Epidemiology of pertussis in children of Flanders Belgium: can healthcare professionals be involved in the infection?

Pertussis is a communicable disease whose registration incidence in the Flemish region of Belgium has increased since 2003. Originally, this increment was obvious only in the province of Antwerp, but since 2012, there has also been an increase in the registered cases of pertussis in other Flemish provinces. The overall registration incidence for pertussis in Flanders was 5.6 per 100 000 in 2012. The majority of these cases were identified among young children, but older children and adults were also affected. Increased awareness, new diagnostic tools, better registration, waning immunity, and circulation of new strains were most likely associated with the increase in reporting. Although many of the pertussis infections we studied occurred within family units, several healthcare workers who had been in contact with young children were also identified as sources of pertussis. A number of these were index cases, while others were secondary infections. Finally, a fatal neonatal pertussis case is presented to illustrate the severity of the disease in young unvaccinated children.