Travel Medicine and Infectious Disease

BackgroundOn January 23, 2020, a quarantine was imposed on travel in and out of Wuhan, where the 2019 novel coronavirus (2019-nCoV) outbreak originated from. Previous analyses estimated the basic epidemiological parameters using symptom onset dates of the confirmed cases in Wuhan and outside China. MethodsWe obtained information on the 46 coronavirus cases who traveled from Wuhan before January 23 and have been subsequently confirmed in Hong Kong, Japan, Korea, Macau, Singapore, and Taiwan as of February 5, 2020. Most cases have detailed travel history and disease progress. Compared to previous analyses, an important distinction is that we used this data to informatively simulate the infection time of each case using the symptom onset time, previously reported incubation interval, and travel history. We then fitted a simple exponential growth model with adjustment for the January 23 travel ban to the distribution of the simulated infection time. We used a Bayesian analysis with diffuse priors to quantify the uncertainty of the estimated epidemiological parameters. We performed sensitivity analysis to different choices of incubation interval and the hyperparameters in the prior specification. ResultsWe found that our model provides good fit to the distribution of the infection time. Assuming the travel rate to the selected countries and regions is constant over the study period, we found that the epidemic was doubling in size every 2.9 days (95% credible interval [CrI], 2 days--4.1 days). Using previously reported serial interval for 2019-nCoV, the estimated basic reproduction number is 5.7 (95% CrI, 3.4--9.2). The estimates did not change substantially if we assumed the travel rate doubled in the last 3 days before January 23, when we used previously reported incubation interval for severe acute respiratory syndrome (SARS), or when we changed the hyperparameters in our prior specification. ConclusionsOur estimated epidemiological parameters are higher than an earlier report using confirmed cases in Wuhan. This indicates the 2019-nCoV could have been spreading faster than previous estimates.

BackgroundMpox (formerly Monkeypox) virus has affected the lives of thousands of individuals both in endemic and non-endemic countries. Before the May 2022 outbreak, Mpox infections were sporadically endemic in Central and Western Africa, still research into Mpox has been limited and lacking epidemiological data. Thus, identification of potential risk factors to better understand who is at risk of being infected is critical for future prevention and control. ObjectiveTo synthesize comprehensive evidence on risk factors associated with human Mpox transmission both in endemic and non-endemic countries from inception to March 31, 2024. MethodsThe Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in conducting the systematic review. Electronic databases were searched. Two reviewers sifted the articles that were included in the review: firstly, by title and abstract, and secondly, by full text. We used the Newcastle-Ottawa Scale (NOS) to assess the risk of bias for included articles. Fixed or random effects meta-analysis were conducted when at least two studies reported odds ratios (OR), relative risks (RR), with 95% confidence intervals (CI). Heterogeneity was assessed using the I2 statistic and sensitivity analysis was also done. The study protocol has been registered under PROSPERO with ID: CRD42023459895. Results947 articles were identified from the database search and 31 articles were eligible to be included in the systematic review. The findings of the meta-analysis showed that interaction with infected animals (OR = 5.61, 95% CI = 2.83, 11.13), HIV (OR = 4.46, 95% CI = 3.27, 6.08), other STIs (OR = 1.76, 95% CI = 1.42, 2.91), sexual contact/activities (OR = 1.53, 95% CI = 1.13, 4.82), contact with an infected person (OR = 2.39, 95%CI = 1.87, 3.05), being identified as men who have sex with men (MSM) (OR = 2.18, 95%CI = 1.88, 2.51), and having multiple sexual partners Mpox (OR = 1.61, 95%CI = 1.24, 2.09), were associated with an increased risk of contracting Mpox. However, patients who were vaccinated against smallpox had a lower risk of Mpox infection (OR = 0.24, 95%CI = 0.11, 0.55). ConclusionThis study is the first meta-analysis on reported risk factors for Mpox. Our analysis demonstrated that certain factors were associated with increased risk of Mpox, whereas smallpox vaccination had a protective role against contracting Mpox. The study findings could facilitate future strategic public health planning and targeted intervention. Key messages of this articleO_ST_ABSWhat is already known on this topicC_ST_ABSO_LIMpox (monkeypox) is a zoonotic infectious disease of notable global public health importance due to recent outbreaks in non-endemic countries. C_LIO_LIPrior outbreaks of Mpox have been associated with travel to endemic areas in Western and Central Africa, contact with infected animals, and close contact with infectious lesions, particularly among household members. C_LI What this study addsO_LIThis study is the first meta-analysis on reported risk factors for Mpox. Our study findings add to the body of evidence on Mpox research efforts and could assist in future Mpox global strategic intervention and control. C_LIO_LIOur meta-analysis revealed a strong correlation between increased risk of Mpox infection, HVI, other STIs, physical and sexual contacts, and being identified as MSM. C_LIO_LIWhile HIV infection may be a risk factor for Mpox, Mpox lesions could also facilitate the transmission of HIV and other STIs. C_LI How this study might affect research, practice or policyO_LIThe results of this systematic review and meta-analysis provide evidence to support policymakers in future Mpox intervention and prevention in both endemic and non-endemic countries based on identified risk factors. C_LI

