Comparison of washing and swabbing procedures for collecting genital fluids to assess cervicovaginal shedding of herpes simplex virus type 2 DNA

Twenty years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO prioritiesfor research in HSV-2 epidemiology and diagnostics

INTRODUCTION

Low-income and middle-income countries (LMICs) have a high burden of herpes simplex virus type 2 (HSV-2) infection, which has been strongly associated with HIV. In 2001, the WHO hosted a workshop to set research priorities for HSV-2 in LMICs. Periodic re-evaluation of research priorities is essential to ensure effective allocation of resources. This study describes the progress made between 2000 and 2020 in addressing the priorities identified in two of the five thematic areas that were the workshop's focus: HSV-2 epidemiology and diagnostics. The remaining areas are addressed in a companion paper.

METHODS

A systematic search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary and secondary research studies conducted in LMICs, written in English and published from 2000-2020 were included. Two independent researchers screened, identified papers and extracted preidentified variables from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS V.26.

RESULTS

Overall, 4445 discrete papers were identified, of which 165 publications were eligible for inclusion. The highest general population HSV-2 prevalence was reported in South and West Africa. Prevalence was higher among women than men and increased with age. HSV-2 prevalence studies among key populations were few, and the majority were in East and South Asia. Cohort studies of HSV-2 incidence among younger populations (mean age=25 years) and HSV-2 infection prevalence in North Africa and the Middle East were few. The most researched topic in HSV-2 diagnostics addressed serological techniques and direct molecular biology. Studies of point-of-care testing were also few.

CONCLUSION

HSV-2 research identified in LMICs has mainly addressed the epidemiology and diagnostics priorities identified by the 2001 WHO workshop. Unaddressed priorities include point-of-care testing, antiviral resistance and exploration of HSV-2 epidemiology in neglected geographical settings and population subgroups.

20 years of herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries: systematic evaluation of progress made in addressing WHO priorities for research in HSV-2/HIV interactions, HSV-2 control and mathematical modelling

INTRODUCTION

Reviewing and updating research priorities is essential to assess progress and to ensure optimal allocation of financial and human resources in research. In 2001, WHO held a research priority setting workshop for herpes simplex virus type 2 (HSV-2) research in low-income and middle-income countries (LMICs). This study aimed to describe progress between 2000 and 2020 in three of the five key research priority areas outlined in the workshop: HSV-2/HIV interactions, HSV-2 control measures and HSV-2 mathematical modelling. The remaining priorities are addressed in a companion paper.

METHOD

A systematic literature search of MEDLINE, CINAHL, Global Health and Cochrane databases was carried out. Relevant primary research studies based in LMICs, written in English and published on 2000-2020 were included. Papers were screened by two independent reviewers, and suitable variables were selected for manual extraction from study texts. Data were organised into an Excel spreadsheet and analysed using IBM SPSS.

RESULTS

In total, 3214 discrete papers were identified, of which 180 were eligible for inclusion (HSV-2/HIV interactions, 98; control measures, 58; mathematical modelling, 24). Most studies were conducted in East Africa. The majority of the 2001 WHO HSV-2 research priorities were addressed at least in part. Overall, despite several studies describing a strong relationship between HSV-2 and the acquisition and transmission of HIV, HSV-2 control repeatedly demonstrated little effect on HIV shedding or transmission. Further, although mathematical modelling predicted that vaccines could significantly impact HSV-2 indicators, HSV-2 vaccine studies were few. Studies of antiviral resistance were also few.

CONCLUSION

Since 2000, LMIC HSV-2 research addressing its control, HIV interactions and mathematical modelling has largely addressed the priorities set in the 2001 WHO HSV-2 workshop. However, key knowledge gaps remain in vaccine research, antiviral cost-effectiveness, antiviral resistance and specific geographical areas.

Comparison of sampling methods to measure HIV RNA viral load in female genital tract secretions

PROBLEM

How does menstrual cup (MC) compare to other genital sampling methods for HIV RNA recovery?

