We conducted a cross-sectional analytical study to assess the performance of insecticide-treated net (ITN) distribution through routine Expanded Programme on Immunization (EPI) services in public health facilities across seven Provincial Health Divisions (PHDs) in the Democratic Republic of Congo (DRC).

Only public health facilities supported by the Global Fund through SANRU were included in the sampling frame. The Global Fund, through SANRU, implements continuous ITN distribution activities in 17 provinces of the DRC. The Global Fund, through SANRU as principal recipient, implements continuous ITN distribution activities in 17 provinces of the DRC.

The study population consisted of all children aged 6 to 23 months received at the EPI and all pregnant women received at the ANC services; mothers or child keepers of children aged 6 to 23 months for the household side of the survey.

The sample size for the quantitative component was calculated using the formula for estimating a proportion in a population:

$n=\left(Z^2\cdot p\cdot \left(1-p\right)\right)/d^2$

where: i) n is the required sample size, ii) Z is the Z-score corresponding to the desired confidence level (1.96 for 95%), iii) p is the estimated prevalence of poor ITN distribution performance (assumed at 50% to maximize sample size), and iv) d is the margin of error (set at 5%).

Based on these assumptions, the minimum sample size required was 384 households. To account for design effect due to cluster sampling and potential non-response, the sample size was increased by a factor of 3.25, resulting in a final target of approximately 1247 households. This adjustment ensures adequate statistical power and reliability of the findings. The calculation was performed manually and cross-validated using Epi Info software version 7.2.

A multi-stage cluster sampling approach was used to select study participants. Among the 17 Provincial Health Divisions (PHDs) supported by the Global Fund through SANRU, seven were purposively selected based on the degree of discrepancy observed between ITN distribution at ANC and EPI services, as reported in the national DHIS2 database. This included three PHDs with lower discrepancies and four with higher discrepancies. Based on this rationale, we selected Kinshasa, Kongo Central, Kwilu, Nord Kivu, Tshopo, Sud Ubangi, and Equateur ( Figure 1 ).

Within each selected PHD, three health zones (HZs) were randomly chosen, except for Kinshasa, where eight HZs were included due to its larger population and greater observed disparity. In total, 26 HZs were surveyed, representing 8.1% of all HZs in the country.

In each HZ, six health areas (HAs) were randomly selected using the cluster Lot Quality Assurance Sampling (cLQAS) method. Within each HA, ten villages were randomly selected, and one household per village was chosen through segment sampling. Households were visited sequentially until one with an eligible child aged 6 to 23 months was identified, based on the assumption—derived from the 2017-2018 MICS survey—that 60% of households include at least one child under five [14] .

This sampling strategy was designed to ensure geographic diversity and representation of both urban and rural settings, while maintaining feasibility within logistical constraints.

For the household survey, the following inclusion and exclusion criteria were used:

Inclusion Criteria:

Exclusion Criteria

In parallel, institutional visits were conducted in the selected health areas to assess ITN distribution practices at the facility level. At this level, the following inclusion and exclusion criteria were used:

Inclusion Criteria

Exclusion Criteria

Data were collected between January and June 2023 using structured questionnaires administered to mothers or primary caregivers of children aged 6 to 23 months in selected households. The questionnaires captured information on socio-demographic characteristics, child immunization status, and receipt of insecticide-treated nets (ITNs) through EPI services.

Data collection was conducted electronically using the ODK Collect mobile application. Trained field investigators visited each selected household and obtained written informed consent prior to administering the survey. For each eligible child, data were cross-verified with vaccination cards and facility registers when available.

In parallel, institutional data were extracted from health facility records in the selected health areas. This included monthly tallies of ITNs received and distributed through ANC and EPI services, as well as the number of children vaccinated with the first dose of measles vaccine. Registers reviewed included EPI service logs, ANC attendance records, stock cards, and essential drug registers.

All data were transferred to SPSS version 26 for cleaning and analysis. Quality control procedures included daily review of submissions, validation checks, and supervision by the central research coordination team.

The household questionnaire was developed by the SANRU’s Operational Research Unit in collaboration with experts from the Ministry of Health. It was designed to capture key variables related to ITN distribution performance, including child immunization status, ITN receipt, socio-demographic characteristics of caregivers, and exposure to community sensitization activities.

