RESUMEN

This study aimed to analytically describe the epidemiology of herpes simplex virus type 1 (HSV-1) infection in the United States through a systematic review and meta-analytics. We reviewed 159 publications, identifying 190 seroprevalence measures and 43 proportions of HSV-1 detection in genital herpes. The pooled mean HSV-1 seroprevalence was 38.0% (95% CI: 30.9-45.4) among general-population children and 63.5% (95% CI: 61.3-65.7) among general-population adults. Age explained 43% of the seroprevalence variation, with rates increasing progressively with age. Seroprevalence declined by 0.99-fold (95% CI: 0.99-0.99) per year. The pooled mean proportion of HSV-1 detection in genital herpes was 15.4% (95% CI: 10.8-20.6), increasing by 1.02-fold (95% CI: 1.00-1.04) per year. Recurrent genital herpes had a 0.17-fold (95% CI: 0.09-0.32) lower proportion of HSV-1 detection compared to first-episode cases. The epidemiology of HSV-1 is shifting, marked by a decline in oral acquisition during childhood and an increase in genital acquisition during adulthood.

RESUMEN

BACKGROUND: This study aimed to examine the transmission dynamics of Neisseria gonorrhoeae (NG) in heterosexual sex work networks (HSWNs) and the impact of variation in sexual behavior and interventions on NG epidemiology. METHODS: The study employed an individual-based mathematical model to simulate NG transmission dynamics in sexual networks involving female sex workers (FSWs) and their clients, primarily focusing on the Middle East and North Africa region. A deterministic model was also used to describe NG transmission from clients to their spouses. RESULTS: NG epidemiology in HSWNs displays two distinct patterns. In the common low-partner-number HSWNs, a significant proportion of NG incidence occurs among FSWs, with NG prevalence 13 times higher among FSWs than clients, and three times higher among clients than their spouses. Interventions substantially reduce incidence. Increasing condom use from 10 % to 50 % lowers NG prevalence among FSWs, clients, and their spouses from 12.2 % to 6.4 %, 1.2 % to 0.5 %, and 0.4 % to 0.2 %, respectively. Increasing symptomatic treatment coverage among FSWs from 0 % to 100 % decreases prevalence from 10.6 % to 4.5 %, 0.8 % to 0.4 %, and 0.3 % to 0.1 %, respectively. Increasing asymptomatic treatment coverage among FSWs from 0 % to 50 % decreases prevalence from 8.2 % to 0.4 %, 0.6 % to 0.1 %, and 0.2 % to 0.0 %, respectively, with very low prevalence when coverage exceeds 50 %. In high-partner-number HSWNs, prevalence among FSWs saturates at a high level, and the vast majority of incidence occurs among clients and their spouses, with a limited impact of incremental increases in interventions. CONCLUSION: NG epidemiology in HSWNs is typically a "fragile epidemiology" that is responsive to a range of interventions even if the interventions are incremental, partially efficacious, and only applied to FSWs.

Asunto(s)

RESUMEN

BACKGROUND: Hepatitis A virus (HAV) is the predominant cause of acute viral hepatitis worldwide; however, data on HAV antibody prevalence (seroprevalence) among migrant populations are limited. This study aimed to investigate HAV seroprevalence among Qatar's migrant craft and manual workers (CMWs), constituting approximately 60% of the country's population. METHODS: HAV antibody testing was conducted on stored serum specimens obtained from CMWs during a nationwide severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) population-based cross-sectional survey between July 26 and September 9, 2020. Associations with HAV infection were investigated through regression analyses. RESULTS: Of the 2,607 specimens with HAV antibody test results, 2,393 were positive, and 214 were negative. The estimated HAV seroprevalence among CMWs was 92.0% (95% CI: 90.9-93.1%). HAV seroprevalence was generally high but exhibited some variation, ranging from 70.9% (95% CI: 62.4-78.2%) among Sri Lankans to 99.8% (95% CI: 98.2-99.9%) among Pakistanis. The multivariable regression analysis identified age, nationality, and educational attainment as statistically significant factors associated with HAV infection. Relative to CMWs aged ≤29 years, the adjusted relative risk (ARR) was 1.06 (95% CI: 1.03-1.10) in CMWs aged 30-39 years and reached 1.15 (95% CI: 1.10-1.19) in those aged ≥50 years. In comparison to Indians, the ARR was lower among Sri Lankans, assessed at 0.81 (95% CI: 0.72-0.91), but higher among Nepalese at 1.07 (95% CI: 1.04-1.11), Bangladeshis at 1.10 (95% CI: 1.07-1.13), Pakistanis at 1.12 (95% CI: 1.09-1.15), and Egyptians at 1.15 (95% CI: 1.08-1.23). No evidence for differences was found by geographic location or occupation. CONCLUSIONS: HAV seroprevalence among Qatar's CMW population is very high, with over nine out of every ten individuals having been exposed to this infection, likely during childhood.

