SEROPREVALENCE AND RISK FACTORS OF HERPES SIMPLEX VIRUS TYPE 2 AMONGST PATIENTS’ ATTENDING RETROVIRAL CLINIC IN FEDERAL MEDICAL CENTER ABEOKUTA, SOUTH-WEST NIGERIA

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V.U. Nwadike¹, P. Osinupebi², O.Y. Ojo³, G.B. Imhonopi³, O.A. Oyesola³, C.J. Elikwu⁴, and W.O. Oladosu⁵

1. Department of Medical Microbiology, Federal Medical Centre, Abeokuta.
2. Department of Medical Microbiology, Olabisi Onabanjo University, Ago Iwoye, Ogun State.
3. Department of Community Medicine and Primary Care, FMC Abeokuta.
4. Department of Medical Microbiology, Babcock University, Ilishan, Ogun State.
5. Department of Chemical Pathology, Federal Medical Centre, Abeokuta.

Abstract

Herpes simplex virus type 2 (HSV-2) is the primary cause of genital herpes worldwide and also has a role in facilitating human immunodeficiency virus (HIV) transmission. The aim of the study was to determine seroprevalence of HSV-2 among the subjects and associated risk factors. In this cross-sectional study, 207 HIV Positive subjects attending a retroviral Clinic in Federal Medical Center, Abeokuta, Ogun state were interviewed and had blood samples taken. The patients were interviewed using a structured questionnaire and their serum samples were tested for HSV-2 specific immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay (ELISA) for consented participation. Prevalence of HSV-2 antibodies was ascertained and related to demographics and behavioral variables. A total of 207 participants were recruited for this study comprising of Sixty-three (30.4%) male and 144 (69.6%) female HIV positive subjects. Seroprevalence of HSV-2 was 70.0%. Only 58(28%) had current history of genital ulcer. Logistic regression revealed a history of multiple sexual partners (P value=0.003), oral sex (P value=0.02) were found to be associated with HSV-2 acquisition in HIV patients. All other risk factors such as history of transactional sex, age at sexual debut and condom use were not significant. The results highlight the potential public health impact of HSV-2 particularly in a developing country like Nigeria where HSV-2 testing is not included in our testing and treatment protocol for HIV. This result should lead to commencement of HSV type-specific serological testing in the HIV infected population and also high risk groups should be targeted for behavioral modification messages.

Keywords: Seroprevalence, Risks, Factors, Herpes simplex, HIV.

Introduction

Genital herpes is an infection commonly caused by human herpes simplex virus type 2 (HSV-2). In Nigeria and in most regions of the world it has been described as a silent pandemic with different countries being at different stages of the epidemic¹.

Herpes Simplex Virus (HSV) is an infection that occurs globally and estimates of its prevalence differ widely depending largely on the patient population studied. HSV has largely been described as a very successful pathogen largely due to its high prevalence, successful sexual transmissibility rate, association with immune compromised patients and ability to cause recurrent disease. Herpes genitalis is the most frequent sexually transmitted disease (STD) amongst HIV positive patients, which when symptomatic, is characterized by periodic recurrences of painful genital ulcers.² Worldwide incidence of HSV ranges from roughly 65% to 90% and most persons seropositive for HSV type 2 (HSV-2) have an intermittent reactivation of the virus on mucosal surfaces³.

Disruption of the epithelial surface and inflammation of HSV genital ulcers appear to increase the risk of HIV transmission. Acute or reactivated HSV infection may stimulate HIV replication, leading to the progression of HIV disease. On the reverse side, HIV induced immunosuppression results in alterations in the natural history of HSV leading to more severe HSV outbreaks and more frequent viral shedding in persons co-infected with HIV and HSV compared with those \without HIV infection. The treatment of HSV can be more challenging in HIV-infected patients. Higher doses of antiviral drugs may be required, and persons infected with HIV have an increased incidence of acyclovir resistant HSV-2.

In the United States, one in four sexually active adults had HSV-2 infection with a 31% increase in HSV-2 prevalence between 1978 and 1990. About 40-60% attendees in STD clinics have already acquired genital herpes and 20-35% of pregnant women are HSV-2 seropositive. Also Studies have shown that 22% of adults have antibodies to HSV-2 and that about 1.6million new cases of HSV-2 infection occur yearly in the United States.^4,5

Comparably, high HSV-2 rates have been observed in sub Saharan Africa where HIV prevalence is the highest. In recent years, a parallel and interesting epidemiological association has emerged between HSV-2 and HIV infection. HSV-2 seroprevalence rates are higher in HIV positive than in HIV negative individuals and are especially high among HIV positive persons in sub- Saharan Africa. Multiple mechanisms may explain these observations; genital ulceration provides a site for HIV entry on HIV negative persons and the associated inflammation increases the number of activated cells that can be targeted by HIV.⁶ Although symptomatic and asymptomatic HSV-2 reactivations may promote HIV shedding in the genital tract and increase HIV levels in blood⁷.

Because asymptomatic HSV-2 infections in HIVpositive persons may be associated with increased transmission of HIV and may accelerate the course of HIV disease, screening should generally be offered to patients with documented HIV and without a history of genital herpes. HSV specific education and counseling should be provided for individuals with either HSV-2- negative or HSV-2-positive results, because HSV-2-negative, HIV-infected patients have a significantly increased risk of HSV-2 acquisition¹.

The HSV-2 pandemic is further reinforced by the HIV pandemic and vice versa; and it is becoming clear that the efforts at controlling the spread of HIV may remain ineffective if control of HSV-2 infection, along with other sexually transmitted infections (STI) is not integrated.

The diagnosis of HSV presents a challenge for public health programmes and for clinicians in developing countries.¹ The present study aims to determine the prevalence of HSV-2 antibodies and identify probable risk factors among HIV patients.