Investigator(s)
| WHO Technical Officer |
Mohammad Ahmad WCO India- Research Mohammad Ahmad 
|
| Principal Investigator |
Dr Farzana Islam Hamdard Institute of Medical Science & Research (HIMSR Delhi) Dr Farzana Islam
|
Title(s) and abstract
| Scientific title | Household Transmission Investigation (HHTI) & Associated Risk Factors for Influenza A, Influenza B and Respiratory Syncytial Virus (RSV) infection amongst Residents of Delhi, India. |
| Public title | Risk of Household Transmission of Influenza Viruses in Delhi |
| Background | Respiratory Syncytial Virus (RSV) is a leading cause of severe acute respiratory infections among children under five in the WHO South-East Asia Region, with India carrying a significant burden. Surveillance data consistently identify RSV as the primary viral cause of hospitalization for lower respiratory tract infections in this age group. Following a review of the global response to the last influenza pandemic (2009 influenza pandemic H1N1), the global Consortium for the Standardization of Influenza Seroepidemiology (CONSISE), and World Health Organization’s (WHO) Influenza Pandemic Special Investigations and Studies initiative were established to develop a suite of standardized early investigation protocols, supported by the Global Influenza Programme and the Pandemic Influenza Preparedness (PIP) Framework. Studies in households allow determination of the transmission dynamics (reproduction number and serial interval) of the virus, as well as aiding understanding of the clinical spectrum of illness in secondary cases. The present protocol has been designed to investigate households setting transmission of the influenza virus as a part of UNITY Studies. |
| Objectives | The objectives are to study: A. Transmissibility 1. Secondary infection rate (SIR) of influenza A, Influenza B and RSV infection overall, and by key factors such as age and sex; 2. Secondary clinical attack rate (SCAR) as a proxy measure of influenza A, Influenza B and RSV infection among household contacts, overall, and by key factors such as age and sex; B. Severity 1. Clinical presentation of influenza A, Influenza B and RSV infection and the course of the disease. 2. Symptomatic and asymptomatic proportions of influenza A, Influenza B and RSV cases. 3. Preliminary case- and infection-hospitalization and fatality ratios. |
| Study Methods | This HHTI investigation is a case-ascertained prospective household setting study of index cases of influenza A, Influenza B and RSV and household contacts. The study will be carried out in HIMSR Hospital which is situated in South East Delhi. The details of influenza A, Influenza B and RSV positive patients will be collected from the institute’s lab on the same day of testing. The population under investigation consists of the confirmed cases of influenza A, Influenza B and RSV and their close contacts in their households. Households will be enrolled in the study once a confirmed influenza A, Influenza B and RSV case is identified in at least one member of the household. Households will be subsequently followed up to observe secondary infections on day 7,14 and 28. Every effort will be made to include all identified household contacts of cases of laboratory-confirmed influenza A, Influenza B and RSV. Once an index case has been identified and recruited into the investigation, a study visit (if case is hospitalized due to severe illness/isolation purposes or isolating at home) or phone interview will need to be conducted to identify all household contacts for recruitment into the investigation. Household contacts found to be positive with influenza A, Influenza B and RSV by laboratory confirmatory tests would be reclassified as confirmed cases (dotted line in Figure 2) and follow-up would occur as described in the case investigation algorithm. The data collection process may or may not be re-triggered in this instance, but would depend on the country resources and type of contact. |
| Expected outcomes and use of results | 1- Understanding the epidemiology of the RSV in Delhi state including transmissibility indicators and clinical presentation 2- Create a baseline understanding of the RSV infection to compare with any future epidemics 3- Sensitize the Unity Study network that was in place for the WHO Unity studies conducted by HIMSR and learn to implement an adapted WHO Unity Study Protocol for any future similar event |
| Keywords | RSV Unity Study Delhi 2025 |
Research Details
| Student research | No |
| Start Date | 08-Sep-2025 |
| End Date | 30-Nov-2025 |
| Key Implementing Institution | Hamdard Institute of Medical Science & Research, Delhi |
| Multi-country research | No |
| Nationwide research | No |
| India | |
| Research Domain(s) | Communicable Disease Research |
| Research field(s) | Infectious Disease |
| Involves human subjects | Yes |
| Population-Based Survey | |
| Data Collection | Primary data |
| Proposal reviewed by other Committee | Under Review |