Asunto(s)

RESUMEN

Background: There is a need for statistical methodologies that scrutinize civilian casualties in conflicts, evaluating the degree to which the conduct of war affects civilians and breaches the laws of war. Employing an epidemiological method, this study introduced, developed, and applied a novel approach for investigating mortality of civilians versus combatants in conflicts. Methods: A deterministic mathematical model, structured by age and sex, was developed to describe the process of conflict-related deaths among both combatants and civilians. The model was calibrated using demographic and conflict-related data from different Israel-Gaza conflicts. To quantify the extent of the impact on civilians and determine whether they are the primary focus of a conflict, a statistical metric, the index of killing civilians, along with associated criteria, was devised. Results: The model-estimated proportion of deaths in Gaza categorized as combatants was 62.1% (95% uncertainty interval (UI): 57.6-66.2%), 51.1% (95% UI: 47.1-54.9%), and 12.7% (95% UI: 9.7-15.4%) in the 2008-2009, 2014, and 2023 Israel-Gaza conflicts, respectively. The index of killing civilians was 0.61 (95% UI: 0.51-0.74), 0.96 (95% UI: 0.82-1.12), and 7.01 (95% UI: 5.50-9.29) in the 2008-2009, 2014, and 2023 conflicts, respectively. These index values indicate strong evidence for civilians being an object of war in the 2008-2009 and 2014 conflicts, but combatants were still identified as the primary focus of the conflict. In the 2023 conflict, there is robust evidence for civilians being an object of war, with civilians identified as the primary focus of the conflict. Conclusion: Findings imply a progressive shift in Israel's rules of engagement over time, with a trend towards higher acceptance of casualties among civilians. The 2023 conflict stands apart from preceding Israel-Gaza conflicts, with civilians identified as the primary focus of the conflict.

Asunto(s)

RESUMEN

Biocrusts dominate the soil surface in deserts and are composed of diverse microbial communities that provide important ecosystem services. Cyanobacteria in biocrusts produce many secondary metabolites, including the neurotoxins BMAA, AEG, DAB, anatoxin-a(S) (guanitoxin), and the microcystin hepatotoxins, all known or suspected to cause disease or illness in humans and other animals. We examined cyanobacterial growth and prevalence of these toxins in biocrusts at millimeter-scales, under a desert-relevant illumination gradient. In contrast to previous work, we showed that hydration had an overall positive effect on growth and toxin accumulation, that nitrogen was not correlated with growth or toxin production, and that phosphorus enrichment negatively affected AEG and BMAA concentrations. Excess illumination positively correlated with AEG, and negatively correlated with all other toxins and growth. Basic pH negatively affected only the accumulation of BMAA. Anatoxin-a(S) (guanitoxin) was not correlated with any tested variables, while microcystins were not detected in any of the samples. Concerning toxin pools, AEG and BMAA were good predictors of the presence of one another. In a newly conceptualized scheme, we integrate aspects of biocrust growth and toxin pool accumulations with arid-relevant desertification drivers.

