
Dengue is endemic in Bangladesh. As compared to the previous four years (2018 to 2021), the Rohingya refugee/Forcibly Displaced Myanmar Nationals (FDMN) [1] camps in Cox’s Bazar district, are experiencing an acute surge in dengue cases, that started at the end of May 2022 (epi week 22). As of 24 July (end of epi week 29), a total of 7687 confirmed cases and 6 deaths have been reported, with 93% (7178) of the cumulative number of cases being reported since the start of the surge at the end of May 2022 (Figure 1). A similar surge has not been observed in the larger Cox’s Bazar district outside of the Rohingya refugee/FDMN camps nor at the national level with case numbers and trends within expected levels of incidence for the same period. As dengue is recurrent in this part of the country, the population may be at risk of secondary infection, which puts them at higher risk for severe disease.
Description of the outbreak
From 1 January to 24 July 2022, a total of 7687 cases of dengue, confirmed by rapid diagnostic test (RDT), and six deaths (case fatality rate, 0.08%) have been reported from the Rohingya refugee/FDMN camps in Cox’s Bazar district, Ukhia Upazila and Teknaf Upazila (sub-districts), with the former sub-district being the most affected of the two. An acute surge of cases began during the week commencing 23 May (epi week 22), and peaked the week ending 26 June (epi week 25), with 93% (7178) of the cumulative number of cases being reported between 23 May and 24 July. A decreasing trend in reported dengue cases was observed following the peak when 1291 cases were reported in epi week 25; however case numbers remain high despite the decline: epi week 26 (1241), epi week 27 (1152), epi week 28 (962), epi week 29 (1000).
Cases of reported dengue in Rohingya refugee/FDMN camps are significantly higher as compared to similar periods over the past four years; 2018 (4 cases), 2019 (7 cases), 2020 (3 cases), and 2021 (1530 cases and 3 deaths with a surge from October to December) (Figure 1). However, at a national level and in the larger Cox’s Bazar district, case numbers have been within expected endemic levels of incidence; by comparison to the dengue case from the camps, the larger Cox’s Bazar district reported approximately 121 cases from 1 January to the end of June (epi week 27).
Camps located in Ukhia Upazila are predominantly affected by the outbreak. Camp 3 accounted for over 50% of all reported cases and Camps 4 and 1W each account for less than 10% of cases as of 24 July 2022. More than two-thirds of cases (67%) were among persons 15 years and older with males accounting for 60% of cases. The majority of cases (81%) were hemodynamically stable – not showing any warning signs for severe dengue syndrome (such as dengue hemorrhagic fever (DHF) or Dengue Shock syndrome (DSS)) nor having any coexisting conditions – while approximately 15% of cases were mild and required observation and admission to primary health facilities. Severe dengue with signs of DHF and DSS was observed in 0.3% of cases and required admission to Cox’s Bazar District Hospital located within the camp. Among patients admitted to the hospital, 1% required blood transfusion. Previous dengue infection was reported in 1% of current cases.
Serotyping results from 10 samples processed at the Institute of Epidemiology, Disease Control and Research (IEDCR) reference laboratory in the capital Dhaka identified DENV-3 (5 samples), DENV-2 (3 samples). Two samples had inconclusive results.
Dengue is endemic in Bangladesh with recurrent outbreaks. The Rohingya refugee/FDMN camps in Cox’s Bazar district previously experienced an acute dengue outbreak from October to December 2021 during which 1530 cases, including 3 deaths, were reported. Case numbers began to decline at the beginning of 2022, and by the end of February, the event was under control until the resurgence of cases in May 2022.