HPV Prevalence Among Men in Sub-Saharan Africa
HPV Prevalence Among Men in Sub-Saharan Africa
From the systematic review, we identified 11 studies comprising 9342 men examining the prevalence of HPV DNA among men in sub-Saharan Africa. These studies included six cross-sectional studies and five randomised controlled trials (RCTs) in which HPV prevalence were obtained either at baseline or at follow-up (Table 1). All identified studies were from southern Africa (n=6) or eastern Africa (n=5). Altogether six studies were from South Africa, two studies were conducted in Kenya and three studies were from Rwanda, Tanzania and Uganda, respectively. No studies from western Africa or middle Africa were identified. In the two RCTs of male circumcision from which baseline data were obtained, all study participants were uncircumcised. In all other studies, the circumcision prevalence ranged from 7.2% to 96.6%. The RCT of male circumcision conducted in Kenya included only HIV-negative men and one study from South Africa comprised only HIV-positive men. For the remaining studies, the prevalence of HIV ranged between 2% and 49.5%. In three studies, the majority of men had symptoms of HPV infection: Müller et al included 214 sexual health clinic attendees of whom 108 had ano-genital warts, in the study by Firnhaber et al all men (n=74) had penile warts and Vogt et al included 34 men attending an HIV testing centre. One study sampled exfoliated cells from the urethra only, while the remaining studies sampled other penile sites (eg, glans, coronal sulcus and shaft). For the detection of HPV DNA, 10 studies used PCR-based methods and one study used a non-PCR-based method (Hybrid Capture 2) (Table 1).
In Table 1 the prevalence of any HPV and HR HPV for each study is shown. Among the 11 studies identified, nine presented data on the prevalence of any HPV and seven studies had data on HR HPV. The prevalence of any HPV ranged from 19.1% (95% CI 17.2 to 21.0) to 100% (95% CI 85.3 to 100.0) and the prevalence of HR HPV from 16.2% (95% CI 14.5 to 17.9) to 84.9% (95% CI 76.7 to 93.1). The lowest HPV prevalence was seen in the study by Auvert et al sampling the urethra only and in the study by Olesen et al using a non-PCR-based method. The highest HPV prevalence was observed among HIV-positive men.
In PCR-based studies, the pooled prevalence was 61.1% (95% CI 44.1 to 78.1) for any HPV and 41.6% (95% CI 23.3 to 60.0) for HR HPV using random effects meta-analysis. Among men with symptoms of HPV infection, the pooled prevalence of any HPV was 79.0% (95% CI 60.8 to 97.3) and 46.0% (95% CI 27.7 to 64.3) among asymptomatic men (p=0.0425). In studies sampling other penile sites (eg, glans, coronal sulcus and shaft), the pooled prevalence of any HPV was 61.3% (95% CI 44.7 to 77.8) (data not shown).
In all studies, the prevalence of any HPV and HR HPV was higher among HIV-positive men than among HIV-negative men (figure 1 and online supplementary table S1 http://sti.bmj.com/content/90/6/455/suppl/DC2). Using random effects meta-analysis, the pooled prevalence of any HPV was 78.2% (95% CI 54.2 to 91.6) among HIV-positive and 49.4% (95% CI 30.4 to 68.6) among HIV-negative men (p=0.0632). The pooled HR HPV prevalence was 58.6% (95% CI 21.0 to 91.0) among HIV-positive and 25.0% (95% CI 10.5 to 43.2) among HIV-negative men (p=0.0503). In PCR-based studies, the pooled prevalence of any HPV was 84.5% (95% CI 74.2 to 91.2) among HIV-positive and 56.4% (95% CI 49.7 to 62.9) among HIV-negative men (p<0.0001) and the pooled HR HPV prevalence was 74.2% (95% CI 70.0 to 78.2) among HIV-positive and 30.5% (95% CI 15.8 to 47.6) among HIV-negative men (p=0.0003) (data not shown).
(Enlarge Image)
Figure 1.
Prevalence of any human papillomavirus (HPV) (A) and high-risk (HR) HPV (B) in relation to HIV status among men in sub-Saharan Africa*. *Please see online supplementary table S1 for the exact numbers used in the graph.
Although based on few studies (n=5), the HPV prevalence appeared to be higher among uncircumcised men than circumcised men (see online supplementary table S2 http://sti.bmj.com/content/90/6/455/suppl/DC2), and this was observed in the random effects meta-analysis also (uncircumcised men 70.4%; 95% CI 46.6 to 89.5 vs circumcised men 57.0%; 95% CI 37.4 to 75.4; p=0.4059 for any HPV) (data not shown).
