Epidemiology Of HPV (How Many People Have HPV?) Male
Women are able to mount much more effective antibody response to HPV then men. 32% of women and only 12% of men are able to mount antibodies against HPV in the National Health and Nutrition examination survey (NHANES).
Antibodies do not always develop after a person has been infected. Even if a person has been close to an HPV infection develop antibodies, persistence of these antibodies over time is variable.
The zero prevalence of HPV vaccine types increase with age. 42% of women (30-39 years old) and 18% of men (50-59 years old) had antibodies against HPV vaccine-types (6, 11, 16, 18).
The seroprevalence of any HPV vaccine type among men is higher in Australia reaching 32% (at 40-49 years of age) compared to 18% (at 50-59 years of age) in the United States.
Studies indicate a higher incidence of HPV infections in men, with rates similar to a higher incidence in females.
A follow-up of female and male patients who both initially had positive HPV 16 antibodies, demonstrated more percentage of males then females remained HPV 16 positive 6 months after initially becoming positive (39% of men versus 62% of women remained positive).
There are > 100 types of HPV.
Approximately 40 HPV types are sexually transmitted. These types are categorized as either being high risk or low risk on a basis of there association with different disease outcomes.
HPV DNA prevalence is useful for measuring current infections, but does not reflect cumulative HPV exposure. Seroprevalence data (percentage of patients given at one point in time having positive antibody levels) can underestimate cumulative exposure, because only 55%-70% of women with HPV type 6, 16, or 18 infection develop detectable antibodies, which is a considerable variation amongst the different HPV types.
Seroprevalence of any HPV vaccine type varied by race/ethnicity.
On the assumption that 60% of females develop antibody after infection, that would suggest that among women age 30-39 years of age, 36% have been exposed to HPV 16 and 70% have been exposed to any HPV vaccine type.
Age and lifetime sexual partners are associated with high increased antibody levels for any HPV vaccine type in men.
Age, lifetime number of sexual partners and poverty levels are significant risk factors for positive antibody levels in women.
There is a decrease in seropositivity at older ages.
Current infection indications how many people are infected at this point in time. Most HPV infections clear. Cumulative exposure indicates the person’s chance of having been exposed to or had an HPV infection at any point in their lifetime.
The decrease in antibody levels in women as they get older could be due to decreasing antibody titers – cohort effect, as older women have a decrease in exposure and a consequent lower exposure to HPV. For example, women age 40-49 years and 50-59 years of age in one study reported a median of 4 and 2.8 lifetime sexual partners respectively, suggesting lower exposure in the oldest age groups.
The frequency of antibody levels in non-Hispanic blacks of any HPV vaccine type were higher than those observed in non-Hispanic whites or Mexican American.
Non-Hispanic blacks had the highest seroprevalence among females than males.
There is notably no significant difference of race/ethnicity for HPV 16 seroprevalence among females.
The lower antibody levels (lower seroprevalence) in males are probably due to differences in immune response by the HPV infection rather than to lower infection rates. Multiple studies have actually found a high prevalence of HPV infection among males.
________ HPV infections of the keratinized epithelium in males may be less likely than an infection of mucosal surfaces, i.e., the vagina in women (to do similar response). Another explanation for the lower seroprevalence is that the duration in the infection in men may be shorter, and antibodies are less likely to develop after transient HPV infection. Differences and persistence of antibodies can also contribute.