RESUMEN

OBJECTIVES: Hepatitis C virus (HCV) infection poses a global health challenge. By the end of 2021, the WHO estimated that less than a quarter of global HCV infections had been diagnosed. There is a need for a public health tool that can facilitate the identification of people with HCV infection and link them to testing and treatment, and that can be customised for each country. METHODS: We derived and validated a risk score to identify people with HCV in Egypt and demonstrated its utility. Using data from the 2008 and 2014 Egypt Demographic and Health Surveys, two risk scores were constructed through multivariable logistic regression analysis. A range of diagnostic metrics was then calculated to evaluate the performance of these scores. RESULTS: The 2008 and 2014 risk scores exhibited similar dependencies on sex, age and type of place of residence. Both risk scores demonstrated high and similar areas under the curve of 0.77 (95% CI: 0.76 to 0.78) and 0.78 (95% CI: 0.77 to 0.80), respectively. For the 2008 risk score, sensitivity was 73.7% (95% CI: 71.5% to 75.9%), specificity was 68.5% (95% CI: 67.5% to 69.4%), positive predictive value (PPV) was 27.8% (95% CI: 26.4% to 29.2%) and negative predictive value (NPV) was 94.1% (95% CI: 93.5% to 94.6%). For the 2014 risk score, sensitivity was 64.0% (95% CI: 61.5% to 66.6%), specificity was 78.2% (95% CI: 77.5% to 78.9%), PPV was 22.2% (95% CI: 20.9% to 23.5%) and NPV was 95.7% (95% CI: 95.4% to 96.1%). Each score was validated by applying it to a different survey database than the one used to derive it. CONCLUSIONS: Implementation of HCV risk scores is an effective strategy to identify carriers of HCV infection and to link them to testing and treatment at low cost to national programmes.

Asunto(s)

RESUMEN

Wastewater-based epidemiology (WBE) has been proven effective for the monitoring of infectious disease outbreaks during mass gathering events and for timely public health interventions. As part of Qatar's efforts to monitor and combat the spread of infectious diseases during the FIFA World Cup Qatar 2022™ (FWC'22), wastewater surveillance was used to monitor the spread of SARS-CoV-2, human enterovirus, and poliovirus. The screening covered five major wastewater treatment plants servicing the event locations between October 2022 and January 2023. Viruses were concentrated from the wastewater samples by PEG precipitation, followed by qRT-PCR to measure the viral load in the wastewater. As expected, SARS-CoV-2 and enterovirus RNA were detected in all samples, while poliovirus was not detected. The concentration of SARS-CoV-2 was correlated with population density, such as areas surrounding the World Cup venues, and with the number of reported clinical cases. Additionally, we observed temporal fluctuations in viral RNA concentrations, with peak levels coinciding with the group stage matches of the FWC'22. This study has been useful in providing public health authorities with an efficient and cost-effective surveillance system for potential infectious disease outbreaks during mega-events.

RESUMEN

OBJECTIVE: This study investigated the association between Coronavirus Disease 2019 mRNA vaccination and stroke in Qatar. METHODS: Between December 1, 2020, and April 11, 2023, a matched case-control study was conducted to investigate the association between 3036 acute stroke cases and 3036 controls drawn from the entire population of Qatar. RESULTS: The adjusted odds ratio (aOR) for vaccination among cases compared to controls was 0.87 (95% CI: 0.75-1.00). The aOR was 0.74 (95% CI: 0.45-1.23) for a single vaccine dose, 0.87 (95% CI: 0.73-1.04) for primary-series vaccination (two doses), and 0.91 (95% CI: 0.66-1.25) for booster vaccination (three or more doses). The aOR was 0.87 (95% CI: 0.72-1.04) for BNT162b2 and 0.86 (95% CI: 0.67-1.11) for mRNA-1273. Subgroup analyses, considering different durations since vaccination, also demonstrated no association. Subgroup analyses based on nationality, age, number of coexisting conditions, or prior infection status yielded similar results. Subgroup analysis, stratified by stroke type, suggested an association between vaccination and cerebral venous sinus thrombosis (aOR of 2.50 [95% CI: 0.97-6.44]), but it did not reach statistical significance. CONCLUSION: There was no evidence of an increased risk of stroke following vaccination, both in the short term and in the long term, extending beyond a year after receiving the vaccine.

