RESUMEN
Infection of human papillomaviruses (HPVs) has been shown to play an important role in the development of cervical cancer from precancerous lesions known as cervical intraepithelial neoplasia (CIN-I, CIN-II and CIN-III). In Thailand, cervical cancer is the most common cancer in women. Fifty tissue samples diagnosed as CIN-III and 50 tissues of normal histopathologic appearance as controls were examined for the presence of HPV-DNA and HPV typing using PCR and dot hybridization (DH) methods. All specimens used in this study were formalin-fixed paraffin embedded tissues. HPV-DNA was detected in 74% (37/50) of CIN-III and 6% (3/50) of the control group giving a crude odd ratio of 44.58 (95% confidence interval of 15.2-130). Among the CIN-III group, the most prevalent type was HPV-16; 48.65% (18/37) followed by HPV-18; 16.2% (6/37) and HPV-33; 10.8% (4/37). Mixed infection was identified in 4 specimens, ie HPV-6/16, HPV-16/18, HPV-16/33, and HPV-16/18/33. Twelve samples were untyped. In the control group, only one sample (33.3%) was detected to contain HPV-6 DNA and the remaining ones were untyped. Our results revealed infection with HPV, especially HPV-16 and HPV-18, to be strongly associated with CIN-III in Thai women.