Travel Medicine and Infectious Disease

The panzootic highly pathogenic avian influenza (HPAI) H5N1 virus has now been detected on the Australian mainland, with incursions from the sub-Antarctic region posing an increasing threat to domestic wildlife and poultry populations. Our study aimed to predict the risk of HPAI H5N1 poultry outbreaks across Australia at the local government area (LGA) level using a range of influential risk factors. We first used a Maximum Entropy (MaxEnt) model to estimate the environmental suitability for HPAI H5N1 occurrence across Australia. The resulting suitability layer was then integrated with five additional predictor layers, including abundance data for two Southern Ocean wild birds, one of which has introduced HPAI H5N1 into Australia; abundance data for 28 native Australian wild birds; native bird flyways across Australia; Australian chicken density; and poultry farm density. The six layers were aggregated and averaged to generate an HPAI H5N1 risk map for poultry outbreaks across Australian LGAs. Although most incursions have occurred in Western Australia (WA) and South Australia (SA), we identified New South Wales (NSW) and Victoria (VIC) as having the highest predicted risk of HPAI H5N1 poultry outbreaks. Additional high-risk areas were identified in WA, SA, and Tasmania (TAS). In contrast, the Northern Territory (NT) and large parts of Queensland (QLD), WA, and SA were predicted to be at low risk. These findings provide a spatially explicit framework to support targeted surveillance, preparedness, and biosecurity measures aimed at mitigating the impact of future HPAI H5N1 outbreaks in Australian poultry.

Background Typhoid fever, despite being preventable, places a significant burden on low- and middle-income countries. Although understanding of the global burden of typhoid fever is improving, evidence on the economic burden of typhoid fever remains limited. This study estimated the cost of illness associated with typhoid fever in the Kisantu Health Zone of the Democratic Republic of the Congo. Methods A standardized patient-level survey was conducted to estimate the cost of illness associated with typhoid fever. Patients with typhoid fever were recruited from eight health centers and one hospital. Multiple interviews were conducted to capture the full costs incurred throughout the illness episode. Results From March 2022 to March 2025, among 140 enrolled patients, 91 were classified as mild cases and 49 as severe cases with suspected intestinal perforation/peritonitis. The mean cost of illness for typhoid fever was US$ 108 (95% CI: US$ 90-127) for mild cases and US$ 579 (95% CI: US$ 506-663) for severe cases, indicating that costs for severe cases were more than five times higher than those for mild cases. All direct medical costs were paid out-of-pocket by patients, and no patients were covered by insurance or government subsidies. Conclusions Typhoid fever imposes a substantial economic burden in the Democratic Republic of the Congo. These findings provide important evidence for evaluating the economic value of typhoid conjugate vaccine introduction in high-burden settings.

U.S.-bound refugees from sub-Saharan Africa arrive from countries where parasitic infections are highly endemic (including hookworm, ascariasis, trichuriasis, strongyloidiasis, schistosomiasis, and malaria). These infections are rare in the United States and may be underdiagnosed or misdiagnosed. This evaluation examined costs and health outcomes of four alternatives: 1) 'Overseas Presumptive Treatment', 2) Domestic Screening and Treatment', 3) 'Domestic Presumptive Treatment', and 4) 'No Program' using decision trees terminating in Markov transition state models. The current program, 'Overseas Presumptive Treatment', is the least expensive and most effective alternative with baseline parameter estimates. Relative to 'No Program', the net cost per QALY gained for 'Overseas Presumptive Treatment' has 95% uncertainty interval (UI) from cost-saving to $52,000, 'Domestic Screening and Treatment': 95% UI: $6,700-$580,000, and 'Domestic Presumptive Treatment': 95% UI $12,000-$1.29 million. Even using conservative parameter assumptions, overseas presumptive treatment is cost-effective and reduces the burden of parasitic infections among sub-Saharan refugees.