PurposeThe Gamma variant of SARS-CoV-2, first detected in travellers from Brazil, was found to have high transmissibility and virulence; following this finding, this paper aims to describe the epidemiology of Gamma cases in England from its first detection on 12 February 2021 to 31 August 2021. MethodsThe demographic analysis of Gamma cases was stratified by travel exposure. Travel-associated cases were further analysed by countries travelled from, stratified by categories set in place by the Red (highest risk countries), Amber, Green (lowest risk countries) travel policy, which was implemented from May to October 2021. ResultsThere were 251 confirmed Gamma cases detected in England in the study period. 35.1% were imported, 5.6% were secondary, and 29.5% were not travel associated. Early cases were predominantly travel-associated, with later cases likely obtained through community transmission. 51.0% of travel-related cases were travellers from Amber countries, and 40.2% had at least one Red country in their journey. ConclusionThe Gamma variant has not seen the same expansion as other variants such as Delta, most likely due to Delta out-competing community transmission of Gamma. Findings indicate the travel policy requiring quarantine for Red and Amber list travellers may have also contributed to preventing onward transmission of Gamma.

Background and AimsWolbachia are bacteria that inhibit dengue virus replication within the mosquito. A cluster-randomized trial found Wolbachia reduced virologically-confirmed dengue cases by 77% and previous models predicted Wolbachia to be highly cost-effective in Indonesia, Vietnam, and Brazil. in Colombia, Wolbachia was introduced in the Aburra Valley in 2015 and Cali in 2020. To inform decisions about future extensions, we performed economic evaluations of the potential expansion of Wolbachia deployments to 11 target Colombian cities. MethodsWe assembled quantities and the distribution by severity of reported dengue cases from Colombias national disease surveillance system and the health service provision registry (RIPS). An epidemiological panel of three experts estimated the shares of non-medical cases and adjustments for under-reporting and misclassifications. We determined costs (in 2020 US dollars) of treating dengue illness from the benchmark insurance tariff, RIPS data on treatment services per symptomatic dengue case, and the national government database for establishing insurance premiums. A cluster randomized trial quantified the effectiveness of Wolbachia against symptomatic dengue cases. ResultsProjecting impact over 10 years for Cali, we estimated a net health-sector savings of USD4.95 per person. We also estimated averting 369 disability-adjusted life years (DALYs) per 100,000 population. From a societal perspective, at 10 years Wolbachia deployment is expected to have highly favorable ConclusionsOver 10 years, Wolbachia is highly beneficial on economic grounds, and almost universally cost saving. That is, Wolbachias savings in health care costs alone would more than offset deployment costs nationally and in 9 target cities (those with adjusted annual dengue incidence at least 50/100,000 population). In these 9 target cities, Wolbachia would generate at least USD3.00 in benefits per dollar invested, giving substantial confidence that Wolbachia deployment would be cost-beneficial in Colombia.