The type-specific prevalence of HPV6/11/16/18/31/33/45/52/58 is shown in Table 2. Among the HR HPV types, HPV16 was the most common type in six studies and among these HPV52 was the second most common type in three studies. In two studies, HPV52 was the most frequent type followed by HPV16. HPV6 was the most common LR HPV type in all studies, except one in which HPV11 was more common than HPV6.
Only six studies provided data on age-specific HPV prevalence. Of these, two studies had information on age-specific HPV prevalence stratified by HIV status and one study included only HIV-negative men. In figure 2 (and online supplementary table S3 http://sti.bmj.com/content/90/6/455/suppl/DC2) the overall age-specific HPV prevalence is shown. No clear trend in the overall age-specific prevalence of HPV was seen; Ng'ayo et al found a high HPV prevalence (61%–64%) in the youngest age groups (18–30 year olds), then a decrease to 44% in 31–40 year olds followed by a slight increase to 54% in men above 40 years old, while Müller et al reported a slight increase in the prevalence of any HPV from 72% among 18–29 year olds to 83% among men ≥40 years old. In the studies stratifying by HIV status, Olesen et al reported a flat prevalence curve for any HPV among HIV-negative men (17%–26% HPV-positive in all age groups) and an increase in the prevalence of any HPV among HIV-positive men (from 22% in 25–29 year olds to 52% in men ≥50 years old). Among HIV-negative men, Tobian et al found a HR HPV prevalence of 29% among 15–19 year olds, then a peak HR HPV prevalence in the age group 20–24 years old (48%) and a subsequent decline to 29% in men ≥35 years old, while among HIV-positive men a more constant and high HR HPV prevalence was seen in all age groups (71%–87%) (data not shown).
(Enlarge Image)
Figure 2.
Overall age-specific prevalence of any and/or high-risk human papillomavirus (HR HPV) and 95% CIs among men in sub-Saharan Africa*,†,‡,§. *When estimates were presented for an age group, the mean of the age range was used for graphical presentation of data points; †For Tobian et al24 the age-specific prevalence of HR HPV is shown, while for all other studies the age-specific prevalence of any HPV is shown; ‡For Smith et al12 the estimates presented for the glans specimen were used; §Please see online supplementary table S3 for the exact numbers used in the graph.
Results
Description of Studies
From the systematic review, we identified 11 studies comprising 9342 men examining the prevalence of HPV DNA among men in sub-Saharan Africa. These studies included six cross-sectional studies and five randomised controlled trials (RCTs) in which HPV prevalence were obtained either at baseline or at follow-up (Table 1). All identified studies were from southern Africa (n=6) or eastern Africa (n=5). Altogether six studies were from South Africa, two studies were conducted in Kenya and three studies were from Rwanda, Tanzania and Uganda, respectively. No studies from western Africa or middle Africa were identified. In the two RCTs of male circumcision from which baseline data were obtained, all study participants were uncircumcised. In all other studies, the circumcision prevalence ranged from 7.2% to 96.6%. The RCT of male circumcision conducted in Kenya included only HIV-negative men and one study from South Africa comprised only HIV-positive men. For the remaining studies, the prevalence of HIV ranged between 2% and 49.5%. In three studies, the majority of men had symptoms of HPV infection: Müller et al included 214 sexual health clinic attendees of whom 108 had ano-genital warts, in the study by Firnhaber et al all men (n=74) had penile warts and Vogt et al included 34 men attending an HIV testing centre. One study sampled exfoliated cells from the urethra only, while the remaining studies sampled other penile sites (eg, glans, coronal sulcus and shaft). For the detection of HPV DNA, 10 studies used PCR-based methods and one study used a non-PCR-based method (Hybrid Capture 2) (Table 1).
Prevalence of HPV
In Table 1 the prevalence of any HPV and HR HPV for each study is shown. Among the 11 studies identified, nine presented data on the prevalence of any HPV and seven studies had data on HR HPV. The prevalence of any HPV ranged from 19.1% (95% CI 17.2 to 21.0) to 100% (95% CI 85.3 to 100.0) and the prevalence of HR HPV from 16.2% (95% CI 14.5 to 17.9) to 84.9% (95% CI 76.7 to 93.1). The lowest HPV prevalence was seen in the study by Auvert et al sampling the urethra only and in the study by Olesen et al using a non-PCR-based method. The highest HPV prevalence was observed among HIV-positive men.