The initial draft of the questionnaire was reviewed by a panel of public health specialists and field supervisors to ensure content validity and contextual relevance. The tool was then pre-tested in two non-sampled health zones to assess clarity, flow, and respondent comprehension. Feedback from the pilot was used to refine question wording, response options, and skip logic.

The final version of the questionnaire was digitized using the ODK Collect platform, with built-in validation rules to minimize data entry errors and ensure consistency across interviews. Enumerators received standardized training on questionnaire administration and ethical procedures prior to field deployment.

All quantitative data were exported from the ODK Collect platform and analyzed using SPSS version 26. Descriptive statistics were used to summarize socio-demographic characteristics and ITN distribution indicators. Categorical variables were presented as frequencies and percentages, while continuous variables were summarized using means and standard deviations or medians and interquartile ranges, depending on the distribution.

The primary outcome was poor ITN distribution performance, defined as a positive difference between the number of ITNs distributed through ANC services and those distributed through EPI services within the same health facility. Bivariate analysis was conducted using the chi-square test to assess associations between independent variables and the outcome.

Multivariate analysis was performed using logistic regression to identify independent predictors of poor ITN distribution performance. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Statistical significance was set at a p-value < 0.05.

This study was conducted with the formal authorization of the Ministry of Public Health of the Democratic Republic of Congo. Prior to data collection, institutional approval was obtained from provincial health authorities and relevant program managers overseeing malaria control and immunization services.

All participants were informed of the study’s objectives, procedures, and their rights as respondents. Written informed consent was obtained from literate participants before administering the questionnaire. For participants who were illiterate, verbal consent was obtained following a standardized explanation of the study in the local language, in the presence of a neutral witness who confirmed the participant’s understanding and voluntary agreement to participate.

Participation was entirely voluntary, and respondents were informed of their right to decline or withdraw at any time without any consequences. No personal identifiers were collected, and all data were anonymized to ensure confidentiality and privacy.

Table 1 shows the characteristics of the surveys according to whether they had already been vaccinated or not.

a: x ± SD; b: median (EIQ).

Table 1 shows that the age of the mothers interviewed was 28.4 years, with a median of 2 children at home. The average age of the last child was 15 months. Most of these children (87.2%) received the measles vaccine at 9 months of age during vaccination sessions at the health center. Most mothers (78.7%) had been sensitized by community health workers (CHWs). Most of the mothers were married, had a secondary education, were housewives, had a low level of education, and lived in mud houses.

Table 2 presents the results obtained from the continuous distribution of ITNs to children under one year of age during the EPI services and to pregnant women during the ANC services.

ITN*: Insecticide-Treated Bed Net; ANC^£: Antenatal Care; Gap measles vaccine-ITN^a: Number of children vaccinated with measles vaccine minus number of children receiving insecticide-treated bed nets. % difference^b: Gap measles vaccine-ITN divided by number of children vaccinated with the measles vaccine.

Of the total number of ITNs distributed (80,669), 43.0% (34,707) concerned children in SPC and 57% (45,962) concerned pregnant women in ANC. The difference between children who received the first dose of the measles vaccine (MV1) and those who received ITNs was 34%, with monthly peaks of up to 54%. There was a 34% difference between children who received MV1 and those who received ITNs, with monthly peaks of up to 54% ( Table 2 ).

Figure 2 shows that of all ITNs received, 55.2% were distributed to pregnant women and 41.7% to children at the EPI services. This figure shows that the gap between ITN distribution at the EPI and MV1 vaccination was almost constant every month.

This figure shows that of all ITNs distributed, 57% were distributed to pregnant women in ANC services and 43% to children in EPI services. This more frequent distribution to pregnant women at ANC compared with children at EPI services was constant almost every month.

Of the 151 HAs surveyed, 101 showed poor performance of MIIs distribution in EPI services, i.e., a frequency of 66.9% ( Figure 3 ).

Table 3 shows the factors associated with poor performance, based on data from the household survey.