BackgroundDengue is a major public health challenge and a growing problem due to climate change. The release of Aedes aegypti mosquitoes infected with the intracellular bacterium Wolbachia is a novel form of vector control against dengue. However, there remains a need to evaluate the benefits of such an intervention at a large scale. In this paper, we evaluate the potential economic impact and cost-effectiveness of scaled Wolbachia deployments as a form of dengue control in Vietnam - targeted at the highest burden urban areas. MethodsTen settings within Vietnam were identified as priority locations for potential future Wolbachia deployments (using a population replacement strategy). The effectiveness of Wolbachia deployments in reducing the incidence of symptomatic dengue cases was assumed to be 75%. We assumed that the intervention would maintain this effectiveness for at least 20 years (but tested this assumption in the sensitivity analysis). A cost-utility analysis and cost-benefit analysis were conducted. ResultsFrom the health sector perspective, the Wolbachia intervention was projected to cost US$420 per disability-adjusted life year (DALY) averted. From the societal perspective, the overall cost-effectiveness ratio was negative, i.e. the economic benefits outweighed the costs. These results are contingent on the long-term effectiveness of Wolbachia releases being sustained for 20 years. However, the intervention was still classed as cost-effective across the majority of the settings when assuming only 10 years of benefits. ConclusionOverall, we found that targeting high burden cities with Wolbachia deployments would be a cost-effective intervention in Vietnam and generate notable broader benefits besides health gains.

Background and objectiveIn Japan, routine administration of two-dose immunization for varicella to one-year-old children was introduced in October, 2014. The objective of this study was measurement of the effectiveness of routine two-dose immunization for varicella to onset and assessment of severity in a nursery school setting. MethodThe study period extended from the beginning of April, 2017 through March, 2018. The study area was Nursery school B in a city A. Subjects were 120 children in all. We analyzed vaccine efficacy (VE) as an observational study and assessed severity using Fishers exact test. We also assessed VE for severity using linear regression. Severity was defined as the length of school absence attributable to varicella infection. ResultsFor one dose or more, VE was 48.1% for all ages and 49.2% among children three years old and older. No significant VE was found. Vaccination using one dose or more can reduce severity significantly. Discussion and conclusionLow VE was found in a nursery school setting, although results were not significant. VE for severity was confirmed, but a second dose might not reduce severity.

BackgroundRespiratory Syncytial Virus (RSV) is one of the leading causes of acute respiratory infections and severe cases can lead to hospitalization or death. The epidemiology and health resource utilization of RSV infection in Colombia is not well understood. Given the recent availability of new RSV preventatives, this study estimated the economic burden of RSV in Colombia. MethodsThis cost-of-illness study employed a retrospective cohort design and bottom-up costing approach to estimate direct healthcare costs associated with RSV-related acute respiratory infections (ARI) across pediatric and adult populations. Administrative data from sentinel surveillance centers belonging to the National Epidemiological Surveillance System of the Colombian National Institute of Health, the database for the study of the Capitation Payment Unit database, and the Integrated Social Protection Information System were utilized to estimate RSV incidence, mortality, and healthcare costs. Costs were expressed in U.S. dollars (USD). ResultsA total of 264,744 RSV-related healthcare consultations were identified in 2019. The highest incidence was among infants under one year (61.8 per 1,000), while general mortality was highest in adults [≥]75 years (46.6 per 100,000), followed by infants (42.4 per 100,000). Total direct healthcare costs were estimated at $682.87 million (95% CI: $281.39-$1,084.35 million), with the largest share, contributed by individuals aged [≥]15 years. Among infants under one year, ICU patients had the highest average cost ($3,619), and hospitalization accounted for 49% of total spending, followed by ICU care (29%) and medications (8%). ConclusionsRSV poses a significant economic burden on Colombias healthcare system. These findings support the need for targeted prevention strategies and efficient resource allocation. Future research should incorporate indirect costs and long-term impacts. HighlightsO_LIThe study provides the first national-level estimate of the economic burden of RSV in Colombia using comprehensive administrative data. C_LIO_LIThe highest incidence and healthcare costs are observed in infants under one year and adults over 75, highlighting the need for targeted prevention strategies. C_LIO_LIThe findings can inform health policy and resource allocation decisions in Colombias universal healthcare system. C_LI