METHOD OF STUDY

We compared HIV RNA levels between MC, endocervical swab (ECS), and ECS-enriched cervicovaginal lavage (eCVL) specimens in 51 HIV-positive, antiretroviral therapy-naive women at enrollment, 3 and 6 months, with order rotated by visit. Paired comparisons were analyzed with McNemar's exact tests, signed-rank tests, and an extension of Somer's D for pooled analyses across visits.

RESULTS

MC specimens had the highest proportion of quantifiable HIV VL at enrollment and month 3, but more MC specimens (n=12.8%) were insufficient for testing, compared with ECS (2%, P=0.006) and eCVL (0%, P<0.001). Among sufficient specimens, median VL was significantly higher for MC (2.62 log10 copies/mL) compared to ECS (1.30 log10 copies/mL, P<0.001) and eCVL (1.60 log10 copies/mL, P<0.001) across visits.

CONCLUSION

MC may be more sensitive than eCVL and CVS, provided insufficient specimens are reduced.

Development and clinical evaluation of a novel fully automated qualitative PCR assay for the diagnosis of anogenital herpes simplex virus infection

Molecular detection of viral infections has the potential to improve microbial diagnostics, particularly with the emergence of rapid automated systems. We describe the design of the IDbox fully automated cassette-based system for nucleic acid extraction and real-time PCR amplification and perform a clinical evaluation for the diagnosis of genital herpes simplex infections. At optimal cutoff values determined by receiver-operator curves, the IDbox showed sensitivities of 94.9% (95% confidence interval [CI] 84.9-98.7%) and 97.0% (95% CI 88.5-99.5%) and specificities of 96.7% (95% CI 91.2-98.9%) and 97.3% (95% CI 91.9-99.3%) relative to herpes simplex virus culture and PCR, respectively. We discuss relevant design characteristics and approaches used for each step of the analytical process to enhance assay sensitivity and provide accurate results in the presence of potential cross-reactive organisms and interfering substances.

Changes in plasma viral load and penile viral shedding after circumcision among HIV-positive men in Kisumu, Kenya

BACKGROUND

We conducted a prospective cohort study of HIV-positive men aged 18-35 years in Kisumu, Kenya to determine if medical circumcision of ART-naive HIV-positive men leads to increased viral load and penile viral shedding.

METHODS

From 108 HIV-positive men circumcised by forceps-guided method and followed up weekly for 6 weeks, 29 men were evaluated for penile viral shedding. HIV-1 RNA was measured in plasma from 19 men and in penile lavage samples from 29 men. Samples were collected before circumcision and at weekly intervals for 6 weeks or until the circumcision wound was healed. CD4 T-cell counts from 102 HIV-positive men were determined at baseline and at 2 weeks thereafter. Wounds with healthy scar, no scab or opening, and no suture tracks were deemed healed.

RESULTS

Among 65 ART-naive men, mean CD4 T-cell count increased from 417 cells per cubic millimeter at baseline to 456 cells per cubic millimeter after 2 weeks (P = 0.04), but did not change in the 37 men on ART (P = 0.81). There was no change in HIV plasma viral load (P = 0.36), but penile viral shedding rose significantly within 1 week after circumcision then declined to undetectable levels by 6 weeks (multivariate analysis of variance; P < 0.001). In 28 of 29 men (96.6%), there was no detectable viral shedding after certification of wound healing.

CONCLUSIONS

Medical circumcision among ART-naive HIV-infected men results in a transitory rise in penile viral shedding before complete wound healing, which should pose no additional risk of HIV transmission if men adhere to 6 weeks postcircumcision sexual abstinence and use condoms consistently.

Comparison of lavage and swabs for the collection of genital ulcer specimens to measure HIV RNA shedding

BACKGROUND

The optimum collection procedure for the evaluation of HIV-1 burden in ulcer secretions has not been well defined.

OBJECTIVES

The objective of this study was to compare ulcer swabs and ulcer lavages for the detection and quantitation of HIV-1 RNA in genital ulcers.

