Human Papillomavirus (HPV) refers to a group of over 200 related viruses. While many HPV types do not cause health concerns, certain types can lead to genital warts or different forms of cancer. This widespread virus is the most common sexually transmitted infection globally.
Global Picture of HPV Prevalence
It is estimated that over 80% of sexually active individuals, both women and men, will acquire at least one HPV infection by the age of 45. Nearly all sexually active men and women will contract HPV at some point in their lives.
A meta-analysis of close to one million women with normal cervical findings showed an average global prevalence of 12% for detectable cervical HPV infection. For men, a recent study revealed that almost one in three men worldwide are infected with at least one genital HPV type, and about one in five men carry one or more high-risk HPV types.
Prevalence by Demographics
HPV prevalence varies across different demographic groups. For women, the highest prevalence of HPV infection is observed in young adults, peaking in their late teens to early twenties, and then decreases and stabilizes with age. Some regions, like Latin America and Africa, show a bimodal pattern with a second peak in prevalence among women aged 45 years and older.
Among men, HPV prevalence is high in young adults, peaking between the ages of 25 and 29 years, after which it stabilizes or slightly decreases. Males often show a higher prevalence of both any HPV and high-risk HPV compared to females, though age-specific patterns vary.
Geographic regions also show distinct patterns in HPV prevalence. Sub-Saharan Africa has the highest prevalence of cervical HPV among women at 24%, followed by Latin America and the Caribbean at 16%, Eastern Europe at 14%, and South-East Asia also at 14%. These regional differences are linked to the economic development levels of countries, with higher-income regions like North America and Western Europe have lower HPV infection rates compared to less developed areas.
Prevalence of HPV Types
There are over 200 types of HPV, categorized into low-risk and high-risk based on their disease potential. Low-risk HPV types, such as HPV 6 and 11, are associated with genital warts. Before the introduction of HPV vaccines, these types caused an estimated 340,000–360,000 cases of genital warts annually.
High-risk HPV types are linked to various cancers, including cervical, anal, and oropharyngeal cancers. HPV types 16 and 18 are the most common high-risk types worldwide and are responsible for approximately 70% of cervical cancers. Globally, HPV-16 is the most prevalent high-risk HPV genotype. Other common oncogenic types include HPV 52, 31, 58, 39, 56, and 51.
Dynamics of HPV Prevalence
The high prevalence of HPV is largely maintained by several factors inherent to the virus and its transmission. Many HPV infections are asymptomatic, meaning individuals can be infected and transmit the virus unknowingly. This contributes to the continued spread of the virus.
Most HPV infections are transient, with about 90% of genital HPV infections in women clearing naturally within two years. Despite this natural clearance, new infections constantly occur, leading to a sustained high overall prevalence. The duration of infectivity is short, yet the high transmissibility of the virus ensures ongoing circulation.
HPV is primarily transmitted through skin-to-skin contact, most commonly during sexual activity. This includes both penetrative and non-penetrative sexual contact, such as genital-genital, oral-genital, and anal-genital contact. Vaccination programs and screening efforts aim to reduce the prevalence of specific high-risk HPV types by preventing new infections and detecting precancerous changes.