HPV Genotypes: High-Risk and Low-Risk HPV Types Explained

Human papillomavirus (HPV) is the most common sexually transmitted infection in the world, and most people who have it never know. If a test report mentions HPV genotypes, or names types such as HPV 16 or HPV 18, it's telling you which members of the HPV family were found. This guide explains what the numbers mean, which types matter, and what to do next. Ovio's HPV test is done at home in Bangkok.

What Is HPV?

HPV is a large group of related viruses that infect the skin and the moist linings of the body, such as the cervix, vagina, vulva, penis, anus, mouth and throat. The types that affect the genital area spread through close skin-to-skin contact during vaginal, anal and oral sex. Condoms lower the risk but don't remove it, because they don't cover all the skin.

It's extremely common. According to the US Centers for Disease Control and Prevention (CDC), most sexually active people who aren't vaccinated will get HPV at some point. In most of them the immune system clears it quietly, with no symptoms at all.

How Common Is HPV, and Why Does It Matter?

HPV matters mainly because of cervical cancer. The World Health Organization (WHO) says more than 95% of cervical cancers are caused by HPV, and just two types, HPV 16 and HPV 18, cause about 70% of them. Cervical cancer is one of the most common cancers in women worldwide, including in Thailand, which is why screening and vaccination programmes focus so closely on those two types.

The other side of the picture is reassuring: cancer develops only in a small minority of people whose high-risk infection persists for many years, usually 15 to 20, and screening can find the changes long before that.

What Are HPV Genotypes?

A genotype is a type of HPV defined by its DNA. More than 200 types have been identified and they're numbered roughly in the order they were discovered, so the number says nothing about how dangerous a type is. About 40 of them infect the genital area. They share the same basic structure, but small differences in their DNA change what they do: which tissues they infect, whether they cause warts, and whether they can drive cells towards cancer.

Think of dog breeds: a Chihuahua and a Great Dane are both dogs, but they behave very differently. HPV types are similar. That's why knowing the type, not just "HPV positive", helps a doctor judge your risk.

High-Risk vs Low-Risk HPV Genotypes

High-risk HPV genotypes

High-risk (oncogenic) types can interfere with the controls that stop cells growing out of turn. If an infection persists for years, it can cause precancerous changes and, eventually, cancer. The International Agency for Research on Cancer classes 12 types as causing cancer: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59. Most high-risk HPV tests also include 66 and 68, which are probable or possible causes.

Low-risk HPV genotypes

Low-risk types don't cause cancer. Some cause visible but harmless growths such as genital warts (condylomata acuminata) or minor cell changes that settle by themselves. HPV 6 and 11 cause about 90% of genital warts. Others are found mainly in the mouth: HPV 13 and 32 cause Heck's disease (focal epithelial hyperplasia), small painless bumps inside the mouth that aren't cancerous.

Common HPV Genotypes and What They Mean

Symptoms and Health Conditions Linked to HPV

Most HPV infections cause no symptoms and clear within one to two years. When HPV does cause problems, they depend on the type:

1. Genital warts: small, skin-coloured bumps, cauliflower-like clusters or flat patches on the genitals or around the anus, from low-risk types such as 6 and 11. They're usually painless, sometimes itchy.
2. Cervical cell changes: caused by high-risk types and completely silent. Only screening finds them.
3. Cervical cancer: if high-risk changes are left for years. It can cause bleeding after sex, between periods or after the menopause, unusual discharge or pelvic pain.
4. Other cancers: much more rarely, of the vagina, vulva, penis, anus or the back of the throat, tongue base and tonsils. Throat cancer may show as a sore throat, hoarseness or a lump in the neck that doesn't go away.

The key difference is between a transient infection, which your immune system clears, and a persistent high-risk infection, which stays for years. Persistence is what allows precancerous changes to develop. Smoking and a weakened immune system, including HIV, make persistence more likely.

HPV Incubation and When You Can Test

HPV doesn't follow a fixed clock, so it has no window period in the usual sense:

• Warts (low-risk types): usually appear weeks to a few months after contact, sometimes much later, and sometimes never.
• High-risk types: can stay silent for years. Cell changes develop slowly, and cancer takes 15 to 20 years.

Because HPV can be silent for so long, a positive result can't tell you when you caught it or from whom. It may date from a partner years ago, so a new result in a long relationship isn't a sign of infidelity. It also means HPV testing isn't something you time from a single exposure, the way you would a chlamydia test or HIV test. For people with a cervix, it's done on a regular screening schedule. There's no routine HPV screening test for men; warts are diagnosed by a doctor looking at them.

