Sero-epidemiologic study of influenza A(H7N9) infection among exposed populations, China 2013-2014.
Influenza Other Respir Viruses
; 11(2): 170-176, 2017 03.
Article
en En
| MEDLINE
| ID: mdl-27762061
ABSTRACT
BACKGROUND:
The first human infections of novel avian influenza A(H7N9) virus were identified in China in March 2013. Sentinel surveillance systems and contact tracing may not identify mild and asymptomatic human infections of influenza A(H7N9) virus.OBJECTIVES:
We assessed the seroprevalence of antibodies to influenza A(H7N9) virus in three populations during the early stages of the epidemic. PATIENTS/METHODS:
From March 2013 to May 2014, we collected sera from the general population, poultry workers, and contacts of confirmed infections in nine Chinese provinces reporting human A(H7N9) infections and, for contacts, second sera 2-3 weeks later. We screened for A(H7N9) antibodies by advanced hemagglutination inhibition (HI) assay and tested sera with HI titers ≥20 by modified microneutralization (MN) assay. MN titers ≥20 or fourfold increases in paired sera were considered seropositive.RESULTS:
Among general population sera (n=1480), none were seropositive. Among poultry worker sera (n=1866), 28 had HI titers ≥20; two (0.11%, 95% CI 0.02-0.44) were positive by MN. Among 61 healthcare and 117 non-healthcare contacts' sera, five had HI titers ≥20, and all were negative by MN. There was no seroconversion among 131 paired sera.CONCLUSIONS:
There was no evidence of widespread transmission of influenza A(H7N9) virus during March 2013 to May 2014, although A(H7N9) may have caused rare, previously unrecognized infections among poultry workers. Although the findings suggest that there were few undetected cases of influenza A(H7N9) early in the epidemic, it is important to continue monitoring transmission as virus and epidemic evolve.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Estudios Seroepidemiológicos
/
Gripe Humana
/
Subtipo H7N9 del Virus de la Influenza A
/
Anticuerpos Antivirales
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Animals
/
Female
/
Humans
/
Male
País/Región como asunto:
Asia
Idioma:
En
Revista:
Influenza Other Respir Viruses
Asunto de la revista:
VIROLOGIA
Año:
2017
Tipo del documento:
Article
País de afiliación:
China