|My age:||I am 63|
Jennifer S. Smith, N. Information on age- and sex-specific prevalence of herpes simplex virus HSV types 2 and 1 infections is essential to optimize genital herpes control strategies, which increase in importance because accumulating data indicate that HSV-2 infection may increase acquisition and transmission of human immunodeficiency virus. This review summarizes data from peer-reviewed publications of type-specific HSV seroepidemiologic surveys. HSV-2 prevalence is, in general, highest in Africa and the Americas, lower in western and southern Europe than in northern Europe and North America, and lowest in Asia.
HSV-2 and -1 prevalence, overall and by age, varies markedly by country, region within country, and population subgroup. Age-specific HSV-2 prevalence is usually higher in women than men and in populations with higher risk sexual behavior. HSV-2 prevalence has increased in the United States but national data from other countries are unavailable.
HSV-1 infection is acquired during childhood and adolescence and is markedly more widespread than HSV-2 infection. Further studies are needed in many geographic areas.
Herpes simplex virus HSV establishes latency in sensory ganglia following initial acquisition, causing an infection that persists for life. HSV-2 infection is the primary cause of genital herpes and is one of the most prevalent sexually transmitted infections STIs worldwide [ 1 ]. HSV-2 prevalence is negligible among persons who have never been sexually active [ 2 ]. Persons with HSV-2 infection do not necessarily develop clinical disease, but most intermittently shed virus from the genital tract [ 3 ].
Neonatal herpes simplex infection
Genital herpes is associated with substantial morbidity and can also cause serious, but relatively rare, sequelae such as meningitis and neonatal herpes [ 1 ]. HSV-1 infection is usually transmitted during childhood and adolescence and, if symptomatic, is commonly characterized by oral or facial lesions [ 4 ].
Although HSV-1 is most often transmitted via nonsexual contact, recent data from some developed countries indicate that a non-negligible proportion of first-episode genital herpes is caused by HSV-1 [ 5 ]. The prevalence of HSV-2 and HSV-1 infections overall and by age varies markedly by country, region within country, and population subgroup.
In order to compare the prevalence of herpes infection between geographic areas or countries, age-specific or age-adjusted prevalence among similar populations is necessary. Estimates of HSV-2 and -1 prevalence presented as single summary measures e.
For example, HSV-2 seroprevalence in young adults with a mean age of 20 years would be expected to be lower than in older persons in the same population. Reliable data on the prevalence of HSV-2 and -1 serum antibodies provide an epidemiologic measure of the population Hsv too seeking single female 38 55 of these infections.
The presence of HSV-2 antibody almost exclusively indicates past exposure to a genital infection [ 2 ] but may underestimate the prevalence of genital herpes infections in areas where genital HSV-1 infection is more common. The strong association between HSV-2 prevalence and sexual behavior in different studies [ 67 ] suggests that age-specific HSV-2 prevalence may, in some circumstances, provide a useful marker for sexual behavior.
Type-specific seroprevalence data may be useful to identify particular population subgroups that have a notably higher risk of HSV infection [ 8 ]. Perhaps of more importance, given the strong associations observed between HSV-2 and human immunodeficiency virus HIV seropositivity [ 9—12 ], data on HSV-2 antibody status may be useful in predicting those at greater risk of acquiring and transmitting HIV infection and thus may be valuable for guiding HIV prevention efforts [ 12 ].
This review summarizes and clarifies current knowledge of the prevalence of HSV-2 and -1 serum antibodies by age for different populations worldwide and highlights areas where further studies are needed. Studies citing the use of nonspecific serologic assays only i. Articles were included for review only if data on age were available. Conference abstracts and other unpublished manuscripts were excluded since the detailed information required was rarely available.
For each study, we extracted the following information: date of sample collection or, if not known, manuscript submission date; serologic test methodology; population studied e. When published were presented only graphically, estimates of prevalence were obtained directly from the graphs. In some cases, age-specific sample sizes were not available.
Non—high-risk and higher risk populations are presented separately for non—high-risk populations table 1 and for higher risk groups table 2. Non—high-risk populations were defined as those with no specific high-risk sexual behavior or characteristics. Within each geographic area, studies are ordered by country and then by region or state within the country.
HSV-2 and HSV-1 prevalence estimates from non—high-risk populations by continent, country, and study year. HSV-2 and HSV-1 prevalence estimates from higher risk populations by continent, country, and study year.
Time trends Table 3 shows trends for prevalence of HSV-2 and -1 infections over time for both non—high-risk and higher risk populations. UK data are presented separately from the rest of Europe because of the extensive information available. The figures use the same scale and present age-specific HSV-2 prevalence in each geographic area for Hsv too seeking single female 38 55 and higher risk populations.
HSV-2 prevalence by age in Africa among non—high-risk and higher risk populations A, B respectively by country and study. Where HSV data are defined in the tables for individuals above or below a certain age, the data points on the graphs are plotted at the age specified. HSV-2 prevalence by age in the UK among non—high-risk and higher risk populations A, B respectively by location and study.
F, females dashed lines ; M, males solid lines.
Hsv in pursuit of a vaccine
C Prevalence among higher risk populations. Data are shown by country and study. Comparisons of the prevalence of HSV-2 and -1 infections by geographic area or country are hampered by differences among populations surveyed and the use of different serologic assays. However, some general trends are apparent. HSV-2 prevalence was in general highest in areas of Africa and in parts of the Americas.
