tetano
Editor, Senior Moderator
PLoS One. 2013 Aug 16;8(8):e72196. doi: 10.1371/journal.pone.0072196.
Prospective Study of Avian Influenza Virus Infections among Rural Thai Villagers.
Krueger WS, Khuntirat B, Yoon IK, Blair PJ, Chittagarnpitch M, Putnam SD, Supawat K, Gibbons RV, Bhuddari D, Pattamadilok S, Sawanpanyalert P, Heil GL, Gray GC.
Source
College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
Abstract
BACKGROUND:
In 2008, 800 rural Thai adults living within Kamphaeng Phet Province were enrolled in a prospective cohort study of zoonotic influenza transmission. Serological analyses of enrollment sera suggested this cohort had experienced subclinical avian influenza virus (AIV) infections with H9N2 and H5N1 viruses.
METHODS:
After enrollment, participants were contacted weekly for 24mos for acute influenza-like illnesses (ILI). Cohort members confirmed to have influenza A infections were enrolled with their household contacts in a family transmission study involving paired sera and respiratory swab collections. Cohort members also provided sera at 12 and 24 months after enrollment. Serologic and real-time RT-PCR assays were performed against avian, swine, and human influenza viruses.
RESULTS:
Over the 2 yrs of follow-up, 81 ILI investigations in the cohort were conducted; 31 (38%) were identified as influenza A infections by qRT-PCR. Eighty-three household contacts were enrolled; 12 (14%) reported ILIs, and 11 (92%) of those were identified as influenza infections. A number of subjects were found to have slightly elevated antibodies against avian-like A/Hong Kong/1073/1999(H9N2) virus: 21 subjects (2.7%) at 12-months and 40 subjects (5.1%) at 24-months. Among these, two largely asymptomatic acute infections with H9N2 virus were detected by >4-fold increases in annual serologic titers (final titers 1∶80). While controlling for age and influenza vaccine receipt, moderate poultry exposure was significantly associated with elevated H9N2 titers (adjusted OR = 2.3; 95% CI, 1.04-5.2) at the 24-month encounter. One subject had an elevated titer (1∶20) against H5N1 during follow-up.
CONCLUSIONS:
From 2008-10, evidence for AIV infections was sparse among this rural population. Subclinical H9N2 AIV infections likely occurred, but serological results were confounded by antibody cross-reactions. There is a critical need for improved serological diagnostics to more accurately detect subclinical AIV infections in humans.
PMID:
23977250
[PubMed - in process]
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/23977250
Prospective Study of Avian Influenza Virus Infections among Rural Thai Villagers.
Krueger WS, Khuntirat B, Yoon IK, Blair PJ, Chittagarnpitch M, Putnam SD, Supawat K, Gibbons RV, Bhuddari D, Pattamadilok S, Sawanpanyalert P, Heil GL, Gray GC.
Source
College of Public Health and Health Professions and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America.
Abstract
BACKGROUND:
In 2008, 800 rural Thai adults living within Kamphaeng Phet Province were enrolled in a prospective cohort study of zoonotic influenza transmission. Serological analyses of enrollment sera suggested this cohort had experienced subclinical avian influenza virus (AIV) infections with H9N2 and H5N1 viruses.
METHODS:
After enrollment, participants were contacted weekly for 24mos for acute influenza-like illnesses (ILI). Cohort members confirmed to have influenza A infections were enrolled with their household contacts in a family transmission study involving paired sera and respiratory swab collections. Cohort members also provided sera at 12 and 24 months after enrollment. Serologic and real-time RT-PCR assays were performed against avian, swine, and human influenza viruses.
RESULTS:
Over the 2 yrs of follow-up, 81 ILI investigations in the cohort were conducted; 31 (38%) were identified as influenza A infections by qRT-PCR. Eighty-three household contacts were enrolled; 12 (14%) reported ILIs, and 11 (92%) of those were identified as influenza infections. A number of subjects were found to have slightly elevated antibodies against avian-like A/Hong Kong/1073/1999(H9N2) virus: 21 subjects (2.7%) at 12-months and 40 subjects (5.1%) at 24-months. Among these, two largely asymptomatic acute infections with H9N2 virus were detected by >4-fold increases in annual serologic titers (final titers 1∶80). While controlling for age and influenza vaccine receipt, moderate poultry exposure was significantly associated with elevated H9N2 titers (adjusted OR = 2.3; 95% CI, 1.04-5.2) at the 24-month encounter. One subject had an elevated titer (1∶20) against H5N1 during follow-up.
CONCLUSIONS:
From 2008-10, evidence for AIV infections was sparse among this rural population. Subclinical H9N2 AIV infections likely occurred, but serological results were confounded by antibody cross-reactions. There is a critical need for improved serological diagnostics to more accurately detect subclinical AIV infections in humans.
PMID:
23977250
[PubMed - in process]
Free full text
http://www.ncbi.nlm.nih.gov/pubmed/23977250