Performance of influenza rapid point-of-care tests in the detection of swine lineage A(H1N1) influenza viruses.

Influenza Other Respi Viruses. 2009 Jul;3(4):171-6

Authors: Hurt AC, Baas C, Deng YM, Roberts S, Kelso A, Barr IG

BACKGROUND: In April 2009, an A(H1N1) influenza virus of swine lineage was detected in humans in the USA, and in just over a month has infected over 10,000 people in more than 40 countries. OBJECTIVES: To determine the performance of the Binax Now, BD Directigen EZ, and the Quidel QuickVue influenza rapid point-of-care (POC) tests for the detection of the recently emerged swine lineage A(H1N1) virus. METHODS: Swine lineage A(H1N1) and human seasonal influenza strains were cultured and then diluted to specific infectivity titres. Viral dilutions were assayed by the rapid POC tests and by real-time RT-PCR. RESULTS: All three of the rapid POC tests successfully detected the swine lineage A(H1N1) viruses at levels between 10(3) and 10(5) TCID(50)/ml (tissue culture infectious dose(50)), with the BD Directigen test demonstrating marginally greater sensitivity than the other two tests. Viral infectivity and RNA load data for viruses at the detection limit of the rapid test kits, suggested that both the Quidel and the Binax tests were less sensitive for the detection of swine lineage A(H1N1) viruses than for human seasonal strains. In comparison the BD Directigen demonstrated similar sensitivity when detecting swine lineage A(H1N1) and human seasonal viruses. CONCLUSIONS: The three rapid POC tests all detected the emergent swine lineage A(H1N1) virus when it was present at high virus concentrations. Early diagnosis of infection can assist in the rapid treatment. However the tests are significantly less sensitive than PCR assays and as such, negative results should be verified by a laboratory test.

PMID: 19627374 [PubMed - indexed for MEDLINE]

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H1N1 swine origin influenza infection in the United States and Europe in 2009 may be similar to H1N1 seasonal influenza infection in two Australian states in 2007 and 2008.

Influenza Other Respi Viruses. 2009 Jul;3(4):183-8

Authors: Kelly H, Grant K, Williams S, Smith D

BACKGROUND: The population-based impact of infection with swine origin influenza A (H1N1) virus infection was not clear in the early days of the epidemic towards the end of May 2009. Australia had seven confirmed cases by 22 May 2009. We aimed to compare available data on swine origin influenza A (H1N1) virus infection overseas with seasonal influenza A (H1N1) virus infection in Australia to assist with forward planning. METHODS: Data on infection with seasonal influenza A (H1N1) virus in patients recruited through sentinel general practices in Victoria and Western Australia in 2007 and 2008 were compared with early publications on infection with swine origin influenza A (H1N1) virus in the United States and Europe. RESULTS: Influenza A (H1N1) virus infection was predominantly a disease of younger people, regardless of whether the virus was of swine or human origin. The median age of infection with swine origin virus was 20 years in the United States and 22 years in Spain, while the median age of infection with human origin virus was 18 years in Western Australia and 23 years in Victoria. CONCLUSIONS: The median age of infection with influenza A (H1N1) virus was around 20 +/- 3 years, independent of the origin of the H1N1 virus but a higher proportion of swine origin influenza infections occurred in people aged 10-18 years. This is at least partially explained by biased sampling among surveillance patients, although it may also reflect a different infection pattern.

PMID: 19627376 [PubMed - indexed for MEDLINE]

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National pandemic influenza preparedness planning.

Influenza Other Respi Viruses. 2009 Jul;3(4):189-96

Authors: Azziz-Baumgartner E, Smith N, González-Alvarez R, Daves S, Layton M, Linares N, Richardson-Smith N, Bresee J, Mounts A

The recent outbreaks of influenza A/H5N1 and ‘swine influenza’ A/H1N1 have caused global concern over the potential for a new influenza pandemic. Although it is impossible to predict when the next pandemic will occur, appropriate planning is still needed to maximize efficient use of resources and to minimize loss of life and productivity. Many tools now exist to assist countries in evaluating their plans but there is little to aid in writing of the plans. This study discusses the process of drafting a pandemic influenza preparedness plan for developing countries that conforms to the International Health Regulations of 2005 and recommendations of the World Health Organization. Stakeholders from many sectors should be involved in drafting a comprehensive pandemic influenza plan that addresses all levels of preparedness.

PMID: 19627377 [PubMed - indexed for MEDLINE]

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