HSV-2 prevalence in Asia tended to be lower than in all other geographic areas. Most studies have been limited to women and men aged 15—49 years. Striking increases in HSV-2 seropositivity were observed with age figure 1Aparticularly among younger women 15—24 years [ 1018—20 ]. Central and South America Of several studies in Central and South America table 1only one study in Costa Rica in the mids was based on a national representative sample [ 25 ]. HSV-2 prevalence by age in Central and South America among non—high-risk and higher risk populations A, B respectively by country and study.
Among older women, HSV-2 prevalence appears to increase or plateau with age in most countries. In Peru, HSV-2 prevalence increased dramatically among women in their 30s; in men it remained notably lower than in their female counterparts [ 33 ].
Prevalence among black Americans was more than double that of whites and about twice that of Mexican Americans.
Herpes simplex virus type 2 seropositivity and relationship status among u.s. adults age 20 to a population-based analysis
In studies conducted in different states, HSV-2 prevalence varied by area, population, age, and sex table 1. Asia including Australia Studies have been conducted in Hong Kong [ 66 ], Japan [ 6768 ], Thailand [ 7172 ], Australia [ 61—63 ], and New Zealand [ 6970 ] table 1. There is a Hsv too seeking single female 38 55 paucity of data on HSV-2 prevalence in non—high-risk populations in Asia.
HSV-2 prevalence tended to be lower than in other areas of the world, with the possible exceptions of Thailand [ 7172 ] and Australia [ 61—63 ]. Although still relatively low, other Japanese studies found higher HSV-2 prevalence e. Europe and the Middle East Data from non—high-risk populations are available for many European countries: Denmark [ 73 ], Finland [ 74—76 ], Germany [ 77—80 ], Greenland [ 73 ], Italy [ 82—84 ], Norway [ 8687 ], Spain [ 2788—90 ], Sweden [ 91—94 ], Switzerland [ 95 ], and the UK [ 698— ] table 1. For the Middle East, information is only available for Israel [ 81 ], Jordan [ 85 ], Syria [ 96 ], and Turkey [ 97 ] table 1.
In one study, HSV-2 seroprevalence increased from 1. In another Spanish study, HSV-2 infection was not associated with age [ 88 ]. Data on age-specific HSV-2 prevalence were available for three Italian studies [ 82—84 ] table 1. HSV-2 prevalence was low 0. The highest prevalence was in London females [ 6].
In another study among London antenatal patients, HSV-2 prevalence was similar, increasing from 4. In the Middle East, no women and only 1 man of a combined total of surveyed in Syria were HSV-2 seropositive [ 96 ].
A study of pregnant women in Turkey found high levels of HSV In populations with evidence of higher risk sexual behavior and in STI clinic attendees, the prevalence of HSV-2 infection was consistently higher than in non—high-risk populations. Across geographic areas, STI clinic attendees consistently had higher prevalences of HSV-2 infection than did non—high-risk groups e.
HSV-2 prevalence was also higher among homosexual than in heterosexual STI clinic attendees of similar ages in Rome [ ], Amsterdam [ ], and London [ 6 ]. HSV-2 seroprevalence by sex Few surveys have been carried out in men relative to studies in women table 1. In younger women aged 15—19 yearsHSV-2 prevalence was about three-fold or more higher than in men of similar age in Tanzania [ 18 ] and Uganda [ 19 ] and in one study in Seattle [ 59 ].
In contrast, in some Asian and European countries, age-specific HSV-2 antibody prevalence among women and men was similar, particularly where HSV-2 prevalence was relatively low, for example, Hong Kong [ 66 ], Japan [ 67 ], Germany [ 77 ], and Spain [ 88 ]. Prevalence of HSV-1 infection was high in most geographic areas worldwide and was more prevalent than HSV-2 infection in all non—high-risk populations surveyed.
In a study in Japan, about one-third of study participants aged 20—29 years were HSV-1 positive [ 67 ]. In most studies, HSV-1 prevalence increased consistently with age across the age spectrum or plateaued after age Some trends may be drawn from this systematic review of type-specific HSV prevalence in different geographic areas and subpopulations.
First, HSV-2 prevalence is highly variable and depends on many factors, including country and region of residence, population subgroup, sex, and age. Second, HSV-2 prevalence is, in general, higher among higher risk sexual behavior groups. Third, HSV-2 prevalence is generally higher in women than men. Striking variations in HSV-2 prevalence were noted in different geographic regions. HSV-2 prevalence is highest in areas of Africa and parts of the Americas.
In Asia, HSV-2 prevalence appears lower than in other geographic areas. Direct comparisons in overall prevalence from independent studies should be made with caution given substantial differences in the populations surveyed, age distributions, and HSV serologic test methods. Comparisons of age-specific HSV-2 prevalence among similar populations in different regions may be useful and further data acquired by using the same serologic methods would be desirable.
HSV-2 prevalence was consistently higher in higher risk populations compared with those considered at a lower risk. In some countries such as the USA, HSV-2 prevalence was strongly dependent on race; black Americans had a much higher prevalence of infection than whites and Mexican Americans of all ages [ 35 ]. These suggest that within populations, the risk of acquiring HSV-2 infection is highly variable.
Most studies reviewed were undertaken in women. However, in those involving both men and women, higher HSV-2 prevalence was almost always found in women.