In PCR-based studies, the pooled prevalence was 61.1% (95% CI 44.1 to 78.1) for any HPV and 41.6% (95% CI 23.3 to 60.0) for HR HPV using random effects meta-analysis. Among men with symptoms of HPV infection, the pooled prevalence of any HPV was 79.0% (95% CI 60.8 to 97.3) and 46.0% (95% CI 27.7 to 64.3) among asymptomatic men (p=0.0425). In studies sampling other penile sites (eg, glans, coronal sulcus and shaft), the pooled prevalence of any HPV was 61.3% (95% CI 44.7 to 77.8) (data not shown).
In all studies, the prevalence of any HPV and HR HPV was higher among HIV-positive men than among HIV-negative men (figure 1 and online supplementary table S1 http://sti.bmj.com/content/90/6/455/suppl/DC2). Using random effects meta-analysis, the pooled prevalence of any HPV was 78.2% (95% CI 54.2 to 91.6) among HIV-positive and 49.4% (95% CI 30.4 to 68.6) among HIV-negative men (p=0.0632). The pooled HR HPV prevalence was 58.6% (95% CI 21.0 to 91.0) among HIV-positive and 25.0% (95% CI 10.5 to 43.2) among HIV-negative men (p=0.0503). In PCR-based studies, the pooled prevalence of any HPV was 84.5% (95% CI 74.2 to 91.2) among HIV-positive and 56.4% (95% CI 49.7 to 62.9) among HIV-negative men (p<0.0001) and the pooled HR HPV prevalence was 74.2% (95% CI 70.0 to 78.2) among HIV-positive and 30.5% (95% CI 15.8 to 47.6) among HIV-negative men (p=0.0003) (data not shown).
(Enlarge Image)
Figure 1.
Prevalence of any human papillomavirus (HPV) (A) and high-risk (HR) HPV (B) in relation to HIV status among men in sub-Saharan Africa*. *Please see online supplementary table S1 for the exact numbers used in the graph.
Although based on few studies (n=5), the HPV prevalence appeared to be higher among uncircumcised men than circumcised men (see online supplementary table S2 http://sti.bmj.com/content/90/6/455/suppl/DC2), and this was observed in the random effects meta-analysis also (uncircumcised men 70.4%; 95% CI 46.6 to 89.5 vs circumcised men 57.0%; 95% CI 37.4 to 75.4; p=0.4059 for any HPV) (data not shown).
The type-specific prevalence of HPV6/11/16/18/31/33/45/52/58 is shown in Table 2. Among the HR HPV types, HPV16 was the most common type in six studies and among these HPV52 was the second most common type in three studies. In two studies, HPV52 was the most frequent type followed by HPV16. HPV6 was the most common LR HPV type in all studies, except one in which HPV11 was more common than HPV6.
Only six studies provided data on age-specific HPV prevalence. Of these, two studies had information on age-specific HPV prevalence stratified by HIV status and one study included only HIV-negative men. In figure 2 (and online supplementary table S3 http://sti.bmj.com/content/90/6/455/suppl/DC2) the overall age-specific HPV prevalence is shown. No clear trend in the overall age-specific prevalence of HPV was seen; Ng'ayo et al found a high HPV prevalence (61%–64%) in the youngest age groups (18–30 year olds), then a decrease to 44% in 31–40 year olds followed by a slight increase to 54% in men above 40 years old, while Müller et al reported a slight increase in the prevalence of any HPV from 72% among 18–29 year olds to 83% among men ≥40 years old. In the studies stratifying by HIV status, Olesen et al reported a flat prevalence curve for any HPV among HIV-negative men (17%–26% HPV-positive in all age groups) and an increase in the prevalence of any HPV among HIV-positive men (from 22% in 25–29 year olds to 52% in men ≥50 years old). Among HIV-negative men, Tobian et al found a HR HPV prevalence of 29% among 15–19 year olds, then a peak HR HPV prevalence in the age group 20–24 years old (48%) and a subsequent decline to 29% in men ≥35 years old, while among HIV-positive men a more constant and high HR HPV prevalence was seen in all age groups (71%–87%) (data not shown).
(Enlarge Image)
Figure 2.
Overall age-specific prevalence of any and/or high-risk human papillomavirus (HR HPV) and 95% CIs among men in sub-Saharan Africa*,†,‡,§. *When estimates were presented for an age group, the mean of the age range was used for graphical presentation of data points; †For Tobian et al24 the age-specific prevalence of HR HPV is shown, while for all other studies the age-specific prevalence of any HPV is shown; ‡For Smith et al12 the estimates presented for the glans specimen were used; §Please see online supplementary table S3 for the exact numbers used in the graph.
