Household-level risk factors for secondary influenza-like illness in a rural area of Bangladesh

This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Objective To describe household‐level risk factors for secondary influenza‐like illness (ILI), an important public health concern in the low‐income population of Bangladesh. Methods Secondary analysis of control participants in a randomised controlled trial evaluating the effect of handwashing to prevent household ILI transmission. We recruited index‐case patients with ILI – fever (<5 years); fever, cough or sore throat (≥5 years) – from health facilities, collected information on household factors and conducted syndromic surveillance among household contacts for 10 days after resolution of index‐case patients’ symptoms. We evaluated the associations between household factors at baseline and secondary ILI among household contacts using negative binomial regression, accounting for clustering by household. Results Our sample was 1491 household contacts of 184 index‐case patients. Seventy‐one percentage reported that smoking occurred in their home, 27% shared a latrine with one other household and 36% shared a latrine with >1 other household. A total of 114 household contacts (7.6%) had symptoms of ILI during follow‐up. Smoking in the home (RRadj 1.9, 95% CI: 1.2, 3.0) and sharing a latrine with one household (RRadj 2.1, 95% CI: 1.2, 3.6) or >1 household (RRadj 3.1, 95% CI: 1.8–5.2) were independently associated with increased risk of secondary ILI. Conclusion Tobacco use in homes could increase respiratory illness in Bangladesh. The mechanism between use of shared latrines and household ILI transmission is not clear. It is possible that respiratory pathogens could be transmitted through faecal contact or contaminated fomites in shared latrines

Impact of Intensive Handwashing Promotion on Secondary Household Influenza-Like Illness in Rural Bangladesh: Findings from a Randomized Controlled Trial

<div><p>Rationale</p><p>There is little evidence for the efficacy of handwashing for prevention of influenza transmission in resource-poor settings. We tested the impact of intensive handwashing promotion on household transmission of influenza-like illness and influenza in rural Bangladesh.</p><p>Methods</p><p>In 2009–10, we identified index case-patients with influenza-like illness (fever with cough or sore throat) who were the only symptomatic person in their household. Household compounds of index case-patients were randomized to control or intervention (soap and daily handwashing promotion). We conducted daily surveillance and collected oropharyngeal specimens. Secondary attack ratios (SAR) were calculated for influenza and ILI in each arm. Among controls, we investigated individual risk factors for ILI among household contacts of index case-patients.</p><p>Results</p><p>Among 377 index case-patients, the mean number of days between fever onset and study enrollment was 2.1 (SD 1.7) among the 184 controls and 2.6 (SD 2.9) among 193 intervention case-patients. Influenza infection was confirmed in 20% of controls and 12% of intervention index case-patients. The SAR for influenza-like illness among household contacts was 9.5% among intervention (158/1661) and 7.7% among control households (115/1498) (SAR ratio 1.24, 95% CI 0.92–1.65). The SAR ratio for influenza was 2.40 (95% CI 0.68–8.47). In the control arm, susceptible contacts <2 years old (RR_adj 5.51, 95% CI 3.43–8.85), those living with an index case-patient enrolled ≤24 hours after symptom onset (RR_adj 1.91, 95% CI 1.18–3.10), and those who reported multiple daily interactions with the index case-patient (RR_adj 1.94, 95% CI 1.71–3.26) were at increased risk of influenza-like illness.</p><p>Discussion</p><p>Handwashing promotion initiated after illness onset in a household member did not protect against influenza-like illness or influenza. Behavior may not have changed rapidly enough to curb transmission between household members. A reactive approach to reduce household influenza transmission through handwashing promotion may be ineffective in the context of rural Bangladesh.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/show/NCT00880659?term=NCT00880659&rank=1" target="_blank">NCT00880659</a></p></div

Impact of intensive handwashing promotion on secondary attack risks (SAR) of influenza-like illness, and influenza, among household compound members of index case-patients, Kishoregonj, Bangladesh, 2009–2010.

