Human Papillomavirus – HPV
Human papillomavirus (HPV) infection
Human papillomavirus (HPV) infection is the most common sexually transmitted viral infection of the lower genital tract. There are many subtypes of this virus, and infections by different varieties lead to disparate clinical conditions. These include genital warts (condylomata acuminata), sub-clinical infection, abnormal growth of epithelial cells (intraepithelial neoplasia), and/or carcinoma of the vulva, vagina, and cervix. In fact, more than 60 subtypes of HPV have been identified, but only a few cause infections of the genital tract. Subtypes 6 and 11 are more often associated with genital warts (overt condylomata acuminata), hut subtypes 16 and 18 are more likely to promote progression to premalignancies or malignancies. HPV infection is widespread. As many as 60% of women tested for HPV DNA with sensitive molecular biology techniques (polymerase chain reaction, or PCR) are positive. Although the majority who test positive are asymptomatic, there is always the risk of reactivation, with subsequent serious consequences, because this virus remains in a woman’s system for life once she is infected.
Health care providers diagnose warts by their typical appearance on physical examination. They can be flat or raised; pink, white, or other pigments; large or small; and they can appear singly or in clusters. Pap smears provide an important screening test to determine the presence of warts. One diagnostic method involves applying 5% acetic acid to the affected area and then examining it microscopically. A colposcopic examination offers a more definitive diagnosis. The surgical excision or biopsy of suspicious tissue and examination of it by a pathologist are often required. Symptoms include occasional itching or bleeding but usually not much pain, in pregnancy, if the wart becomes large it can interfere with a vaginal delivery. Although rare, the vocal cords of vaginally delivered infants have become infected. The most appropriate treatment depends on the location of the lesion, its extent, the severity of the disease, and whether the patient is pregnant. There are several chemical treatments (podophyllin, bichloroacetic acid, trichloroacetic acid, and 5-fluorouracil [5-FLJ]). Physical treatments include freezing the lesion (cryotherapy), laser therapy, electrotherapy, and surgical excision. Immunotherapy also is used in severe cases. Although each of these methods has a success rate that approaches 95% in properly selected patients, recurrences are common. We need research to develop agents that would confer immunity, eradicate latent infection, improve the treatment of overt infection, and further clarify the association between this virus and malignancy.