector control using long-lasting insecticidal nets (LLINs). However, this intervention has prompted widespread insecticide resistance (IR) and been associated with changes in mosquito behaviour that reduce their contact with LLINs. The relative importance and rate at which IR and behavioural adaptations emerge are poorly understood. We conducted surveillance of mosquito behaviour and IR at 12 sites in Burkina Faso to assess the magnitude and temporal dynamics of insecticide, biting and resting behaviours in vectors in the 2-year period following mass LLIN distribution. Insecticide resistance was present in all vector populations and increased rapidly over the study period. In contrast, no longitudinal shifts in LLIN-avoidance behaviours (earlier or outdoor biting and resting) were detected. There was a moderate but statistically significant shift in vector species composition from Anopheles coluzzii to Anopheles gambiae which coincided with a reduction in the proportion of bites preventable by LLINs; possibly driven by between-species variation in behaviour. These findings indicate that adaptations based on insecticide resistance arise and intensify more rapidly than behavioural shifts within mosquito vectors. However, longitudinal shifts in mosquito vector species composition were evident within 2 years following a mass LLIN distribution. This ecological shift was characterized by a significant increase in the exophagic species (An. gambiae) and coincided with a predicted decline in the degree of protection expected from LLINs. Although human exposure fell through the study period due to reducing vector densities and infection rates, such ecological shifts in vector species along with insecticide resistance were likely to have eroded the efficacy of LLINs. While both adaptations impact malaria control, the rapid increase of the former indicates this strategy develops more quickly in response to selection from LLINS. However, interventions targeting both resistance strategies will be needed.

Intensity of pyrethroid resistance in Anopheles gambiae before and after a mass distribution of insecticide-treated nets in Kinshasa and in 11 provinces of the Democratic Republic of Congo

BackgroundBetween 2011 and 2018, an estimated 134.8 million pyrethroid-treated long-lasting insecticidal nets (LLINs) were distributed nationwide in the Democratic Republic of Congo (DRC) for malaria control. Pyrethroid resistance has developed in DRC in recent years, but the intensity of resistance and impact on LLIN efficacy was not known. Therefore, the intensity of resistance of Anopheles gambiae sensu lato (s.l.) to permethrin and deltamethrin was monitored before and after a mass distribution of LLINs in Kinshasa in December 2016, and in 6 other sites across the country in 2017 and 11 sites in 2018.MethodsIn Kinshasa, CDC bottle bioassays using 1, 2, 5, and 10 times the diagnostic dose of permethrin and deltamethrin were conducted using An. gambiae s.l. collected as larvae and reared to adults. Bioassays were conducted in four sites in Kinshasa province 6 months before a mass distribution of deltamethrin-treated LLINs and then two, six, and 10 months after the distribution. One site in neighbouring Kongo Central province was used as a control (no mass campaign of LLIN distribution during the study). Nationwide intensity assays were conducted in six sites in 2017 using CDC bottle bioassays and in 11 sites in 2018 using WHO intensity assays. A sub-sample of An. gambiae s.l. was tested by PCR to determine species composition and frequency of kdr-1014F and 1014S alleles.ResultsIn June 2016, before LLIN distribution, permethrin resistance intensity was high in Kinshasa; the mean mortality rate was 43% at the 5× concentration and 73% at the 10× concentration. Bioassays at 3 time points after LLIN distribution showed considerable variation by site and time and there was no consistent evidence for an increase in pyrethroid resistance intensity compared to the neighbouring control site. Tests of An. gambiae s.l. in 6 sites across the country in 2017 and 11 sites in 2018 showed all populations were resistant to the diagnostic doses of 3 pyrethroids. In 2018, the intensity of resistance varied by site, but was generally moderate for all three pyrethroids, with survivors at ×5 the diagnostic dose. Anopheles gambiae sensu stricto (s.s.) was the most common species identified across 11 sites in DRC, but in Kinshasa, An. gambiae s.s. (91%) and Anopheles coluzzii (8%) were sympatric.ConclusionsModerate or high intensity pyrethroid resistance was detected nationwide in DRC and is a serious threat to sustained malaria control with pyrethroid LLINs. Next generation nets (PBO nets or bi-treated nets) should be considered for mass distribution.

