 |
|
|
|
| EPI-NEWS |
National surveillance of communicable diseases
Dept. of Epidemiology
|
|
| Editor: Peter Henrik Andersen |
| . |
|
Phone: +45 3268 3038 - Fax: +45 3268 3874
|
| - ISSN: 1396-4798 |
|
|
|
|
| Laboratory diagnosed whooping cough 2002-2004 |
This report includes whooping cough diagnosed on culture and/or PCR in the period 2002-2004, and is nationwide, table 1. The report is based on data from laboratory diagnosed cases of whooping cough from Copenhagen County (Clinical Microbiology Department, Herlev Hospital (culture)), Viborg County (Clinical Microbiology Department, Viborg (PCR)) and Funen County (Clinical Microbiology Department, Odense University Hospital (PCR)), SSI, Department of Bacteriology, Mycology and Parasitology, DBMP, (culture and PCR)), covering the rest of Denmark, table 2. Since 1 January 1998, reports of laboratory diagnosed whooping cough have included cases confirmed by culture and/or PCR; each case is only counted once, table 3. In the period 1999 to 2001, around 1,000 cases were diagnosed annually, and the average incidence of whooping cough for the whole population was 18 per 105 per annum. In the period 2002-2004, the average incidence was 24 per 100,00 per annum.
Specimen-taking and diagnostics
For investigation by culture and/or PCR, nasopharyngeal secretions submitted in Stuart’s transport medium is still recommended. Culture results are available after 4-6 days, PCR results after 1-2 days. It is recommended to take at least two specimens simultaneously. On investigation for infectiousness culture should be used, as PCR detects DNA from both dead and live bacteria.
Commentary
Whooping cough appears epidemically every three to five years. The year 2002 was an epidemic year with two to three times higher incidence than for non-epidemic years. 2002 saw thus an expected increase in incidence of whooping cough five years after the last epidemic in 1997.
The change in the diagnostic methods used is of significance when one compares with the incidence of whooping cough before 1998, figure 1. After the introduction of PCR for whooping cough diagnosis, there has apparently been an increase in the incidence in all age groups. An increased number of specimens and a higher sensitivity of PCR may explain the fact that the incidence of laboratory diagnosed whooping cough has also increased in non-epidemic years. In 2004, whooping cough diagnostics were introduced in a further two Clinical Microbiology Departments, table 2. A continued nationwide surveillance of dia-nosed whooping cough in all age groups is important for the continued evaluation of the pertussis vaccination programme, and there is, in addition, great support for the clinical notification system for whooping cough in children under the age of two, EPI-NEWS 22/05. In the first three quarters of 2005, 485 cases of whooping cough were notified to the SSI national laboratory surveillance of whooping cough in the DBMP.
(M.S. Kaltoft, DBMP, J. Madsen, QA Dept., J.O. Jarløv, Herlev Hospital, T.G. Jensen, Odense University Hospital, J. Prag, Viborg Hospital)
Rational use of Tamiflu
The recent discussion of avian influenza has brought about a great pressure on the GPs to issue prescriptions for Tamiflu® (oseltamivir) for purposes including private stocks and use in foreign travel. For this reason, the National Board of Health has decided to provide advice about the rational use of Tamiflu® in the event of seasonal influenza, avian influenza and a possible influenza pandemic. Tamiflu is for the time being the only pharmaceutical agent on the Danish market for the treatment of influenza. It can be used for both treatment and prevention as a supplement to influenza vaccination. Tamiflu does not replace influenza vaccination. Under normal circumstances, avian influenza does not constitute a risk of infection to humans. For this reason, there is no indication to prescribe Tamiflu to people travelling to areas abroad with avian influenza, unless they come into very close contact with sick birds (this will usually be for occupational reasons). Nor is there a need for private stocking in case of an influenza pandemic.
(National Board of Health)
Weekly updates
Individually notifiable diseases, selected laboratory diagnosed infections & sentinel surveilance of the influenza activity
16 November 2005
|
|
|
|
|
|
|
|
|
|
