Pertussis (whooping cough)
Published: 09.02.05 Updated: 09.02.2005 18:18:56
Pertussis is a notifiable disease in the entire region. Denmark, Finland and Iceland only report laboratory confirmed cases. Norway report both laboratory confirmed cases and cases epidemiologically linked to a laboratory confirmed case. Lithuania reports both laboratory confirmed cases and cases with typical clinical picture without laboratory confirmation. Northwest Russia, Estonia and Sweden report laboratory confirmed cases, cases with typical clinical picture without laboratory confirmation and cases epidemiologically linked to a laboratory confirmed case.
Figure 26. Number of cases of pertussis notified in 2003 per 100 000 population (1).
Since the introduction of a pertussis vaccine in the 1950s, most countries in the region experienced stable incidences of pertussis. In Sweden, vaccination ceased in 1979 resulting in high numbers of cases until childhood vaccination was re-introduced in 1996. In 1997, Norway experienced a sharp, epidemic-like increase in reported cases of pertussis. This rise was not related to a fall in vaccination coverage, and the overwhelming majority of cases were diagnosed among older children and adults. These high rates may be partly explained by increased awareness of the disease. Incidence rates have remained exceptionally high in Norway. The same increase has in recent years been seen in both Estonia and Finland. In Northwest Russia, vaccination coverage fell in the early 1990s resulting in local outbreaks especially in St. Petersburg. In 1992, the vaccination coverage in the city was down to 32.6% (17).
Improved regional vaccination campaigns have since led to a considerable decrease in the number of cases in the youngest children in Northwest Russia. However, the number of cases in older children has, like in Norway, remained high.
Vaccination, usually given as a combined vaccine together with diphtheria and tetanus vaccines, is the best measure to decrease the incidence and the subsequent risk of children less than 2 years of age contracting the disease. In all countries in the region pertussis vaccine is given as part of the national vaccination programmes. In Russia, the Baltic countries and Finland a total of four doses of pertussis vaccine is given to children. In Iceland an additional dose at school entry is recommend. The remaining countries only give three doses, the last at approximately at 12 months of age. Many of these countries are considering a fourth dose given at school entry. Acellular pertussis vaccine has been introduced in Denmark, Norway, Iceland and Sweden. The remaining countries still use whole-cell vaccine, with the exception of Latvia and Lithuania that use a combination of whole-cell and acellular vaccines. Vaccination coverage in the region is now generally high.