Rapid shifts in the age-specific burden of malaria following successful control interventions in four regions of Uganda

BackgroundMalaria control using long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) has been associated with reduced transmission throughout Africa. However, the impact of transmission reduction on the age distribution of malaria cases remains unclear.MethodsOver a 10-year period (January 2009 to July 2018), outpatient surveillance data from four health facilities in Uganda were used to estimate the impact of control interventions on temporal changes in the age distribution of malaria cases using multinomial regression. Interventions included mass distribution of LLINs at all sites and IRS at two sites.ResultsOverall, 896,550 patient visits were included in the study; 211,632 aged < 5 years, 171,166 aged 5–15 years and 513,752 > 15 years. Over time, the age distribution of patients not suspected of malaria and those malaria negative either declined or remained the same across all sites. In contrast, the age distribution of suspected and confirmed malaria cases increased across all four sites. In the two LLINs-only sites, the proportion of malaria cases in < 5 years decreased from 31 to 16% and 35 to 25%, respectively. In the two sites receiving LLINs plus IRS, these proportions decreased from 58 to 30% and 64 to 47%, respectively. Similarly, in the LLINs-only sites, the proportion of malaria cases > 15 years increased from 40 to 61% and 29 to 39%, respectively. In the sites receiving LLINs plus IRS, these proportions increased from 19 to 44% and 18 to 31%, respectively.ConclusionsThese findings demonstrate a shift in the burden of malaria from younger to older individuals following implementation of successful control interventions, which has important implications for malaria prevention, surveillance, case management and control strategies.

Factors associated with utilization of LLINs among women of child-bearing age in Igabi, Kaduna State, Nigeria

BackgroundThe long-lasting insecticidal nets (LLIN) are effective against prevention of malaria and its utilization has been proven to save lives. Despite the mass distribution of LLIN, Nigeria remains the country with the highest malaria burden in Africa. The awareness of LLIN in Nigeria is high, but the utilization is low. The aim of this work is to describe factors associated with the utilization of LLIN among women of child-bearing age (WCBA) in Igabi, Kaduna, Nigeria.MethodsA cross-sectional survey was conducted among 630 WCBA selected using a multi-stage sampling at 63 randomly selected villages in Igabi Local Government Area of Kaduna State. Trained female data collectors administered pre-tested structured questionnaires adapted from the Malaria Indicator Survey. Information collected were demographic profile, knowledge of LLIN as a preventive strategy for malaria, and LLIN ownership and utilization. LLIN utilization was assessed by identifying household members that slept under the hanged LLIN the night before the survey. Questions on the awareness of LLIN, ability to define what it is, use of LLIN, what differentiates LLIN from other bed nets, and duration of use before replacement, were scored and categorized as good, average and poor knowledge of LLIN.ResultsA total of 629 WCBA was sampled, their mean age (± SD) was 29.3 (± 6.2) years, 22.0% were pregnant, 40.5% had no formal education, 41.1% were employed, and 47.7% lived in rural communities. Awareness and good knowledge about LLINs for the prevention of malaria was 96.0% and 24.0%, respectively. The proportion of women who slept under a LLIN the night before the survey (utilization) was 70.0% and slightly higher (74.0%) among pregnant WCBA. Women who lived in rural communities were more likely to utilize LLINs compared to their urban counterparts (OR 3.4; 95% CI 2.3–4.9). Younger women (aged < 30 years) were less likely to utilize LLINs compared to the older women (OR 0.7; 95% CI 0.5–0.9).ConclusionsThe knowledge of LLIN among WCBA was poor, but LLIN utilization was moderate. Living in rural communities and older WCBA were significant characteristics associated with LLIN utilization. Strategies that will improve the utilization of LLIN among the young and urban WCBA should be the focus of the Malaria Elimination Programme (MEP).

Free mass distribution of long lasting insecticidal nets lead to high levels of LLIN access and use in Madagascar, 2010: A cross-sectional observational study.