STUDY DESIGN

A convenience sample of the first 84 HIV-positive participants in a randomized double blind placebo controlled trial of acyclovir episodic treatment among men with genital ulcer disease were included in this evaluation. At baseline, participants were screened for HIV, syphilis and HSV-2 by serology and for ulcer etiology by PCR. Ulcer specimens were collected by using (1) a non-traumatic washing procedure with 10ml of PBS, and (2) sterile dry swabs. Ulcer samples were tested with HIV-1 Amplicor 1.5 Ultra Sensitive Assay with a lower threshold of 50 copies/ml.

RESULTS

Of ulcer samples 35 (41.7%) had HIV detected by ulcer lavage and 32 (38.1%) by swabs (p=0.68). Overall, 45 (53.6%) were positive by one or both methods. The overall proportion of agreement was 73% (61/84). The chance-corrected proportion of agreement was 0.46 (95% CI: 0.26, 0.65) as estimated by the Kappa statistic. The log mean viral load from lavages (1.49log(10) copies/ml, 95% CI: 1.17-1.81) did not differ significantly from that of swabs (1.41log(10) copies/ml, 95% CI: 1.16-1.71) (p=0.29) with a mean difference of 0.08log copies/ml (SD 0.96).

CONCLUSION

Ulcer lavage and ulcer swab performed in moderate agreement in the detection and quantitation of HIV RNA from ulcer specimens.

Comparison of cervicovaginal lavage, cervicovaginal lavage enriched with cervical swab, and vaginal tampon for the detection of HIV-1 RNA and HSV-2 DNA in genital secretions

METHODS

We compared the performance of 3 collection methods for cervicovaginal secretions [cervicovaginal lavage (CVL), CVL enriched with a cervical swab (eCVL), and vaginal tampon (VT)] to identify the most reliable method for detection of cervicovaginal HIV-1 and herpes simplex virus type 2 (HSV-2). HIV-1 RNA (Nuclisens EasyQ; BioMerieux, Marcy-l'Etoile, France), HSV-2 DNA (real-time polymerase chain reaction), and microscopic blood and semen traces were detected in samples from 19 HIV-1-HSV-2-coinfected women seen at 4 weekly visits.

RESULTS

HIV-1 RNA was detected in 49 (79%) of 62 eCVLs, 41 (61%) of 67 CVLs, and 27 (57%) of 47 VTs. Detection of HIV-1 RNA was higher in eCVL compared with CVL [45/58 (78%) vs. 32/58 (55%); risk ratio 1.41, 95% confidence interval 1.05 to 1.88].

CONCLUSIONS

Although more eCVLs were contaminated with microscopic blood (29%) than CVLs (22%) or VTs (7%), detection of HIV-1 RNA remained higher using eCVL compared with CVL (risk ratio 1.43, 95% confidence interval 1.02 to 2.02) in uncontaminated samples. HSV-2 DNA was detected in less than 10% of samples by each method but in 7 (37%) of 19 women overall by 1 or more methods.

Reconsideration of viral protein immunoblotting for differentiation of human herpes simplex viruses

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) are ubiquitous human pathogens that infect their hosts for life and reactivate to cause disease at or near the initial site of infection. As the incidence of genital HSV-1 infections increase, there is an increased demand for valid viral typing diagnostics. In this report, we reconsidered and developed a triple-phase immune-typing procedure that compares differences in electrophoretic mobilities of viral ICP4, ICP27, and VP22 proteins between HSV-1 and HSV-2 strains. We isolated and immunotyped 5 primary HSV-1 strains derived from orofacial, ocular, and genital areas along with 2 primary HSV-2 strains from the genital area. Advantages of this methodology include its general technical simplicity, sensitivity, and ability to definitively type HSV. It is anticipated that this methodology will be useful in distinguishing viruses obtained in clinical cultures.