Asunto(s)

RESUMEN

Limited data exist on viral hepatitis among migrant populations. This study investigated the prevalence of current hepatitis B virus (HBV) infection and lifetime hepatitis C virus (HCV) infection among Qatar's migrant craft and manual workers (CMWs), constituting 60% of the country's population. Sera collected during a nationwide COVID-19 population-based cross-sectional survey on CMWs between July 26 and September 9, 2020, underwent testing for HBsAg and HCV antibodies. Reactive samples underwent confirmatory testing, and logistic regression analyses were employed to explore associations with HBV and HCV infections. Among 2528 specimens tested for HBV infection, 15 were reactive, with 8 subsequently confirmed positive. Three samples lacked sufficient sera for confirmatory testing but were included in the analysis through multiple imputations. Prevalence of current HBV infection was 0.4% (95% CI 0.2-0.7%). Educational attainment and occupation were significantly associated with current HBV infection. For HCV infection, out of 2607 specimens tested, 46 were reactive, and 23 were subsequently confirmed positive. Prevalence of lifetime HCV infection was 0.8% (95% CI 0.5-1.2%). Egyptians exhibited the highest prevalence at 6.5% (95% CI 3.1-13.1%), followed by Pakistanis at 3.1% (95% CI 1.1-8.0%). Nationality, geographic location, and occupation were significantly associated with lifetime HCV infection. HBV infection is relatively low among CMWs, while HCV infection falls within the intermediate range, both compared to global and regional levels.

Asunto(s)

RESUMEN

Introduction: We aimed to investigate the overlapping epidemiologies of human immunodeficiency virus (HIV), herpes simplex virus type 2 (HSV-2), chlamydia, gonorrhea, and syphilis in sexual networks of men who have sex with men (MSM), and to explore to what extent the epidemiology of one sexually transmitted infection (STI) relates to or differs from that of another STI. Methods: An individual-based Monte Carlo simulation model was employed to simulate the concurrent transmission of STIs within diverse sexual networks of MSM. The model simulated sexual partnering, birth, death, and STI transmission within each specific sexual network. The model parameters were chosen based on the current knowledge and understanding of the natural history, transmission, and epidemiology of each considered STI. Associations were measured using the Spearman's rank correlation coefficient (SRCC) and maximal information coefficient (MIC). Results: A total of 500 sexual networks were simulated by varying the mean and variance of the number of partners for both short-term and all partnerships, degree correlation, and clustering coefficient. HSV-2 had the highest current infection prevalence across the simulations, followed by HIV, chlamydia, syphilis, and gonorrhea. Threshold and saturation effects emerged in the relationship between STIs across the simulated networks, and all STIs demonstrated moderate to strong associations. The strongest current infection prevalence association was between HIV and gonorrhea, with an SRCC of 0.84 (95% CI: 0.80-0.87) and an MIC of 0.81 (95% CI: 0.74-0.88). The weakest association was between HSV-2 and syphilis, with an SRCC of 0.54 (95% CI: 0.48-0.59) and an MIC of 0.57 (95% CI, 0.49-0.65). Gonorrhea exhibited the strongest associations with the other STIs while syphilis had the weakest associations. Across the simulated networks, proportions of the population with zero, one, two, three, four, and five concurrent STI infections were 48.6, 37.7, 11.1, 2.4, 0.3, and < 0.1%, respectively. For lifetime exposure to these infections, these proportions were 13.6, 21.0, 22.9, 24.3, 13.4, and 4.8%, respectively. Conclusion: STI epidemiologies demonstrate substantial overlap and associations, alongside nuanced differences that shape a unique pattern for each STI. Gonorrhea exhibits an "intermediate STI epidemiology," reflected by the highest average correlation coefficient with other STIs.