BackgroundMadagascar conducted the first two phases of a national free mass distribution campaign of long-lasting insecticidal nets (LLINs) during a political crisis in 2009 aiming to achieve coverage of two LLINs per household as part of the National Malaria Control Strategy. The campaign targeted households in 19 out of 91 total health districts.MethodsA community-based cross-sectional household survey using a three-stage cluster sample design was conducted four months post campaign to assess LLIN ownership, access and use. Multivariable logistic regression analysis was used to identify factors associated with household LLIN access and individual LLIN use.ResultsA total of 2211 households were surveyed representing 8867 people. At least one LLIN was present in 93.5% (95% confidence interval [CI], 91.6–95.5%) of households and 74.8% (95% CI, 71.0–78.6%) owned at least two LLINs. Access measured as the proportion of the population that could potentially be covered by household-owned LLINs was 77.2% (77.2% (95% CI, 72.9–81.3%) and LLIN use by all individuals was 84.2% (95% CI, 81.2–87.2%). LLIN use was associated with knowledge of insecticide treated net use to prevent malaria (OR = 3.58, 95% CI, 1.85–6.94), household ownership of more LLINs (OR 2.82, 95% CI 1.85–4.3), presence of children under five (OR = 2.05, 95% CI, 1.67–2.51), having traveled to the distribution point and receiving information about hanging a bednet (OR = 1.56, 95% CI, 1.41–1.74), and having received a post-campaign visit by a community mobilizer (OR = 1.75, 95% CI, 1.26–2.43). Lower LLIN use was associated with increasing household size (OR = 0.81 95% CI 0.77–0.85) and number of sleeping spaces (OR = 0.55, 95% CI, 0.44–0.68).ConclusionsA large scale free mass LLIN distribution campaign was feasible and effective at achieving high LLIN access and use in Madagascar. Campaign process indicators highlighted potential areas for strengthening implementation to optimize access and equity.

Physical durability of two types of long-lasting insecticidal nets (LLINs) three years after a mass LLIN distribution campaign in Mozambique, 2008-2011.

We conducted a prospective evaluation to measure the physical durability of two brands of long-lasting insecticidal nets (LLINs) distributed during a campaign in 2008 in Nampula Province, Mozambique. Households with LLINs tagged during the campaign (6,000) were geo-located (34%) and a random sample was selected for each of 3 years of follow-up. The LLINs were evaluated in the field and a laboratory for presence of holes and a proportional hole index (pHI) was calculated following the World Health Organization guidelines. We performed 567 interviews (79.0%) and found 75.3% (72.1-78.4%) of households retained at least one LLIN after 3 years; the most common cause of attrition was damage beyond repair (51.0%). Hole damage was evident after 1 year, and increased by year. Olyset had a significantly greater mean number of holes and pHI compared with PermaNet 2.0 brand (all P values ≤ 0.001). Additional information about LLIN durability is recommended to improve malaria control efforts.

Effects of changing mosquito host searching behaviour on the cost effectiveness of a mass distribution of long-lasting, insecticidal nets: a modelling study

BackgroundThe effectiveness of long-lasting, insecticidal nets (LLINs) in preventing malaria is threatened by the changing biting behaviour of mosquitoes, from nocturnal and endophagic to crepuscular and exophagic, and by their increasing resistance to insecticides.MethodsUsing epidemiological stochastic simulation models, we studied the impact of a mass LLIN distribution on Plasmodium falciparum malaria. Specifically, we looked at impact in terms of episodes prevented during the effective life of the batch and in terms of net health benefits (NHB) expressed in disability adjusted life years (DALYs) averted, depending on biting behaviour, resistance (as measured in experimental hut studies), and on pre-intervention transmission levels.ResultsResults were very sensitive to assumptions about the probabilistic nature of host searching behaviour. With a shift towards crepuscular biting, under the assumption that individual mosquitoes repeat their behaviour each gonotrophic cycle, LLIN effectiveness was far less than when individual mosquitoes were assumed to vary their behaviour between gonotrophic cycles. LLIN effectiveness was equally sensitive to variations in host-searching behaviour (if repeated) and to variations in resistance. LLIN effectiveness was most sensitive to pre-intervention transmission level, with LLINs being least effective at both very low and very high transmission levels, and most effective at around four infectious bites per adult per year. A single LLIN distribution round remained cost effective, except in transmission settings with a pre-intervention inoculation rate of over 128 bites per year and with resistant mosquitoes that displayed a high proportion (over 40%) of determined crepuscular host searching, where some model variants showed negative NHB.ConclusionsShifts towards crepuscular host searching behaviour can be as important in reducing LLIN effectiveness and cost effectiveness as resistance to pyrethroids. As resistance to insecticides is likely to slow down the development of behavioural resistance and vice versa, the two types of resistance are unlikely to occur within the same mosquito population. LLINs are likely cost effective interventions against malaria, even in areas with strong resistance to pyrethroids or where a large proportion of host-mosquito contact occurs during times when LLIN users are not under their nets.