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Influenza: point-of-care testing, care and treatment

Mark Jones
MSc BSc(Hons)Nurs RN RHV
Primary Care Policy and Practice Adviser
Royal College of Nursing
London

Brian Smyth gives a thorough synopsis of flu aetiology, symptoms and treatment on pages 85 and 86, but as we move further into an age of increased responsibility for our own health and the ever more well-informed patient, a question often being asked is whether earlier testing and diagnosis will be of any value to individuals and to society in general.

Most commentators, including national bodies responsible for information on infectious diseases such as the UK Public Health Laboratory Service (PHLS) and the US Centers for Disease Control (CDC), agree that while flu can be an irritating condition for many people, it is self-limiting and best treated with rest and low-level antipyretic and nonsteroidal anti-inflammatory drugs.(1-3)

However, public perception remains that the flu is a significant problem and can pose a threat, particularly in the elderly. The latter point does have some truth in it - the frail elderly and children can experience more serious complications such as pneumonia in comparison with other viral respiratory infections.(4)
 
Other "at-risk" groups that should be targeted for vaccination include those with a chronic heart or chest complaint such as asthma, chronic kidney disease or diabetes, and those with lowered immunity due to disease or treatment, such as steroid or cancer medication.(1,2)
 
The real problem is that flu is antigenetically unstable, with shifts occurring in the genetic makeup of the virus making it difficult to vaccinate against with a "one-off" vaccination, and leading to the possibility of infection even in people previously vaccinated.(1,2)
 
There is an ongoing fight to predict the prevalent strains of influenza virus and thus select the most appropriate vaccine. Efforts are even being made to use the latest technology in decoding the virus structure to predict the dominant strain of flu with virtual certainty.(5,6)
 
In the UK, significant efforts are being made to vaccinate at-risk groups, but other people often believe they have contracted the virus and wait their turn in the GP surgery or NHS walk-in centre to confirm their diagnosis. There is little evidence to suggest why people do this - after all, if their suspicions are confirmed, the advice will be to go home, self-medicate and rest; no GP would prescribe the anti­biotics that are so often requested.

There is some merit in collecting samples from patients for whom there is a strong suspicion of influenza infection, as this provides a useful source of information for assessing the scale of an outbreak and the effectiveness of the vaccination programme, but testing is not generally seen as part of the treatment pathway.(3)
 
Nevertheless, there are several tests available for £10-15 which allow people to determine whether they have flu or not, such as QuickVue (Quidel) and Zystat Flu (ZymeTx). The manufacturers of these tests emphasise the positive aspects of actually knowing whether one has flu or not. These include not putting other people at risk of infection, getting further advice and assistance if in an at-risk group, and even avoiding the unnecessary prescription of antibiotics.(7) The QuickVue test also emphasises the public health benefits of home testing by including a freepost reply card with the kit to allow data to be passed on to the PHLS.

In the final analysis, however, it would seem that efforts should be concentrated on identifying at-risk groups and maximising their vaccine uptake, while reassuring other patients who think they have flu that the illness is self-limiting. Those who actually do have flu may well have unpleasant fever and body aches for 3-5 days, with a cough and lack of energy lasting two or more weeks, but they will in time get better.

Home testing kits have their use in reassuring people that they do not have flu, or, if testing positive, that they should try to minimise infecting others and be ready for more than just a couple of days off work, and that they need to stock up on some good old over-the-counter medication to help get them through.

References

  1. Public Health Laboratory Service. Frequently asked questions on flu. London: PHLS; 2002. Available from URL: http://www.phls.org.uk/topics_az/ influenza/flufaq.htm
  2. Public Health Laboratory Service. Influenza briefing. London: PHLS; 2002. Available from URL: http://www.phls. org.uk/topics_az/influenza/flu.htm
  3. Communicable Disease Center. Laboratory diagnostic procedures for influenza. 2002. Available from URL: http://www.cdc.gov/ncidod/diseases/flu
  4. World Health Organization. Influenza (fact sheet 211). Geneva: WHO; 1999. Available from URL: http://www.who.int/inf-fs/en/fact211.html
  5. BBC News Online. Predicting the flu of the future. 2 Dec 1999. Available from URL: http://news.bbc.co.uk/hi/ english/sci/tech/newsid_547000/547318.stm
  6. Database information. Influenza database at LANL. Human Genome News 1999;10(2):1. Available from URL:http://www.ornl.gov/hgmis/publicat/hgn/v10n1/21databa.html
  7. Why test for influenza? 2002. Available from URL: http://www.haveigotflu.com

Resources
QuickVue W:www.flu-test.co.uk
Zystat Flu
W:www.zymetx.com