Use of routine HIV testing data for early detection of emerging HIV epidemics in high-risk subpopulations: A concept demonstration study

Epidemiology of gonorrhea in countries of the Middle East and North Africa: systematic review, meta analyses, and meta regressions

BACKGROUND

The epidemiology of Neisseria gonorrhoeae (NG) infection in the Middle East and North Africa (MENA) region remains poorly understood, despite the global recognition of its disease burden and the growing concern regarding antimicrobial resistance. This study aimed to systematically review the evidence on NG prevalence in MENA, estimate the pooled mean prevalence across different populations, and explore population-level associations with prevalence as well as sources of between-study heterogeneity.

METHODS

The study conducted a systematic review, risk of bias assessment, meta-analyses, and meta-regressions, utilizing both published and unpublished evidence sourced from international, regional, and national databases, in adherence to PRISMA guidelines. Random-effects meta-analyses and meta-regressions were employed to analyze the data.

RESULTS

The study identified 341 NG prevalence measures from 21 countries in MENA. The pooled mean prevalence of current urogenital infection was 1.9% (95% confidence interval (CI) 1.1-2.8%) in the general population, with a higher pooled prevalence in studies with sample sizes < 200 (3.1%; 95% CI 1.5-5.0%) compared to those with sample sizes ≥ 200 (1.1%; 95% CI 0.5-1.9%). Among specific populations, the pooled prevalence was 6.5% (95% CI 4.4-9.0%) in female sex workers, 7.5% (95% CI 2.8-14.0%) in attendees of infertility clinics, 3.0% (95% CI 0.4-7.0%) in women with miscarriage or ectopic pregnancy, 3.9% (95% CI 2.7-5.3%) in symptomatic women, and 41.4% (95% CI 34.9-48.1%) in symptomatic men. For male sex workers and men who have sex with men, the pooled prevalence of current urogenital infection was 1.6% (95% CI 0.4-3.4%), while the prevalence of current anorectal infection was 10.4% (95% CI 4.6-18.0%). Through multivariable meta-regressions, 64% of the prevalence variation was explained, revealing a hierarchical pattern in prevalence by population type and sex, and a prevalence decline at a rate of 1% per year.

CONCLUSIONS

NG prevalence in MENA is comparable to the global prevalence, underscoring a neglected and underrecognized disease burden, with social and economic consequences. Persistent transmission of NG among key populations and other populations at risk increases the potential for the emergence of new drug-resistant strains. MENA is far from achieving the World Health Organization's target of reducing NG incidence by 90% by 2030.

Expanding syphilis test uptake using rapid dual self-testing for syphilis and HIV among men who have sex with men in China: A multiarm randomized controlled trial

BACKGROUND

Low syphilis testing uptake is a major public health issue among men who have sex with men (MSM) in many low- and middle-income countries. Syphilis self-testing (SST) may complement and extend facility-based testing. We aimed to evaluate the effectiveness and costs of providing SST on increasing syphilis testing uptake among MSM in China.

METHODS AND FINDINGS

An open-label, parallel 3-arm randomized controlled trial (RCT) was conducted between January 7, 2020 and July 17, 2020. Men who were at least 18 years of age, had condomless anal sex with men in the past year, reported not testing for syphilis in the last 6 months, and had a stable residence with mailing addresses were recruited from 124 cities in 26 Chinese provinces. Using block randomization with blocks of size 12, enrolled participants were randomly assigned (1:1:1) into 3 arms: standard of care arm, standard SST arm, and lottery incentivized SST arm (1 in 10 chance to win US$15 if they had a syphilis test). The primary outcome was the proportion of participants who tested for syphilis during the trial period and confirmed with photo verification and between arm comparisons were estimated with risk differences (RDs). Analyses were performed on a modified intention-to-treat basis: Participants were included in the complete case analysis if they had initiated at least 1 follow-up survey. The Syphilis/HIV Duo rapid test kit was used. A total of 451 men were enrolled. In total, 136 (90·7%, 136/150) in the standard of care arm, 142 (94·0%, 142/151) in the standard of SST arm, and 137 (91·3%, 137/150) in the lottery incentivized SST arm were included in the final analysis. The proportion of men who had at least 1 syphilis test during the trial period was 63.4% (95% confidence interval [CI]: 55.5% to 71.3%, p = 0.001) in the standard SST arm, 65.7% (95% CI: 57.7% to 73.6%, p = 0.0002) in the lottery incentivized SST arm, and 14.7% (95% CI: 8.8% to 20.7%, p < 0.001) in the standard of care arm. The estimated RD between the standard SST and standard of care arm was 48.7% (95% CI: 37.8% to 58.4%, p < 0.001). The majority (78.5%, 95% CI: 72.7% to 84.4%, p < 0.001) of syphilis self-testers reported never testing for syphilis. The cost per person tested was US$26.55 for standard SST, US$28.09 for the lottery incentivized SST, and US$66.19 for the standard of care. No study-related adverse events were reported during the study duration. Limitation was that the impact of the Coronavirus Disease 2019 (COVID-19) restrictions may have accentuated demand for decentralized testing.

