Ngatu et al. Malar J (2019) 18:53 https://doi.org/10.1186/s12936-019-2679-0 Malaria Journal RESEARCH Open Access Environmental and sociodemographic factors associated with household malaria burden in the Congo Nlandu Roger Ngatu1* , Sakiko Kanbara2, Andre Renzaho3, Roger Wumba4, Etongola P. Mbelambela5, Sifa M. J. Muchanga6, Basilua Andre Muzembo1, Ngombe Leon‑Kabamba7, Choomplang Nattadech1, Tomoko Suzuki1, Numbi Oscar‑Luboya8, Koji Wada1, Mitsunori Ikeda2, Sayumi Nojima2, Tomohiko Sugishita9 and Shunya Ikeda1 Abstract Background: Malaria is one of the most severe public health issues that result in massive morbidity and mortality in most countries of the sub‑Saharan Africa (SSA). This study aimed to determine the scope of household, accessibility to malaria care and factors associated with household malaria in the Democratic Republic of Congo (DRC). Methods: This was a community‑based cross‑sectional study conducted in an urban and a rural sites in which 152 households participated, including 82 urban and 70 rural households (1029 members in total). The ‘malaria indicator questionnaire’ (MIQ) was anonymously answered by household heads (respondents), reporting on malaria status of household members in the last 12 months. Results: There were 67.8% of households using insecticide‑treated bed nets (ITN) only, 14.0% used indoor residual spraying (IRS) only, 7.3% used ordinary bed nets (without insecticide treatment), 1.4% used mosquito repelling cream, 2.2% combined ITN and IRS, whereas 7.3% of households did not employ any preventive measure; p < 0.01). In addi‑ tion, 96.7% of households were afected by malaria (at least one malaria case), and malaria frequency per household was relatively high (mean: 4.5 3.1 cases reported) in the last 12 months. The mean individual malaria care expendi‑ ture was relatively high (101.6 ± 10.6 USD) in the previous 12 months; however, the majority of households (74.5%) earned less than 50 USD monthly.± In addition, of the responders who sufered from malaria, 24.1% did not have access to malaria care at a health setting. Furthermore, a multivariate analysis with adjustment for age, education level and occupation showed that household size (OR 1.43 0.13; 95% CI 1.18–1.73; p < 0.001), inappropriate water source (OR 2.41 0.18; 95% CI 1.17–2.96; p < 0.05) =absence± of periodic water, sanitation and hygiene (WASH) intervention in residential= ±area (OR 1.63 1.15; 95% CI 1.10–2.54; p < 0.05), and rural residence (OR 4.52 2.47; 95% CI 1.54–13.21; p < 0.01) were associated= with± household malaria. = ± Conclusion: This study showed that household size, income, WASH status and rural site were malaria‑associated fac‑ tors. Scaling up malaria prevention through improving WASH status in the residential environment may contribute to reducing the disease burden. Keywords: Environment, Household malaria, Income, Sanitation *Correspondence: [email protected] 1 School of Medicine and Graduate School of Public Health, International University of Health and Welfare, Narita, Japan Full list of author information is available at the end of the article © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creat iveco mmons .org/ publi cdoma in/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Ngatu et al. Malar J (2019) 18:53 Page 2 of 9 Background Methods Recent reports from the World Health Organization Study design, sites and participants (WHO) show progress made by several countries in Tis was an observational community-based cross- reducing malaria burden, with a decline in preventable sectional study conducted in two sites located in two child deaths over the 15-year period of the implemen- diferent provinces: Kasangulu, a rural town in Kongo tation of millennium development goals (MDGs). Epi- central province, and Limete, an urban county located demiologic figures show that over 6.2 million malaria in the capital Kinshasa. Invitations were sent to two deaths were averted between 2000 and 2015 in sub- communities in each study sites to join this survey and Saharan Africa (SSA) [1]. Malaria is an infectious dis- 181 survey sheets were distributed, of which 152 were ease that continues to pose a major health challenge; it completed. Tus, this study sample was 152 households is still endemic in 97 countries, including the Demo- (82 from urban and 70 from rural study sites), consist- cratic Republic of Congo (DRC) where only 56% of ing of 1029 individuals. Home visits were carried out children under age five sleep under insecticide-treated for to evaluate WASH status, the quality of malaria pre- bed nets [2–4]. In several malaria-affected countries, vention tools used by households. scale-up interventions are being implemented to Participation was voluntary, and heads of households reduce the disease burden, such as long-lasting