Healthcare resource utilisation pattern and costs associated with herpes simplex virus diagnosis and management: a systematic review

Toward the Eradication of Herpes Simplex Virus: Vaccination and Beyond

Herpes simplex virus (HSV) has coevolved with Homo sapiens for over 100,000 years, maintaining a tenacious presence by establishing lifelong, incurable infections in over half the human population. As of 2024, an effective prophylactic or therapeutic vaccine for HSV remains elusive. In this review, we independently screened PubMed, EMBASE, Medline, and Google Scholar for clinically relevant articles on HSV vaccines. We identified 12 vaccines from our literature review and found promising candidates across various classes, including subunit vaccines, live vaccines, DNA vaccines, and mRNA vaccines. Notably, several vaccines-SL-V20, HF10, VC2, and mRNA-1608-have shown promising preclinical results, suggesting that an effective HSV vaccine may be within reach. Additionally, several other vaccines such as GEN-003 (a subunit vaccine from Genocea), HerpV (a subunit vaccine from Agenus), 0ΔNLS/RVx201 (a live-attenuated replication-competent vaccine from Rational Vaccines), HSV 529 (a replication-defective vaccine from Sanofi Pasteur), and COR-1 (a DNA-based vaccine from Anteris Technologies) have demonstrated potential in clinical trials. However, GEN-003 and HerpV have not advanced further despite promising results. Continued progress with these candidates brings us closer to a significant breakthrough in preventing and treating HSV infections.

Rapid diagnosis of herpes simplex virus 1 and 2 bloodstream infections utilizing a sample-to-answer platform

Bloodstream HSV-1 and HSV-2 infections can cause devastating outcomes with high morbidity and mortality, especially in neonates or immunocompromised individuals. Proper patient management for herpes simplex virus (HSV) bloodstream infections is time-sensitive and requires a rapid, accurate, and definitive diagnosis. The absence of the U.S. Food and Drug Administration (FDA)-approved molecular assays for HSV detection in blood, coupled with a lack of consensus on the optimal sample type, underscores the unmet need for improved diagnostics. We prospectively compared the cycle threshold values in paired samples including whole blood (WB), plasma, serum, and peripheral blood mononuclear cells (PBMCs) from patients with bloodstream HSV infections. This analysis employed a modified use of the FDA-cleared Simplexa HSV-1 & 2 Direct assay. The clinical performance in serum was assessed by comparing the results of 247 remnant specimens on this sample-to-answer platform to established laboratory-developed tests in a blinded fashion. Serum samples exhibited significantly lower cycle thresholds than whole blood samples [2.6 cycle threshold (Ct) bias, P < 0.001]. The modified Simplexa assay demonstrated 100% positive percent agreement for the detection of HSV-1 and HSV-2 DNA in serum samples and yielded an overall agreement of 95% (95% CI, 0.92 to 0.97), with a κ statistic of 0.75 (95% CI, 0.62 to 0.86) compared to the composite reference method. Discordance rates were 5.20% for HSV-1 and 0.81% for HSV-2. This investigation demonstrates that serum is an optimal specimen type for HSV detection when compared to several blood compartments. Serum offers a promising sample type for rapid and accurate diagnosis of HSV bloodstream infections using the modified Simplexa assay.

IMPORTANCE

Rapid, accurate, and definitive diagnosis of herpes simplex virus (HSV) infections is crucial in clinical settings for patient management. The absence of FDA-authorized molecular assays for HSV-1/2 detection in blood, coupled with a lack of consensus on the optimal sample type, underscores the need for improved diagnostic methods. Furthermore, rapid diagnosis of HSV bloodstream infections enables timely administration of antiviral treatment, influences patient management decisions for those at high risk, and can contribute to shorter hospital stays, thereby reducing healthcare costs.

Estimated global and regional economic burden of genital herpes simplex virus infection among 15-49 year-olds in 2016

BACKGROUND

Globally, herpes simplex virus (HSV)-2 and -1 infections contribute to a large disease burden, but their full economic consequences remain unclear. This study aims to estimate the global economic impact of genital HSV-2 and HSV-1 infection and its consequences for people with genital ulcer disease, neonatal herpes, and human immunodeficiency virus (HIV) infection attributable to HSV-2.

METHODS

Using a societal perspective, the economic burden was calculated at the country level and presented by World Health Organization (WHO) regions and World-Bank income levels. The disease burden was obtained from previously published global disease burden studies in 2016 and disaggregated for 194 countries. Estimates of healthcare resource utilisation were sourced from a literature review, and online interviews were conducted with 20 experts from all 6 WHO regions. Relevant costs were obtained from the literature and estimated in 2016 international dollars (I$).

