tetano
Editor, Senior Moderator
J Infect. 2014 Jan 31. pii: S0163-4453(14)00028-0. doi: 10.1016/j.jinf.2014.01.008. [Epub ahead of print]
PANDEMIC H1N1 virus transmission and shedding dynamics IN index case households OF A prospective VIETNAMESE cohort.
Thai PQ1, Mai LQ1, Welkers MR2, Le Khanh Hang N1, Thanh LT1, Viet Dung VT3, Thu Yen NT1, Duong TN1, Minh Hoa LN3, Thoang DD4, Huyen Trang HT3, de Jong MD2, Wertheim H5, Hien NT1, Horby P5, Fox A6.
Author information
Abstract
OBJECTIVES:
Influenza household transmission studies are required to guide prevention strategies but most passively recruit index cases that seek healthcare. We investigated A(H1N1)pdm09 transmission in a household-based cohort during 2009.
METHODS:
Health-workers visited 270 households weekly, and collected swabs from influenza-like-illness cases. If A(H1N1)pdm09 was RT-PCR-confirmed, all household members had symptoms assessed and swabs collected daily for 10-15 days. Viral RNA was quantified and sequenced and serology performed on pre-pandemic sera.
RESULTS:
Index cases were detected in 20 households containing 81 people. 98.5% lacked A(H1N1)pdm09 neutralizing antibodies in pre-pandemic sera. Eleven (18.6%, 95%CI 10.7 - 30.4%) of 59 contacts were infected. Virus genetic diversity within households was negligible and less than between households. Index and secondary cases were distributed between mothers, daughters and sons, and had similar virus-RNA shedding and symptom dynamics. Fathers were rarely infected. Five secondary cases (45%) had no apparent symptoms and three shed virus before symptoms. Secondary infection was associated with index case wet cough (OR 1.56, 95%CI 1.22 - 1.99).
CONCLUSIONS:
In this cohort of A(H1N1)pdm09 susceptible persons, virus sequencing was capable of discriminating household from community transmission. Household transmission involved mothers and children but rarely fathers. Asymptomatic or pre-symptomatic shedding was common.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
antibody, household, index, influenza, pandemic, secondary, serial interval, shedding, symptoms, transmission
PMID:
24491598
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24491598
PANDEMIC H1N1 virus transmission and shedding dynamics IN index case households OF A prospective VIETNAMESE cohort.
Thai PQ1, Mai LQ1, Welkers MR2, Le Khanh Hang N1, Thanh LT1, Viet Dung VT3, Thu Yen NT1, Duong TN1, Minh Hoa LN3, Thoang DD4, Huyen Trang HT3, de Jong MD2, Wertheim H5, Hien NT1, Horby P5, Fox A6.
Author information
Abstract
OBJECTIVES:
Influenza household transmission studies are required to guide prevention strategies but most passively recruit index cases that seek healthcare. We investigated A(H1N1)pdm09 transmission in a household-based cohort during 2009.
METHODS:
Health-workers visited 270 households weekly, and collected swabs from influenza-like-illness cases. If A(H1N1)pdm09 was RT-PCR-confirmed, all household members had symptoms assessed and swabs collected daily for 10-15 days. Viral RNA was quantified and sequenced and serology performed on pre-pandemic sera.
RESULTS:
Index cases were detected in 20 households containing 81 people. 98.5% lacked A(H1N1)pdm09 neutralizing antibodies in pre-pandemic sera. Eleven (18.6%, 95%CI 10.7 - 30.4%) of 59 contacts were infected. Virus genetic diversity within households was negligible and less than between households. Index and secondary cases were distributed between mothers, daughters and sons, and had similar virus-RNA shedding and symptom dynamics. Fathers were rarely infected. Five secondary cases (45%) had no apparent symptoms and three shed virus before symptoms. Secondary infection was associated with index case wet cough (OR 1.56, 95%CI 1.22 - 1.99).
CONCLUSIONS:
In this cohort of A(H1N1)pdm09 susceptible persons, virus sequencing was capable of discriminating household from community transmission. Household transmission involved mothers and children but rarely fathers. Asymptomatic or pre-symptomatic shedding was common.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
antibody, household, index, influenza, pandemic, secondary, serial interval, shedding, symptoms, transmission
PMID:
24491598
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24491598