HPV Genotyping Explained: HPV 16, HPV 18 and Extended Genotyping

HPV DNA testing can determine whether high-risk HPV is detected. Genotyping goes a step further by providing information about which HPV genotype — or group of genotypes — is present.

That distinction matters because high-risk HPV types do not all carry identical clinical risk.

The important question is therefore not simply:

“Is HPV detected?”

It can also be:

“Which high-risk HPV genotype or risk group has been detected, and how can that information be used within an appropriate clinical pathway?”

HPV is often discussed in the context of cervical cancer because persistent infection with high-risk HPV is the central cause of cervical cancer and cervical screening provides one of the clearest established applications for HPV DNA testing.

But HPV infection is not restricted to women.

HPV can affect the genital area, anus and oropharynx, and persistent infection with carcinogenic HPV types is associated with cancers affecting both women and men.

A useful distinction is therefore:

HPV infection and HPV-associated disease affect both sexes.

But:

HPV testing does not have the same established screening role across every anatomical site or population.

This distinction is particularly important when discussing men’s health.

The existence of HPV-associated disease in men should not be interpreted to mean that cervical HPV screening algorithms can simply be transferred to routine screening of men.

High-risk HPV DNA testing identifies the presence of HPV types associated with increased risk of cervical precancer and cancer.

A basic high-risk HPV result may therefore answer:

High-risk HPV detected

or

High-risk HPV not detected

That information is already highly valuable for cervical cancer screening.

But a positive high-risk HPV result does not necessarily tell us which carcinogenic HPV type is present.

Genotyping adds another layer of information.

Genotyping therefore should not be viewed simply as producing a longer laboratory report.

Its value comes from whether the additional information can support an appropriate clinical decision pathway.

Carcinogenic HPV types differ in their association with cervical precancer and cancer.

HPV 16 and HPV 18 are particularly important high-risk genotypes and are frequently differentiated from other carcinogenic HPV types in molecular screening assays.

This is why many HPV assays do not report only:

High-risk HPV: Positive

Instead, they may report:

This approach is often described as limited or partial genotyping.

The purpose is not merely to identify HPV by name.

It is to provide additional risk information that can be incorporated into an appropriate cervical-screening algorithm.

HPV molecular tests can provide different levels of genotype information.

No Genotyping

The assay reports whether one or more targeted high-risk HPV types are detected, without separately identifying specific genotypes.

A result may therefore be reported simply as:

High-risk HPV detected

or

High-risk HPV not detected

This answers the primary screening question but provides limited genotype-specific risk information.

Limited Genotyping

Limited genotyping differentiates selected particularly important genotypes — commonly HPV 16 and HPV 18 — from other high-risk HPV types.

Conceptually:

HPV 16 · HPV 18 · Other high-risk HPV

This provides additional information that may be used for risk stratification and triage.

Extended Genotyping

Extended genotyping provides additional differentiation among carcinogenic HPV types or clinically meaningful genotype groups beyond HPV 16 and HPV 18.

The exact reporting architecture varies by assay.

Some systems may identify multiple individual genotypes.

Others may identify selected individual genotypes while grouping additional types according to risk categories.

The important distinction is: extended genotyping provides more differentiated genotype information. It does not automatically mean that every genotype requires a unique clinical action.

A pooled high-risk HPV-positive result tells us that at least one targeted carcinogenic HPV type has been detected.

Extended genotyping can provide additional information about the specific genotype or genotype risk group responsible for that result.

This can potentially allow HPV-positive individuals within a cervical-screening programme to be stratified more precisely according to genotype-associated risk.

Recent international guidance increasingly recognizes this possibility.

However, genotype information should be interpreted within a validated clinical framework.

No.

The number of genotypes reported is only one characteristic of an HPV assay.

A larger genotype panel can provide greater differentiation, but additional information is useful only when it can be interpreted appropriately.

Laboratories and screening programmes should consider questions such as:

The factors that determine usefulness include:

The appropriate question is therefore not:

“Which test reports the most HPV types?”

It is:

“Which HPV testing and genotyping approach provides the information required by the intended clinical pathway?”

Cervical cancer screening is currently the major established population-screening application for high-risk HPV testing.

Malaysia’s cervical cancer screening guideline uses high-risk HPV testing as a primary screening approach and distinguishes between:

HPV 16/18 positive

and

non-16/18 high-risk HPV positive

within its management pathway.

This illustrates an important principle:

A positive high-risk HPV result is not necessarily the end of the molecular information pathway. Genotype information can help determine what happens next.

However, screening algorithms are programme-specific.

Recommendations concerning triage, cytology, repeat testing, colposcopy or other management should follow the applicable national guideline and clinical context rather than being inferred from the laboratory result alone.

Genotyping is useful because carcinogenic HPV types are not associated with identical levels of cervical disease risk.

This creates the possibility of moving from:

HPV positive / negative

towards:

The World Health Organization’s 2026 guidance evaluates HPV screening strategies using:

No genotyping, limited genotyping, and extended genotyping, and considers how genotype information can support risk stratification and molecular triage within cervical cancer screening programmes.

The appropriate strategy depends not only on analytical capability, but also on programme capacity, feasibility, available follow-up and treatment services, quality assurance and resources.

HPV is relevant to men’s health.

Persistent infection with carcinogenic HPV types can contribute to cancers affecting the penis, anus and oropharynx. Anal and oropharyngeal HPV-associated disease can affect both women and men.

This makes HPV prevention relevant across sexes.

However, there is an important difference between:

High-risk HPV molecular testing has a well-established role in cervical cancer screening.

That does not mean that the same testing algorithm should automatically be applied to men.

Routine HPV testing is not generally recommended simply to determine a man’s overall “HPV status,” and the clinical role of HPV testing outside cervical screening depends strongly on anatomical site, population, intended use and applicable clinical guidance.

High-risk HPV — particularly HPV 16 in several settings — is also associated with other HPV-related malignancies, including oropharyngeal and anal cancers.

However, identifying an HPV genotype at another anatomical site does not automatically have the same interpretation or management pathway as identifying that genotype in cervical screening.

HPV vaccination can prevent infections caused by important vaccine-targeted HPV types and contributes to prevention of HPV-associated disease in both females and males.

Screening serves a different purpose.

Vaccination aims to prevent HPV infection and subsequent disease.

Cervical screening aims to identify individuals at increased risk of cervical precancer or cancer so that appropriate follow-up and treatment can occur.

These approaches are complementary rather than interchangeable.

HPV control therefore extends beyond a single test or intervention.

The appropriate HPV testing strategy begins with the intended application.

A practical evaluation can consider:

The final decision should therefore connect:

There is no universal requirement that every HPV molecular test provide the maximum possible genotype resolution.

A laboratory may require an assay that differentiates HPV 16 and HPV 18 from other high-risk types.

Another programme or application may benefit from broader genotype differentiation.

The appropriate approach depends on the question being asked.

More information can be valuable.

But:

This is why HPV assay selection should consider both analytical capability and the surrounding clinical programme.