Evaluation of the new communicable disease notification system in Turkey

A new communicable disease notification system has been launched in Turkey in 2005. Major innovation in the system is introduction of standard probable and confirmed case definitions. Our aim was to evaluate the effect of the change in the system on communicable disease statistics.
 Methods: Statistical yearbooks of ministry of health for 2003-2006 were used. Numbers of cases and morbidity rates were compared for two years before and after change. Provinces of Turkey were compared according to the presence of notifications in 2004-2006. As a possible indicator of consistency of the system, the variation in disease morbidity among the 81 provinces were calculated by finding the proportions of the morbidities of provinces with minimum and maximum morbidity. Chi-square and Wilcoxon signed rank tests were used for analysis.
 Results: Among diseases with comparable morbidity in both systems, the morbidity of four had increased while 13 decreased. There is a 250-fold decrease in measles. Among diseases for which both probable and confirmed cases are notified to the ministry, morbidity of pertussis remained similar in comparison to 2003 and 2004 when probable cases were added, while it decreased for measles and typhoid fever. A statistically significant decrease in the number of provinces notifying pertussis, measles, meningococcal meningitis, shigellosis, typhoid and paratyphoid fever was found in 2004-2006. 
 High variation in morbidity was found among provinces in 2004 and 2006. Variation had increased only for three of the comparable diseases (kala-azar, anthrax, shigellosis) and decreased for the other 14.
 Conclusion: There is much difference in the implementation of the notification system among provinces. The inclusion of non-notifying provinces into the system would make an important contribution to morbidity of diseases. The necessity of laboratory confirmation could be causing undernotification. The notification of probable cases for more diseases could be useful in this transition period.