The type of tests conducted for HSV-2 serology in these studies was not able to be confirmed or clari25 fied, despite repeated attempts. Some of these studies also tended 20 to convey limited knowledge of HSV-2 epidemiology. 15 Figure 10.1 shows the agestratified prevalence in a study 10 from Morocco.27 The prevalence grows rather slowly for both males 5 and females compared to other regions,28 suggesting that it takes a long time after sexual debut for 0 0 5 10 15 20 25 30 35 40 45 50 the risk of exposure to this STI to age be appreciable in magnitude. An alternative explanation might be a HSV-2 prevalence among adult females HSV-2 prevalence among adult males changing experience of successive birth cohorts in being exposed to Source: Cowan et al. 2003. HSV-2 infection in different eras.29 However, this explanation seems unlikely because recent healthy university students aged 18–24 years.19 trends suggest increasing, rather than declining, In Saudi Arabia, a prevalence of 27% was sexual risk behaviors. reported among pregnant women.20 Finally, in Turkey, a prevalence of 63% was reported among pregnant women,21 53.5% was reported Implications, limitations, and future applications among general population women in a rural The above data suggest that HSV-2 prevalence area,22 and 26% was reported among men who in the general population in MENA is low, and have sex with men (MSM).23 indeed among the lowest globally compared However, some of the results of these studies to other regions (table 10.2).30 This provides appear to contradict the results in table 10.1 an indication that the levels of sexual risk and need confirmation, because the serology behavior in the general population are low tests used appear to suffer from high levels of and that HIV infection is likely to have limited cross-reactivity with herpes simplex virus type 1 inroads into this population. However, HSV-2 (HSV-1) antibodies and use of nonspecific prevalence levels in populations with identifiserologic assays.24 HSV-1 infection is predomable risk behaviors are considerable, and cominantly transmitted orally (not sexually), has parable to those in other regions, though at 25 a very high prevalence in MENA, and shows somewhat lower levels.31 This suggests the extensive sequence homology with HSV-2.26 potential for HIV to spread among priority populations. 19 prevalence (%)
Figure 10.1 HSV-2 Prevalence for Selected Populations, by Age Group in Morocco
Abuharfeil and Meqdam, “Seroepidemiologic Study.” Ghazi, Telmesani, and Mahomed, “TORCH Agents in Pregnant Saudi Women.” 21 Duran et al., “Asymptomatic Herpes.” 22 Maral et al., “Seroprevalences of Herpes.” 23 Cengiz et al., “Detection of Herpes”; Cengiz et al., “Demonstration of Herpes.” 24 Ashley et al., “Inability of Enzyme Immunoassays to Discriminate”; R. Ashley, personal communication (2007); Abu-Raddad et al., “HSV-2 Serology.” 25 Smith and Robinson, “Age-Specific Prevalence of Infection”; Cowan et al., “Seroepidemiological Study.” 26 R. Ashley, personal communication (2007); H. Weiss, personal communication (2007). 20
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Cowan et al., “Seroepidemiological Study.” Smith and Robinson, “Age-Specific Prevalence of Infection”; Cowan et al., “Seroepidemiological Study.” 29 Burchell et al., “Chapter 6.” 30 O’Farrell, “Increasing Prevalence of Genital Herpes”; Smith and Robinson, “Age-Specific Prevalence of Infection”; Weiss, “Epidemiology of Herpes”; Pebody et al., “The Seroepidemiology of Herpes”; Paz-Bailey et al., “Herpes Simplex Virus Type 2.” 31 Smith and Robinson, “Age-Specific Prevalence of Infection.” 28