MASSIVE SCABIES OUTBREAK IN ROHINGYA REFUGEE CAMPS, COXS BAZAR: SEASONALITY AND ASSOCIATION WITH CLIMATIC FACTORS (2021 to 2023)

BackgroundScabies is a common skin condition and poses a substantial disease burden in resource-poor tropical settings. The Rohingya refugee camps in Coxs Bazar, Bangladesh represent one of the worlds largest and most protracted humanitarian crises. Using three years of data from 2021 to 2023 and applying rigorous analytical methods, this study describes the seasonality of scabies and examines its association with climatic factors. MethodologyThis is a retrospective observational study conducted in the Rohingya refugee camps and adjacent host communities in Ukhiya and Teknaf, Coxs Bazar. All patients clinically diagnosed with scabies and who received treatment at 35 International Organization for Migration (IOM)-supported health facilities between 1 January 2021 and 31 December 2023 were included. Climate data, including daily mean, minimum and maximum temperature and total and maximum rainfall, were obtained from the Bangladesh Meteorological Department. Seasonal-trend decomposition using Loess (STL) was applied. Associations between climatic variables and the decomposed seasonal component of scabies cases, as well as overall scabies case counts, were assessed using Pearson correlation tests. ResultsA total of 323,106 new scabies cases were reported from IOM-supported health facilities between January 2021 and December 2023. Children aged under 5 years and 6-18 years accounted for the highest proportion of cases (32.08% and 38.95%, respectively). The average monthly number of scabies cases was highest in November (12,625) and lowest in May (5,862). Case numbers increased from November to February (high season), with a peak between October and November, and declined between April and June (low season). An inverse relationship was observed between temperature and scabies incidence, with higher case numbers during cooler months and lower numbers during warmer months. Pearson correlation analysis demonstrated a strong and significant negative correlation between the seasonal component of scabies and maximum (r = -0.492, p = 0.002), minimum (r = -0.506, p = 0.002), and mean temperature (r = -0.525, p = 0.001). No significant association was observed between scabies seasonality and humidity or rainfall. ConclusionThis study identified a distinct seasonal pattern of scabies, with higher caseloads during late autumn and winter (October to February) and lower caseloads during summer months (April to June). Temperature showed a strong negative association with the seasonal component of scabies. These findings may inform the timing of public health strategies, including mass drug administration, intensified case management, and social and behavioural change communication, in humanitarian settings.