Hidden strains of HPV found in 'virus-negative' genital warts

July 11, 2013

There are 170 established HPV types. Cancerous human papillomavirus (HPV) viruses are the main cause of cervical cancer, and are found in close to 100% of cervical tumors.

Cervical cancer and genital warts are caused by HPV. However, testing for the virus using standard techniques can sometimes give a negative result—in these cases, the condylomas are called 'virus-negative' warts.

In a new study published in Virology, researchers assessed the DNA found in samples taken from 40 patients with 'virus-negative' genital warts. Through a general DNA sequencing approach, the researchers showed that several of the negative samples did in fact contain HPV DNA.

This means that virus-negative warts can harbor small amounts of more distantly related viruses that escaped previous detection. According to the research, there is a diverse pool of previously unknown HPV types that infect humans and are detectable on .

The findings have implications for the knowledge of diversity of HPV types, as these viruses are currently undetectable using traditional testing methods.

Ten pools of four samples taken from virus-negative warts were tested using genetic material straight from the patient—including viral, bacterial and human DNA. Five of the pools contained HPV, and three of these contained new strains of the virus.

Altogether, 1337 pieces of HPV-related DNA were detected, representing 23 new types of HPV, 10 established types of HPV and two known HPV DNA sequences.

This new style of testing has highlighted previously unknown forms of the virus. As such, we learn more about the evolution of different HPV types. It is possible that the previously unknown forms of the virus do not cause condyloma but may be secondary invaders of condyloma.

Explore further: How cervical cancer vaccines came to be

More information: This article is "Metagenomic sequencing of "HPV-negative" condylomas detects novel putative HPV types" by Hanna Johansson, Davit Bzhalava, Johanna Ekström, Emilie Hultin, Joakim Dillner, and Ola Forslund (DOI: 10.1016/j.virol.2013.01.023) and appears in Virology.

Related Stories

Virology: A marker for a cancer-causing virus

February 13, 2013

(Phys.org)—Depending on the strain, or genotype, of the human papillomavirus (HPV) (see image), the lesions it causes can range from relatively benign to cancer-causing. Differentiating between lesions caused by low-risk ...

Recommended for you

In sub-Saharan Africa, cancer can be an infectious disease

August 26, 2016

In 1963, Irish surgeon Denis Parson Burkitt airmailed samples of an unusual jaw tumor found in Ugandan children to his colleague, Anthony Epstein, at Middlesex Hospital in London. Epstein, an expert in chicken viruses and ...

Zika virus may persist in the vagina days after infection

August 25, 2016

The Zika virus reproduces in the vaginal tissue of pregnant mice several days after infection, according to a study by Yale researchers. From the genitals, the virus spreads and infects the fetal brain, impairing fetal development. ...

Team discovers how Zika virus causes fetal brain damage

August 24, 2016

Infection by the Zika virus diverts a key protein necessary for neural cell division in the developing human fetus, thereby causing the birth defect microcephaly, a team of Yale scientists reported Aug. 24 in the journal ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.