Herpes in the time of AIDS: a comparison of the epidemiology of HIV-1 and HSV-2 in young men in northern Thailand

Seroprevalence of ToRCH Pathogens in Southeast Asia

ToRCH is the acronym for several pathogens associated with pregnancy complications and sequelae in the unborn or newborn child. Particularly primary infections during pregnancy are associated with increased risk. Seroprevalence data of ToRCH infections are important, especially in countries with weak disease surveillance systems, to estimate immunity and vaccination levels, as well as exposure rates and thus the risk of infection during pregnancy. A systematic literature search spanning a 30-year time period was conducted to identify serosurveys on ToRCH pathogens in Southeast Asia. The 96 identified studies showed that some pathogens were well studied, while only limited data were available for others. Studies from the better-developed countries of the region were more abundant. Moreover, seroprevalence data were often limited to a certain geographical region within the country or to certain cohorts, there was an evident lack of recent serosurveys, and the study quality was often not adequate. Well-designed and area-wide serosurveys of ToRCH pathogens are clearly warranted. If combined with risk factor analysis, these studies may guide the development and implementation of effective measures for infection prevention, especially during pregnancy. In addition, educational programs for health care workers and for pregnant women during antenatal care are urgently needed.

Interim modelling analysis to validate reported increases in condom use and assess HIV infections averted among female sex workers and clients in southern India following a targeted HIV prevention programme

Objectives

This study assesses whether the observed declines in HIV prevalence since the beginning of the ‘Avahan’ India HIV/AIDS prevention initiative are consistent with self-reported increases in condom use by female sex workers (FSWs) in two districts of southern India, and provides estimates of the fraction of new infections averted among FSWs and clients due to increases in condom use in commercial sex after 2004.

Methods

A deterministic compartmental model of HIV/sexually transmitted infection (STI) transmission incorporating heterogeneous sexual behaviour was developed, parameterised and fitted using data from two districts in Karnataka, India. Three hypotheses of condom use among FSWs were tested: (H₀), that condom use increased in line with reported FSW survey data prior to the Avahan initiative but remained constant afterwards; (H₁) that condom use increased following the Avahan initiative, in accordance with survey data; (H₂) that condom use increased according to estimates derived from condom distribution data. The proportion of fits to HIV/STI prevalence data was examined to determine which hypothesis was most consistent.

Results

For Mysore 0/36/82.7 fits were identified per million parameter sets explored under hypothesis H₀/H₁/H₂, respectively, while for Belgaum 9.7/8.3/0 fits were identified. The HIV epidemics in Belgaum and Mysore are both declining. In Mysore, increases in condom use during commercial sex between 2004 and 2009 may have averted 31.2% to 47.4% of new HIV infections in FSWs, while in Belgaum it may have averted 24.8% to 43.2%, if there was an increase in condom use.

Discussion

Increased condom use following the Avahan intervention is likely to have played a role in curbing the HIV epidemic in Mysore. In Belgaum, given the limitations in available data, this method cannot be used alone to decide if there has been an increase in condom use.

A pooled analysis of the effect of condoms in preventing HSV-2 acquisition

BACKGROUND

The degree of effectiveness of condom use in preventing the transmission of herpes simplex virus 2 (HSV-2) is uncertain. To address this issue, we performed a large pooled analysis.

METHODS

We identified prospective studies with individual-level condom use data and laboratory-defined HSV-2 acquisition. Six studies were identified through a review of publications through 2007: 3 candidate HSV-2 vaccine studies, an HSV-2 drug study, an observational sexually transmitted infection (STI) incidence study, and a behavioral STI intervention study. Study investigators provided us individual-level data to perform a pooled analysis. Effect of condom use was modeled using a continuous percentage of sex acts during which a condom was used and, alternatively, using absolute numbers of unprotected sex acts.

