TMSS Medical College Journal

Background: Refugee settlements can face increased risks of communicable diseases because of population density, environmental constraints, population mobility, and pressure on health services. Cox's Bazar hosts a large Rohingya refugee population and has experienced recurrent dengue transmission and substantial viral hepatitis concerns. Objective: To describe laboratory test positivity patterns for dengue, malaria, syphilis, hepatitis B virus (HBV), and hepatitis C virus (HCV) among clients tested at three health posts in Camps 1E, 11, and 22 of Cox's Bazar, Bangladesh. Materials and Methods: We conducted a retrospective cross-sectional analysis of cumulative laboratory register data from July 2024 through April 2026. The dataset comprised 5,053 test records for dengue NS1 antigen, dengue IgM and IgG, hepatitis B surface antigen (HBsAg), anti-HCV, venereal disease research laboratory (VDRL) testing, and malaria rapid diagnostic tests and/or microscopy. Positivity was summarized as percentages with 95% confidence intervals (CIs) using the Wilson method. Chi-square tests were used to assess differences in positivity across the three camps. Because the source data were aggregate and test-based, the analysis did not estimate population prevalence, incidence, or patient-level risk. Results: HCV had the highest observed positivity, 23.3% (367/1,573; 95% CI 21.3-25.5), with the highest camp-specific positivity in Camp 11 (31.2%). Dengue NS1 positivity was 16.2% (76/468; 95% CI 13.1-19.9), ranging from 2.3% in Camp 1E to 28.7% in Camp 22 (p<0.001). Dengue IgG positivity was 15.0% (44/293), while IgM positivity was 2.2% (7/318). HBsAg positivity was 3.3% (51/1,549), and VDRL positivity was 0.6% (5/823). No positive malaria tests were recorded among 29 tests. Anti-HCV results represent screening positivity and do not establish active HCV infection. Conclusion: The findings demonstrate substantial HCV test positivity and marked between-camp variation in dengue NS1 positivity among clients who were tested. These findings support continued decentralized hepatitis diagnosis and linkage to treatment, camp-specific dengue surveillance and vector-control activities, and stronger routine laboratory surveillance. The results should not be interpreted as population prevalence or as evidence of temporal trends because the analysis was based on cumulative test records without monthly counts or individual-level denominators.

Displaced populations may experience increasedexposure to communicable diseases because ofcrowded living conditions, population mobility,environmental constraints, interrupted access topreventive services, and limited health-systemcapacity. In humanitarian settings, blood-borneinfections and vector-borne diseases may coexist andplace different demands on surveillance and clinicalservices. Global WHO reporting continues to identify viral hepatitis B and C as major public health priorities,while dengue has expanded geographically andreached historically high levels of global reporting.'” In Bangladesh, the Rohingya refugee response inCox’s Bazar comprises densely populated camps withsubstantial and continuing health-service needs.Dengue has been repeatedly reported in the camps andsurrounding host communities, including a majorupsurge during 2024. WHO described the 2024 dengue outbreak in the Rohingya camps and host communitiesas the largest and most prolonged since 2018.34 Viral hepatitis is also an important concern in theRohingya refugee population. Previous studies andhumanitarian health reports have documentedsubstantial HCV seropositivity and active infection inthis population. WHO reporting from Cox’s Bazar hasalso highlighted the need to expand HCV diagnosisand access to treatment.*°The epidemiological information available at districtor response level may mask differences betweenindividual camps. Camp-specific laboratory data cantherefore provide operationally useful information forprioritizing surveillance, clinical services, referral, andprevention. However, positivity among people who aretested is not equivalent to population prevalence, andaggregate laboratory data do not permit patient-levelrisk-factor analysis. The present study therefore describes laboratory testpositivity for dengue, malaria, syphilis, HBV, andHCV among clients tested at three GonoshasthayaKendra (GK)-operated health posts in Camps 1E, 11,and 22. The study specifically examines differencesbetween camps and avoids interpreting cumulative testpositivity as population prevalence or temporalincidence.