ABSTRACT Background Cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) may involve parasite dissemination from the primary skin lesion to clinically healthy mucosal sites, a process potentially relevant to the development of mucosal leishmaniasis. Parasite burden and Leishmania RNA Virus 1 (LRV1) have been proposed as factors influencing parasite persistence, dissemination, and treatment response. We investigated whether parasite load and LRV1 detection in skin lesions were associated with Leishmania in clinically healthy nasal mucosa and, in a subset of patients, with therapeutic outcome. We also assessed the relationship between LRV1 and parasite load. Methodology/Principal findings We conducted a prospective observational cohort study. Parasite load and LRV1 were assessed by qPCR in skin lesions and clinically healthy nasal mucosa from patients with localized cutaneous leishmaniasis in Rondonia, Brazilian Amazon. Samples were evaluated before treatment (D0), at the end of treatment (D20), and during follow-up (D90-180). Among 178 patients screened, CL was confirmed in 113. LRV1 was detected in skin lesions in 34.51% of patients and in nasal mucosa in 24.13%. Leishmania DNA was detected in clinically healthy nasal mucosa in 12.38% of patients. LRV1 detection in the skin lesion was associated with detection of Leishmania in the nasal mucosa. Higher parasite loads were observed in more recent lesions. Among patients evaluated for therapeutic outcome, higher parasite load before treatment was associated with treatment failure and was the factor most strongly associated with an unfavorable response in multivariate analysis. Conclusions/Significance LRV1 detection in cutaneous lesions was associated with Leishmania in clinically healthy nasal mucosa, although the significance of this association and its relationship with parasite dissemination require further investigation. In contrast, parasite burden was associated with therapeutic outcome, with higher pre-treatment loads observed in patients who experienced treatment failure. The absence of an association between LRV1 and parasite load suggests that these two parameters may provide distinct information regarding parasite detection at mucosal sites and therapeutic response.

Typhoid fever remains a significant burden in low- and middle-income countries (LMICs). The World Health Organization recommends incorporating typhoid conjugate vaccines (TCVs) into the routine immunization programs of typhoid-endemic countries. Although TCV has been shown to be safe, well tolerated, and effective, evidence on its delivery costs in African settings remains limited. This study provides economic evidence on the cost of implementing TCV catch-up campaigns. This retrospective provider-perspective costing study evaluated TCV catch-up vaccination campaigns conducted in the Asante-Akim North District of Ghana and the Kisantu Health Zone of the Democratic Republic of the Congo (DRC). The campaigns targeted children aged 9 months to 15 years. An incremental costing approach was used, and a Microsoft Excel-based tool was developed to estimate costs. The total number of vaccinated individuals was 54,814; 10,052 in Ghana and 44,762 in the DRC. The financial cost per fully immunized person (FIP), including vaccine and vaccination supply costs, was estimated at US$ 5.78 in Ghana and US$ 5.47 in the DRC. The corresponding economic costs were estimated at US$ 6.09 in Ghana and US$ 5.89 in the DRC. Vaccine procurement and vaccination supplies represented the largest cost component, accounting for US$ 2.76 per FIP in Ghana and US$ 2.39 per FIP in the DRC, followed by service delivery and service delivery support activities. This study provides empirical estimates of the financial and economic costs of TCV catch-up campaigns in Ghana and the DRC. These findings provide country-specific evidence to inform planning, budgeting, economic evaluation, and policy decisions regarding future TCV introduction in typhoid-endemic settings.

The radical cure of Plasmodium vivax requires treatment of the dormant liver stages with either primaquine or tafenoquine but is constrained by the risk of severe hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. A revised case-management package, New Primaquine Treatment (NPT), was designed to support safe radical cure in Indonesia, and included G6PD screening, targeting high dose primaquine and early clinical review. A decision-tree model was constructed using individual-level data from a study, that treated patients with 7mg/kg primaquine according to their G6PD activity: primaquine administered over 7 days (G6PD normal individuals), 14 days (individuals with intermediate G6PD deficiency), or 8 weeks (if severely G6PD deficient). The model incorporated costs, adverse events, and P. vivax recurrence over a six-month time horizon. A business-as-usual comparator was created using historical P. vivax recurrence data for Indonesia overall and the three provinces separately. The primary outcome was disability-adjusted life-years (DALYs) averted. Costs were analyzed from health system and societal perspectives, and incremental cost-effectiveness ratios (ICERs) were compared with Indonesias Health Technology Assessment recommended willingness-to-pay thresholds of 1 and 3 gross domestic product per capita (US$4,925 and $14,475). One-way and probabilistic sensitivity analyses were conducted to assess uncertainty. Overall NPT averted 0.0011 DALYs per patient with an incremental cost of US$7.40 per patient from a health system perspective. This resulted in an ICER of US$6,636 per DALY averted, which was not cost-effective at the $4,925 threshold. Cost-effectiveness varied across settings: from US$5,098 per DALY averted in Papua to US$20,051 per DALY averted in southern Sumatra and US$80,825 per DALY averted in northern Sumatra. The ICER reduced when the societal perspective was included, with NPT cost-effective in Indonesia overall ($2,261/DALY averted) and in Papua ($675/DALY averted). The risk of P. vivax recurrence and intervention costs were the most influential parameters on the ICER. Overall, NPT was between the 1-3x GDP per capita cost-effectiveness thresholds in Indonesia; however, cost-effectiveness varied significantly across settings, indicating that NPT may not be an optimal use of resources in areas with low incidence.

