Epidemiology and Infection最新文献

This study aims to estimate the prevalence of human papillomavirus (HPV) infection and describe its genotype distribution in MSM in Hong Kong. In this longitudinal study on Chinese MSM, multi-anatomic site self-sampling and testing for HPV, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) were performed following survey completion at baseline and one-year follow-up. Overall, 41% (288/701) of MSM completed self-sampled HPV testing. HPV positivity was 29% (78/270) and 33% (42/127) at any anatomic site at baseline and follow-up timepoints, respectively. By anatomic site, HPV positivity was 26%-30%, 2%-4% and 0%-1% from rectal, penile, and pharyngeal specimens, respectively. The incidence of HPV infection was 21.2/100 and 18.9/100 person-years at any anatomic site and rectal site, respectively. Among 109 successfully genotyped samples, the most prevalent were HPV 6 (17%) and HPV 11 (16%), of which 60% of the genotyped samples were vaccine-preventable. Group sex engagement and less frequent condom use were positively associated with HPV infection (P<0.05). The HPV prevalence and incidence in MSM in this study is lower than in Western countries, and low-risk HPV genotypes are more prevalent. The high proportion of vaccine-preventable HPV subtypes underscores the importance of HPV vaccination in preventing infections in MSM.

Leptospirosis remains a significant occupational zoonosis in New Zealand, and emerging serovar shifts warrant a closer examination of climate-related transmission pathways. This study aimed to examine whether total monthly rainfall is associated with reported leptospirosis in humans in New Zealand. Poisson and negative binomial models were developed to examine the relationship between rainfall at 0-, 1-, 2-, and 3-month lags and the incidence of leptospirosis during the month of the report. Total monthly rainfall was positively associated with the occurrence of human leptospirosis in the following month by a factor of 1.017 (95% CI: 1.007-1.026), 1.023 at the 2-month lag (95% CI:1.013-1.032), and 1.018 at the 3-month lag (95% CI: 1.009-1.028) for every additional cm of rainfall. Variation was present in the magnitude of association for each of the individual serovars considered, suggesting different exposure pathways. Assuming that the observed associations are causal, this study supports that additional human cases are likely to occur associated with increased levels of rainfall. This provides the first evidence for including rainfall in a leptospirosis early warning system and to design targeted communication and prevention measures and provide resource allocation, particularly after heavy rainfall in New Zealand.

Scrub typhus is a mite-borne infection, largely affecting rural populations in many parts of Asia. This cohort study explored socio-demographic, behavioural, and spatial risk factors at different levels of endemicity. 2206 rural residents from 37 villages in Tamil Nadu, South India, underwent a questionnaire survey and blood sampling at baseline and annually over 2 years to detect sero-conversion. Satellite images were used for visual land use classification. Local sero-prevalence was estimated using 5602 baseline blood samples.Two hundred and seventy cases of seroconversions occurred during 3629 person-years (incidence rate 78/1000, 95%CI 67, 91). Older age was associated with scrub typhus in crude but not in multivariable analysis adjusting for socio-economic factors. By contrast, the increased risk in females compared to males (RR 1.4) was unaffected by adjusting for confounders. In multivariable analysis, agricultural and related outdoor activities were only weakly associated with scrub typhus. However, agricultural activities were strongly associated with scrub typhus if local sero-prevalence was low, but not if it was high. Females were at a higher risk than males in high-prevalence areas but not in low-prevalence areas. To conclude, agricultural activities were not strongly associated with scrub typhus. Transmission within human settlements may predominate in highly endemic settings.

Bloodstream infections (BSIs) caused by Candida are a significant cause of morbidity and mortality. Geographical variations exist in the epidemiology of candidemia, with a paucity of data in the many low- and middle-income countries. We performed a retrospective study of candidemia from 2017 to 2022 at a 289-bed teaching hospital in the Dominican Republic (DR). A total of 197 cases were reviewed. Overall mortality rate was 49.2%. Age and vasopressor use were associated with mortality. The most prevalent Candida species were C. tropicalis and C. parapsilosis. C. albicans was 12% resistance to amphotericin B. These findings underscore the importance of understanding local epidemiology and may help inform empiric therapy and the development of treatment guidelines in the DR.

Dengue is an arboviral infection that poses a substantial public health concern, with early diagnosis being a critical factor in effective management. However, limited diagnostic expertise in developing countries contributes to the under-reporting of dengue cases. This review compares the accuracy of rapid diagnostic tests (RDTs) and the tourniquet test (TT) in diagnosing dengue fever (DF) in non-laboratory-based settings. Relevant original articles on the use of RDTs and TT for dengue diagnosis were retrieved from PubMed, Scopus, and ScienceDirect. The STARD and QUADAS-2 tools were employed to evaluate the methodological quality of the included studies. Search terms included combinations of 'fever', 'dengue', and '"diagnosis'. In total, 23 articles were eligible for inclusion. The RDTs demonstrated mean sensitivities and specificities of 76.2% (SD = 13.8) and 91.5% (SD = 10.3), respectively, while the TT showed mean sensitivity and specificity values of 48.6% (SD = 24.9) and 79.5% (SD = 14.9), respectively. Overall, RDTs exhibited superior diagnostic performance compared to the TT. Our findings suggest that the TT is an inadequate stand-alone diagnostic tool for dengue. RDTs should be prioritized for dengue diagnosis in resource-limited settings. However, in situations where RDTs are unavailable, the TT may serve as a supplementary option.

