Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma.

OBJECTIVE To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer. METHODS A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization. RESULTS Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions. CONCLUSIONS An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence.