Prevalence of human papillomavirus genotypes in women of different ethnicity from rural northwestern Ecuador.

BACKGROUND

In Ecuador, cervical cancer is the third most common cancer among women and the second most common cause of cancer-related death in women. Although HPV represents a serious public health problem worldwide, the information about its prevalence and genotypes in remote communities of Ecuador is limited. The aim of this study was to determine the distribution of HPV genotypes among ethnic minority women from two remote communities of the northwestern region of Ecuador: Afro-Ecuadorians and Chachis (Amerindian group).

METHODS

We included 291 women who responded to a short survey and were screened for HPV by the amplification of the L1 gene and a nested multiplex PCR to detect 14 high risk (HR) genotypes. A survey collected information on ethnicity, age, community access, and sexual and gynecological history. We identified risk factors associated with HPV infection and co-infection using multivariate logistic regression to calculate odds ratio (OR) and Wald 95% confidence intervals (CI).

RESULTS

Overall, HPV prevalence in the study cohort was 56%, and the five most common HR-HPV genotypes were HPV-58, -16, -68, -39, and -43; however, the distribution of HPV genotypes varied according to ethnicity. We identified lineage A (European variant) for HPV-16 and sublineage A2 for HPV-58 in both ethnic groups. Adjusting for ethnicity, age, community access, and number of sexual partners, we found that Afro-Ecuadorian women were less likely to have an HPV infection than Chachi women (OR: 0.49, 95% CI: 0.25, 0.96), and that participants in communities only accessible by river had 64% less chances of an HPV infection when compared to women in communities accessible by road (OR: 0.36, 95% CI: 0.19, 0.71), and women with 2 to 3 sexual partners had 2.47 times the odds of HPV infection than participants with 0-1 partners (OR: 2.47, 95% CI: 1.32, 4.6). Similar associations were observed with prevalence of co-infection.

CONCLUSIONS

This study provides baseline knowledge regarding the prevalence and distribution of HPV genotypes in ethnic groups of the northwestern coastal Ecuador and essential information for the implementation of appropriate HPV testing and vaccination program to prevent cervical cancer.