In-house environmental factors and childhood acute respiratory infections in under-five children: a hospital-based matched case-control study in Bangladesh.

BACKGROUND: Acute respiratory infection (ARI) is one of the leading causes of morbidity and mortality among children under five globally, particularly in regions like South Asia and sub-Saharan Africa. Bangladesh has made substantial progress in reducing child mortality, yet pneumonia remains a significant contributor to under-five deaths. This study aimed to investigate the association between in-house environmental factors and childhood ARI, considering factors such as household crowding, smoking, and sanitation facilities. METHODS: This case-control study was conducted at a tertiary-level children's hospital in Dhaka, Bangladesh, from March to September 2019. The study included children aged 6-59 months. Cases were children with ARI symptoms, while controls were children without such symptoms. Rigorous matching by age and gender was employed to ensure comparability. Data were collected through structured questionnaires, and bivariate and conditional logistic regression analyses were performed. RESULTS: Several household environmental factors were significantly associated with childhood ARIs. Children from overcrowded households (AOR = 2.66, 95% CI = 1.52-4.71; p < 0.001), those using unclean cooking fuels (OR = 2.41, 95% CI: 1.56, 3.73; p = < 0.001), those exposed to in-house smoking (AOR = 1.74, 95% CI = 1.01, 3.05; p = 0.04) and those with unimproved sanitation facilities faced higher odds (AOR = 4.35, 95% CI = 2.14-9.26) of ARIs. Additionally, preterm birth and higher birth order were associated with an increased risk of ARI. In contrast, exclusive breastfeeding was a protective factor. CONCLUSION: In-house environmental factors, including sanitation, crowding and in-house smoking, significantly influence childhood ARIs. Additionally, birth order and preterm birth play a crucial role. Promoting exclusive breastfeeding is associated with a lower ARI risk among under-five children in Bangladesh. These findings can guide interventions to reduce ARIs in low-income regions, particularly in South Asia.

Influenza-associated mortality in 2009 in four sentinel sites in Bangladesh.

OBJECTIVE: To estimate influenza-associated mortality in Bangladesh in 2009. METHODS: In four hospitals in Bangladesh, respiratory samples were collected twice a month throughout 2009 from inpatients aged < 5 years with severe pneumonia and from older inpatients with severe acute respiratory infection. The samples were tested for influenza virus ribonucleic acid (RNA) using polymerase chain reaction. The deaths in 2009 in five randomly selected unions (the smallest administrative units in Bangladesh) in each hospital's catchment area were then investigated using formal records and informal group discussions. The deaths of those who had reportedly died within 14 days of suddenly developing fever with cough and/or a sore throat were assumed to be influenza-associated. The rate of such deaths in 2009 in each of the catchment areas was then estimated from the number of apparently influenza-associated deaths in the sampled unions, the proportion of the sampled inpatients in the local hospital who tested positive for influenza virus RNA, and the estimated number of residents of the sampled unions. FINDINGS: Of the 2500 people known to have died in 2009 in all 20 study unions, 346 (14%) reportedly had fever with cough and/or sore throat within 14 days of their deaths. The estimated mean annual influenza-associated mortality in these unions was 11 per 100,000 population: 1.5, 4.0 and 125 deaths per 100,000 among those aged < 5, 5-59 and > 59 years, respectively. CONCLUSION: The highest burden of influenza-associated mortality in Bangladesh in 2009 was among the elderly.

Respiratory Viruses Associated Hospitalization among Children Aged <5 Years in Bangladesh: 2010-2014.

BACKGROUND: We combined hospital-based surveillance and health utilization survey data to estimate the incidence of respiratory viral infections associated hospitalization among children aged < 5 years in Bangladesh. METHODS: Surveillance physicians collected respiratory specimens from children aged <5 years hospitalized with respiratory illness and residing in the primary hospital catchment areas. We tested respiratory specimens for respiratory syncytial virus, parainfluenza viruses, human metapneumovirus, influenza, adenovirus and rhinoviruses using rRT-PCR. During 2013, we conducted a health utilization survey in the primary catchment areas of the hospitals to determine the proportion of all hospitalizations for respiratory illness among children aged <5 years at the surveillance hospitals during the preceding 12 months. We estimated the respiratory virus-specific incidence of hospitalization by dividing the estimated number of hospitalized children with a laboratory confirmed infection with a respiratory virus by the population aged <5 years of the catchment areas and adjusted for the proportion of children who were hospitalized at the surveillance hospitals. RESULTS: We estimated that the annual incidence per 1000 children (95% CI) of all cause associated respiratory hospitalization was 11.5 (10-12). The incidences per 1000 children (95% CI) per year for respiratory syncytial virus, parainfluenza, adenovirus, human metapneumovirus and influenza infections were 3(2-3), 0.5(0.4-0.8), 0.4 (0.3-0.6), 0.4 (0.3-0.6), and 0.4 (0.3-0.6) respectively. The incidences per 1000 children (95%CI) of rhinovirus-associated infections among hospitalized children were 5 (3-7), 2 (1-3), 1 (0.6-2), and 3 (2-4) in 2010, 2011, 2012 and 2013, respectively. CONCLUSION: Our data suggest that respiratory viruses are associated with a substantial burden of hospitalization in children aged <5 years in Bangladesh.