ImportanceThe increasing incidence and prevalence of dengue in Latin America is well-documented. Historical case-control series also highlight that secondary infections are a risk factor for severe dengue, hospitalization, and death. This has generated alarm among some sectors of the population and the scientific community. However, there has been no examination based on the results of randomized clinical trials that analyzes the risk of severe events in individuals with and without prior dengue infection. ObjectiveTo evaluate the association between serologically confirmed prior dengue infection (DVC) and the subsequent risk of DVC, severe dengue (DS), dengue hospitalization (DHOSP), dengue-related death, and all-cause mortality. MethodsA systematic review and meta-analysis were conducted following PRISMA guidelines. Studies were searched in PubMed, CINAHL, Medline, Cochrane Library, and Web of Science, including only phase III randomized clinical trials of vaccine efficacy with data on participants in the placebo groups and information on previous infections. Random-effects models were applied to calculate combined odds ratios (OR), and heterogeneity among studies was assessed. ResultsA total of four studies corresponding to three phase III clinical trials were included. Participants with prior infection had a lower likelihood of developing DVC during follow-up (OR: 0.85; 95% CI: [0.75; 0.98]; p=0.024) and the same risk of dengue hospitalization as those without prior dengue (OR: 1.18; 95% CI: [0.92; 1.53]; p=0.198). However, they had a higher rate of DS during follow-up (OR: 2.91; 95% CI: [1.23; 6.87]; p=0.015). No dengue-related deaths were observed in any of the clinical trials during follow-up. ConclusionsPrior dengue infection significantly reduces the risk of DVC and increases the risk of DS, although it does not significantly affect the risk of dengue hospitalization or dengue-related death during follow-up. The findings of this study highlight the need to reconsider the value of prior infection as an independent risk factor.

BACKGROUNDMigrants could be disproportionately affected by the COVID-19 pandemic, yet little is known so far of the epidemiology of the disease among them, especially in low- and middle-income countries. OBJECTIVETo describe the epidemiology of suspect cases of COVID-19 in migrants in transit and asylum seekers in Mexico, and to compare their characteristics with those of non-migrants. METHODSThis was a secondary analysis of information from the surveillance system of Mexico from January 1 to May 3 2020, identifying persons from the main sending countries of mixed migrant flows in Mexico (Central America, the Caribbean, Venezuela and African countries), in northern and southern Mexican border states. We compared the demographic and clinical characteristics, risk conditions, and epidemic curves for migrants and non-migrants. Also, we estimated the cumulative incidence for non-migrants, and for migrants in two scenarios defined by different estimations of their population size. RESULTSMigrants were on average younger, had less accompanying risk conditions, and a lower percentage of suspect cases tested positive for COVID-19. The odds of hospitalization were lower among migrants, but the difference disappeared after adjusting by age, gender and underlying risk conditions. The cumulative incidence ratios comparing migrants with non-migrants were 6.12 (CI95% 4.75,7.77) for the first scenario, and 1.49 (CI95% 1.15,1.89) for the second scenario. CONCLUSIONMigrants and asylum seekers in Mexico are at increased risk for infectious respiratory diseases, and could be disproportionately affected by COVID-19. It is important to continue monitoring the situation, with more detailed information about migration status, living conditions and other determinants of migrants health.

BackgroundThe Gonococcal Isolate Surveillance Project (GISP) is a sentinel surveillance system to monitor the spread of antimicrobial-resistant (AMR) gonorrhea. Under GISP surveillance strategy, urethral isolates are utilized for monitoring the spread of the resistance and the obtained estimates are used for informing the gonorrhea treatment guidelines. In 2017, the enhanced Gonococcal Isolate Surveillance Project (eGISP) was established which also includes the non-urethral isolates. Using eGISP estimates for informing the gonorrhea treatment guidelines is an alternative surveillance strategy that can be used. MethodsWe utilized our previously developed continuous-time agent-based model of gonorrhea transmission among the US men who have sex with men (MSM) population and calculated the total number of discounted quality-adjusted life years (QALYs) and total discounted costs over 25 years under GISP and eGISP surveillance strategy. We also evaluated cost-effectiveness of both surveillance strategies. ResultsUnder GISP surveillance strategy, $2.9M (95% uncertainty interval: $23,131, $9.4M) were saved and 31.3 (0, 134.9) QALYs were gained in the simulated cohort of 10,000 US MSM over 25 years compared to no surveillance. Performing eGISP surveillance strategy instead would result in additional $57,449 (-$100,914, $221,663) saved and 0.59 (-0.79, 2.5) QALYs gained. ConclusionThe current GISP surveillance strategy significantly reduces the costs and increases the health benefits compared to no surveillance. However, switching from the current strategy to eGISP strategy is cost saving and should be considered in order to improve the population health and reduce the financial burden of gonorrhea.