RESULTS

A total of 5384 HSV-2-negative people at baseline contributed 2 040 894 follow-up days; 415 persons acquired laboratory-documented HSV-2 during follow-up. Consistent condom users (used 100% of the time) had a 30% lower risk of HSV-2 acquisition compared with those who never used condoms (hazard ratio [HR], 0.70; 95% confidence interval [CI], 0.40-0.94) (P = .01). Risk for HSV-2 acquisition increased steadily and significantly with each unprotected sex act (HR, 1.16; 95% CI, 1.08-1.25) (P < .001). Condom effectiveness did not vary by gender.

CONCLUSIONS

To our knowledge, this is the largest analysis using prospective data to assess the effect of condom use in preventing HSV-2 acquisition. Although the magnitude of protection was not as large as has been observed with other STIs, we found that condoms offer moderate protection against HSV-2 acquisition in men and women.

Prevalence and risk factors for herpes simplex virus type 2 antibodies among low- and high-risk populations in Indonesia

OBJECTIVES/GOAL

Data on prevalence of herpes simplex virus type 2 (HSV-2) infections are limited in Asia. This study investigated the seroprevalence of, and risk factors for, antibodies to HSV-2 among low- and high-risk, predominantly asymptomatic populations in Indonesia.

STUDY DESIGN

We screened women attending maternal and child health, obstetric, gynecology, and sexually transmitted infection (STI) clinics; men attending STI clinics; and female sex workers (FSWs) for type-specific HSV-2 antibodies using the HerpesSelect 2 enzyme-linked immunosorbent assay IgG and Western blot.

RESULTS

HSV-2 antibodies were detected in 153 of 176 FSWs (86.9%; 95% confidence interval [CI], 81.0-91.5); increasing age was the only significant independent risk factor (odds ratio [OR], 1.15; 95% CI, 1.06-1.24; P = 0.001). Among non-sex worker females, HSV-2 antibodies were detected in 78 of 418 (18.7%; 95% CI, 15.0-22.7); significant independent associations were any contraceptive use (OR, 2.24, 95% CI = 1.33-3.85, P = 0.003), symptoms or signs of genital ulcer (OR, 2.69; 95% CI, 1.27-5.70; P = 0.01) and younger age of sexual debut (OR, 0.92; 95% CI, 0.86-0.99; P = 0.03). HSV-2 antibodies were detected in 25 of 116 men (21.6%; 95% CI, 14.5-30.1).

CONCLUSIONS

HSV-2 seroprevalence reported here is in the upper range of that reported in nearby regions. Health promotion is needed to encourage affected individuals to recognize symptoms of genital herpes and seek care and advice on reducing transmission. The high seroprevalence among FSWs has potentially serious implications for the HIV epidemic in Indonesia.

Prevalence of infection with herpes simplex virus types 1 and 2 in Australia: a nationwide population based survey

BACKGROUND

Studies demonstrating previous herpes simplex virus (HSV) type 2 infection as a risk factor for HIV transmission, and the development of a HSV vaccine candidate, have emphasised the need for worldwide population based studies of HSV seroprevalence. The only nationwide seroprevalence studies have been conducted in the United States.

METHODS

An Australia-wide, population based study of HSV-1 and HSV-2 seroprevalence was conducted, using serum and sociodemographic data collected between 1999-2000, for a representative study of risk factors for diabetes in over 11 000 adults. A stratified random sample of 4000 was tested for HSV-2 and 1000 for HSV-1, with sampling and weighting for various demographic factors.

RESULTS

Seroprevalence of HSV-2 in Australian adults was 12%. Prevalence in women (16%) was twice that in men (8%). Rural populations had a lower prevalence (9%) than metropolitan (13%), and Indigenous had a higher prevalence (18%) than the non-Indigenous populations (12%). The seroprevalence of HSV-1 was 76% with significant differences by age group, sex and Indigenous status.

CONCLUSION

These are the first nationwide data to compare with US studies. HSV-2 infection is less common in Australia than the United States, and this will allow planning for combating HIV transmission in high prevalence populations in northern Australia. In addition, the high HSV-1 seroprevalence will be important for future deployment of genital herpes vaccines.

