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PLoS One. 2015 Jun 11;10(6):e0125200. doi: 10.1371/journal.pone.0125200. eCollection 2015.
Impact of Intensive Handwashing Promotion on Secondary Household Influenza-Like Illness in Rural Bangladesh: Findings from a Randomized Controlled Trial.
Ram PK1, DiVita MA1, Khatun-E-Jannat K2, Islam M2, Krytus K1, Cercone E1, Sohel BM2, Ahmed M2, Rahman AM2, Rahman M2, Yu J3, Brooks WA2, Azziz-Baumgartner E2, Fry AM4, Luby SP2.
Author information
Abstract
RATIONALE:
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.
METHODS:
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.
RESULTS:
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 (RRadj 5.51, 95% CI 3.43-8.85), those living with an index case-patient enrolled ≤24 hours after symptom onset (RRadj 1.91, 95% CI 1.18-3.10), and those who reported multiple daily interactions with the index case-patient (RRadj 1.94, 95% CI 1.71-3.26) were at increased risk of influenza-like illness.
DISCUSSION:
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.
TRIAL REGISTRATION:
ClinicalTrials.gov NCT00880659.
PMID: 26066651 [PubMed - in process] Free full text
Impact of Intensive Handwashing Promotion on Secondary Household Influenza-Like Illness in Rural Bangladesh: Findings from a Randomized Controlled Trial.
Ram PK1, DiVita MA1, Khatun-E-Jannat K2, Islam M2, Krytus K1, Cercone E1, Sohel BM2, Ahmed M2, Rahman AM2, Rahman M2, Yu J3, Brooks WA2, Azziz-Baumgartner E2, Fry AM4, Luby SP2.
Author information
Abstract
RATIONALE:
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.
METHODS:
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.
RESULTS:
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 (RRadj 5.51, 95% CI 3.43-8.85), those living with an index case-patient enrolled ≤24 hours after symptom onset (RRadj 1.91, 95% CI 1.18-3.10), and those who reported multiple daily interactions with the index case-patient (RRadj 1.94, 95% CI 1.71-3.26) were at increased risk of influenza-like illness.
DISCUSSION:
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.
TRIAL REGISTRATION:
ClinicalTrials.gov NCT00880659.
PMID: 26066651 [PubMed - in process] Free full text