The Prevalence, Genotype Distribution and Risk Factors of Human Papillomavirus in Tunisia: A National-Based Study

Abstract

There are limited national population-based studies on HPV genotypes distribution in Tunisia, thus making difficult an assessment of the burden of vaccine-preventable cervical cancer. In this context, we conducted a national survey to determine the HPV prevalence and genotypes distribution and the risk factors for HPV infections in Tunisian women. This is a cross-sectional study performed between December 2012 and December 2014. A liquid-based Pap smear sample was obtained from all women and samples' DNAs were extracted. Only women with betaglobin-positive PCR were further analysed for HPV detection and typing by a nested-PCR of the L1 region followed by next-generation sequencing. A multiple logistic regression model was used for the analysis of associations between the variables. A total of 1517 women were enrolled in this study, and 1229 out of the 1517 cervical samples were positive for the betaglobin control PCR and tested for HPV. Overall HPV infection prevalence was measured to be 7.8% (96/1229), with significant differences between the grand regions, ranging from 2% in the North to 13.1% in Grand Tunis. High-risk HPV genotypes accounted for 5% of the infections. The most prevalent genotypes were HPV 31 (1%), 16 (0.9%), 59 (0.7%). HPV18 was detected only in four cases of the study population. Potential risk factors were living in Grand Tunis region (OR: 7.94 [2.74-22.99]), married status (OR: 2.74 [1.23-6.13]), smoking habit (OR: 2.73 [1.35-5.51]), occupation (OR: 1.81 [1.09-3.01]) and women with multiple sexual partners (OR: 1.91 [1.07-3.39]). These findings underscore the need to evaluate the cost effectiveness of HPV vaccine implementation, contribute to the evidence on the burden of HPV infections, the critical role of sexual behaviour and socioeconomic status, and call for increased support to the preventive program of cervical cancer in Tunisia.

Keywords: HPV infection; Tunisian women; epidemiology; vaccine.

Figure 1

Flow chart of the study samples.

Figure 2

Distribution of cytological profiles of the study population.

Figure 3

High-risk and Low-risk HPV genotypes prevalence in Tunisian population. HPV16 (1%) and HPV31 (0.9) are the most prevalent high-risk HPV genotypes. HPV70, HPV53 and HPV18 occupied the 8th position, with a prevalence of 0.33%. HPV6 1.6%) and HPV40 (1.1%) are the most prevalent low risk HPV genotypes followed by HPV42 (0.57%), HPV74 (0.41). HPV81, HPV89 and HPV11 are presented with a prevalence of 0.24%.

Figure 4

High risk and Low risk HPV genotypes distribution according to the cytological profiles. Histogram reporting the number of samples with high-risk HPV (HR) and low risk HPV (LR) according to the cytological profile.

Figure 5

Global HPV Prevalence and High risk and Low risk HPV genotypes distribution according to age-groups. Blue line represents the distribution of global HPV prevalence according to age groups. Histograms represent the distribution of high-risk HPV (HR) and low risk HPV (LR) genotypes according to age groups.

Figure 6

HPV distribution according to the Tunisian regions. The highest prevalence (orange colour) is observed in the regions of South-West (Kebili, Gafsa and Tozeur governorates) and Grand Tunis (Manouba, Tunis, Ariana and Ben Arous) with a prevalence of 13% and 13.1% respectively. The North-East (Nabeul, Zaghouan and Bizerte), North-West (Beja, Jendouba, Kef and Siliana) and Central-West (Kairouan, Kasserine and Sidi Bouzid) regions showed the lowest (Green colour) prevalence of HPV (2.4%, 2.2% and 2% respectively). Central East (Sousse, Mahdia, Monastir and Sfax) and South-West (Gafsa, Tozeur and Kebeli) regions presented a prevalence of 8.6% and 8.3%, respectively.