<p>*All susceptible contacts in both index case-patient and secondary households included.</p><p>**Confidence intervals and P-values generated using log binomial regression model with generalized estimating equations to estimate significance of ratio of secondary attack risks in treatment arms.</p><p>Impact of intensive handwashing promotion on secondary attack risks (SAR) of influenza-like illness, and influenza, among household compound members of index case-patients, Kishoregonj, Bangladesh, 2009–2010.</p

Individual-level risk factors for secondary transmission of influenza-like illness among susceptible household members in the control arm, Kishoregonj, Bangladesh, 2009–2010 (N = 1498).

<p>¹ Attack rates for influenza-like illness calculated for susceptible members in the control arm who were exposed and unexposed to each characteristic at baseline. Attack rate ratios and confidence intervals generated using log binomial regression models, with generalized estimating equations to account for clustering among household members.</p><p>^<b>2</b>Analysis restricted to household members of index case-patients > 5 years old.</p><p>^<b>3</b>Information missing for 295 household members.</p><p>^<b>4</b>Only queried in 2010.</p><p>^<b>5</b>Only reported for members of index case-patient household.</p><p># multivariable model includes the following variables: contact < 2 years old (or contact < 5 years old); Index case-patient with fever onset 24 hours prior to enrollment; and contact interacts multiple times daily with index case-patient.</p><p>Individual-level risk factors for secondary transmission of influenza-like illness among susceptible household members in the control arm, Kishoregonj, Bangladesh, 2009–2010 (N = 1498).</p

Multivariable analysis of impact of intensive handwashing promotion on secondary attack risks (SAR) of influenza-like illness, and influenza, among household compound members of index case-patients, Kishoregonj, Bangladesh, 2009–2010.

<p>Multivariable analysis of impact of intensive handwashing promotion on secondary attack risks (SAR) of influenza-like illness, and influenza, among household compound members of index case-patients, Kishoregonj, Bangladesh, 2009–2010.</p

Baseline characteristics of index case-patients, household compounds, and household members, by treatment arm, Kishoregonj, Bangladesh, 2009–2010.

<p>*Data not collected for 67 children, all of whom were under 5 years old and enrolled in 2009.</p><p>**Only queried in 2010; denominators were 934 for intervention arm and 890 for control arm.</p><p>***Only reported for members of index case-patient household; denominators were 863 in the intervention arm and 727 in the control group.</p><p>Baseline characteristics of index case-patients, household compounds, and household members, by treatment arm, Kishoregonj, Bangladesh, 2009–2010.</p

Flow diagram to describe screening, inclusion, exclusion, and randomization, Kishoregonj, Bangladesh, 2009–2010.

<p>Flow diagram to describe screening, inclusion, exclusion, and randomization, Kishoregonj, Bangladesh, 2009–2010.</p

Neighborhood-Level Factors Associated with Physical Dating Violence Perpetration: Results of a Representative Survey Conducted in Boston, MA

Neighborhood-level characteristics have been found to be associated with different forms of interpersonal violence, but studies of the relationship between these characteristics and adolescent dating violence are limited. We examined 6 neighborhood-level factors in relation to adolescent physical dating violence perpetration using both adolescent and adult assessments of neighborhood characteristics, each of which was aggregated across respondents to the neighborhood level. Data came from an in-school survey of 1,530 public high school students and a random-digit-dial telephone survey of 1,710 adult residents of 38 neighborhoods in Boston. Approximately 14.3% of the youth sample reported one or more acts of physical aggression toward a dating partner in the month preceding the survey. We calculated the odds of past-month physical dating violence by each neighborhood-level factor, adjusting for school clustering, gender, race, and nativity. In our first 6 models, we used the adolescent assessment of neighborhood factors and then repeated our procedures using the adult assessment data. Using the adolescent assessment data, lower collective efficacy (AOR = 1.95, 95% CI = 1.09–3.52), lower social control (AOR = 1.92, 95% CI = 1.07–3.43), and neighborhood disorder (AOR = 1.19, 95% CI = 1.05–1.35) were each associated with increased likelihood of physical dating violence perpetration. However, when we used the adult version of the neighborhood assessment data, no neighborhood factor predicted dating violence. The implications and limitations of these findings are discussed