Bangladesh, an endemic country for dengue fever, is currently experiencing a seasonal upsurge with an exponential increase in caseloads since June 2023. This current upsurge appears to be larger by scale and severity compared to that for 2022. The upsurge has recorded 69,483 confirmed cases, 327 related deaths and accounted for 0.47% of the Case Fatality Rate (CFR) between 01 January to 7 August 2023 in all 64 districts of the country. 43,854 confirmed cases including 204 deaths were recorded in July. This accounted for 63 % and 62 % of the total cases and deaths respectively.
Dengue is a mosquito-borne viral infection that is common in warm, tropical climates. This infection causes a severe flu-like illness and may lead to a potentially lethal complication called severe dengue.
Upsurge in Rohingya Camps
Rohingya Camps have also recorded a cyclic and recurrent upsurge of dengue fever since the last quarter of 2021 leading to an endemic transmission in three years. In 2022, the camps experienced the largest upsurge in five years that recorded 15,373 cases including 23 deaths and accounted for a 0.2% CFR.
From 01 January to 12 August 2023, 6127 confirmed dengue cases including 06 deaths have been reported in all the 33 Camps. 51% of the cases have been recorded five camps as follows: Camp 3 (1277 cases), Camp 4 (514 cases), Camp 9 (464 cases), Camp 1 (454 cases) and Camp 17 (391 cases). This establishes a hotspot in Camp 3 and four surrounding camps similar to the case in 2022 where Camp 3 accounted for 53% of the total cases reported.
However, current upsurge is still lower in terms of number of caseloads and severity compared to that for 2022.
From 8 July to 5 August 2023, 3,937 confirmed cases were reported in Rohingya camps and surrounding communities. This number accounted for 71% of the total cases reported in 2023 as shown in Figure 1 below.
Figure 1: Annual Trends of Dengue fever cases from 2018-2023 in Rohingya Refugee Camps and surrounding host population
The current upsurge started at the beginning of July 2023 with a four-fold increase in weekly cases from 105 between 25 June to 1 July (Epi week 26) to 413 between 2 July to 8 July (Epi week 27).
It is important to mention that 38% of the dengue cases have been reported among the younger age groups (<9 years) while the risk of infection seems to drop drastically with the older age groups. However, infection of males accounted for 55% of the upsurge.
The proportion of severe cases (Case Management category B and C) is 14% (845 cases). The cases are admitted in 29 health facilities across the camps. Critical cases have been referred to Cox’s Bazar District Hospital. The proportional distribution of cases in terms of severity is shown in Figure 2 below.
Figure 2: The proportionate distribution of confirmed dengue cases by severity among Rohingya Refugees/FDMN and the surrounding host population from 6 –12 August 2023
WHO response
Given the upsurge, WHO-led Health Sector with technical guidance from Epidemiology, case management and IPC TWG, continues to lead and guide the multi-sectoral response.
WHO in collaboration with WASH, Environment and Shelter sectors continue to identify and destroy various breeding sites of Aedes Aegypti vectors. The environment sector and campsite management have equally organized weekly cleaning campaigns, clearing all potential water-holding receptacles, rooftops, and water channels within the hotspot camps and the other camps.
The Community Health Working Group with its network of 1672 Community Health Workers has shared danger prevention and control messages with household members during routine weekly household visitations in the respective camps. The Risk Communication and Community Engagement Technical Working Group has also scaled up awareness messages.
WHO has started the distribution of over 11,000 Rapid Diagnostic Test (RDT) kits for timely and optimal detection of dengue at Sentinel site facilities. An additional 20,000 RDT kits are under procurement for emergency response. Additionally, 350,000 Long Lasting Treated Nets (LLINs) were distributed in the Rohingya camps and further 50,000 LLINs were distributed in the surrounding host population.
WHO has equally trained over 100 Health Care Workers and has provided them with dengue fever detection, management, and prevention protocols to aid effective management.
WHO Epidemiology and Surveillance Team has further recommended the activation of 116 available SARI ITC beds. The activation will allow for the appropriate management of additional severe and critical cases and prevent the healthcare system from being overwhelmed in case of a severe upsurge in subsequent weeks. WHO continues to encourage joint efforts to control the mosquito vector population and minimize individual exposure such as using mosquito repellents and wearing long-sleeved clothes.