Asunto(s)

RESUMEN

BACKGROUND: We analyzed the prevalence of active infection with common curable sexually transmitted infections (STIs) including N. gonorrhea, C. trachomatis, T. vaginalis, and T. pallidum, as well as active infection with HPV, herpes simplex virus types I (HSV-1) and II (HSV-2), M. hominis, M. genitalium, C. albicans, and Ureaplasma in 351 Lebanese women. METHODS: A cross-sectional study, involving 351 sexually active women, 40 years or younger, who were recruited from outpatient Obstetrics and Gynecology clinic attendees between September 2016 and November 2017. RESULTS: The prevalence of active infection was low at 0.3% for N. gonorrhea, 0.6% for HSV-2, 2.8% for C. trachomatis, and 2.9% for any curable STIs. Prevalence of active HPV infection was high assessed at 15.7% for high-risk and 12.2% for low-risk genotypes. Furthermore, the prevalence was 2.0% for M. genitalium, 6.8% for ureaplasma, 13.7% for Candida albicans, and 20.5% for M. hominis. No active infections with T. vaginalis, T. pallidum, or HSV-1 were observed. Significant age differences were noted in the prevalence of high-risk and low-risk HPV genotypes, but no such differences were noted in the prevalence of other infections. No appreciable variations were identified in the prevalence of key STIs based on smoking, marital status, or the number of sexual partners. CONCLUSIONS: The study documented active infection with substantial prevalence for multiple STIs among women attending outpatient gynecology and obstetrics clinics in Lebanon. These findings underscore the importance of strengthening STI surveillance, linkage to care, and prevention interventions in reducing STI incidence among women.

Asunto(s)

RESUMEN

BACKGROUND: Vaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and mRNA-1273 mRNA vaccines against a spectrum of SARS-CoV-2 infection symptoms and severities. METHODS: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests. Vaccine effectiveness was estimated against asymptomatic, symptomatic, severe coronavirus disease 2019 (COVID-19), critical COVID-19, and fatal COVID-19 infections. Data sources included Qatar's national databases for COVID-19 laboratory testing, vaccination, hospitalization, and death. RESULTS: Effectiveness of two-dose BNT162b2 vaccination was 75.6% (95% CI: 73.6-77.5) against asymptomatic infection and 76.5% (95% CI: 75.1-77.9) against symptomatic infection. Effectiveness against each of severe, critical, and fatal COVID-19 infections surpassed 90%. Immediately after the second dose, all categories-namely, asymptomatic, symptomatic, severe, critical, and fatal COVID-19-exhibited similarly high effectiveness. However, from 181 to 270 days post-second dose, effectiveness against asymptomatic and symptomatic infections declined to below 40%, while effectiveness against each of severe, critical, and fatal COVID-19 infections remained consistently high. However, estimates against fatal COVID-19 often had wide 95% confidence intervals. Analogous patterns were observed in three-dose BNT162b2 vaccination and two- and three-dose mRNA-1273 vaccination. Sensitivity analyses confirmed the results. CONCLUSION: A gradient in vaccine effectiveness exists and is linked to the symptoms and severity of infection, providing higher protection against more symptomatic and severe cases. This gradient intensifies over time as vaccine immunity wanes after the last vaccine dose. These patterns appear consistent irrespective of the vaccine type or whether the vaccination involves the primary series or a booster.