The rapid evolution of SARS-CoV-2 has led to the emergence of variants of concern (VOCs) characterized by increased transmissibility, pathogenicity, and resistance to neutralizing antibodies. Identifying these variants is essential for guiding public health efforts to control COVID-19. Although whole genome sequencing (WGS) is the gold standard for variant identification, its implementation is often limited in developing countries due to resource constraints. In Bolivia, genomic surveillance is a challenge due to its limited technological infrastructure and resources. An RT-qPCR-based strategy was designed to address these limitations and detect the mutations associated with VOCs and variants of interest (VOIs). The multiplex RT-qPCR commercial kits Allplex^TM Master and Variants I (Seegene®) and the ValuPanel^TM (Biosearch®) were used to target mutations such as HV69/70del, E484K, N501Y, P681H, and K417N/T. They are characteristic of the Alpha (B.1.1.7), Beta (B.1.531), Gamma (P.1), Omicron (B.1.1.529), Mu (B.1.621), and Zeta (P.2) variants. A total of 157 samples collected in Cochabamba from January to November 2021 were evaluated, identifying 44 Gamma, 2 Zeta, 20 Mu, and 10 Omicron were identified. The strategy's effectiveness was validated against WGS data generated with Oxford Nanopore^TM technology, showing a concordance rate of 0.96. This highlights the value of the RT-qPCR strategy in guiding the selection of samples for WGS, enabling broader detection of new variants that cannot be identified by RT-qPCR alone.

Limited studies on the seasonality of pharyngitis and tonsillitis suggest subtle but unexplained fluctuations in case numbers that deviate from patterns seen in other respiratory diagnoses. Data on weekly acute respiratory infection diagnoses from 2010-2022, provided by the Polish National Healthcare Fund, included a total of 360 million visits. Daily mean temperature and relative humidity were sourced from the Copernicus Climate Data Store. Seasonal pattern was estimated using the STL model, while the impact of temperature was calculated with SARIMAX. A recurring early-summer wave of an unspecified pathogen causing pharyngitis and tonsillitis was identified. The strongest pattern was observed in children under 10, though other age groups also showed somewhat elevated case numbers. The reproductive number of the pathogen is modulated by warmer temperatures; however, summer holidays and pandemic restrictions interrupt its spread. The infection wave is relatively flat, suggesting either genuinely slow spread or multiple waves of related pathogens. Symptomatic data unambiguously demonstrate existence of pathogens of quite distinct characteristics. Given its consistent year-to-year pattern, identifying these potential pathogens could enhance respective treatment, including antibiotic therapy.

Despite the appeal of screening travellers to prevent case importation during infectious disease outbreaks, evidence shows that symptom screening is largely ineffective in delaying the geographical spread of infection. Molecular tests offer high sensitivity and specificity and can detect infections earlier than symptom screening, suggesting potential for improved outcomes. However, they were used to screen travellers for COVID-19 with mixed success. To investigate molecular screening's role in controlling COVID-19, and to quantify the effectiveness of screening for future pathogens of concern, we developed a probabilistic model that incorporates within-host viral kinetics. We then evaluated the potential effectiveness of screening travellers for influenza A, SARS-CoV-1, SARS-CoV-2, and Ebola virus. Even under highly optimistic assumptions, we found that the inability to detect recent infections always limits the effectiveness of traveller screening. We quantify this fundamental limit by proposing an estimator for the fraction of transmission that is preventable by screening. We also demonstrate that estimates of ascertainment overestimate reductions in transmission. These results highlight the essential role that quarantine and repeated testing play in infectious disease containment. Furthermore, our findings indicate that improving screening effectiveness requires the ability to detect infection much earlier than current state-of-the-art molecular tests.

Anonymous online surveys using financial incentives are an essential tool for understanding sexual networks and risk factors including attitudes, sexual behaviors, and practices. However, these surveys are vulnerable to bots attempting to exploit the incentive. We deployed an in-person, limited audience survey via QR code at select locations in North Carolina to assess geolocation application use among men who have sex with men to characterize the role of app usage on infection risk and behavior. The survey was unexpectedly posted on a social media platform and went viral. Descriptive statistics were performed on repeat responses, free-text length, and demographic consistency. Between August 2022 and March 2023, we received 4,709 responses. Only 13 responses were recorded over a 6-month period until a sharp spike occurred: over 500 responses were recorded in a single hour and over 2,000 in a single day. Although free-text responses were often remarkably sophisticated, many multiple-choice responses were internally inconsistent. To protect data quality, all online surveys must incorporate defensive techniques such as response time validation, logic checks, and IP screening. With the rise of large language models, bot attacks with sophisticated responses to open-ended questions pose a growing threat to the integrity of research studies.

The Secretary of the US Department of Health & Human Services, Robert Kennedy Jr is leading a political agenda against vaccination. This is undermining the delivery of life-saving vaccination programmes and provision of evidence-based information on the safety and effectiveness of vaccines for the public and health professionals. Inconsistent and conflicting messaging between health practitioners and government health agencies erodes trust in public health programmes, creating a vacuum which is often filled with mis/disinformation that presents severe consequences for families. Due to the transnational spread of diseases, we consider the implications of events in the US for routine childhood vaccination programmes in the UK. Public health agencies across the world need to be 'Kennedy ready'; pragmatic steps must be taken to mitigate threats posed to vaccine confidence and the control of vaccine preventable diseases.