There are over a hundred different versions of the human papillomavirus (HPV) known to exist, so scientists have numbered each strain. Studies of the particular strains have found that the presence of HPV 16 and 18 is a strong factor in determining if a woman might eventually develop cervical cancer. Cervical cancer may take years to develop, and a routine pap smear might detect the presence of HPV 16 and 18 and allow for the early detection of the disease.
HPV is a sexually-transmitted disease, which means it is spread from one person to another through sexual contact of some kind. This is true for HPV 16 and 18 as well. About 30 of the over 100 strains of the virus can result in consequences like genital warts in men or women and cervical cancer in women, but most men who have HPV never develop symptoms. The large number of HPV viruses makes it difficult to isolate which strain causes which symptoms.
Since most people who have some form of HPV never develop symptoms or never get tested, it is hard to estimate how many people may be infected. Some studies have put the number of infected Americans in the tens of millions, which would make it the most common sexually-transmitted disease in the US. The only guaranteed prevention of the disease is total abstinence from any sexual contact.
There is a test that can be run during a routine pap smear which can identify the presence of HPV 16 and 18. Once the strains are identified, frequent follow-up visits to a gynecologist are required. The doctor will check for dysplasia, or the abnormal growth of cells. This does not necessarily mean that cervical cancer will develop, but is only a warning sign.
Currently, there is no cure for HPV 16 and 18 or any of the other strains, but the practice of safe sex greatly reduces the odds of contracting the virus. If a female is diagnosed with HPV, she should be sure to follow up with her doctor regularly. If cervical cancer cells are detected early, then it is very curable and may not require more than outpatient treatment. In very rare cases, a man can develop cancer of the penis or anus as a result of exposure to HPV, and so he should be sure to check for the presence of genital warts if he is sexually active.