Asunto(s)

Asunto(s)

RESUMEN

Introduction: Reinfections are increasingly becoming a feature in the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, accurately defining reinfection poses methodological challenges. Conventionally, reinfection is defined as a positive test occurring at least 90 days after a previous infection diagnosis. Yet, this extended time window may lead to an underestimation of reinfection occurrences. This study investigated the prospect of adopting an alternative, shorter time window for defining reinfection. Methods: A longitudinal study was conducted to assess the incidence of reinfections in the total population of Qatar, from February 28, 2020 to November 20, 2023. The assessment considered a range of time windows for defining reinfection, spanning from 1 day to 180 days. Subgroup analyses comparing first versus repeat reinfections and a sensitivity analysis, focusing exclusively on individuals who underwent frequent testing, were performed. Results: The relationship between the number of reinfections in the population and the duration of the time window used to define reinfection revealed two distinct dynamical domains. Within the initial 15 days post-infection diagnosis, almost all positive tests for SARS-CoV-2 were attributed to the original infection. However, surpassing the 30-day post-infection threshold, nearly all positive tests were attributed to reinfections. A 40-day time window emerged as a sufficiently conservative definition for reinfection. By setting the time window at 40 days, the estimated number of reinfections in the population increased from 84,565 to 88,384, compared to the 90-day time window. The maximum observed reinfections were 6 and 4 for the 40-day and 90-day time windows, respectively. The 40-day time window was appropriate for defining reinfection, irrespective of whether it was the first, second, third, or fourth occurrence. The sensitivity analysis, confined to high testers exclusively, replicated similar patterns and results. Discussion: A 40-day time window is optimal for defining reinfection, providing an informed alternative to the conventional 90-day time window. Reinfections are prevalent, with some individuals experiencing multiple instances since the onset of the pandemic.

RESUMEN

Background: Monitoring progress towards the WHO global target to eliminate hepatitis C virus (HCV) infection by 2030, entails reliable prevalence estimates for HCV infection in different populations. Little is known about the global burden of HCV infection in pregnant women. Here, for the first time to our knowledge, we estimated the global and regional seroprevalence of HCV antibody (Ab) and determinants in pregnant women. Methods: In this systematic review and meta-analysis study, we searched PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO databases for peer-reviewed observational studies between January 1, 2000 and April 1, 2023, without language or geographical restrictions. Pooled global seroprevalence (and 95% confidence interval, CI) were estimated using random-effects meta-analysis and seroprevalences were categorised according to World Health Organization regions and subregions, publishing year, countries' income and human development index (HDI) levels. We used sensitivity analysis to assess the effect of four large sample size studies on pooled global prevalence through the "leave-one-out" method. We also investigated the association of potential risk factors with HCV seropositivity in pregnant women by subgroup and meta-regression analyses. The Protocol was registered in PROSPERO CRD42023423259. Findings: We included 192 eligible studies (208 datasets), with data for 148,509,760 pregnant women from 53 countries. The global seroprevalence of HCV Ab in pregnant women was 1.80% (95% CI, 1.72-1.89%) and 3.29% (3.01-3.57%) in overall and sensitivity analyses, respectively. The seroprevalence was highest in the Eastern Mediterranean region (6.21%, 4.39-8.29%) and lowest in the Western Pacific region (0.75%, 0.38-1.22%). Subgroup analysis indicated that the seroprevalence of HCV Ab among pregnant women was significantly higher for those with opioid use disorder (51.94%, 95% CI: 37.32-66.39) and HIV infection (4.34%, 95% CI: 2.21-7.06%) than for the general population of pregnant women (1.08%, 95% CI: 1.02-1.15%), as confirmed by multivariable meta-regression (p < 0.001). A significant decreasing trend was observed with increasing human development index levels. Other important risk factors for HCV seropositivity included older age, lower educational levels, poly sexual activity, history of blood transfusion, hospitalization, surgery, abortion and sexual transmitted diseases, having scarification/tattoo or piercing, and testing hepatitis B positive. Interpretation: This meta-analysis showed relatively high burden of exposure to HCV infection (2.2-5.3 million) in pregnant women globally. However, due to substantial heterogeneity between studies, our estimates might be different than the true seroprevalence. Our findings highlighted the need to expand HCV screening for women of reproductive age or during pregnancy, particularly in countries with high prevalence; as well as for more studies that assess safety of existing therapeutic drugs during pregnancy or potentially support development of drugs for pregnant women. Funding: There was no funding source for this study.