We aimed to estimate the effectiveness of CYD-TDV in preventing symptomatic dengue cases during a campaign targeting individuals aged 15-27 years in selected municipalities in Parana, Brazil. Additionally, we examined whether a history of dengue, as recorded by the surveillance system, modified the vaccines effectiveness. MethodsWe conducted a case-cohort analysis comparing the frequency of vaccination, with at least one dose of CYD-TDV, in individuals confirmed to have dengue by RT-PCR, identified by the surveillance system during 2019 and 2020, with the vaccination coverage in the target population. Moreover, with a case-control design using weighted controls, we assessed the history of dengue as a modifier of the vaccines effectiveness. The analyses were performed using a logistic random-effects regression model, with data clustered in municipalities and incorporating covariates such as the incidence of dengue before the campaign, age, and sex. ResultsDuring the study period, 1,869 cases of dengue were identified. The vaccination frequency among these cases was significantly lower than the overall vaccination coverage of the participating municipalities (50.4% vs. 57.2%, respectively; adjusted odds ratio: 0.79; 95% confidence interval: 0.72-0.87). In individuals with a history of dengue, vaccination was more than 70% effective in reducing the incidence of dengue. However, vaccination was not associated with significantly reducing the overall dengue case risk in individuals without a history of dengue. ConclusionVaccination significantly decreased dengue cases in the target population. The case-control design suggested that this reduction was primarily driven by the benefits seen in individuals with a history of dengue. Previous dengue diagnosis recorded by epidemiological surveillance could serve as a criterion for the recommendation of CYD-TDV, especially in endemic regions with limited serological testing facilities.

Cervical cancer is one of the most prevalent cancer diseases in women caused by persistent infection with one of 13 sexually transmitted high-risk human papillomavirus (HPV) types. Vaccination can significantly reduce the prevalence of this burden in low-middle income countries. However, HPV vaccination is not included in the Tunisian immunization program. Since the economic evaluation of HPV vaccines is crucial to inform public-health decisions, the World Health Organization (WHO) recommends that a cost-effectiveness analysis of HPV vaccination is conducted before nationwide introduction. This study aimed to conduct a cost-effectiveness analysis of incorporating different HPV vaccines into the national immunisation schedule in Tunisia. The potential health and economic impacts of human papillomavirus (HPV) vaccination were evaluated through comparative modelling analysis using two published static models (UNIVAC and Papillomavirus Rapid Interface for Modelling and Economics (PRIME)). Academic literature and anecdotal evidence were included on the demographic variables, cervical cancer incidence and mortality, treatment costs, vaccine delivery costs and other model parameters. The cost of vaccination, treatment costs saved, net costs, cases and deaths averted, life years saved, disability-adjusted life years (DALYs) prevented, and incremental cost-effectiveness ratios were predicted and reported as primary outcomes. The incremental cost-effectiveness ratios (ICERs) were estimated per disability-adjusted life years (DALYs) averted using the cost-effectiveness threshold (CET) defined by the World Health Organisation (WHO). All HPV vaccines were very cost effective (with every disability-adjusted life-year averted costing less than the cost-effectiveness threshold). The analyses were done from a health system and societal perspective. Despite model differences, the PRIME and UNIVAC models yielded similar vaccine-impact estimates.