What Is an HPV Genotyping Test?

An HPV test looks for the virus's DNA in a sample of cells, usually from the cervix or vagina. In the lab, PCR copies tiny amounts of viral DNA until there's enough to detect, and probes then identify which types are present. Tests report results in different ways:

• High-risk HPV test: answers one question, whether any high-risk type is present.
• Partial genotyping: reports HPV 16 and 18 separately, and the other high-risk types as one group.
• Extended or full genotyping: names each type found, high-risk and sometimes low-risk.

Knowing the type changes the follow-up. HPV 16 or 18 usually leads straight to a closer look at the cervix (colposcopy). Other high-risk types are often followed by a Pap smear or a repeat test in a year. Finding the same type again on a later test shows the infection is persisting.

WHO recommends an HPV DNA test as the main cervical screening test, from age 30 and every 5 to 10 years, or from 25 and every 3 years for women living with HIV. Self-collected vaginal samples are an accepted option in many countries. For how this compares with a Pap smear, and how often to screen, see HPV test vs Pap smear.

Can HPV Be Cured?

There's no medicine that kills HPV itself. That sounds worse than it is: about 90% of infections clear by themselves within two years. What doctors treat is the effect of the virus, and those treatments work well:

• Genital warts: prescription creams, freezing (cryotherapy) or minor removal procedures.
• Mild cervical cell changes: often watched with repeat tests, because many go back to normal.
• Precancerous changes: removed or destroyed in a short outpatient procedure, such as LEEP (loop excision) or ablation, long before cancer develops.
• HPV-related cancers: treated with surgery, radiotherapy or chemotherapy. Outcomes are much better when found early.

HPV Prevention and Vaccination

Vaccination is the most effective protection against the types that cause cancer and warts. Older vaccines covered two types (16 and 18) or four (6, 11, 16 and 18). The 9-valent vaccine (Gardasil 9) covers nine:

• Low-risk: 6 and 11, the main causes of genital warts.
• High-risk: 16, 18, 31, 33, 45, 52 and 58.

The vaccine works best before sex begins, so WHO's main target is girls aged 9 to 14. US guidance recommends it at 11 to 12 (from 9) for all children, with catch-up vaccination up to 26, and some adults up to 45 after discussing it with a doctor. The vaccine prevents new infections but doesn't clear one you already have, and it doesn't cover every high-risk type. That's why vaccinated people still need cervical screening. Condoms lower the risk, and not smoking helps your body clear HPV.

HPV Testing in Bangkok

HPV tests and Pap smears are available at hospitals and clinics across Bangkok. If you'd prefer privacy, Ovio's at-home STI testing brings a doctor to your home, condo, hotel or office at a date and time you choose, for Thai and international clients.

Ovio's HPV test checks for 32 HPV genotypes, including the high-risk types 16 and 18, for ฿4,990. It's also part of the Ovio Plus package (฿7,990), where clinically appropriate, alongside HIV, syphilis, hepatitis B and C and an 18-infection PCR panel. The doctor explains your result and, if a high-risk type is found, the follow-up you need. Wondering what else to test for? See which STI tests should I get?

Frequently Asked Questions

Which HPV genotypes are high-risk?

Twelve types are classed as causing cancer: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59. HPV 16 and 18 carry the highest risk. Most tests also include 66 and 68.

I tested positive for HPV 16. Does that mean I have cancer?

No. It means the virus was found, not abnormal cells or cancer, and most HPV 16 infections still clear by themselves. Because 16 carries the highest risk, the next step is usually a colposcopy, a closer look at the cervix, so that any changes can be found and treated early.

Is HPV 32 dangerous?

No. HPV 32 is a low-risk type found mainly in the mouth, where it can cause small harmless bumps (Heck's disease). It isn't linked to cancer. Don't confuse it with a "32-genotype" test, which simply detects 32 different types.

Can HPV go away on its own?

Usually, yes. About 90% of infections clear within two years. A test that later turns negative means your immune system has controlled it. Having one type doesn't protect you from others, and you can be infected again.

Can men be tested for HPV genotypes?

There's no approved routine HPV screening test for men. Genital warts are diagnosed by examination. For some higher-risk groups, such as men who have sex with men and people living with HIV, a doctor may discuss anal cancer screening, which is a specialist assessment.

Do I still need screening if I've had the HPV vaccine?

Yes. The vaccine prevents the types most likely to cause cancer, but not all of them, and it doesn't treat an infection you already had. Keep up cervical screening at the recommended ages.