High-Risk HPV DNA (Non 16/18): What a Positive Result Means

A positive result for high-risk HPV DNA other than types 16 or 18 means your screening test detected one or more of roughly a dozen other cancer-associated HPV strains in your cervical sample. These types do carry real risk, but as a group they are less likely than HPV 16 or 18 to progress to serious cervical disease, and the large majority of these infections clear without treatment. The result puts you on a watchful pathway rather than an emergency one, though the specifics of follow-up depend on your cytology (Pap) result and your screening history.

Which Viruses Fall Into This Category

Standard HPV screening tests detect 14 high-risk genotypes. Two of them, HPV 16 and HPV 18, get singled out because they account for the largest share of cervical cancers worldwide. The remaining 12 high-risk types are HPV 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68.¹ When your result says “high-risk HPV detected, non-16/18,” the lab’s test flagged one or more of these 12 types but did not individually name which one. Some newer assays do provide extended genotyping, but the most widely used platforms lump these 12 together into a single “other high-risk” pool.

This pooling is practical for labs and keeps costs down, but it obscures a meaningful difference: not all 12 types pose the same threat.

Not All Non-16/18 Types Carry the Same Risk

Research consistently shows a tier within this group. Types 31, 33, 35, 45, 52, and 58 behave more aggressively and are more commonly found in precancerous lesions and cancers. One study that separated these types from the remaining six found that women positive for HPV 31/33/35/45/52/58 had roughly 12 times the odds of having a precancerous lesion compared to HPV-negative women, while those positive for HPV 39/51/56/59/66/68 had about 2.4 times the odds. For context, HPV 16/18 carried about 18 times the odds in the same analysis.²

A large multicenter study looking specifically at women who had normal Pap results but tested positive for HPV zeroed in on individual genotypes. Among the non-16/18 types, HPV 33 and HPV 58 stood out with elevated odds of moderate or severe cervical changes, while HPV 52 was associated with increased risk of the most severe precancerous grades.³ So even within the “non-16/18” bucket, some types deserve closer attention than others. Unfortunately, unless your lab ran extended genotyping, you probably won’t know which specific type you carry.

What Happens After a Positive Non-16/18 Result

Clinical management hinges on what your Pap cytology shows alongside the HPV result. If your Pap is normal and the HPV result is non-16/18 positive, current guidelines generally recommend repeating both tests in about a year rather than jumping straight to colposcopy. The rationale is that the risk of having a hidden precancerous lesion is roughly five times lower in this scenario than in someone who tests positive for HPV 16 or 18 with a normal Pap.⁴ That lower immediate risk buys you time to see whether your immune system clears the infection on its own.

If your Pap shows any abnormality, even mild changes, the threshold for colposcopy drops and your provider will likely refer you sooner. And if the non-16/18 HPV infection persists on a repeat test a year later, colposcopy becomes strongly recommended even with normal cytology, because persistence is the single biggest signal that something more serious may be developing.⁵

Most of These Infections Go Away on Their Own

This is the single most reassuring piece of the picture. The majority of high-risk HPV infections, regardless of type, are cleared by the immune system within one to two years. A large natural-history study found that new high-risk HPV infections lasted on average between 5 and 15 months depending on the specific type, with most clearing well before the two-year mark.⁶ Infections that had already been present when a person entered a study (prevalent infections, often of unknown duration) took somewhat longer to resolve, averaging closer to 18 months.

The infections that matter clinically are those that refuse to go away. Persistent infection with non-16/18 types was actually a stronger predictor of disease progression than HPV 16/18 infection in one study following women who initially had mild cervical abnormalities. The authors found that genotyping only for HPV 16/18 would have missed the majority of women whose mild lesions later progressed to more serious ones.⁷ This is why the repeat-test-in-a-year approach matters so much. The first positive result tells you relatively little about your long-term trajectory; the follow-up test tells you much more.

How High-Risk HPV Types Cause Cervical Changes

All high-risk HPV types share the same basic playbook. The virus produces two proteins, called E6 and E7, that interfere with your cells’ built-in brakes against uncontrolled growth. E6 targets a tumor-suppressing protein called p53 and accelerates its destruction. E7 disrupts another tumor suppressor, the retinoblastoma protein, freeing cells to divide when they normally would not.⁸ Think of it as the virus simultaneously cutting the brake lines and jamming the gas pedal.

The reason HPV 16 is particularly dangerous is that its versions of E6 and E7 are especially aggressive at these tasks. The non-16/18 types use the same molecular strategy, but their versions of these proteins are generally less potent. That is the biological basis for the risk difference your screening result reflects. It also explains why persistence matters: the longer these proteins are active in your cells, the more accumulated damage they can cause. A brief infection rarely gives the virus enough time to produce meaningful changes.

Factors That Influence Whether the Virus Clears

Your immune system does the heavy lifting in clearing HPV, and several factors seem to tilt the odds. Smoking is one of the most consistently identified risk factors for persistent HPV infection. In a study of early-stage cervical cancer patients, smoking was associated with roughly seven-fold higher odds of persistent HPV infection after treatment.⁹ That study also identified disrupted vaginal microbiota as a factor linked to persistence.

A cohort study of university students found that daily vegetable consumption appeared to increase the rate of HPV clearance regardless of virus type, while consistent condom use was associated with faster clearance of low-risk types specifically.¹⁰ None of these individual factors is a magic lever, but they do suggest that general immune health, avoiding cigarettes, and maintaining a healthy vaginal flora work in your favor.

The Emotional Weight of a Positive Result

If you feel anxious or unsettled after getting this result, you are in extremely common company. Studies consistently find that women who test positive for HPV report higher levels of anxiety and worry than those who test negative, even when their cytology is completely normal.¹¹ In one study, women who were HPV-positive with normal cytology had nearly double the odds of very high anxiety compared to a control group that hadn’t undergone HPV testing at all.

