Indoor bacterial and fungal aerosols as predictors of lower respiratory tract infections among under-five children in Ibadan, Nigeria

Adekunle Gregory Fakunle; Nkosana Jafta; Lidwien A M Smit; Rajen N Naidoo

doi:10.1186/s12890-022-02271-w

Indoor bacterial and fungal aerosols as predictors of lower respiratory tract infections among under-five children in Ibadan, Nigeria

BMC Pulm Med. 2022 Dec 9;22(1):471. doi: 10.1186/s12890-022-02271-w.

Authors

Adekunle Gregory Fakunle^{1

2}, Nkosana Jafta³, Lidwien A M Smit⁴, Rajen N Naidoo⁵

Affiliations

¹ Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban, 4041, South Africa. fakunz@yahoo.com.
² Department of Public Health, College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria. fakunz@yahoo.com.
³ Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban, 4041, South Africa.
⁴ Institute for Risk Assessment (IRAS), Utrecht University, Utrecht, The Netherlands.
⁵ Discipline of Occupational and Environmental Health, University of KwaZulu-Natal, 321 George Campbell Building Howard College Campus, Durban, 4041, South Africa. naidoon@ukzn.ac.za.

Abstract

Background: This study aimed to investigate the association between exposure to diverse indoor microbial aerosols and lower respiratory tract infections (LRTI) among children aged 1 to 59 months in Ibadan, Nigeria.

Methods: One hundred and seventy-eight (178) hospital-based LRTI cases among under-five children were matched for age (± 3 months), sex and geographical location with 180 community-based controls (under-five children without LRTI). Following consent from caregivers of eligible participants, a child's health questionnaire, clinical proforma and standardized home-walkthrough checklist were used to collect data. Participant homes were visited and sampled for indoor microbial exposures using active sampling approach by Anderson sampler. Indoor microbial count (IMC), total bacterial count (TBC), and total fungal count (TFC) were estimated and dichotomized into high (> median) and low (≤ median) exposures. Alpha diversity measures including richness (R), Shannon (H) and Simpson (D) indices were also estimated. Conditional logistic regression models were used to test association between exposure to indoor microbial aerosols and LRTI risk among under-five children.

Results: Significantly higher bacterial and fungal diversities were found in homes of cases (R = 3.00; H = 1.04; D = 2.67 and R = 2.56; H = 0.82; D = 2.33) than homes of controls (R = 2.00; H = 0.64; D = 1.80 and R = 1.89; H = 0.55; D = 1.88) p < 0.001, respectively. In the multivariate models, higher categories of exposure to IMC (aOR = 2.67, 95% CI 1.44-4.97), TBC (aOR = 2.51, 95% CI 1.36-4.65), TFC (aOR = 2.75, 95% CI 1.54-4.89), bacterial diversity (aOR = 1.87, 95% CI 1.08-3.24) and fungal diversity (aOR = 3.00, 95% CI 1.55-5.79) were independently associated with LRTI risk among under-five children.

Conclusions: This study suggests an increased risk of LRTI when children under the age of five years are exposed to high levels of indoor microbial aerosols.

Keywords: Ibadan; Indoor microbial aerosols; Lower respiratory tract infections; Sub-Saharan Africa; Under-five children.

MeSH terms

Bacteria
Child
Colony Count, Microbial
Humans
Infant
Nigeria / epidemiology
Respiratory Aerosols and Droplets*
Respiratory Tract Infections* / epidemiology