BackgroundDengue poses a significant public health challenge in Peru and other endemic countries worldwide. While severe dengue is known to be associated with secondary infection at the individual level, the factors that elevate the risk of severe dengue at the population level remain poorly understood. This study leverages over 16 years of secondary data from a Peruvian dengue surveillance system to assess which type of serotype-specific circulation is associated with an increased risk of cumulative incidence of severe dengue or dengue with warning signs (SD-DWS). MethodologyThis is a retrospective analysis of secondary data using the Peruvian Ministry of Health databases of dengue cases and serotyping. A mixed negative binomial regression model for repeated measures over time was employed to estimate the association between the cumulative incidence of reported SD-DWS cases per 100,000 inhabitants and serotype-specific circulation. Crude and adjusted incidence ratios (IRR) were estimated. Principal findingsThe study analyzed data from 2007 to 2022 across 19 regions of Peru, totaling 304 region-years. Data from nearly 58,000 serotype identification reports and 57,966 cases of SD-DWS were analyzed. The regions with most cumulative incidence of SD-DWS per 100,000 inhabitants during 2007 to 2022 were Madre de Dios (3859), Loreto (1518), Ucayali (1492), Tumbes (1335), and Piura (722). The adjusted model revealed a higher risk of cumulative incidence of SD-DWS when there was specific circulation of DENV-123 (aIRR 7.57 CI 4.00 - 14.31), DENV-12 (aIRR 4.66 CI 2.57 - 8.44), DENV-23 (aIRR 3.55 CI 1.75 - 7.21), or when there was circulation of DENV-2 alone or co-circulating with other serotypes (aIRR 27.7 CI 15.46 -49.63). ConclusionsCirculation of DENV-2 was associated with higher average incidence rate ratios of SD-DWS. Author summaryWe investigated how the circulation of different dengue virus (DENV) serotypes are associated with the incidence of severe dengue and dengue with warning signs in Peru, a country where dengue is endemic. We analyzed 16 years of data from the dengue surveillance system, including nearly 58,000 serotype identification reports and 57,966 cases of severe dengue and dengue with warning signs. We found that regions with specific circulation of DENV-2, either alone or in combination with other serotypes, had higher incidence rates of severe dengue and dengue with warning signs. Our findings highlight the importance of monitoring DENV serotype circulation to manage and prevent severe dengue, especially in regions where DENV-2 is prevalent.

Backgroundmpox (formerly Monkeypox) virus (MPXV) was considered a rare zoonotic disease prior to May 2022, when a global epidemic of cases in non-endemic countries led to the declaration of a Public Health Emergency of International Concern. Previously, mpox infection was associated with symptoms similar to smallpox, although substantially less severe, including fever, an extensive characteristic rash and swollen lymph nodes. AimElucidating the origin and molecular characteristics of the virus circulating in the Republic of Ireland in the period between May and November 2022. MethodsWhole-genome sequencing of all MPXV cases (80%; n=178/219) analysed against sequences from public databases (n=2695). Bayesian approaches were used to infer the divergence time between sequences from different subclades and transmission events involving different countries. ResultsThe circulating virus belonged to the clade IIb B.1 lineage and, notably, the presence of twelve separable and highly-supported subclades consistent with multiple introductions into the country. Such a hypothesis of multiple importation events was supported further by the estimation of the time to the divergence of subclades. Additionally, inferred MPXV transmissions involving different countries and continents were indicative of an extended international spread. The analysis of the mutations in the Irish sequences revealed 93% of the mutations were from cytosine to thymine (or from guanine to adenine), leading to a high number of non-synonymous mutations across the subclades. ConclusionIn the context of extremely high national sequencing coverage, we provide new insights into the international origin and transmission dynamics supporting multiple introductions into the Republic of Ireland. Conflict of InterestsNone to declare.