Introduction: Antimicrobial resistance poses a major global health threat, yet evidence on its economic impact in low- and middle-income countries remains limited. This study estimated the economic burden of infections caused by ESBL-producing Escherichia coli (E. coli), a key resistant pathogen, in Laos. Methods: A prospective cost-of-illness study was conducted among patients with laboratory-confirmed infections in Setthathirath hospital in Vientiane, Laos, collecting cost data through repeated interviews and medical records. Descriptive analyses and econometric modeling approaches, including inverse probability weighting (IPW) and instrumental variable (IV) analyses, were used to estimate out-of-pocket expenditures, public expenditures, total cost of illness, and length of stay, accounting for potential confounding. Results: ESBL-producing E. coli was consistently associated with higher economic burden across all analyses. The unadjusted per-patient cost was US$ 689.0 for ESBL-producing E. coli, compared with US$ 489.4 for non-ESBL-producing E. coli and US$ 537.6 for non-E. coli. The association remained statistically significant for out-of-pocket cost after IPW-adjustment (US$156.2; 95% CI, 14.3 to 298.1; P = 0.03), while other outcomes were not statistically significant. Instrumental variable analyses showed consistent directional effects but with wide confidence intervals and no statistically significant differences. Conclusions: Findings suggest that ESBL-producing E. coli may be associated with increased economic burden in Laos; however, this association was not consistently statistically robust across analytical approaches. These findings suggest a potential economic impact of ESBL infection, although uncertainty remains regarding the magnitude of the effect. Strengthening antimicrobial stewardship, infection prevention and control, and improved diagnostic capacity remain essential to mitigate the potential AMR burden.

Background. The objective was through an analysis of longitudinal data from the DepIST-H cohort to estimate the incidence, describe the dynamics and factors associated with CT/NG infection in MSM in Togo. Methods. A total of 200 MSM in Lome, Togo, were included in the ANRS I MIE 12400/DepIST-H cohort, half living with HIV. After inclusion in the study, participants received follow-up clinical visits at 6 and 18 months, and laboratory tests were performed at baseline (M0) and at 12 and 24 months (M12 and M24). PCR tests for CT and NG were performed from pharyngeal, anal and urine samples collected using the Xpert(R) CT/GC kit (Sunnyvale, CA, USA). To identify the factors associated with anal bacterial STIs, offset term Poisson regression models were performed. Results. Among 200 MSM (median age 24 years), CT and NG incidence rates were high ({approx}22 cases per 100 person-years), particularly at the anal site. Multiple partners significantly increased anal NG incidence (aIRR 2.35). Anal NG incidence was significantly lower among participants with income-generating activity (aIRR 0.57). Trends suggested higher anal CT and NG incidence in the presence of pharyngeal infection, but associations were not statistically significant Conclusion. This study confirms that MSM remain highly exposed to STIs in Togo and highlights the need to strengthen prevention efforts within this population. Postexposure doxycycline prophylaxis and multisite pooled-sample screening represent promising avenues to strengthen prevention efforts within these populations.