Type specific seroprevalence of HSV-1 and HSV-2 in four geographical regions of Poland

OBJECTIVE

To examine the type specific seroprevalence of herpes simplex virus (HSV) types 1 and 2 infections, stratified by age and gender, and associated risk factors for HSV-2 seropositivity in Poland.

METHODS

2257 serum samples of individuals from 15-65 years were randomly selected from serum banks in four different geographical regions of Poland, including the Zachodnio-pomorskie, Warmińsko-mazurskie, Lubelskie, and Mazowieckie districts. Type specific serum antibodies to HSV-1 and HSV-2 were detected using HerpeSelect IgG ELISA tests.

RESULTS

Overall prevalences of type specific HSV-1 and HSV-2 serum antibodies were 90.4% and 9.3%, respectively. Age standardised HSV-2 seroprevalence was higher in women (9.7%) than men (8.8%) (p = 0.06), and increased notably with age from 4% in 15-24 year olds to 12% in those aged 50-65 years. HSV-1 seroprevalence was consistently higher than HSV-2 seroprevalence in each specific age group, ranging from 74.5% in 15-24 year olds to 98.8% in 50-65 year olds. HSV-2 seroprevalence varied significantly by geographical region, with the highest prevalence in the Zachodnio-pomorskie district (12%). Significant multivariate risk factors for HSV-2 seropositivity included older age, female gender, and geographical place of residence.

CONCLUSION

This large survey found a notably high seroprevalence of HSV-1, even among young female adolescents 15-19 years of age (80%). HSV-2 seropositivity was under 12% in all age groups surveyed in Poland, tending to be among the lowest overall HSV-2 seropositivity rates reported thus far in Europe.

Age-specific prevalence of infection with herpes simplex virus types 2 and 1: a global review

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.

Educational attainment and HIV-1 infection in developing countries: a systematic review

OBJECTIVES

To assess whether educational status is associated with HIV-1 infection in developing countries by conducting a systematic review of published literature.

METHODS

Articles were identified through electronic databases and hand searching key journals. Studies containing appropriately analysed individual level data on the association between educational attainment and HIV-1 status in general population groups were included.

RESULTS

Twenty-seven articles with appropriately analysed results from general population groups in developing countries were identified, providing information on only six countries. Large studies in four areas in Africa showed an increased risk of HIV-1 infection among the more educated, whilst among 21-year-old Thai army conscripts, longer duration of schooling was strongly protective against HIV infection. The association between education and schooling in Africa was stronger in rural areas and in older cohorts, but was similar in men and women. Serial prevalence studies showed little change in the association between schooling and HIV over time in Tanzania, but greater decreases in HIV prevalence among the more educated in Uganda, Zambia and Thailand.

CONCLUSIONS

In Africa, higher educational attainment is often associated with a greater risk of HIV infection. However, the pattern of new HIV infections may be changing towards a greater burden among less educated groups. In Thailand those with more schooling remain at lower risk of HIV infection.

Antenatal seroprevalence of herpes simplex virus type 2 (HSV-2) in Canadian women: HSV-2 prevalence increases throughout the reproductive years

BACKGROUND

This study sought to provide the first population estimates of herpes simplex type 2 (HSV-2) seroprevalence in Canada.

GOAL

To measure the antenatal seroprevalence of HSV-2 antibodies in reproductive age women.

STUDY DESIGN

An anonymous unlinked seroprevalence study used stored sera collected from pregnant women in British Columbia during 1999. Randomized sampling within age strata selected a total of 1215 subjects, ages 15 to 44 years. Serologic testing used the Gull Meridian Test. Overall prevalence was directly standardized to the 1999 Canadian female population.

RESULTS

The age-adjusted prevalence for HSV-2 was 17.3% (95% CI, 15.2-19.4). Prevalence ranged from 7.1% (ages, 15-19 years) to 28.1% (ages, 40-44 years), with the largest increases after the age of 24 years.