RESUMEN

The COVID-19 pandemic has highlighted the need to use infection testing databases to rapidly estimate effectiveness of prior infection in preventing reinfection ($P{E}_S$) by novel SARS-CoV-2 variants. Mathematical modeling was used to demonstrate a theoretical foundation for applicability of the test-negative, case-control study design to derive $P{E}_S$. Apart from the very early phase of an epidemic, the difference between the test-negative estimate for $P{E}_S$ and true value of $P{E}_S$ was minimal and became negligible as the epidemic progressed. The test-negative design provided robust estimation of $P{E}_S$ and its waning. Assuming that only 25% of prior infections are documented, misclassification of prior infection status underestimated $P{E}_S$, but the underestimate was considerable only when >50% of the population was ever infected. Misclassification of latent infection, misclassification of current active infection, and scale-up of vaccination all resulted in negligible bias in estimated $P{E}_S$. The test-negative design was applied to national-level testing data in Qatar to estimate $P{E}_S$ for SARS-CoV-2. $P{E}_S$ against SARS-CoV-2 Alpha and Beta variants was estimated at 97.0% (95% CI: 93.6-98.6) and 85.5% (95% CI: 82.4-88.1), respectively. These estimates were validated using a cohort study design. The test-negative design offers a feasible, robust method to estimate protection from prior infection in preventing reinfection.

RESUMEN

Background: Hepatitis C virus (HCV) infection levels in Jordan remain uncertain. No HCV national population-based survey has ever been conducted in the country. To meet the World Health Organization's target of reducing HCV incidence to ≤5 per 100,000 people per year by 2030, it is essential to determine the infection levels, identify affected individuals and populations, and provide appropriate treatment using direct-acting antivirals to individuals carrying the virus. Methods: The study utilized the HCV testing database of 28,798 attendees of Biolab Diagnostic Laboratories in Jordan, covering the period from January 19, 2010, to May 26, 2023. Cross-sectional and cohort study analyses were conducted, including estimating HCV antibody (Ab) prevalence, examining associations with HCV Ab positivity, determining the HCV viremic rate, and estimating HCV incidence rate using a retrospective cohort study design. Results: A total of 27,591 individuals, with a median age of 31.3 and 52.9% being females, underwent HCV Ab testing, while 1,450 individuals, with a median age of 42.2 and 32.8% being females, underwent HCV RNA PCR testing. The study sample HCV Ab prevalence was 4.0% (95% CI: 3.7-4.2%). After applying probability weights, the weighted HCV Ab prevalence was 5.8% (95% CI: 4.6-7.3%). Age was strongly associated with HCV Ab positivity, particularly among individuals aged 50 years or older, who had 10-fold higher odds of being HCV Ab positive compared to those aged 10-19 years. Males had 2.41-fold higher odds of testing positive for HCV Ab compared to females. The HCV viremic rate was 54.1% (95% CI: 43.0-65.0%). The cumulative incidence of HCV infection, after 5 years of follow-up, was estimated to be 0.41% (95% CI: 0.17-0.99%). The HCV incidence rate was calculated at 1.19 per 1,000 person-years (95% CI, 0.50-2.87). Conclusion: Prevalence and incidence of HCV infection were substantial, estimated at ~5% and 1 per 1,000 person-years, respectively, and highlighting the presence of core groups actively engaged in the virus' acquisition and transmission. The high observed viremic rate indicates the need for expanding HCV treatment efforts to effectively control HCV transmission in Jordan. Utilizing quality diagnostic laboratories and innovative testing strategies is key to identifying infection carriers and facilitating linkage to treatment and care.