BackgroundThe dengue virus, transmitted by Aedes mosquitoes, causes an estimated 100-390 million infections annually. With no treatment available, mitigation and prevention involves reducing mosquito breeding and limiting feeding opportunities. Due to changing climate conditions, Aedes mosquitoes are increasingly established in Europe causing more local cases. In this context, understanding population knowledge, attitudes, and practices in areas where dengue is an emerging threat is necessary for effective prevention. MethodsWe designed a survey collecting knowledge, attitudes, and beliefs about dengue in the general population, leveraging the French and Italian 2024 cohorts of the participatory surveillance network InfluenzaNet. Responses from 2,500 participants in mainland France and 404 in Italy were pooled for the analysis. Via bias-adjusted (i.e., age, sex and education) logistic and ordinal regression, we examined determinants of awareness of dengue and knowledge of its characteristics, adoption of preventive measures, and vaccination willingness. ResultsOver 91% of included participants were aware of dengue circulating in Europe or the rest of the world, and 16% had sought information. Seeking information and concerns about dengue were significant determinants of knowledge, preventive measures adoption, and vaccination willingness. Better knowledge of dengue characteristics, vaccination status, residence in areas with detected autochthonous cases, and presence of comorbidities were associated with greater adoption of preventive measures. Living in rural areas was associated with lower knowledge and vaccination willingness but higher adoption of preventive measures. Finally, 0.4% of participants had received a dengue vaccine (not recommended to the general population), and 54.6% would accept a vaccine if offered. Low-risk perception was the most common reason for refusal. ConclusionsOur study highlights the interplay between knowledge, attitudes, behaviours, socio-demographic, individual and contextual characteristics of the participants related to dengue in a non-endemic context. Information search and concern levels correlated with knowledge, adoption of measures, and willingness to vaccinate, while, knowledge was associated with the adoption of preventive measures, alongside perceived efficacy, local epidemiological context, occupation of participants, sex, vaccination and symptom history. Targeted communication strategies accounting for these factors are essential to enhance preparedness and outbreak prevention in regions where dengue represents an emerging threat.

While the novel coronavirus continues to spread worldwide, the reported incubation period has varied between studies and is imprecise due to limited data. A literature search with certain selection criteria was conducted on May 30, 2020. In total, sixty-four articles were included, and 854 individual-level data were extracted from 30 studies for pooled analysis. Of these studies, 72% of them reported a median or mean incubation period of 4-7 days, while our estimated median was 4.9 days (95% confidence interval [CI]: 4.6-5.2). However, the inclusion of 81 asymptomatic and presymptomatic patients, as well as 31 cases with incubation periods exceeding 14 days, led to our estimation of 97.5 th percentile with 19.3 days (95% CI: 17.4-21.4), beyond the currently suggested 14-day quarantine period. Therefore, we appeal to prolong the quarantine duration, especially for areas that have insufficient testing resources, to protect susceptible populations from being infected. Article Summary LineThis article reviewed the COVID-19 studies involving incubation period and provided pooled estimation based on available data from these studies.The result showed that our estimated median incubation period is consistent with the estimates of formal studies but the 97.5 percentile is larger than ever on account of including a number of asymptomatic and presymptomatic patients.These finds suggested that we should properly prolong the isolation or quarantine period in order to identify more patients with longer incubation period and those without any symptoms.

IntroductionIn August 2024, the World Health Organization (WHO) declared a public health emergency due to the rapid spread of mpox in African and beyond. International travel controls (ITCs), such as health screening and viral testing, could help avoid/delay the global spread of the monkeypox virus (MPXV), fostering preparedness and response efforts. However, it is not clear whether the viral tests at immigration are sufficient to avoid importation of MPXV and which samples should be used on the viral tests. MethodsWe conducted a simulation study using epidemiological and viral load data to assess the effectiveness of health screening and PCR testing at immigration. This provides estimates of the proportion of infected travelers identified with this policy. Viral dynamics models were used to estimate false-negative rates of PCR tests with different detection limits according to testing regimens at three different sites: oropharynx, saliva, and rectum. We also simulated the effects of these border control methods on the recommended duration of a monitoring period for travelers from mpox-affected regions, during which individuals would self-monitor for symptoms and practice cautionary behavior. ResultsOur results show that the combination of health screening and PCR testing of saliva swabs under an endemic scenario identify only 74% of MPXV infected travelers. The use of rectal swabs combined with health screening allows the identification of a marginally larger share of infected travelers (79%) compared to saliva swabs. A similar identification rate could be achieved by using more sensitive PCR tests (detection limit [DL]: 10 copies/mL vs. 250 copies/mL used in our baseline analysis). We estimated that travelers from mpox-affected areas should monitor themselves and practice precautionary behavior for 16 days. ConclusionHealth screening and PCR testing at immigration are likely to miss a significant proportion of MPXV-infected travelers, thus a lengthy quarantine period would be required to prevent onward local transmission. Careful consideration on other factors such as economic costs and likelihood of widespread local outbreak will need to be weighed against the adoption of these measures to prevent local mpox transmission given MPXV transmissibility and severity.

