Image of the herpes simplex virus type 2.
New World Health Organization (WHO)-led global estimates for herpes simplex virus type 2, published by the journal PLOS ONE, show that more than 400 million people worldwide were infected with the virus in 2012. The estimates underline the extent to which herpes simplex virus type 2 – the virus which causes genital herpes – is widespread throughout the world, causing a significant global burden of disease.
The new study is the first update of global herpes simplex virus type 2 estimates, since estimates for 2003 were published in 2008. Lead author Dr. Katharine Looker from the University of Bristol, says, “Approximately 19 million people are newly infected with the virus each year”. More women are infected with the disease than men – in 2012, it was estimated that 267 million women and 150 million men were living with the infection. In 2012, prevalence was estimated to be highest in Africa (31.5 percen) followed by the Americas (14.4 percent), but high rates were seen across all regions, making herpes a global public health concern.
Herpes simplex virus type 2 is mainly sexually transmitted, and can cause genital ulcer disease, which is characterized by the occasional appearance of painful genital ulcers. People infected with genital herpes can often experience feelings of stigmatisation and loneliness. Dr. Lori Newman, a WHO expert on sexually transmitted infections, and senior author of the study, states, “Genital herpes can have a devastating effect on the social and psychological wellbeing of people who are infected.”
Genital herpes can also cause neonatal herpes when the virus is transmitted by a mother to a newborn baby during labour through shedding of the virus. While this is a relatively rare disease, it has devastating consequences, and is often fatal for the baby.
Herpes simplex virus type 2 is of particular concern due to its relationship with HIV. Studies have shown that people who are infected with herpes simplex virus type 2 are approximately three times more likely to become infected with HIV, and people with both HIV and herpes are more likely to spread HIV to others. In addition, infection with herpes simplex virus type 2 in people living with HIV often has a more severe presentation and can lead to serious but rare complications such as brain, eye, or lung infections.
There is no cure for herpes, but there are antiviral medicines, such as acyclovir, famciclovir and valacyclovir which can reduce symptoms. In addition, the consistent and correct use of condoms as well as abstaining from sex while experiencing any of the symptoms of genital herpes can provide partial protection and help to reduce the spread of genital herpes. The authors of the study underline their hope that the new global estimates will help to advocate and provide support for research and efforts to help prevent infection.
WHO and partners are working to accelerate research to develop HSV vaccines and topical microbicides (compounds that can be applied inside the vagina or rectum to protect against sexually transmitted infections [STIs]), with the aim of improving current prevention strategies. Several candidate vaccines and microbicides are currently being studied in countries around the world.
Newman states, “The ultimate tool to prevent herpes is the development of a vaccine, but global partners will have to commit resources to help develop an effective vaccine that can be made available to people all over the world.”