Bangladesh has experienced recurrent dengue outbreaks since 2000, driven by climatic changes and socio-demographic vulnerabilities. Limited evidence on circulating serotypes and immune diversity has hindered preparedness for severe dengue (SD). Identifying clinical and laboratory predictors of progression to severe dengue is key to strengthening outbreak response and clinical management. A longitudinal cohort study was conducted in four hospitals in Dhaka between January and November 2024. Patients with confirmed dengue with warning signs were enrolled. Clinical data and blood samples were collected at enrollment, clinical deterioration/discharge, and convalescence (day 21 ± 7). Multivariable logistic regression identified factors associated with SD compared with dengue with warning signs (DWS). Associations were expressed as odds ratios (OR) with 95% confidence intervals (CIs) and p-values < 0.05 considered y significant. Among 3135 dengue patients, 354 with warning signs were enrolled. 62 (17.5%) progressed to SD, including 2 deaths. Most of the patients (60%) were aged between 21 and 40 years, and 76% were male. Lethargy was more frequent in SD patients (29%) than DWS patients (11%). DEN-2 was the predominant serotype (90%). Multivariable logistic regression, adjusted for potential confounders, identified arthralgia (95% CI: 1.04–3.98), anorexia (95% CI: 1.40–11.7), lethargy (95% CI: 1.97–10.7), diabetes mellitus (95% CI: 1.01–6.17), pleural effusion (95% CI: 4.97–21.1) and prolonged APTT (95% CI: 1.02–1.08) as independent predictors for SD. The findings show that a few simple and easily measurable indicators can support early risk assessment and guide timely hospital admission and clinical management. 10.13039/100000200 United States Agency for International Development (USAID) under the Crisis Modifier Grant (GR-01909) in response to the dengue outbreak in Bangladesh.

In low- and middle-income countries, Shigella is an important cause of diarrheal disease, and infections often occur without clinical symptoms. Asymptomatic individuals may act as reservoirs for ongoing community transmission, but their contribution to the overall burden remains poorly understood. This analysis aimed to generate evidence on asymptomatic and symptomatic Shigella infection in Dhaka, Bangladesh, to enlighten surveillance and prevention strategies. We analyzed data from the hospital-based diarrheal disease surveillance system (DDSS) of icddr,b Dhaka Hospital and asymptomatic participants from the community, covering January to December 2025. Stool or rectal swabs were cultured and serotyped for Shigella species. In 2025, Shigella was detected in 68 (2.5%, 95% CI: 2.0–3.1%) among 2738 diarrheal patients, compared with 51 of 784 asymptomatic community participants (6.5%, 95% CI: 5.0–8.4%) and this difference was significant (p value < 0.001). In both groups, participants aged 5–17 years had the highest positivity (hospital 6.2% and community 12.1%). Positivity was also significantly higher in the community for both males (7.6% vs. 2.8%, p < 0.001) and females (5.3% vs. 2.1%, p = 0.001). S. flexneri was predominant in both populations (64.7% and 58.8%). S. sonnei was more common among hospital patients (29.4% vs. 5.9%), whereas S. boydii was more common among community participants (31.4% vs. 4.4%). Hospital positivity was observed throughout the year, with no clear seasonal peak, whereas community positivity climbed in October and December. Integrated hospital and community surveillance may provide a more complete understanding of Shigella transmission and guide prevention strategies.