In both univariate and multivariate analyses, the mother’s low level of education, low level of income, complete immunization of the child, and mother/caregiver sensitization by CHWs were the determinants significantly associated with poor performance of ITN distribution in EPI services.

The factors explaining the poor performance of ITN distribution at EPI, according to the opinions of the players involved in the ITN distribution service chain for children at EPI services, are presented in Table 4 .

ITN*: Insecticide-Treated Bed Net; CHWs^£: Community Health Workers; RDV^¥: Rendez-vous.

The first 3 explanatory factors mentioned were: the influx of more pregnant women to ANC than children for vaccination (33.1%), advanced sites not supported by ITNs (23.1%), and the low involvement of CHWs in making mothers aware of the need to attend the next appointment.

This discrepancy was attributed to both demand-side and supply-side factors, including low maternal education, low household income, incomplete child immunization, and limited community sensitization by CHWs.

In Ghana, Nigeria, and Kenya, studies have consistently shown that maternal education and household wealth are strong predictors of ITN ownership and use. For instance, Konlan et al. (2022) found that high literacy levels, female-headed households, and antenatal clinic attendance were positively associated with ITN utilization among children under five [15] . Similarly, in Uganda, mothers with secondary or higher education were significantly more likely to use ITNs for their children.

The DRC findings reinforce this pattern, with low maternal education and low household income emerging as the most influential predictors of poor ITN coverage through EPI. Mothers with limited education were eight times more likely (aOR = 8.22) to miss ITN distribution, while low-income households had a fivefold increased risk (aOR = 5.00). These findings align with studies from Ghana, Uganda, and Kenya, which consistently demonstrate that maternal education and economic status are critical determinants of ITN use and access among children under five. Inadequate sensitization by community health workers (CHWs) also significantly contributed to poor coverage (aOR = 3.03), underscoring the vital role of CHWs in demand creation.

The findings reveal a significant disparity in ITN coverage between pregnant women attending antenatal care (ANC) and children under five attending EPI services, with only 43% of ITNs reaching children compared to 57% for pregnant women. This discrepancy persisted despite similar service delivery platforms, suggesting systemic inefficiencies in the EPI distribution channel.

This study highlights a significant gap in the continuous distribution of ITNs to children under five years of age through EPI in the DRC. Despite the strategic integration of ITN distribution with routine immunization services, only 43% of ITNs were distributed to children, compared to 57% to pregnant women attending antenatal care (ANC). The overall poor performance rate of 66.9% in health areas surveyed underscores systemic inefficiencies in the EPI delivery channel.

These findings differ from general regional trends. A recent multi-country review of ITN routine distribution data across seven sub-Saharan African countries—including Ghana, Senegal, Zambia, and Uganda—reported median ITN issuing rates of 64% at ANC and 78% at Expanded Programme on Immunization (EPI) clinics, with country-specific ranges from 31% to 93% at ANC and 39% to 92% at EPI [16] . Compared to these benchmarks, the DRC’s performance through EPI is notably lower, particularly in the EPI distribution channel.

The overall poor performance rate of 66.9% in health areas surveyed aligns with previous reports from the National Malaria Control Program (NMCP), which highlighted suboptimal ITN coverage in routine services despite adequate stock availability [12] . The observed 34% gap between measles vaccination and ITN receipt among children further underscores missed opportunities for integrated service delivery.

Multivariate analysis identified four key factors significantly associated with poor ITN distribution performance: low maternal education, low household income, incomplete child immunization, and lack of sensitization by community health workers (CHWs). These findings are consistent with earlier studies in sub-Saharan Africa, which have demonstrated that maternal education and socioeconomic status are critical determinants of health service utilization and adherence to preventive interventions [5] [8] .

The role of CHWs emerged as particularly salient. Mothers who were not sensitized by CHWs were three times more likely to miss ITN distribution opportunities. In the DRC, lack of sensitization by CHWs (ORa = 3.03) was a key barrier. This finding reinforces the importance of community-based health promotion and the integration of CHWs into routine immunization and malaria prevention programs [6] . This is consistent with findings from Sierra Leone and Rwanda, where active CHW engagement significantly improved ITN coverage and adherence.