Background. In 2025, the World Health Organization pre-qualified an integrated antenatal care (ANC) testing panel that tests for HIV (including p24 antigen and antibody), syphilis, and hepatitis B (HBV) with one finger prick. The panel would accelerate the triple elimination of vertically transmitted infections by shortening the HIV detection window and increasing testing rates. Nigeria is considering adoption but needs performance and cost projections. Methods. We constructed deterministic (with Microsoft Excel) and probabilistic (with Python) models, including parallel testing and treatment post-exposure prophylaxis algorithms for positive p24. We calibrated the models to Nigeria's 6.4 million women entering ANC annually using epidemiologic literature, product prices, and occasionally expert opinion. We compared costs (in 2025 US dollars) and outcomes between current and projected future (2027) practices. Results. The panel would avert 562 of the current 3,299 vertical infections per 100,000 women in ANC. Per woman in ANC, the panel would avert 0.0656 disability adjusted life years (DALYs) at a net cost of US$7.55. With low current testing rates. HBV testing averts the most DALYs (33%), followed by acute HIV (29%), chronic HIV (25%), and syphilis (14%). The incremental cost-effectiveness ratio (ICER) is $115 (95% confidence interval: $91-$143) per DALY averted--more favorable than Nigeria's conservative historical $137 average. The benefit-cost ratio is also favorable (1.19; 95% confidence interval: 0.93-1.51). Conclusions. The integrated ANC testing panel would be a valuable and cost-effective addition to ANC care. Piloting in Nigeria and similar sub-Saharan African countries would refine parameters for potential scale up.

Background: Dengue continues to place a heavy clinical and organizational burden on health care systems, particularly during epidemics, when the high volume of cases adds pressure on triage, decisions regarding hospitalization, and the monitoring of patients at higher risk of severe outcomes. Despite the growing body of literature on dengue prediction, many studies still exhibit heterogeneity in outcomes, insufficiently detailed analytical designs, and a lack of validation. Objective: To describe the protocol for a study on the development and validation of predictive models for the outcomes of hospitalization among reported cases and mortality among hospitalized patients. Methods: A retrospective study will be conducted using secondary data from the Brazilian Notifiable Diseases Information System (SINAN), covering the period from 2017 to 2025. We will build two independent models: one to predict hospitalization among reported dengue cases and another to predict mortality among patients hospitalized for dengue. The protocol will follow TRIPOD+AI guidelines and include prior definition of eligible predictors, restriction to variables available at the clinically appropriate time of decision-making, handling of missing data, comparison between regression and machine learning algorithms, internal and temporal validation, and assessment of discrimination, calibration, and clinical utility. Conclusion: The study aims to establish a transparent and reproducible analytical protocol to support the development of risk models that could be applied to clinical screening and surveillance for dengue.

Background: Direct microscopy remains a practical first-line test for cutaneous leishmaniasis (CL), but it can miss infections when parasite numbers are low or lesions are chronic. We evaluated whether PCR could detect and identify Leishmania in Giemsa-stained smears that had already been reported as microscopy-negative. Methods: We retrospectively analyzed 131 microscopy-negative smears from patients with clinically suspected CL who attended health-center laboratories in Gonbad-e-Qabus and Torbat-e-Jam, Iran, between March 2013 and February 2015. DNA was recovered from the stained slides by phenol- chloroform-isoamyl alcohol extraction. kDNA PCR was used for molecular detection and species identification. Results: Leishmania DNA was detected in 34 of 131 microscopy-negative samples (25.9%; exact 95% CI, 18.7%-34.3%). Twenty-three positive samples (67.6%) were identified as L. major and 11 (32.4%) as L. tropica. All L. major-positive samples came from Gonbad-e-Qabus, whereas all L. tropica-positive samples came from Torbat-e-Jam. Most PCR-positive lesions (27/34, 79.4%) were chronic, secondarily infected, and/or clinically atypical. In a small laboratory verification panel, all 10 microscopy-positive smears were PCR-positive and all 10 non-leishmanial dermatosis controls were PCR-negative. Conclusions: About one in four clinically suspected cases with a negative smear still had detectable Leishmania DNA. PCR of previously stained slides can therefore provide useful second-line confirmation and species information, especially when lesions are chronic or atypical. The small control panel supports assay performance in the study laboratory but is not large enough to provide precise estimates of clinical sensitivity or specificity.