insec- were enrolled in their respective communities (cultural ticide-treated nets (LLIN), indoor residual spraying or social centre, club and church) after attending meet- (IRS), rapid diagnostic tests (RDT) and artemisinin- ings in which a thorough explanation about the survey based combination treatment (ACT). was delivered. Each participating community provided Despite the progress made in the fight against a codifed list of volunteer participants. Te same codes malaria, a number of challenges are currently reduc- were transcribed on questionnaire sheets that were ing the impact of antimalarial interventions such as later distributed to participants. the emergence of drug-resistant malaria parasites and mosquitoes resistant to insecticides, and the existence of fake malaria drugs [3, 5, 6]. Furthermore, many of Survey questionnaire high malaria burden countries such as Nigeria and Te ‘Malaria Indicator Questionnaire (MIQ) [12, 13], a DRC have been reporting significant increases in dis- standardized structured and self-administered survey ease cases [4], suggesting the necessity for further questionnaire, was used in this study. MIQ is a com- research that could culminate in the discovery of new posite questionnaire that comprises items that cor- strategies for malaria control. respond to fve main themes, including personal and Primary health care (PHC) system has been playing household sociodemographic and clinical character- a crucial role in reducing malaria burden in endemic istics of respondents (household heads) at the time of countries, and such an achievement can only be this survey, lifestyle pattern, personal and family medi- reached if adequate infrastructure, delivery mecha- cal history, and information on WASH status at home nisms and uptake for PHC coverage are available, in and in the living environment, and malaria preventive addition to minimum acceptable income. Moreover, in measures and care options. It is a survey questionnaire the context of malaria endemic countries, there is still from ‘Te World Bank and WHO Malaria Programme’ a need to make malaria preventive and curative treat- in Africa, commonly used by many western and eastern ments not only available but also accessible [7–9]. In African countries to evaluate their respective malaria DRC, given extreme poverty and the dysfunction of programmes. Considering the relatively high illiteracy the national health system due to cyclic armed con- rate in the country, the questionnaire was self-admin- flicts, insecurity and governance issues, universal istered for educated respondents; whereas, for illiter- health coverage (UHC) remains a dream. In DRC, pov- ate respondents, the team of surveyors (which included erty-related inaccessibility to health care has caused trained community health nurses and a medical doctor) increased rates of self-medication and use of herbal explained each question in a local dialect and guided medicines [10, 11]. them. This first ‘Congo Malaria and Environment study’ was conducted to determine the frequency of malaria in households, malaria care accessibility and fac- Study outcome variables tors associated with household malaria, as well as the For this study, the outcomes were household malaria impact of water, sanitation, hygiene (WASH) status incidence (number of incident cases) in the previous and income on disease burden. 12 months, and accessibility to malaria care at a medical settings. Ngatu et al. Malar J (2019) 18:53 Page 3 of 9 Ethical considerations and data analysis Table 1 Characteristics of respondents and households Ethical approvals of the study were obtained from the Characteristics N % ethics committee of the Graduate School of Nursing, (1) Respondents (household heads; n 152) University of Kochi, Japan, and the School of Public = Health of the University of Lubumbashi, DRC. Signed Gender written informed consent was obtained from each house- Male 78 51.3 hold head. Female 74 48.7 For data analysis, Stata statistical software version 14 Age (years) (Stata Corp.; TX, US) was employed. Diferences between 20–29 24 15.8 categories of qualitative variables (study site, sociodemo- 30–39 61 40.2 graphic characteristics, preventive measures, and place of 40–49 37 24.3 malaria care) and dichotomized variables (WASH param- 50–70 30 19.7 eters, range of household malaria cases, and household Marital status income status) were assessed with the use of Chi square Married 99 65.1 test. Te breakdown of WASH components was per- Divorced 6 4.0 formed as follows: Widowed 8 5.2 Single with children 22 14.5 1. Household latrine (toilet): appropriate (pit latrine Single without children 17 11.2 with slab and fush; pit latrine with slab and manual Education fush) or inappropriate (pit latrine without slab); Never gone to school 11 7.2 2.