Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort
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...
| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
W.B. Saunders Ltd
2014
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| _version_ | 1797070999139647488 |
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| author | Thai, P Mai, L Welkers, M Hang, N Thanh, LT Dung, V Yen, N Duong, T Hoa, L Thoang, D Trang, H Jong, d Wertheim, H Hien, N Horby, P Fox, A |
| author_facet | Thai, P Mai, L Welkers, M Hang, N Thanh, LT Dung, V Yen, N Duong, T Hoa, L Thoang, D Trang, H Jong, d Wertheim, H Hien, N Horby, P Fox, A |
| author_sort | Thai, P |
| collection | OXFORD |
| description | 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. © 2014 The Authors. |
| first_indexed | 2024-03-06T22:46:56Z |
| format | Journal article |
| id | oxford-uuid:5d808bdf-5c62-49ed-a521-b6f2c3c998e5 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:46:56Z |
| publishDate | 2014 |
| publisher | W.B. Saunders Ltd |
| record_format | dspace |
| spelling | oxford-uuid:5d808bdf-5c62-49ed-a521-b6f2c3c998e52022-03-26T17:34:51ZPandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohortJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5d808bdf-5c62-49ed-a521-b6f2c3c998e5EnglishSymplectic Elements at OxfordW.B. Saunders Ltd2014Thai, PMai, LWelkers, MHang, NThanh, LTDung, VYen, NDuong, THoa, LThoang, DTrang, HJong, dWertheim, HHien, NHorby, PFox, AObjectives: 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. © 2014 The Authors. |
| spellingShingle | Thai, P Mai, L Welkers, M Hang, N Thanh, LT Dung, V Yen, N Duong, T Hoa, L Thoang, D Trang, H Jong, d Wertheim, H Hien, N Horby, P Fox, A Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title | Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title_full | Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title_fullStr | Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title_full_unstemmed | Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title_short | Pandemic H1N1 virus transmission and shedding dynamics in index case households of a prospective Vietnamese cohort |
| title_sort | pandemic h1n1 virus transmission and shedding dynamics in index case households of a prospective vietnamese cohort |
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