Background: Dengue fever has become an epidemiological concern worldwide, with 531,617 cases reported in Argentina during the 2023-2024 season. The El Nino Southern Oscillation (ENSO) phenomenon has been linked to changes in dengue dynamics. This study assessed the relationships among ENSO, local climatic variables, and dengue outbreaks in Argentina from 2018 to 2024. Methods: A nationwide spatiotemporal analysis was conducted using dengue cases and monthly mean temperature, relative humidity, and rainfall. The Southern Oscillation Index (SOI) was used as the ENSO indicator (El Nino phase=< minus0.5, neutral phase= minus0.5 to 0.5, and La Nina phase= > 0.5). We fitted Hierarchical Bayesian models with Integrated Nested Laplace Approximation (INLA). A Negative Binomial distribution of dengue cases was used to account for overdispersion. Spatial dependence was modeled by using the Besag York Mollie 2 (BYM2) structure, adjusted for population. Results: The final model explained 53.7% of the variation in Argentinas departmental monthly dengue cases during the study period. Exposure response curves of posterior probability and 95% credible intervals suggested that dengue risk increased when monthly mean temperatures were between 20 and 30 degrees Celsius during the El Nino or neutral phase, with less consistent effects during the La Nina phase. Humidity >50% was associated with increased dengue risk during the La Nina phase, with less steep or absent associations during El Nino or neutral phases. Negative SOI scores were associated with an increased risk of dengue after controlling for the covariates. Conclusion: Dengue outbreaks in Argentina were independently associated with temperatures between 20 and 30 degrees celsius during the El Nino and neutral phases, humidity > 50% during the La Nina phase, and the El Nino phase of the ENSO. Incorporating ENSO indices into predictive models could enhance early warning systems and timely public health interventions in Argentina.

Introduction Respiratory syncytial virus (RSV) is an important cause of respiratory disease in older adults and adults with chronic medical conditions, contributing substantially to the healthcare burden in Italy. The availability of effective RSV vaccines provides an opportunity to reduce RSV-related morbidity, mortality, and healthcare costs in populations at high risk of severe disease. This study evaluates the potential public health impact and cost-effectiveness of vaccination using mRNA-1345 administered as a single dose compared with no vaccination in Italian high-risk adults aged 60-74 years and all adults aged [&ge;]75 years. Methods A static decision-analytic model was developed to project clinical and economic outcomes over a 5-year time horizon. Economic outcomes were evaluated from the Italian National Health Service (Servizio Sanitario Nazionale, SSN) perspective. Model inputs were informed by the most recent Italian epidemiological, clinical, and economic evidence, supplemented by published international data when necessary. Deterministic, probabilistic, and scenario analyses were conducted to assess the impact of uncertainty in model inputs and assumptions on the study results. Results Vaccination with mRNA-1345 in high-risk adults aged 60-74 years and all adults aged [&ge;]75 years was projected to avert over 19,800 hospitalizations, 4,000 emergency department visits, 381,000 outpatient visits, 6,000 RSV-attributable deaths, and 212,000 antibiotic prescriptions compared with no vaccination over a 5-year period. The total incremental cost of {euro}1,143 million and the additional 47,477 QALYs gained resulted in an ICER of {euro}24,078, which was below the commonly referenced willingness to-pay range of {euro}33,000-40,000 per QALY gained. Sensitivity analyses confirmed robustness of the analysis results. Conclusions Vaccination with mRNA-1345 is a cost-effective strategy for the prevention of RSV in high-risk adults aged 60-74 years and all adults [&ge;]75 years in Italy and has the potential to provide substantial public health benefits.

Background: Curable sexually transmitted infections (STIs) are associated with adverse birth outcomes, yet little cost-effectiveness evidence guides antenatal STI screening policy in high-burden settings. We conducted a cost-effectiveness and cost-utility analysis of the Philani Ndiphile trial in South Africa, comparing One-Time and Two-Time antenatal screening for C. trachomatis, N. gonorrhoeae, and T. vaginalis with standard syndromic management. Methods: A decision-analytic model from the provider perspective simulated costs and outcomes for pregnant women and infants. Costs included diagnostics, treatment, and neonatal hospitalisation for a primary composite outcome of preterm birth and/or low birthweight and its components (secondary trial outcomes). Modelled outcomes included incremental cost (US$) per composite (preterm birth and/or low birthweight) case, per component case and per disability-adjusted life year (DALY) averted. The analysis captured infant outcomes in the first year. Univariate and probabilistic sensitivity analyses were conducted to assess parameter uncertainty and robustness of results. Results: Screening for C. trachomatis, N. gonorrhoeae, and T. vaginalis twice during pregnancy was not cost-effective for preventing the primary composite outcome, nor for preventing low birthweight alone. However, two-time screening was cost-saving for preventing preterm birth alone, averting more DALYs and thereby yielding better health outcomes while reducing healthcare costs compared with syndromic management. One-time screening was not cost-effective for preventing any outcome. Conclusions: Repeat antenatal screening for C. trachomatis, N. gonorrhoeae, and T. vaginalis has the potential to prevent preterm births while reducing healthcare costs in high-burden settings. These findings support further research to confirm the clinical effectiveness of repeat screening and to evaluate longer-term health and economic impacts.