Influence of storage temperature on the stability of HIV-1 RNA and HSV-2 DNA in cervicovaginal secretions collected by vaginal washing

Variability in the handling of samples of genital secretions prior to quantitation of HIV-1 RNA and HSV DNA may profoundly affect both the detection and quantitation of these nucleic acids. Over 144 h, we evaluated, the influence of storage temperature (4 degrees C, 20 degrees C, 30 degrees C) on the quantity of HIV-1 RNA and HSV-2 DNA in HIV and HSV negative cervicovaginal lavage pools spiked with known amounts of HIV-1 and HSV-2 and in HIV-1 and HSV-2 co-infected cervicovaginal lavage pools. The level of viral nucleic acids remained stable at 4 degrees C for 24h but decreased significantly when cervicovaginal lavages were stored at 20 degrees C and 30 degrees C, demonstrating that, cervicovaginal lavages to be quantified for viral RNA or DNA require, at minimum, immediate storage at 4 degrees C.

Real-time PCR quantification of genital shedding of herpes simplex virus (HSV) and human immunodeficiency virus (HIV) in women coinfected with HSV and HIV

The accuracy and usefulness of laboratory-developed real-time PCR procedures using a Light Cycler instrument (Roche Diagnostics) for detecting and quantifying human immunodeficiency virus type 1 (HIV-1) RNA and DNA as well as herpes simplex virus type 1 (HSV-1)/HSV-2 DNA in cervicovaginal secretions from women coinfected with HIV and HSV were evaluated. For HIV-1, the use of the NEC152 and NEC131 primer set and the NEC-LTR probe in the long terminal repeat gene allowed us to detect accurately the majority of HIV-1 subtypes of group M circulating in sub-Saharan Africa, including subtypes A, B, C, D, and G as well as circulating recombinant forms 02 and 11. The detection threshold of real-time PCR for HIV in cervicovaginal lavage samples was 5 copies per assay for both RNA and DNA; the intra- and interassay coefficients of variation of C(T) values were 1.30% and 0.69% (HIV-1 RNA) and 1.84% and 0.67% (HIV-1 DNA), respectively. Real-time PCR for HSV using primers and probe targeting the HSV DNA polymerase gene allowed both detection and quantification of HSV DNA and also differentiation between HSV-1 and HSV-2 genotypes. The detection threshold of real-time PCR for HSV was 5 copies per assay; the intra- and interassay coefficients of variation of C(T) values were 0.96% and 1.49%, respectively. Both manual and automated silica-based procedures were appropriate for combined extraction of HIV and HSV genomes from female genital secretions. Taken together, these findings indicate that real-time PCR may be used as a unique nucleic acid amplification procedure to detect and quantify HIV and HSV genomes in cervicovaginal secretions and thus to assess at reduced costs the genital shedding of both viruses in women included in intervention studies.

Rapid diagnosis of herpes simplex virus infection by a loop-mediated isothermal amplification method

Primers for herpes simplex virus type 1 (HSV 1)-specific loop-mediated isothermal amplification (LAMP) method amplified HSV-1 DNA, while HSV-2-specific primers amplified only HSV-2 DNA; no LAMP products were produced by reactions performed with other viral DNAs. The sensitivities of the HSV-1- and HSV-2-specific LAMP methods, determined by agarose gel electrophoresis, reached 500 and 1,000 copies/tube, respectively. The turbidity assay, however, determined the sensitivity of the HSV-1- and HSV-2-specific LAMP methods to be 1,000 and 10,000 copies/tube, respectively. After initial validation studies, 18 swab samples (in sterilized water) collected from patients with either gingivostomatitis or vesicular skin eruptions were examined. HSV-1 LAMP products were detected by agarose gel electrophoresis in the 10 samples that also demonstrated viral DNA detection by real-time PCR. Nine of these 10 samples exhibited HSV-1 LAMP products by turbidity assay. Furthermore, both the agarose gel electrophoresis and the turbidity assay directly detected HSV-1 LAMP products in 9 of the 10 swab samples collected in sterilized water. Next, we examined the reliability of HSV type-specific LAMP for the detection of viral DNA in clinical specimens (culture medium) collected from genital lesions. HSV-2 was isolated from all of the samples and visualized by either agarose gel electrophoresis or turbidity assay.

