DÄ internationalArchive13/2010Comparison Group Would Have Been Useful
LNSLNS Winzer et al reported their experience with the new influenza virus A(H1N1/09) during the first wave of the pandemic in the summer of 2009 (1). Their hospital clinically examined 3372 suspected cases (including specimens from deep nasal swabbing) on the basis of polymerase chain reaction (PCR). They have contributed fundamental epidemiological and clinical data of the subject. Impressively, only 13% (n=450) of swabs were PCR positive.

The authors describe the distribution of sociodemographic and clinical characteristics—unfortunately only for the PCR positive cases (Table, Figures 2–4). For clinical and practice related reasons, a comparison with the PCR negative cases would have been of interest, including the duration of symptoms at the time of the initial contact. The latter is important in interpreting the duration of illness (with or without treatment).

In the article, data on the duration of illness are available only for the cohort treated with oseltamivir (n=60). These PCR positive cases were treated in accordance with the guidelines and independently of the severity of their illness by administration of oseltamivir until a negative nasal swab was obtained. “In accordance with the guidelines” implies an approach on the basis of solid data with a high evidence level. However, such data are lacking for both diagnosis and treatment. The cited WHO guidelines are recommendations on the basis of low quality or very low quality evidence (2). In particular, no treatment with oseltamivir is re-commended for patients not at risk and with mild or moderate disease. In future, setting up a control group in a randomized study design might therefore be justified. This would put into context the statement that most of the initially symptomatic patients are symptom free after 3 days.

It remains unclear which data the authors used to support their statement “There has not yet been any evidence of oseltamivir resistance.”
DOI: 10.3238/arztebl.2010.0229b

Dr. med. Dirk Moßhammer, MPH
Dr. med. Dipl. Phys. Manfred Eissler
Universität Tübingen
Lehrbereich Allgemeinmedizin
Österbergstr. 9
72074 Tübingen, Germany
dirk.mosshammer@uni-tuebingen.de
2.
Winzer R, et al.: Early clinical experiences with the new influenza A (H1N1/09) [Erste klinische Erfahrungen mit der Neuen Influenza A (H1N1)]. Dtsch. Arztebl Int 2009; 106(47): 770–6. VOLLTEXT
1. WHO Guidelines for Pharmacological Management of Pandemic (H1N1) 2009 Influenza and other Influenza Viruses.
2. Winzer R, et al.: Early clinical experiences with the new influenza A (H1N1/09) [Erste klinische Erfahrungen mit der Neuen Influenza A (H1N1)]. Dtsch. Arztebl Int 2009; 106(47): 770–6. VOLLTEXT