During the 2022 global mpox outbreak, gay, bisexual and other men who have sex with men (gbMSM) were disproportionately affected,s however, the true number of cases is likely higher than reported due in part to the stigma associated with mpox. This stigma may have played an even more influential role on health-seeking behaviour in politically conservative regions, such as the Canadian Prairies. The shifting epidemiology may have also led to misdiagnoses during initial months of the outbreaks. Seroprevalence studies can help assess these gaps in surveillance and population-level immunity. To address this, we conducted a cross-sectional seroprevalence study among 275 individuals who identified as potentially eligible to receive the mpox vaccine in the Canadian provinces of Manitoba and Alberta from June 2024 to December 2025 based on provincial vaccination criteria. This eligibility included, but was not exclusively limited to, gbMSM, gender diverse individuals, and sex workers. Dried blood spots were analyzed using the Meso Scale Discovery Orthopoxvirus assay targeting five orthologous mpox and vaccinia virus antigens. In total, 14.5% of individuals self-reported receiving the mpox vaccine and of those without reported Orthopoxvirus vaccination, 5.9% were seroreactive to multiple mpox antigens. These results suggest the potential for undetected mpox circulation within Manitoba and Alberta. While primarily men who have sex with men were eligible for the mpox vaccine, an expansive range of gender and sexual orientation identities were classified as seroreactive, suggesting a misalignment between those who were seroreactive and vaccine eligibility criteria. This emphasizes how broader mpox vaccine eligibility, not restricted by specific gender and sexuality requirements, may better encompass those at risk of infection.

Background Scabies remains a major neglected tropical disease in correctional facilities due to overcrowding and limited hygiene resources. However, evidence regarding the determinants of scabies infection among inmates in Kenyan prisons remains limited. This study assessed the prevalence and determinants of scabies infection among male inmates at Kiambu Main Prison, Kiambu County, Kenya. Methodology A mixed-methods analytical cross-sectional study was conducted among 188 male inmates recruited using a ward-stratified pragmatic sampling approach between May and June, 2026. Quantitative data were collected using questionnaires and clinical examinations based on the International Alliance for the Control of Scabies (IACS) diagnostic criteria. Qualitative data were obtained through focus group discussions and key informant interviews. Quantitative data were analysed using descriptive statistics, chi-square tests, and logistic regression, whereas qualitative data were analysed thematically. Results The prevalence of scabies was 54.8%, with a weighted prevalence of 54.0% (95% CI: 46.5-61.6%). Daily bathing (AOR = 0.07, 95% CI: 0.01-0.31), bathing 2-3 times per week (AOR = 0.09, 95% CI: 0.01-0.44), and daily clothes washing (AOR = 0.21, 95% CI: 0.06-0.65) were independently associated with lower odds of scabies infection. Remandees had higher odds of infection than convicted prisoners (AOR = 1.97, 95% CI: 1.00-3.91). Qualitative findings identified overcrowding, inadequate hygiene resources, limited health education, medication shortage, and delays in treatment as key contributors to scabies transmission. Conclusion Scabies remains highly prevalent among inmates at Kiambu Main Prison. Both individual hygiene practices and institutional conditions contribute to disease transmission. Strengthening prison health services through routine screening, structured health education, improved access to hygiene resources, and timely diagnosis and treatment may help reduce transmission. These findings provide evidence to inform prison health policies and targeted scabies control programmes in Kenya and other resource-limited correctional settings.

