Please select the arm or intervention descriptions that belong to the clinical trial below.
Title: Prevention of Secondary Transmission of Human Influenza by Promoting Handwashing With Soap: The Bangladesh Interruption of Secondary Transmission of Influenza Study (BISTIS)
Brief Summary: The next influenza pandemic is expected to spread rapidly in resource-poor settings. Influenza viruses spread from human-to-human via large respiratory droplets. Transmission via large-particle respiratory droplets is believed to be mediated by close contact between infected and susceptible persons or contact with droplet-contaminated fomites. Close contact between infected and susceptible persons may consist of skin-to-skin contact (e.g., via hands) or inhalation of respiratory droplets (e.g., due to talking, coughing, or sneezing by the infected person). Airborne transmission, which is expected to result in transmission over long distances (\>1 meter) and which would be mediated by ventilation, is believed to be uncommon. Therefore, the greatest risk of transmission from personal contact comes from those people who are closest to an index case, such as contacts living in the same household. There are, to date, no published estimates of the secondary attack ratio of influenza among household contacts of index case-patients in low-income countries. Moreover, the investigators do not have data on the risk factors for secondary transmission of influenza from index case-patients to their household contacts. There is some data for the benefits of promoting handwashing with soap on the risk of all-cause acute respiratory illness among children \< 15 years old in a resource-poor setting in Pakistan. But, the investigators do not have evidence that promoting handwashing with soap will acutely reduce the risk of secondary transmission. Therefore, the investigators propose to conduct a study in rural Bangladesh to assess the following:

* The secondary attack ratio of influenza among household contacts of an index case-patient with influenza
* The risk factors for secondary transmission of influenza from an index case-patient to household contacts
* The impact of promoting handwashing with soap on the risk of secondary transmission of influenza from an index case-patient to household contacts
* The impact of handwashing promotion on handwashing behavior six months after intervention
* The impact of handwashing promotion on the prevalence of respiratory infections, diarrhea and influenza


Options:
A: Arm Label: 1; Type: EXPERIMENTAL; Interventions: Behavioral: Soap | Arm Label: 2; Type: NO_INTERVENTION; Interventions: N/A | Intervention Type: BEHAVIORAL; Name: Soap; Assigned to Arm(s): 1
B: Arm Label: 1; Type: OTHER; Interventions: Other: Control | Arm Label: 2; Type: OTHER; Interventions: Device: Masks | Arm Label: 3; Type: OTHER; Interventions: Device: Masks & hand hygiene | Intervention Type: DEVICE; Name: Masks; Assigned to Arm(s): 2 | Intervention Type: DEVICE; Name: Masks & hand hygiene; Assigned to Arm(s): 3 | Intervention Type: OTHER; Name: Control; Assigned to Arm(s): 1
C: Arm Label: N95 Respirator; Type: ACTIVE_COMPARATOR; Interventions: Device: N95 Respirator | Arm Label: Medical/surgical mask; Type: ACTIVE_COMPARATOR; Interventions: Device: Medical/surgical mask | Intervention Type: DEVICE; Name: N95 Respirator; Assigned to Arm(s): N95 Respirator | Intervention Type: DEVICE; Name: Medical/surgical mask; Assigned to Arm(s): Medical/surgical mask
D: Arm Label: Vitamin D and gargling; Type: EXPERIMENTAL; Interventions: Dietary Supplement: cholecalciferol (vitamin D3), Behavioral: Gargling | Arm Label: Vitamin D and general health advice; Type: EXPERIMENTAL; Interventions: Dietary Supplement: cholecalciferol (vitamin D3) | Arm Label: Placebo and general health advice; Type: PLACEBO_COMPARATOR; Interventions: Dietary Supplement: Placebo | Arm Label: Placebo and gargling; Type: PLACEBO_COMPARATOR; Interventions: Behavioral: Gargling, Dietary Supplement: Placebo | Intervention Type: DIETARY_SUPPLEMENT; Name: cholecalciferol (vitamin D3); Assigned to Arm(s): Vitamin D and gargling, Vitamin D and general health advice | Intervention Type: BEHAVIORAL; Name: Gargling; Assigned to Arm(s): Placebo and gargling, Vitamin D and gargling | Intervention Type: DIETARY_SUPPLEMENT; Name: Placebo; Assigned to Arm(s): Placebo and gargling, Placebo and general health advice

Answer: A