Comparison of loop-mediated isothermal amplification, real-time PCR, and virus isolation for the detection of herpes simplex virus in genital lesions

This study compares herpes simplex virus (HSV) type-specific loop-mediated isothermal amplification (LAMP) with virus isolation and real-time PCR. Genital tract specimens were obtained from 25 patients with genital lesions; two swab samples were collected from the vulva and cervix of each patient, for a total of 50 specimens. After culturing, 10 of 50 (20%) samples were positive for HSV-1 and 12 of 50 (24%) samples were positive for HSV-2. None of the patients excreted both HSV-1 and HSV-2 virus. An original HSV type-specific LAMP assay (30 min reaction) was compared with virus isolation and HSV type-specific real-time PCR. Viral DNA was detected by LAMP in 9 of 10 HSV-1 isolated samples and 11 of 12 HSV-2 isolated samples. No viral DNA was detected in samples without virus isolation. Thus, if virus isolation was used as the standard method, the LAMP protocol was highly sensitive and specific. In comparing LAMP to real-time PCR, viral DNA was detected by the LAMP method in 9 of 12 HSV-1 DNA positive samples and 11 of 18 HSV-2 DNA positive samples. If real-time PCR was used as the standard method, then, sensitivity of the LAMP method (in particular, for HSV-2) was low. Taking this into consideration, the LAMP reaction was extended to 60 min. This led to an increase in sensitivity, resulting in an additional one and three samples testing positive for HSV-1 LAMP and HSV-2 LAMP, respectively, compared to the original LAMP protocol. Therefore, the sensitivity of the LAMP method increased to about 80%.

Genital tract shedding of herpes simplex virus type 2 in women: effects of hormonal contraception, bacterial vaginosis, and vaginal group B Streptococcus colonization

BACKGROUND

Genital infections due to herpes simplex virus type 2 (HSV-2) are characterized by frequent reactivation and shedding of the virus and by the attendant risk of transmission to sexual partners. We investigated the effects of vaginal coinfections and hormonal contraceptive use on genital tract shedding of HSV-2 in women.

METHODS

A total of 330 HSV-2-seropositive women were followed every 4 months for a year. At each visit, one vaginal swab specimen was obtained for detection of HSV-2 by polymerase chain reaction, a second vaginal swab specimen was obtained for detection of group B Streptococcus (GBS) organisms and yeast by culture, and a vaginal smear was obtained for the diagnosis of bacterial vaginosis by Gram staining.

RESULTS

HSV-2 DNA was detected in 88 (9%) of 956 vaginal swab specimens. Independent predictors of genital tract shedding of HSV-2 were HSV-2 seroconversion during the previous 4 months (adjusted odds ratio [aOR], 3.0; 95% confidence interval [CI], 1.3-6.8), bacterial vaginosis (aOR, 2.3; 95% CI, 1.3-4.0), high-density vaginal GBS colonization (aOR, 2.2; 95% CI, 1.3-3.8), and use of hormonal contraceptives (aOR, 1.8; 95% CI, 1.1-2.8).

CONCLUSIONS

The present study identifies hormonal contraceptive use, bacterial vaginosis, and high-density vaginal GBS colonization as risk factors for genital tract shedding of HSV-2 in women. Because hormonal contraceptives are used by millions of women worldwide and because bacterial vaginosis and vaginal GBS colonization are common vaginal conditions, even modest associations with HSV-2 shedding would result in substantial attributable risks for transmission of the virus.

[Up to date in sexually transmitted infections: epidemiology, diagnostic approaches and treatments]

In the last years, there have been important advances in sexually transmitted infections such as genome sequencing of Treponema pallidum, Chlamydia trachomatis or Mycoplasma genitalium; the new taxonomic position of Calymmatobacterium granulomatis; commercial diagnostic systems based on nucleic acid amplification; the emergence of quinolone resistance in Neisseria gonorrhoeae; new therapeutic approaches in vulvovaginal candidiasis that include boric acid; the demonstration that valacyclovir reduces the risk of transmission of genital herpes or the availability of immune-response modifier in the treatment of genital warts, and that are questions in the goal of this review. Viral hepatitis and HIV were no reviewed by space reasons.