Background: Treponema pallidum quantitative polymerase chain reaction (qPCR) positivity and cycle threshold (Ct) by rapid plasma reagin (RPR), disease stage, and other characteristics are poorly characterized in routine-care specimens, leaving it unclear when qPCR of such specimens is informative for diagnosis. Methods: This Japanese multicenter cross-sectional study explored qPCR positivity and Ct by these characteristics. Nonblood specimens collected during routine care underwent qPCR at a central laboratory for this study. Bayesian logistic and normal regressions modeled positivity and mean Ct of TP0574 and polA with stage-specific continuous automated RPR terms, patient characteristics, collection site, and facility random intercepts. Estimates were standardized over the analyzed specimens. Population-group predictions were instead averaged within each group. Results: Among 154 nonblood specimens from 145 patients (71.7% non-MSM men and women) at 14 facilities, 109 (70.8%) were qPCR positive. At RPR 1, adjusted positivity was 72.2% (95% credible interval, 60.9%--82.9%) in primary and 43.8% (16.7%--69.9%) in secondary syphilis. Positivity showed a modest downward trend with RPR in primary but increased in secondary syphilis, reflecting a stage-by-RPR interaction (secondary-to-primary ratio of odds ratios, 1.78; 1.25--2.65). Predicted positivity showed an upward trend with RPR values among MSM; adjusted positivity was relatively high for genital/urethral/urinary and anal/perianal/rectal specimens. Adjusted mean Ct increased with RPR in primary and followed an inverted-U pattern in secondary syphilis. Conclusions: In primary syphilis, nonblood qPCR positivity was high even at low RPR. When serologic findings remain inconclusive in this stage, qPCR is highly recommended for securing an early diagnosis.

Aim: Brucellosis remains endemic throughout the Mediterranean basin, the Middle East and Central Asia. Genitourinary involvement is an uncommon but clinically consequential focal complication that closely mimics urological emergencies and may precipitate unnecessary surgery. Contemporary data describing its frequency, laboratory signature and treatment outcomes in endemic settings remain limited. Material-Methods: We retrospectively screened all adults ([&ge;]18 years) with confirmed brucellosis managed at a tertiary infectious diseases unit between January 2008 and December 2020. Genitourinary involvement was defined as epididymo-orchitis, orchitis, epididymitis and/or brucellar pyelonephritis. Clinical, laboratory, ultrasonographic, therapeutic and outcome variables were abstracted using a standardised form. Proportions are reported with Wilson score 95% confidence intervals (CI). Reporting followed the STROBE statement. Result: Genitourinary involvement was identified in 18 of 125 patients with brucellosis (14.4%; 95% CI 9.3-21.6); 16 (88.9%) were men and the mean age was 35.2 years (range 22-62). Scrotal disease dominated the male presentation: epididymo-orchitis in 10 of 16 men (62.5%; 95% CI 38.6-81.5), orchitis in 4 (25.0%) and epididymitis in 2 (12.5%). Both women presented with pyelonephritis, one of whom developed a tubo-ovarian abscess requiring drainage. Constitutional features were near-universal (fatigue 100%, night sweats 88.9%, fever 77.8%). Leukocyte counts remained within the reference interval in every patient (mean 5,680/mm3), whereas erythrocyte sedimentation rate (mean 32 mm/h) and C-reactive protein (mean 24.2 mg/L) were only mildly to moderately raised. The Coombs anti-Brucella test was positive in 18 of 18 patients (100%) and the standard agglutination test in 17 of 18 (94.4%), whereas blood culture yielded Brucella melitensis in only 1 of 18 (5.6%). Concomitant extragenitourinary focal disease was present in 8 patients. All patients received doxycycline plus rifampicin; none required modification of the regimen or orchiectomy, and no treatment failure occurred (0 of 18; 95% CI 0-17.6). Median follow-up was 12 weeks (range 6-52) and no relapse was documented within this interval. Conclusions: In endemic regions, genitourinary brucellosis should be suspected in any patient with acute scrotal or flank symptoms accompanied by constitutional complaints, even when the leukocyte count is normal and acute-phase reactants are only marginally elevated. Coombs anti-Brucella serology rather than blood culture is the diagnostic cornerstone, and prompt doxycycline-rifampicin therapy averts surgical intervention.

