This March, during a two-day meeting* at the 5th Scientific Symposium on Tuberculosis in Berlin, international experts discussed the burden, trends and impact of paediatric TB in Europe, Russia and other countries of the former Soviet Union
In Europe, the overall trend of TB in children significantly decreased – by 2.8% -- in the last decade, according to Andreas Sandgren, TB expert at the European Centre for Disease Prevention and Control (ECDC) and co-author of the first comprehensive analysis of childhood TB epidemiology in the EU/EEA. However, in certain ‘low-incidence’ countries (less than 20 cases per 100,000 overall population) childhood TB is actually rising. ‘Up to now, we could not unravel the reasons for this increase,’ he said, assuming that childhood TB in low-incidence countries is particularly sensitive to unusual outbreaks, rather than representing an overall epidemic trend as appears to be the case in high-incidence-countries. ‘The impact of foreign-born children could also affect this relationship, particularly if many of the cases are infected before entering the country,’ he explained, adding that physicians in low-incidence countries might no longer be sufficiently aware of the problem and therefore a TB diagnosis could be delayed, and thus the spread of infection interrupted too late.
Walter Haas, who is responsible for surveillance and prevention of respiratory diseases at German Robert Koch Institute, affirmed that various factors probably contribute to this development: ‘So far, no one knows the exact reason for the increase in these countries.’ In Germany, childhood TB cases increased from 1.2 per 100,000 in 2008 to 1.3 in 2009, a rise so far continuing in 2010. At the same time, although the reduction is smaller than in previous years, adult TB numbers continue to decrease.
‘We have to wait and see whether this increase in childhood TB is an early indicator of a general change of trend in Germany. Perhaps this observation only corresponds to a fluctuation due to small case numbers in children, we still don‘t know,’ Walter Haas pointed out, at the same time, however, emphasising the importance of taking the sign seriously because paediatric TB indicates recent infections. Why? In children, after TB-infection the disease progresses faster and at a higher ratio than in adults. Whether or not the increase in paediatric TB cases is reflected by an increase in infections is not clear, because the number of TB infections identified by contact tracing is not reported.
In 2009, 48.4% of all diagnosed childhood TB cases were detected by active case finding. ‘These cases represent a missed opportunity, because early recognition and treatment of latent infection can effectively prevent disease in children,’ he added. Physicians’ TB awareness should be heightened again and consequently preventive medication should be applied according to existing guidelines to face the increasing TB incidences adequately in children in Germany.
* Organised by the Koch-Metschnikow-Forum, a German-Russian research cooperation.