The virus, also known as HPV, infects only humans. It affects the skin and mucosae or thin and smooth lining of the mouth, respiratory tract, and genitalia.
Most persons with HPV infection do not have signs or symptoms. The virus can be cleared within six to 24 months and the infection resolves spontaneously but in some persons, infection may persist and cause changes in cells that eventually lead to cancer. The virus can become inactive for months or years. The person’s immunologic status and interplay of several factors have a role in the outcome of infection. Signs and symptoms of infection appear in 11 to 12 months in males and in five to six months in females. Warts usually develop six to 10 months after infection.
The United States Centers for Disease Control has estimated that about 80 percent of women and 90 percent of sexually active men get infected with at least one type of HPV at a particular time in their life. The risk of acquiring HPV infection is 50 percent during anyone’s lifetime. More than 80 percent of sexually active women will have been infected by age 50. In the Philippines, about 14 to 15 in every 100,000 females were diagnosed with cervical cancer in 2020.
The Department of Health has estimated that 7,277 new cases of cervical cancer would be diagnosed and 3,807 would die each year due to cervical cancer. Among cancers affecting Filipino women, cervical cancer ranks second only to breast cancer.
Of the more than 200 types of HPV, 40 types have been associated with warts and cancer of the cervix, vulva, vagina, penis, anus, head, neck, and respiratory tract. Types 6 and 11 cause 90 percent of non-cancerous (benign) or low-grade cervical cell abnormalities, warts of the anus and genitals, and laryngeal (throat area) papillomas. The so-called high-risk or cancer-causing types of HPV are 16,18,31,33,35,39,45,51,52,56,58,59,68,69, and 82. These cause 99.7 percent of low-grade cervical cell abnormalities, high-grade cervical cell changes that lead to cancers. Type 16 has been shown to be the cause of more than half of cases of cancer of the cervix, and Type 18 for 20 percent.
HPV has been estimated to be the cause of 90 percent of anal cancer, 65 percent of vaginal cancer, 50 percent of vulvar cancer, and 45 to 90 percent of cancer of the mouth and pharynx.
In some parts of Asia, Africa, and South America, HPV accounts for 10 percent of penile cancer, mostly due to Types 16 and 18.
The virus enters the skin or mucosa and inserts itself to the deeper layer and replicates. While most infections resolve spontaneously, infection may last longer than 12 months. There are risk factors for persistence of HPV infection and these include: cigarette smoking, increasing age, immunodeficiency, longterm use of oral contraceptives, co-infection with HIV or gonorrhea and other sexually-transmitted diseases, diet, genetics, and hormones.
The most documented mode of transmission of HPV infection is through skin-to-skin contact – sexual and non-sexual.
Transmission from an infected mother to her child may occur. HPV DNA has been found in contaminated medical equipment, and in some water and sewage samples.
The virus is repellant to heat and drying and shows 30 percent infectivity after seven days of dehydration. It can live on surfaces, clothing, and frequently used gynecologic medical equipment. One study has shown that HPV Type 16 remained infectious for seven days on wet surfaces. While these findings do not mean that we get HPV from simple exposure to contaminated items, they tell us about the importance of preventive measures (proper sanitation, sterilization of equipment, hygiene) and vaccination.
HPV testing is used for surveillance, research, and in special clinical situations in some countries but is not routinely used for screening or to determine if one may be given a vaccine. In the US, there are still no US Food and Drug Administration-approved blood tests to detect HPV infection.
Routine vaccination of adolescents and young adults has caused a decrease in HPV infection.
In the Philippines, the DOH works closely with other agencies. The Department of Education issued Memorandum 173 for inclusion of HPV vaccination in the school-based immunization program.
The DOH wants to shift to the use of a single-dose vaccine – once approved by the Health Technology Assessment Council or the Department of Science and Technology to improve uptake rates. The target population for vaccination is age nine to 14 years and can extend to age 26 years old.
Consult with a physician or health care authority is advised in order to prevent HPV infection and its consequences. Vaccination is of utmost importance.
April 25, 2024