Enteric fever is endemic to many low- and middle-income countries (LMICs), particularly those in sub-Saharan Africa, South and South-East Asia. The causative agents are typhoidal serovars of Salmonella enterica, including Typhi (S. Typhi) and Paratyphi A (SPA). There are no vaccines currently licensed for SPA, leaving antimicrobials as the only therapeutic option. Multi-drug resistance (MDR) S. Typhi is increasingly prevalent, but to date has not been detected in SPA. In Australia, cases of SPA are notifiable. Here we report on the genomic epidemiology of 208 cases of SPA in returned travellers to Australia, and their close contacts, from 2018 to 2025. A total of 15 unique genotypes were detected, and these were correlated with geographical regions of reported travel. There was a low incidence of antimicrobial resistance with only a single isolate carrying acquired resistance genes. Mutations in quinolone resistance determining regions were common across the genotypes, detected in 95.7% of isolates. A single isolate in a traveller returning from India was resistant to several first line antibiotics including: ampicillin, amoxicillin plus clavulanic acid, ceftriaxone, azithromycin and ciprofloxacin. The isolate carried a plasmid encoding an extended spectrum beta-lactamase (blaCTX-M-231), two macrolide resistance genes (mphA and ermB) and a quinolone resistance gene (qnrS1). Elements of the pangenome were explored, with stable maintenance of small plasmids encoding hypothetical proteins detected in four genotypes. Copy number variation in genes encoding surface antigen biosynthesis genes were detected in six genotypes. These biosynthesis genes are targets for one of the two SPA vaccines in development, and the potential variation in surface antigens could have implications for vaccine efficacy. Linking epidemiological data with genomic studies of SPA provides an opportunity to improve understanding of the emergence, spread and risk of drug-resistant SPA infections, and to better inform empirical treatment guidelines in returned travellers.

Introduction: Nigeria continues to report one of the highest burdens of diphtheria globally, with Kano State accounting for a disproportionate share of cases and deaths. Understanding epidemiological patterns and mortality determinants is essential for guiding targeted interventions. Objectives: To describe the distribution of diphtheria cases in Kano State by socio-demographic and clinical characteristics, Local Government Area, and month of reporting, and identify independent predictors of mortality. Methods: We conducted a retrospective cohort study of 21,369 patients with clinically compatible and laboratory-confirmed diphtheria using secondary data from medical records (2022-2025). Descriptive statistics summarized patient characteristics and disease distribution. Associations with mortality were assessed using chi-square or Fishers exact tests. Multivariable logistic regression identified predictors of mortality, reported as adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Results: Of 21,369 patients, 13,557 (63%) were female, with a median age of 11 years (IQR: 7-13.6). Children aged 5-9 years accounted for 29% of cases. Prior contact with a case was reported in 2,633 (12%) patients, while 168 (1%) were laboratory-confirmed. Overall, 13,468 (63%) patients were unvaccinated and 5,381 (25%) fully vaccinated; Diphtheria antitoxin DAT was administered to 2,035 (10%). Cases occurred in all local government areas (LGAs), with four accounting for 60% of cases. Transmission occurred year-round, peaking in March 2024 and August 2023 and 2025. Overall, 1,131 deaths occurred (CFR: 5.3%). Compared with patients aged [&ge;]20 years, younger age groups had higher odds of mortality: 0-4 years (aOR = 26.74, 95% CI: 17.64-42.72), 5-9 years (aOR = 19.77, 95% CI: 13.17-31.33), 10-14 years (aOR = 8.21, 95% CI: 5.41-13.13), and 15-19 years (aOR = 2.46, 95% CI: 1.45-4.26). Prior contact with a case was associated with lower odds of mortality (aOR = 0.42, 95% CI: 0.30-0.55), whereas laboratory confirmation (aOR = 2.33, 95% CI: 1.48-3.56) and DAT receipt (aOR = 2.55, 95% CI: 2.19-2.96) were associated with higher odds. Prior vaccination was associated with lower odds of mortality among fully vaccinated (aOR = 0.52, 95% CI: 0.44-0.61) and partially vaccinated patients (aOR = 0.61, 95% CI: 0.47-0.80). Conclusions and recommendations: During the study period, diphtheria was more common among younger children, females, and the unvaccinated. Although concentrated in a few LGAs, transmission was widespread and varied seasonally. Mortality was associated with younger age, laboratory-confirmed infection, and use of diphtheria antitoxin, whereas vaccination and prior contact were protective. Reducing the burden requires sustained efforts to strengthen routine immunization, implement targeted vaccination campaigns, ensure early detection and prompt treatment, and improve contact tracing and case management.