CONCLUSIONS

Compared to standard of care, providing SST significantly increased the proportion of MSM testing for syphilis in China and was cheaper (per person tested).

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1900022409.

A network-based model to explore the role of testing in the epidemiological control of the COVID-19 pandemic

BACKGROUND

Testing is one of the most effective means to manage the COVID-19 pandemic. However, there is an upper bound on daily testing volume because of limited healthcare staff and working hours, as well as different testing methods, such as random testing and contact-tracking testing. In this study, a network-based epidemic transmission model combined with a testing mechanism was proposed to study the role of testing in epidemic control. The aim of this study was to determine how testing affects the spread of epidemics and the daily testing volume needed to control infectious diseases.

METHODS

We simulated the epidemic spread process on complex networks and introduced testing preferences to describe different testing strategies. Different networks were generated to represent social contact between individuals. An extended susceptible-exposed-infected-recovered (SEIR) epidemic model was adopted to simulate the spread of epidemics in these networks. The model establishes a testing preference of between 0 and 1; the larger the testing preference, the higher the testing priority for people in close contact with confirmed cases.

RESULTS

The numerical simulations revealed that the higher the priority for testing individuals in close contact with confirmed cases, the smaller the infection scale. In addition, the infection peak decreased with an increase in daily testing volume and increased as the testing start time was delayed. We also discovered that when testing and other measures were adopted, the daily testing volume required to keep the infection scale below 5% was reduced by more than 40% even if other measures only reduced individuals' infection probability by 10%. The proposed model was validated using COVID-19 testing data.

CONCLUSIONS

Although testing could effectively inhibit the spread of infectious diseases and epidemics, our results indicated that it requires a huge daily testing volume. Thus, it is highly recommended that testing be adopted in combination with measures such as wearing masks and social distancing to better manage infectious diseases. Our research contributes to understanding the role of testing in epidemic control and provides useful suggestions for the government and individuals in responding to epidemics.

HSV-2 as a biomarker of HIV epidemic potential in female sex workers: meta-analysis, global epidemiology and implications

This study investigated herpes simplex virus type 2 (HSV-2) seroprevalence utility as a predictor of HIV epidemic potential among female sex workers (FSWs) globally. We updated and analyzed a systematically-assembled database for paired HSV-2 and HIV seroprevalence measures among FSWs. The study identified 231 paired HSV-2/HIV prevalence measures from 40 countries. The pooled mean HIV prevalence using meta-analysis increased from 3.7% (95% CI 0.3-9.9%) among populations of FSWs with HSV-2 prevalence < 25% to 18.7% (95% CI 14.1-23.8%) among those with HSV-2 prevalence 75-100%. HIV prevalence was negligible in FSWs with HSV-2 prevalence ≤ 20% suggesting a threshold effect. Multivariable meta-regressions explained > 65% of HIV prevalence variation, and identified a strong positive HSV-2/HIV association. Compared to populations of FSWs with HSV-2 prevalence < 25%, adjusted odds ratios (AORs) of HIV infection increased from 2.8 (95% CI 1.2-6.3) in those with HSV-2 prevalence 25-49%, to 13.4 (95% CI 6.1-29.9) in those with HSV-2 prevalence 75-100%. HSV-2 is a strong predictor of HIV epidemic potential among FSWs. HSV-2 prevalence of 25-49% indicates potential for intermediate-intensity HIV epidemics, with higher levels indicative of large epidemics. HSV-2 surveillance could inform HIV preparedness in countries where HIV prevalence among FSWs is still limited or at zero-level.