CONCLUSIONS

The HSV-2 seroprevalence among pregnant women in British Columbia is similar to that in the United States and other countries. Seroprevalence continues to rise through the later reproductive years. This observation may relate to continued transmission, an age cohort effect, or both.

Prevalence and risk factors for herpes simplex virus type 2 infection among middle-age women in Brazil and the Philippines

BACKGROUND

Data comparing type-specific herpes simplex virus type 2 (HSV-2) seroprevalence and risk factors between comparable populations are largely unavailable, particularly from less-developed countries.

GOAL

To examine the seroprevalence of HSV-2 infection and the risk factors for this infection among women in São Paulo, Brazil, and Manila, the Philippines.

STUDY DESIGN

Altogether, 552 middle-aged women participating as control subjects in two cervical cancer studies were screened for type-specific HSV-2 antibodies.

RESULTS

Herpes simplex virus type 2 seroprevalence was higher in Brazil (42%) than in the Philippines (9.2%). The mean ages of Brazilian (n = 181) and Filipino (n = 371) women were 52.4 and 46.6 years, respectively. Brazilian participants had more lifetime sexual partners, less education, and more often a husband with other sexual partners than Filipino women. Herpes simplex virus type 2 was independently associated with younger age at first intercourse in both countries. More than one lifetime sexual partner, a husband with other sexual partners, urban/semi-urban residence, and no history of condom use were HSV-2 risk factors in Brazil, but not in the Philippines, where long-term hormonal contraceptive use was associated with increased risk.

CONCLUSIONS

The higher HSV-2 seroprevalence in Brazil than in the Philippines may be explained largely by differences in the sexual behavior of women and their husbands. Herpes simplex virus type 2 seroprevalence data may be used as a marker of past sexual behavior for the direct comparison of different population groups.

Vaccine-induced serum immunoglobin contributes to protection from herpes simplex virus type 2 genital infection in the presence of immune T cells

Herpes simplex type virus 2 (HSV-2) is a sexually transmitted pathogen that causes genital lesions and spreads to the nervous system to establish acute and latent infections. Systemic but not mucosal cellular and humoral immune responses are elicited by immunization of mice with a replication-defective mutant of HSV-2, yet the mice are protected against disease caused by subsequent challenge of the genital mucosa with virulent HSV-2. In this study, we investigated the role of immune serum antibody generated by immunization with a replication-defective HSV-2 vaccine prototype strain in protection of the genital mucosa and the nervous system from HSV-2 infection. Passive transfer of replication-defective virus-immune serum at physiologic concentrations to SCID or B-cell-deficient mice had no effect on replication of challenge virus in the genital mucosa but did significantly reduce the incidence and severity of genital and neurologic disease. In contrast, B-cell-deficient mice immunized with replication-defective HSV-2 were able to control replication of challenge virus in the genital mucosa, but not until 3 days postchallenge, and were not completely protected against genital and neurologic disease. Passive transfer of physiologic amounts of immune serum to immunized, B-cell-deficient mice completely restored their capacity to limit replication of challenge virus in the genital mucosa and prevented signs of genital and systemic disease. In addition, the numbers of viral genomes in the lumbosacral dorsal root ganglia of immunized, B-cell-deficient mice were dramatically reduced by transfer of immune serum prior to challenge. These results suggest that there is an apparent synergism between immune serum antibody and immune T cells in achieving protection and that serum antibody induced by vaccination with replication-defective virus aids in reducing establishment of latent infection after genital infection with HSV-2.

The Interaction Between HIV and the Classic Sexually Transmitted Diseases

Because HIV is sexually transmitted, HIV infection is common in populations with high prevalences of other sexually transmitted diseases (STDs). This epidemiologic coprevalence provides an opportunity for bidirectional influences. The presence of some other STDs increases the transmissibility of HIV and may, in some circumstances, actually affect the course of HIV disease through the stimulation of susceptible cell types. The presence of HIV increases susceptibility to some STDs and modifies the presentation, course, rate of complications, and response to therapy of some of these classic infections. Recent studies and reviews have further defined these interactions but have provided no startlingly new approaches.