A large survey found that the waiting periods are often the hardest part. Anxiety peaked while waiting for initial test results and while waiting for colposcopy or biopsy outcomes. It dropped substantially after treatment or after receiving an all-clear.¹² Knowing that a non-16/18 result carries lower risk than HPV 16 or 18, and that most infections clear without intervention, can help put the waiting period in perspective. But feeling worried despite knowing the statistics is normal and nothing to dismiss. A Taiwanese study found that younger women and those with more negative emotional patterns bore a disproportionate psychological burden from positive HPV results.¹³

What This Means for Your Partner

HPV is transmitted through skin-to-skin sexual contact, and it passes in both directions between partners. A meta-analysis of transmission within heterosexual couples found that the rate of female-to-male transmission was roughly twice the rate of male-to-female transmission, though both directions were common.¹⁴ In a study of couples where the woman was HPV-positive, about 86% of male partners also carried at least one HPV type, though complete type concordance between partners was rare. When there was overlap, it involved a high-risk type the vast majority of the time.¹⁵

There is no approved HPV test for men, and no recommended treatment for HPV infection in men who are asymptomatic. If you’re in a long-term relationship, you’ve likely already shared the virus, and trying to prevent re-transmission between established partners is generally not something guidelines focus on. A new partner, on the other hand, benefits from vaccination if they haven’t been vaccinated already.

How Well Does the HPV Vaccine Cover Non-16/18 Types

The current standard vaccine, Gardasil 9, directly targets five of the non-16/18 high-risk types: HPV 31, 33, 45, 52, and 58. Adding these five types to the original HPV 16 and 18 coverage increases the proportion of cervical cancers potentially prevented from about 70% to roughly 90%.¹⁶ The same five additional types also cover a substantial share of HPV-associated anal, vaginal, and vulvar cancers.¹⁷

That still leaves HPV 35, 39, 51, 56, 59, 66, and 68 without direct vaccine coverage. There is some evidence of cross-protection from vaccination against genetically related types. An 11-year follow-up of women vaccinated with the older four-valent vaccine found that the prevalence of types genetically related to HPV 16 dropped by about 46% among vaccinated women, suggesting their immune response partially protected against cousins of the targeted types. Cross-protection against HPV 18-related types was less clear.¹⁸ Whether the nine-valent vaccine provides broader cross-protection is still being studied.

If you’ve already tested positive for a non-16/18 type, vaccination won’t treat an existing infection. But if you haven’t been vaccinated and are within the recommended age range, the vaccine still protects against the types you haven’t yet encountered.

Which Non-16/18 Types Are Most Common Varies by Region

The mix of high-risk HPV types circulating in a population is not the same everywhere, and this has real implications for how well vaccine programs and screening algorithms work in different parts of the world. In a large European study, HPV 31 was the second most common high-risk type after HPV 16, followed by HPV 18 and HPV 56.¹⁹ In sub-Saharan Africa, the picture is different: HPV 52 is a dominant non-16 type in Eastern and Southern Africa, while HPV 35 takes that role in Western Africa.²⁰ In parts of southwest China, HPV 33 was found at unusually high prevalence in Tibetan populations compared to neighboring ethnic groups.²¹

This geographic variation matters because a “non-16/18 positive” result in one country may represent a quite different risk profile than the same result in another, depending on which types are circulating locally. It also shapes the impact of vaccination programs: regions where HPV 35 or 56 dominate will see less benefit from the nine-valent vaccine than regions where HPV 31, 33, or 52 are the main players, since the former types aren’t directly targeted.

Newer Triage Tools on the Horizon

One of the frustrations with the current approach is that a non-16/18 positive result with a normal Pap can feel like being told to just wait and see. Emerging biomarker tests are trying to close that gap by giving clinicians a better way to sort who truly needs colposcopy from who can safely wait.

The most advanced of these is the p16/Ki-67 dual stain, which looks for two cellular markers that together signal the kind of disrupted cell growth HPV causes. In the large IMPACT trial, an approach using immediate colposcopy for HPV 16/18-positive women and dual-stain triage for all other high-risk types caught about 94% of severe precancerous lesions, outperforming the combination of genotyping plus conventional Pap cytology. It also sent fewer women to colposcopy overall, meaning fewer unnecessary procedures.²² Another study confirmed that dual staining had about 92% sensitivity for detecting severe precancerous changes in high-risk HPV-positive women and higher specificity than Pap cytology alone.²³

Another promising avenue is HPV DNA methylation testing. When HPV starts causing serious trouble in cervical cells, characteristic chemical tags accumulate on the viral DNA. A study covering all 12 non-16/18 high-risk types found that a methylation assay built across all 12 genotypes outperformed conventional cytology in both sensitivity and test positivity rates for identifying severe precancerous changes.²⁴ Neither dual staining nor methylation testing has fully replaced standard triage in most clinical settings yet, but both are working their way into guidelines and could soon give women with non-16/18 results a faster, more definitive answer about what their positive result actually means for them.

Self-Sampling for Screening

Access to screening remains uneven globally, and one development particularly relevant to HPV-primary testing is self-collection. A systematic review and meta-analysis found that self-collected vaginal samples had about 87% sensitivity and 91% specificity for detecting HPV compared to clinician-collected samples.²⁵ Roughly two-thirds of women in the studies preferred self-collection. Because HPV-primary screening detects the virus’s DNA rather than relying on a trained eye to interpret cell morphology, it lends itself to self-sampling in a way that traditional Pap testing does not. For women in underserved areas or those who avoid clinic visits due to discomfort or stigma, self-collection could be the difference between getting screened and not getting screened at all.