ObjectiveTo understand the incidence of varicella in a suburban area of Pudong New District, Shanghai, and provide a scientific basis for relevant prevention and control work. MethodsDescriptive epidemiological methods were used to describe and analyze all reported varicella cases with the residential address in a suburban area from 2011 to 2022. SPSS software was used for statistical processing, and the chi -square test was used for the comparison of rates. ResultsA total of 1,708 varicella cases were reported in a suburban area from 2011 to 2022, with an average incidence rate of 107.72 per 100,000. The incidence showed obvious seasonal changes, presenting a "bimodal distribution", with peaks from May to July and in November. The onset age was concentrated in the 1 - 14 age group, accounting for 54.27% of all cases. The affected population was mainly students (accounting for 37.30%), kindergarten children (accounting for 15.11%) and scattered children (accounting for 13.00%), and there were more males than females. ConclusionStudents and kindergarten children are the key populations for varicella prevention and control. Epidemic monitoring should be strengthened during the peak incidence season every year, and the work of varicella vaccination and booster vaccination should be improved to comprehensively reduce the incidence of varicella.

BackgroundMonkeypox cases keep soaring in non-endemics countries and areas in the last few months, leading to the WHO declaring a Public Health Emergency of International Concern. The ongoing and coming festivals, parties and holidays gathering events are causing increased concerns about possible outbreaks. MethodsWe considered a hypothetical metropolitan city and modelled the transmission of monkeypox virus in humans in high-risk (HRG) and low-risk groups (LRG) using a Susceptible-Exposed-Infectious-Recovered (SEIR) model and incorporated gathering events. Model simulations assessed how the current vaccination strategy combined with other public health measures can contribute to mitigating or halting outbreaks from mass gathering events. ResultsThe risk of a monkeypox outbreak remains high on the occasion of mass gathering events in the absence of public health control measures. However, the outbreaks can be well controlled by cutting off transmission by isolating confirmed cases and inoculating their close contacts. Also, Post Exposure Prophylaxis is more effective for containment in the summer gatherings than a broad vaccination campaign in HRG, considering the time needed for developing the immune response and the availability of vaccine. The number of attendees and effective contacts during the gathering are the factors that need more attention by public health authorities to prevent a burgeoning outbreak. Moreover, restricting attendance through vaccination requirements can help secure mass gathering events. ConclusionGathering events can be made safe with some restrictions of either the number and density of attendees in the gathering, or vaccination requirements. The ring vaccination strategy inoculating close contacts of confirmed cases may not be enough to prevent potential outbreaks, however, mass gatherings can be rendered safe if that strategy is combined with public health measures, including rigorous contact tracing, testing, identifying and isolating cases. Compliance of the community and promotion of awareness are also indispensable to the containment.

ObjectivesRemoval of zero-COVID restrictions in China led to a surge in COVID-19 cases. In response, countries imposed restrictions on Chinese travelers. However, border policies may not provide substantial benefits and their assessment depends on accurate prevalence data. MethodsWe analyzed quarantines and testing sufficient to prevent additional in-country transmission for February 13-19, 2023 based on World Health Organization (WHO) and self-reported infection rates to estimate prevalence. ResultsHere we have shown that self-reported prevalence data indicated more stringent border restrictions compared to WHO-published prevalence statistics. No travel restrictions were required for Singapore for infections to not be greater than in complete border closure, while a 1-day quarantine, 2-day quarantine, and a 3-day quarantine were indicated for England, Germany, and Scotland respectively. A 10-day quarantine, 11-day quarantine, and 13-day quarantine were required for Italy, Japan, and France, respectively, to prevent an increase in the number of within-country infections due to travel, while South Korea required a complete border shutdown. ConclusionsOur results demonstrated the necessity for accurate and timely reporting of pandemic statistics to prevent an increase in viral spread. Through the minimum-quarantine analysis, countries can use science to determine policy, minimize international friction, and improve the cost-efficiency of interventions.