RESULTS

Both genital HSV-2 (I$31·2 billion) and HSV-1 (I$4·0 billion) infections and their consequences were estimated to cost I$35·3 billion globally in 2016. The major economic burden was from the Americas and Western Pacific regions combined, accounting for almost two-thirds of the global burden (I$20·8 billion). High- and upper-middle-income countries bore a large proportion of the economic burden (76·6% or I$27·0 billion). Costs were driven by the large number of HSV-2 recurrences; however, even assuming conservatively that people with symptomatic herpes have on average only one episode a year, global costs were estimated at I$16·5 billion.

CONCLUSIONS

The global costs of genital HSV infection and its consequences are substantial. HSV prevention interventions have the potential to avert a large economic burden in addition to disease burden; thus, efforts to accelerate HSV vaccine development are crucial.

Viral Shedding 1 Year Following First-Episode Genital HSV-1 Infection

IMPORTANCE

Herpes simplex virus type 1 (HSV-1) is the leading cause of first-episode genital herpes in many countries.

OBJECTIVE

To inform counseling messages regarding genital HSV-1 transmission, oral and genital viral shedding patterns among persons with first-episode genital HSV-1 infection were assessed. The trajectory of the development of HSV-specific antibody and T-cell responses was also characterized.

DESIGN, SETTING, AND PARTICIPANTS

Prospective cohort followed up for up to 2 years, with 82 participants followed up between 2013 and 2018. Participants were recruited from sexual health and primary care clinics in Seattle, Washington. Persons with laboratory-documented first-episode genital HSV-1 infection, without HIV infection or current pregnancy, were referred for enrollment.

EXPOSURES

First-episode genital HSV-1 infection.

MAIN OUTCOMES AND MEASURES

Genital and oral HSV-1 shedding and lesion rates at 2 months, 11 months, and up to 2 years after initial genital HSV-1 infection. Participants self-collected oral and genital swabs for HSV polymerase chain reaction testing for 30 days at 2 and 11 months and up to 2 years after diagnosis of genital HSV-1. Blood samples were collected at serial time points to assess immune responses to HSV-1. Primary HSV-1 infection was defined as absent HSV antibody at baseline or evolving antibody profile using the University of Washington HSV Western Blot. HSV-specific T-cell responses were detected using interferon γ enzyme-linked immunospot.

RESULTS

Among the 82 participants, the median (range) age was 26 (16-64) years, 54 (65.9%) were women, and 42 (51.2%) had primary HSV-1 infection. At 2 months, HSV-1 was detected from the genital tract in 53 participants (64.6%) and in the mouth in 24 participants (29.3%). Genital HSV-1 shedding was detected on 275 of 2264 days (12.1%) at 2 months and declined significantly to 122 of 1719 days (7.1%) at 11 months (model-predicted rate, 6.2% [95% CI, 4.3%-8.9%] at 2 months vs 3.2% [95% CI, 1.8%-5.7%] at 11 months; relative risk, 0.52 [95% CI, 0.29-0.93]). Genital lesions were rare, reported on 65 of 2497 days (2.6%) at 2 months and 72 of 1872 days (3.8%) at 11 months. Oral HSV-1 shedding was detected on 88 of 2247 days (3.9%) at 2 months. Persons with primary HSV-1 infection had a higher risk of genital shedding compared with those with nonprimary infection (model-predicted rate, 7.9% [95% CI, 5.4%-11.7%] vs 2.9% [95% CI, 1.7%-5.0%]; relative risk, 2.75 [95% CI, 1.40-5.44]). Polyfunctional HSV-specific CD4+ and CD8+ T-cell responses were maintained during the follow-up period.

CONCLUSIONS AND RELEVANCE

Genital HSV-1 shedding was frequent after first-episode genital HSV-1, particularly among those with primary infection, and declined rapidly during the first year after infection.

Heparan Sulfate and Sialic Acid in Viral Attachment: Two Sides of the Same Coin?

Sialic acids and heparan sulfates make up the outermost part of the cell membrane and the extracellular matrix. Both structures are characterized by being negatively charged, serving as receptors for various pathogens, and are highly expressed in the respiratory and digestive tracts. Numerous viruses use heparan sulfates as receptors to infect cells; in this group are HSV, HPV, and SARS-CoV-2. Other viruses require the cell to express sialic acids, as is the case in influenza A viruses and adenoviruses. This review aims to present, in a general way, the participation of glycoconjugates in viral entry, and therapeutic strategies focused on inhibiting the interaction between the virus and the glycoconjugates. Interestingly, there are few studies that suggest the participation of both glycoconjugates in the viruses addressed here. Considering the biological redundancy that exists between heparan sulfates and sialic acids, we propose that it is important to jointly evaluate and design strategies that contemplate inhibiting the interactions of both glycoconjugates. This approach will allow identifying new receptors and lead to a deeper understanding of interspecies transmission.