Avian Influenza H5N1 Transmission in Households, Indonesia
Open Access
- 4 January 2012
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 7 (1), e29971
- https://doi.org/10.1371/journal.pone.0029971
Abstract
Disease transmission patterns are needed to inform public health interventions, but remain largely unknown for avian influenza H5N1 virus infections. A recent study on the 139 outbreaks detected in Indonesia between 2005 and 2009 found that the type of exposure to sources of H5N1 virus for both the index case and their household members impacted the risk of additional cases in the household. This study describes the disease transmission patterns in those outbreak households. We compared cases (n = 177) and contacts (n = 496) in the 113 sporadic and 26 cluster outbreaks detected between July 2005 and July 2009 to estimate attack rates and disease intervals. We used final size household models to fit transmission parameters to data on household size, cases and blood-related household contacts to assess the relative contribution of zoonotic and human-to-human transmission of the virus, as well as the reproduction number for human virus transmission. The overall household attack rate was 18.3% and secondary attack rate was 5.5%. Secondary attack rate remained stable as household size increased. The mean interval between onset of subsequent cases in outbreaks was 5.6 days. The transmission model found that human transmission was very rare, with a reproduction number between 0.1 and 0.25, and the upper confidence bounds below 0.4. Transmission model fit was best when the denominator population was restricted to blood-related household contacts of index cases. The study only found strong support for human transmission of the virus when a single large cluster was included in the transmission model. The reproduction number was well below the threshold for sustained transmission. This study provides baseline information on the transmission dynamics for the current zoonotic virus and can be used to detect and define signatures of a virus with increasing capacity for human-to-human transmission.Keywords
This publication has 24 references indexed in Scilit:
- Highly Pathogenic Avian Influenza (H5N1): Pathways of Exposure at the Animal‐Human Interface, a Systematic ReviewPLOS ONE, 2011
- The Benefits of Transmission Dynamics Models in Understanding Emerging Infectious DiseasesThe American Journal of the Medical Sciences, 2010
- Dual Seasonal Patterns for Influenza, ChinaEmerging Infectious Diseases, 2010
- What is the evidence of a role for host genetics in susceptibility to influenza A/H5N1?Epidemiology and Infection, 2010
- An early report from newly established laboratory‐based influenza surveillance in Lao PDRInfluenza and Other Respiratory Viruses, 2010
- Influenza epidemiology and characterization of influenza viruses in patients seeking treatment for acute fever in CambodiaEpidemiology and Infection, 2009
- Factors associated with case fatality of human H5N1 virus infections in Indonesia: a case seriesThe Lancet, 2008
- Detecting Human-to-Human Transmission of Avian Influenza A (H5N1)Emerging Infectious Diseases, 2007
- Detecting Emerging Transmissibility of Avian Influenza Virus in Human HouseholdsPLoS Computational Biology, 2007
- Family Clustering of Avian Influenza A (H5N1)Emerging Infectious Diseases, 2005