Prevalence of herpes simplex virus type 2 antibody in Cameroon

An estimate of the global prevalence and incidence of herpes simplex virus type 2 infection

OBJECTIVE

To estimate the global prevalence and incidence of herpes simplex virus type 2 (HSV-2) infection in 2003.

METHODS

A systematic review was undertaken of published seroprevalence surveys describing the prevalence or incidence of HSV-2 by age and gender. For each of 12 regions, pooled prevalence values by age and gender were generated in a random-effect model. HSV-2 incidence was then estimated from these pooled values using a constant-incidence model. Values of the HSV-2 seroprevalence from the model fits were applied to the total population to estimate the numbers of people infected.

FINDINGS

The total number of people aged 15-49 years who were living with HSV-2 infection worldwide in 2003 is estimated to be 536 million, while the total number of people who were newly infected with HSV-2 in 2003 is estimated to be 23.6 million. While the estimates are limited by poor availability of data, general trends are evident. For example, more women than men were infected, and the number infected increased with age. Although prevalence varied substantially by region, predicted prevalence was mostly higher in developing regions than developed regions.

CONCLUSION

The prevalence of HSV-2 is relatively easy to measure since infection is lifelong and has a specific serological test. The burden of disease is less easy to quantify. Despite the often sparse data on which these estimates are based, it is clear that HSV-2 infection is widespread. The dramatic differences in prevalence between regions are worthy of further exploration.

Interactions and management issues in HSV and HIV coinfection

Significant synergistic interactions have been observed between HIV and herpes simplex virus (HSV). HIV-induced immune compromise can cause frequent and persistent HSV disease, while poorly controlled HSV replication may influence HIV pathogenicity and transmission. HSV-2 seroprevalence is high in HIV-infected cohorts worldwide, with rates of over 80% for HSV-1 and ranging from 33% to more than 80% for HSV-2. As seen in HIV-negative individuals, HSV-2 coinfection is associated with female gender, older age and black ethnicity. HSV infection is commonly under-diagnosed in HIV-infected individuals, although the use of PCR for HSV detection in mucocutaneous swabs and HSV type-specific serology can improve the diagnostic yield. In HIV-1-infected patients with frequent clinical episodes of HSV reactivation, suppressive antiviral therapy may prove beneficial in controlling HSV disease while also reducing HSV-mediated promotion of HIV replication. Antiretroviral therapy leads to a gradual recovery of HSV-specific T-cell responses and a reduction in HSV-related morbidity, indicating that successful management of coinfection should target both HIV and HSV replication. The aim of this review is to address the more speculative issues surrounding the management of HSV/HIV coinfection and to summarize the data that inform them.

Herpes simplex virus type 2 (HSV-2) seroprevalence at the time of HIV-1 diagnosis and seroincidence after HIV-1 diagnosis in an ethnically diverse cohort of HIV-1-infected persons

OBJECTIVE

The objective of this study was to determine herpes simplex virus type 2 (HSV-2) seroprevalence at HIV-1 diagnosis and seroincidence > or =1 year after HIV-1 diagnosis.

METHODS

HSV type-specific antibodies were detected by enzyme immunoassay.

RESULTS

The cohort comprised 850 adults diagnosed HIV-positive in 1986-2001 and followed for a median of 3 years. HSV-2 seroprevalence was 63% (95% confidence interval [CI], 60-66%) and was associated with female gender, heterosexual risk group, black ethnicity, and older age. HSV-2 seroincidence was 1.8 per 100 person-years (95% CI, 0.8-2.8) and was associated with other sexually transmitted diseases, including human papilloma virus infection (P = 0.005) and gonorrhea (P = 0.05). A diagnosis of genital herpes was made in 21% HSV-2-seropositive persons and was more likely in those who tested HIV-positive before 1997 (adjusted odds ratio, 5.11; 95% CI, 3.28-7.98; P = 0.0001).

CONCLUSIONS

Results confirm the epidemiologic association between HIV-1 and HSV-2. HSV-2 seroconversion was a marker of high-risk sexual behavior. The likelihood of developing symptoms of genital herpes declined from 1997 onward.

A systematic review of the epidemiology and interaction of herpes simplex virus types 1 and 2

OBJECTIVES

To explore epidemiological evidence about the interaction of herpes simplex virus (HSV) 1 and HSV-2 infections.

METHODS

A systematic review was undertaken of published epidemiological studies describing the pattern of HSV-1 or HSV-2 by age, and the coincidence of the two viral infections.

RESULTS

In cross sectional studies the unadjusted odds of HSV-2 are greater in those with HSV-1 infection in study populations categorised as "low risk" (p = 0.06) and across European populations (p = 0.001). This was not evident in "high risk" populations or in the United States. This increased risk of HSV-2 in those with HSV-1 infection does not agree with the results of prospective studies where there is a non-significant trend towards a lower risk of HSV-2 infection associated with previous HSV-1 infection.

CONCLUSIONS

"Low risk" and European populations have a relatively low HSV-2 seroprevalence and infection is more concentrated in those with characteristics putting them at high risk for both HSV-1 and HSV-2. This confounding could mask any protective effect of HSV-1, which is hinted at, but not demonstrated, in prospective and adjusted studies.