Syphilis surveillance in Portugal, 2000-2005

ARTICLE

Auteur(s) : Ricardo Coelho, Margarida Anes, Candida Fernandes, Sandra Medeiros, Ana Rodrigues, Raquel Santos

GEIDST, Hospital Curry Cabral, Rua da Beneficência N^o 8, 1069-639 Lisboa, Portugal

The annual incidence of acquired syphilis in developed countries dropped to very low levels in the early 1990s, partly due to aggressive HIV campaigns that emphasized condom use. However, a series of syphilis outbreaks have been reported in several northern and western European countries since 1996. These outbreaks have disproportionately involved men who have sex with men (MSM), people who engage in high-risk sexual behavior (e.g., unprotected sex with prostitutes or multiple partners), and people who use new recreational drugs [1]. The purpose of this paper is to analyze the syphilis trends from 2000 to 2005 in Portugal based on data collected by the Sentinel Network for Sexually Transmitted Infections (STIs) Surveillance.

Operating since 2000, the Sentinel Network System was established to collect data on all STIs in Portugal. It involves eight public hospitals and health-center based STI clinics that cover about 70% of the Portuguese population, relies on voluntary participating dermatovenereologists and receives self-referred and physician-referred patients. From 2000 to 2005, 5,020 cases of Sexually Transmitted Infections were reported by this Sentinel Network System and Syphilis testing was routinely offered to all patients.

The organization aims to determine STI incidence trends and to monitor epidemiological profiles of STI patients. Syphilis notifications contain information on gender, residence, sexual orientation, country of birth, HIV status, educational level attained, number of sexual partners during the last six months, intravenous drug and condom use habits. Data security and strict patient confidentiality are always maintained. The data presented in this paper include infectious syphilis cases (primary, secondary and early latent) reported between January 2000 and December 2005. Statistical analyses were performed with SPSS^® v.13.0. Proportions were compared using the Chi-square test.

From 2000 to 2005, 784 cases of recent syphilis were reported in Portugal. Specifically, these include 208 reported in 2000, 149 in 2001, 115 in 2002, 122 in 2003, 91 in 2004 and 99 in 2005. Although the increase from 91 to 99 cases from 2004 to 2005 was not statistically significant, it is worth noting that it was linked to a syphilis outbreak that occurred in 2005 among MSM. Indeed, from 2000 and 2005, the proportion of syphilis cases involving MSM increased (p < 0.001), while that involving females and heterosexual men decreased and remained stable, respectively (figure 1). Of the 767 syphilis cases with HIV status data, 136 (17.3%) were HIV-positive, including 51 patients who received their HIV and syphilis diagnoses concurrently and 85 who had previously been diagnosed as HIV-positive. HIV prevalence was 43.3% in MSM, 11.3% in heterosexual men, and 10.8% in females. There was a general increase in the number of HIV-positive patients in Portugal after 2002 (p < 0.001).

The Sentinel Network data indicate a selective increase in syphilis infections in MSM since 2000, while the number of heterosexually transmitted cases remained relatively stable. However, the proportion of heterosexually transmitted cases was relatively large for Western Europe. The frequent occurrence of syphilis and HIV co-infection is of great concern; these patients are also at risk for gonorrhea, chlamydia infections and L2 chlamydia proctitis [2-4]. Media coverage, syphilis-awareness advertisements in the gay media and distribution of literature to the homosexual community are evidently insufficient to contain syphilis spreading among MSM in Portugal.

In conclusion, there has been a surge in syphilis rates in many Western countries since the late 1990s. However, this trend only emerged in Portugal the past few years. This review of syphilis cases between 2000 and 2005 shows similar findings to epidemiological trends in other European countries. Syphilis screening should be emphasized for MSM, especially for those being treated for HIV.

Acknowledgements

References

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4 Stary A, Stingl G. Sexually transmitted infections. Eur J Dermatol 2007; 17: 107-8.