The changing epidemiology of genital ulcer disease in South Africa: has donovanosis been eliminated?

An Ulcer by Any Other Name

The myriad presentations of ulcerative sexually transmitted infections, other than genital herpes and syphilis, challenge even the most astute clinician given the considerable overlap in clinical presentation and lack of widely available diagnostic resources, such as nucleic acid testing, to confirm the diagnosis. Even so, case prevalence is relatively low, and incidence of chancroid and granuloma inguinale are declining. These diseases still cause substantial morbidity and increased chance for HIV acquisition, and with the recent advent of mpox as a cause, it remains imperative to identify and treat accurately.

Aetiology of genital ulcer disease and associated factors among Mthatha public clinic attendees

Background

Genital ulcer disease (GUD) is a sexually transmitted disease characterised by ulcerating lesions. Despite the introduction of sexually transmitted infections (STIs) syndromic management approach into primary healthcare in South Africa (SA) in 1995, the prevalence of STIs in South Africa remains high.

Objectives

The study investigated the aetiology of GUD and factors influencing it among public community health centre (CHC) attendees in the Eastern Cape, South Africa.

Method

A total of 105 participants were recruited among individuals presenting with GUD from three CHCs located in the Eastern Cape Province, South Africa. Blood and genital ulcer samples were collected from consented participants. Blood samples with suitable sera were tested for human immunodeficiency virus (HIV) and syphilis. Herpes simplex virus types 1/2 (HSV-1/2), Chlamydia trachomatis, Treponema pallidum, Haemophilus ducreyi and Klebsiella granulomatis were detected in nucleic acid extracted from genital ulcer specimens.

Results

Out of the 98 samples with suitable sera, 55.1% and 8.2% were HIV and syphilis seropositive, respectively. Ulcerating STI pathogens were detected in 31.4% of the study participants. Herpes simplex virus type 2 was the most detected pathogen (16.2%) followed by Chlamydia trachomatis (10.5%), HSV-1 (8.6%), Haemophilus ducreyi (8.6%) and Treponema pallidum (6.7%). Multiple pathogens were detected in 13.3% of participants. Detected multiple ulcerating pathogens were common among HIV-positives (p = 0.016).

Conclusion

Molecular methods for diagnosing pathogens have the potential to improve the management of GUD. Data generated from this study would contribute to the limited data on GUD in the Eastern Cape Province. Further research with a larger sample size is recommended.

Contribution

Data generated would contribute to the limited data on GUD in the Eastern Cape province, South Africa.

Genital ulcers caused by sexually transmitted agents

Genital ulcers (GUs) represent a diagnostic challenge and can be secondary to neoplastic and inflammatory processes of different causes. Among those of infectious etiology, there are sexually transmitted infections (STIs), a very frequent reason for seeking the health service. The most common agents are herpes simplex virus and Treponema pallidum and, more rarely, Haemophilus ducreyi, Klebsiella granulomatis and Chlamydia trachomatis. A careful dermatological examination offers important diagnostic elements; however, atypical manifestations are very common. Distinctive characteristics of ulcers to look out for include their margin, edge, bottom, and base. Regional lymph node chain alterations should be evaluated regarding their number, size, mobility, consistency, inflammation, and pain on palpation. Diagnostic tests have variable sensitivity and specificity, and molecular tests are currently considered the reference exams. The rapid immunochromatographic tests represented a significant advance, as they can be performed with blood obtained from the digital pulp, offer results in up to 30 minutes, and do not require a laboratory structure. The treatment of persons affected by GU/STIs must be immediate, as it aims to prevent complications, as well as reduce transmission. It is not always considered that people with GUs/STIs have varying degrees of depression, anxiety, and self-reproach, with an impact on relationships. Establishing a bond and trusting the professional is essential for adherence to treatment and preventive measures that must be discussed individually.

Etiological Surveillance of Genital Ulcer Syndrome in South Africa: 2019 to 2020

BACKGROUND

Herpes simplex virus (HSV) has been the leading cause of genital ulcer syndrome (GUS) in South Africa for more than a decade, and acyclovir therapy is incorporated into syndromic management guidelines. We conducted surveillance at 3 sentinel sites to define the common sexually transmitted etiologies of GUS and to determine whether current syndromic management is appropriate. Secondary objectives of surveillance were to determine the seroprevalence of coinfections (HIV, syphilis, HSV-2) in persons presenting with GUS.

METHODS

Consecutive, consenting adult men and women presenting with visible genital ulceration were enrolled between January 1, 2019, and December 31, 2020. Genital ulcer swab and blood specimens were collected and transported to a central sexually transmitted infection reference laboratory in Johannesburg.

RESULTS

Among 190 participants with GUS, HSV-2 was the most frequently detected ulcer pathogen (49.0%; 95% confidence interval [CI], 41.9%-56.1%). The relative prevalence of the second most common ulcer-derived pathogen, Treponema pallidum, was 26.3% (95% CI, 20.5%-33.1%), with 90% of primary syphilis cases having a positive rapid plasma reagin (RPR) titer. Male sex was independently associated with primary syphilis compared with herpetic ulcers, after adjusting for the effect of casual sex partners and other exposures (adjusted odds ratio, 3.53; 95% CI, 1.35-9.21; P = 0.010). The overall HIV prevalence among participants was 41.3% (78 of 189; 95% CI, 34.2%-48.6%).

CONCLUSIONS

Herpes simplex virus 2 remains the predominant cause of GUS, justifying the continued use of acyclovir in syndromic guidelines. Adequate supplies of benzathine penicillin G for syphilis treatment are essential at primary health care level, in addition to the provision of syphilis and HIV risk reduction services.

Phenotypic and genotypic acyclovir resistance surveillance of genital herpes simplex virus 2 in South Africa

Acyclovir (ACV) is currently included in the syndromic management algorithm for genital ulcer disease in South Africa, and is the recommended first-line treatment for herpes simplex virus 2 (HSV-2). In the majority of cases, HSV-2 resistance to ACV is due to amino acid changes within the viral thymidine kinase (TK). Phenotypic and genotypic ACV resistance surveillance of HSV-2 derived from genital ulcer disease swab specimens was conducted at a primary healthcare facility in Johannesburg between 2018 and 2020. The objectives of this surveillance were to identify ACV resistance-associated mutations and polymorphisms in HSV-2 TK, and to determine the phenotypic ACV resistance profiles of the corresponding clinical HSV-2 isolates. Genotypic analysis of TK from 67 HSV-2 positive genital ulcer swabs revealed 48 specimens with TK mutations, conferring 113 nucleotide changes. No resistance-associated mutations were found, however, we identified nine known natural polymorphisms (R26H, A27T, S29A, G39E, N78D, L140F, T159I, R220K and R284S) and five amino acid changes of unknown significance (R18C, G39K, M70R, P75S and L263P). Phenotypic susceptibility testing of 52 cultivable HSV-2 isolates revealed all to be susceptible to ACV with IC₅₀ values of <2 μg/ml. The five amino acid changes of unknown significance identified by genotypic testing were not correlated to phenotypic ACV resistance, and therefore grouped as natural polymorphisms. We did not detect any unknown or resistance-associated mutations in specimens that could not be phenotypically tested for ACV resistance. Our findings will supplement existing databases of HSV antiviral resistance-associated mutations and polymorphisms that could be used for genotypic ACV resistance screening.