Asunto(s)

RESUMEN

BACKGROUND: We investigated the contribution of age, coexisting medical conditions, sex, and vaccination to incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and of severe, critical, or fatal COVID-19 in older adults since pandemic onset. METHODS: A national retrospective cohort study was conducted in the population of Qatar aged ≥50 years between February 5, 2020 and June 15, 2023. Adjusted hazard ratios (AHRs) for infection and for severe coronavirus disease 2019 (COVID-19) outcomes were estimated through Cox regression models. RESULTS: Cumulative incidence was 25.01% (95% confidence interval [CI]: 24.86-25.15%) for infection and 1.59% (95% CI: 1.55-1.64%) for severe, critical, or fatal COVID-19 after a follow-up duration of 40.9 months. Risk of infection varied minimally by age and sex but increased significantly with coexisting conditions. Risk of infection was reduced with primary-series vaccination (AHR: 0.91, 95% CI: 0.90-0.93) and further with first booster vaccination (AHR: 0.75, 95% CI: 0.74-0.77). Risk of severe, critical, or fatal COVID-19 increased exponentially with age and linearly with coexisting conditions. AHRs for severe, critical, or fatal COVID-19 were 0.86 (95% CI: 0.7-0.97) for one dose, 0.15 (95% CI: 0.13-0.17) for primary-series vaccination, and 0.11 (95% CI: 0.08-0.14) for first booster vaccination. Sensitivity analysis restricted to only Qataris yielded similar results. CONCLUSION: Incidence of severe COVID-19 in older adults followed a dynamic pattern shaped by infection incidence, variant severity, and population immunity. Age, sex, and coexisting conditions were strong determinants of infection severity. Vaccine protection against severe outcomes showed a dose-response relationship, highlighting the importance of booster vaccination for older adults.

Asunto(s)

RESUMEN

In counteracting highly infectious and disruptive respiratory diseases such as COVID-19, vaccination remains the primary and safest way to prevent disease, reduce the severity of illness, and save lives. Unfortunately, vaccination is often not the first intervention deployed for a new pandemic, as it takes time to develop and test vaccines, and confirmation of safety requires a period of observation after vaccination to detect potential late-onset vaccine-associated adverse events. In the meantime, nonpharmacologic public health interventions such as mask-wearing and social distancing can provide some degree of protection. As climate change, with its environmental impacts on pathogen evolution and international mobility continue to rise, highly infectious respiratory diseases will likely emerge more frequently and their impact is expected to be substantial. How quickly a safe and efficacious vaccine can be deployed against rising infectious respiratory diseases may be the most important challenge that humanity will face in the near future. While some organizations are engaged in addressing the World Health Organization's "blueprint for priority diseases", the lack of worldwide preparedness, and the uncertainty around universal vaccine availability, remain major concerns. We therefore propose the establishment of an international candidate vaccine pool repository for potential respiratory diseases, supported by multiple stakeholders and countries that contribute facilities, technologies, and other medical and financial resources. The types and categories of candidate vaccines can be determined based on information from previous pandemics and epidemics. Each participant country or region can focus on developing one or a few vaccine types or categories, together covering most if not all possible potential infectious diseases. The safety of these vaccines can be tested using animal models. Information for effective candidates that can be potentially applied to humans will then be shared across all participants. When a new pandemic arises, these pre-selected and tested vaccines can be quickly tested in RCTs for human populations.

RESUMEN

Laboratory evidence suggests a possibility of immune imprinting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated the differences in the incidence of SARS-CoV-2 reinfection in a cohort of persons who had a primary Omicron infection, but different vaccination histories using matched, national, retrospective, cohort studies. Adjusted hazard ratio for reinfection incidence, factoring adjustment for differences in testing rate, was 0.43 [95% confidence interval (CI): 0.39 to 0.49] comparing history of two-dose vaccination to no vaccination, 1.47 (95% CI: 1.23 to 1.76) comparing history of three-dose vaccination to two-dose vaccination, and 0.57 (95% CI: 0.48 to 0.68) comparing history of three-dose vaccination to no vaccination. Divergence in cumulative incidence curves increased markedly when the incidence was dominated by BA.4/BA.5 and BA.2.75* Omicron subvariants. The history of primary-series vaccination enhanced immune protection against Omicron reinfection, but history of booster vaccination compromised protection against Omicron reinfection. These findings do not undermine the public health utility of booster vaccination.

Asunto(s)