Is there increase of STDs during Carnival? Time series of diagnoses in a STD clinic.

Objective: Sexually transmitted diseases (STDs) are common reasons for seeking medical assistance. Media campaigns on STD/AIDS assume that exposure to risky sexual practices is greater during Carnival. The objective of this study was to analyze the temporal distribution of first appointments in a STD clinic from January 1993 to December 2005 to verify whether there is a seasonal increase in STD after Carnival.

Methods: A total of 2,646 medical records with a diagnosis of gonorrhea, syphilis, or trichomoniasis were selected among patients seeking medical assistance in the STD Unit of Universidade Federal Fluminense, Niterói, Rio de Janeiro, Brazil. Statistical analysis was performed using month-to-month and year-to-year standardized average number of appointments during 13 years, in addition to smoothed time-series data using the Lowess method and the deterministic moving average method.

Results: July and August exhibited the largest number of gonorrhea and syphilis diagnoses, and June and July of trichomoniasis diagnoses. Gonorrhea had its peak value in May, with a falling trend until August. A constant number of syphilis diagnoses was observed between May and August, with smaller numbers in January and February and peak values in November. The seasonal pattern for trichomoniasis diagnosis showed peak values in July, with a consistent falling trend until December and an increase from January on.

Conclusion: Carnival has no influence on the increase in the occurrence of gonorrhea, syphilis, and trichomoniasis in patients attending a STD clinic in Niterói, Rio de Janeiro, Brazil.