Behavioral factors such as perceived malaria risk, seasonal variation, and cultural beliefs also influence ITN use. In Ghana, for example, hot weather, net odor, and lack of visible mosquitoes were cited as reasons for non-use [15] —factors not explicitly explored in the DRC study but potentially relevant.

The DRC study highlighted inequitable ITN allocation, with a bias toward pregnant women at ANC over children at EPI services. This mirrors findings from Tanzania and Mozambique, where stock-outs, logistical bottlenecks, and prioritization of ANC over child health services have led to similar disparities.

Moreover, advanced outreach sites in the DRC were often not supplied with ITNs, a challenge also reported in Ethiopia and Malawi, where remote or mobile clinics frequently lack essential malaria commodities.

Healthcare providers’ opinions corroborated these findings, citing unequal prioritization of ITNs in favor of pregnant women, lack of ITN support at outreach sites, and weak community mobilization as major barriers. These systemic issues reflect gaps in policy implementation and resource allocation, which may undermine the goals of the National Strategic Plan for Malaria Control 2024-2028 [9] .

The findings of this study have important implications for malaria control policy and program implementation in the Democratic Republic of Congo. The persistent underperformance of ITN distribution through EPI services—despite adequate stock availability—highlights systemic inefficiencies in routine service delivery and missed opportunities for integrated child health interventions.

To improve ITN coverage among children under five, national and provincial health authorities should consider the following programmatic actions:

1) Strengthen Equity in ITN Allocation

Current distribution practices favor pregnant women attending ANC services, often at the expense of children at EPI clinics. Policy adjustments are needed to ensure equitable allocation of ITNs across both target groups, particularly in settings with limited stock.

2) Enhance Community Engagement through CHWs

The lack of sensitization by community health workers (CHWs) was a significant predictor of poor ITN uptake. Reinforcing CHW-led outreach and education campaigns can improve caregiver awareness and increase demand for ITNs during immunization visits.

3) Integrate ITN Distribution with Immunization Tracking Systems

Linking ITN distribution to child immunization records—such as measles vaccine administration—can help monitor coverage gaps and ensure that eligible children are not missed.

4) Ensure ITN Availability at All Service Delivery Points

Stock-outs at outreach sites and peripheral health facilities contribute to unequal access. Strengthening supply chain management and forecasting tools is essential to maintain consistent ITN availability, especially in remote areas.

5) Monitor Performance through Routine Data Systems

The use of DHIS2 data to identify discrepancies between ANC and EPI distribution should be institutionalized as part of routine performance monitoring. This can guide targeted supervision and corrective actions at the health zone level.

By addressing these gaps, the DRC can move closer to achieving the objectives outlined in its National Malaria Control Strategic Plan (2024-2028), particularly the goal of reaching 80% ITN coverage among vulnerable populations. This is necessary to optimize the contribution of the EPI, which covers 3.4% of the population, in addition to the PNT, which covers 4% of the population, enabling coverage of nearly 15% of the additional population each year following mass distribution, based on one person sleeping under each ITN. Programmatic reforms should prioritize equity, integration, and accountability to maximize the impact of routine ITN distribution.

This study has several limitations that should be considered when interpreting the findings. First, the analysis was restricted to public health facilities supported by the Global Fund through SANRU, excluding private and non-partnered facilities. This may limit the generalizability of the results to the broader health system in the Democratic Republic of Congo.

Second, although the sampling strategy was designed to ensure geographic diversity, the selection of seven Provincial Health Divisions was purposive and based on observed discrepancies in ITN distribution. As such, the sample may not fully represent provinces with more balanced performance or different operational contexts.

Third, the study did not include a qualitative component, which could have provided deeper insights into operational challenges, provider behaviors, and community perceptions influencing ITN distribution. The absence of this perspective limits the ability to explore contextual and systemic factors beyond those captured quantitatively.

Finally, the cross-sectional design precludes causal inference. While associations between socio-demographic factors and poor ITN distribution performance were identified, longitudinal studies would be needed to confirm causality and assess the impact of targeted interventions over time.

Despite these limitations, the study provides valuable evidence on the structural and behavioral determinants of ITN distribution gaps in routine immunization services and offers actionable insights for program improvement.