Seroincidence of Influenza Among HIV-infected and HIV-uninfected Men During the 2009 H1N1 Influenza Pandemic, Bangkok, Thailand

Abstract Among 368 Thai men who have sex with men with paired serum samples collected before and during the 2009 H1N1 influenza pandemic, we determined influenza A (H1N1)pdm09 seroconversion rates (≥4-fold rise in antibody titers by hemagglutination inhibition or microneutralization assays). Overall, 66 of 232 (28%) participants seroconverted after the first year of A(H1N1)pdm09 activity, and 83 of 234 (35%) participants seroconverted after the second year. Influenza A(H1N1)pdm09 seroconversion did not differ between human immunodeficiency virus (HIV)-infected (55 of 2157 [35%]) and HIV-uninfected (71 of 2211 [34%]) participants (P = .78). Influenza A(H1N1)pdm09 seroconversion occurred in approximately one third of our Thai study population and was similar among HIV-infected and HIV-uninfected participants.

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Origins of the 2009 H1N1 influenza pandemic in swine in Mexico

eLife ◽

10.7554/elife.16777 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 95

Author(s):

Ignacio Mena ◽

Martha I Nelson ◽

Francisco Quezada-Monroy ◽

Jayeeta Dutta ◽

Refugio Cortes-Fernández ◽

...

Keyword(s):

Influenza A ◽

Influenza Pandemic ◽

H1n1 Influenza ◽

Central Mexico ◽

Genome Sequences ◽

Viral Reservoirs ◽

Long Distance ◽

Conflicting Evidence ◽

2009 H1n1 ◽

H1n1 Influenza Pandemic

Asia is considered an important source of influenza A virus (IAV) pandemics, owing to large, diverse viral reservoirs in poultry and swine. However, the zoonotic origins of the 2009 A/H1N1 influenza pandemic virus (pdmH1N1) remain unclear, due to conflicting evidence from swine and humans. There is strong evidence that the first human outbreak of pdmH1N1 occurred in Mexico in early 2009. However, no related swine viruses have been detected in Mexico or any part of the Americas, and to date the most closely related ancestor viruses were identified in Asian swine. Here, we use 58 new whole-genome sequences from IAVs collected in Mexican swine to establish that the swine virus responsible for the 2009 pandemic evolved in central Mexico. This finding highlights how the 2009 pandemic arose from a region not considered a pandemic risk, owing to an expansion of IAV diversity in swine resulting from long-distance live swine trade.

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Pandemic influenza A (H1N1) virus infection and avian influenza A (H5N1) virus infection: a comparative analysisThis paper is one of a selection of papers published in this special issue entitled “Second International Symposium on Recent Advances in Basic, Clinical, and Social Medicine” and has undergone the Journal's usual peer review process.

Biochemistry and Cell Biology ◽

10.1139/o10-017 ◽

2010 ◽

Vol 88 (4) ◽

pp. 575-587 ◽

Cited By ~ 15

Author(s):

Christine Korteweg ◽

Jiang Gu

Keyword(s):

Virus Infection ◽

Influenza A ◽

Peer Review Process ◽

Influenza Pandemic ◽

H1n1 Influenza ◽

Influenza Viruses ◽

Influenza A Viruses ◽

H5n1 Influenza ◽

Influenza A H1n1 ◽

2009 H1n1

The 2009 H1N1 and H5N1 influenza viruses are newly (re-) emerged influenza A viruses (2009 A(H1N1) and A(H5N1), respectively) that have recently posed tremendous health threats in many regions worldwide. With the 2009 outbreak of H1N1 influenza A, the world witnessed the first influenza pandemic of the 21st century. The disease has rapidly spread across the entire globe, and has resulted in hundreds of thousands of cases with confirmed infection. Although characterized by high transmissibility, the virulence and fatality of the 2009 A(H1N1) influenza virus have thus far remained relatively low. The reverse holds true for A(H5N1) influenza; at a fatality rate that exceeds 60%, it is known to cause severe damage to the human respiratory system, but is not presently capable of efficient transmission from human to human. Apart from the clear differences between the two types of influenza, there are some significant similarities that warrant attention. In particular, the more severe and fatal 2009 A(H1N1) influenza cases have shown symptoms similar to those reported in cases of A(H5N1) influenza. Histopathological findings for these cases, to the extent available, also appear to have similarities for both diseases in terms of damage and severity. Here we review important recent publications in this area, and we discuss some of the key commonalities and contrasts between the two influenza A types in terms of their biology, origins, clinical features, pathology and pathogenesis, and receptors and transmissibility.

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Epidemiological analysis of critically ill adult patients with pandemic influenza A(H1N1) in South Korea

Epidemiology and Infection ◽

10.1017/s0950268812001604 ◽

2012 ◽

Vol 141 (5) ◽

pp. 1070-1079 ◽

Cited By ~ 7

Author(s):

S. B. HONG ◽

E. Y. CHOI ◽

S. H. KIM ◽

G. Y. SUH ◽

M. S. PARK ◽

...

Keyword(s):

South Korea ◽

Influenza A ◽

Multivariate Logistic Regression Analysis ◽

H1n1 Influenza ◽

Epidemiological Analysis ◽

Influenza A H1n1 ◽

Failure Assessment ◽

2009 H1n1 ◽

Independent Risk Factors ◽

Chronic Comorbidities

SUMMARYA total of 245 patients with confirmed 2009 H1N1 influenza were admitted to the intensive-care units of 28 hospitals (South Korea). Their mean age was 55·3 years with 68·6% aged >50 years, and 54·7% male. Nine were obese and three were pregnant. One or more comorbidities were present in 83·7%, and nosocomial acquisition occurred in 14·3%. In total, 107 (43·7%) patients received corticosteroids and 66·1% required mechanical ventilation. Eighty (32·7%) patients died within 30 days after onset of symptoms and 99 (40·4%) within 90 days. Multivariate logistic regression analysis showed that the clinician's decision to prescribe corticosteroids, older age, Sequential Organ Failure Assessment score and nosocomial bacterial pneumonia were independent risk factors for 90-day mortality. In contrast with Western countries, critical illness in Korea in relation to 2009 H1N1 was most common in older patients with chronic comorbidities; nosocomial acquisition occurred occasionally but disease in obese or pregnant patients was uncommon.

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