In remarks reported Saturday by the weekly news magazine Focus, Norbert Brockmeyer said, it was 'realistic' to believe that 20,000 to 30,000 prostitutes had entered Germany because of the tournament.
Fears that some of the women have been coerced into sex work, led to unsuccessful calls in Sweden and the US before the World Cup, for a boycott of the tournament.
Prostitution is legal in Germany but police have raided brothels to ensure no one is working under duress to meet the demands of the thousands of male fans expected to seek sex services.
Brockmeyer blamed the current spread of syphilis in the western cities of Cologne and Aachen on a 2001 law change that ended compulsory medical examinations of prostitutes.
The University of the Ruhr medical professor, who also heads the German AIDS Society, said the boom in sex services not only increased the risk of a spread of the syphilis but also of other venereal diseases and AIDS.