Dengue virus (DENV) is an arthropod-borne virus (arbovirus) transmitted by the Aedes mosquitoes, mainly Aedes aegypti. Dengue fever is a rapidly growing disease with expanding geographical distribution worldwide. We investigated a high number of non-malaria febrile cases reported to health clinics in refugee camps in the five states of Darfur between August 2015 and March 2016. The clinical presentation of cases and case definition criteria suggested involvement of one or more arboviral hemorrhagic fevers. Out of 560 suspected cases, we collected and analyzed 204 blood samples and serologically positive samples were confirmed by PCR. We identified 32 (15.7%) dengue viral infections, six West Nile virus infections, and three Crimean–Congo viral infections. Dengue infections were found in four out of the five Darfur states. We reported the first dengue fever outbreak in the Darfur region. Our results highlight the need for public health education and further molecular, phylogenetic, and entomological investigations for a better understanding of the disease transmission and the associated risk factors in the region.

R ift Valley fever (RVF) is an arboviral disease caused by RVF virus (RVFV; genus Phlebovirus, family Phenuiviridae) (1). RVFV periodically emerges to cause epizootics among livestock and epidemics in persons living nearby (2). It is mainly transmitted by the bite of infected mosquitoes or by direct contact with infected animals and their products (3). In addition, RVFV transmission is maintained vertically among both humans and vector mosquito populations (4,5). The public health threat from arboviral diseases is growing rapidly in Sudan (4,6). Increasing human movement, often arising from armed conflict, is driving several arboviral diseases to emerge in Sudan, usually in the form of undifferentiated febrile illness. Recent epidemics include dengue fever (6,7), Crimean-Congo hemorrhagic fever, West Nile virus disease (8), yellow fever, and chikungunya fever (4). RVF outbreaks represent major public health and economic burdens on endemic countries, particularly those such as Sudan that rely on exporting animals and animal products (3,4,9). In a recent study, RVFV infection was also associated with spontaneous abortion among pregnant women in Sudan (10). We describe a unique, undeclared outbreak of RVF in River Nile state, in northern Sudan, leading to the potential spread of the virus to other states in Sudan or neighboring countries.

This study aimed to investigate an outbreak of a non-malaria, undifferentiated febrile illness, among internally displaced persons (IDPs) living in humanitarian camps in North Darfur, Sudan, in 2019. Methods: An investigation team was deployed to North Darfur to identify suspected cases and collect blood samples, and clinical and demographical data. Blood samples were examined microscopically for Plasmodium spp and tested for dengue (DENV) and yellow fever viruses by reverse transcriptasequantitative polymerase chain reaction. Results: Between September 7 and December 18, 2019, we clinically identified 18 (24%), 41 (54%), and 17 (22%) cases of dengue fever, dengue with warning signs, and severe dengue, respectively. Blood samples were collected from 22% of patients, and 47% of these tested positive for DENV-1 RNA. We confirmed 32 malaria cases with 5 co-infections with DENV. This outbreak of dengue was the first among IDPs in the humanitarian camps. Conclusions: Our findings indicate that dengue has become endemic or that there has been a new introduction. Further epidemiological, entomological, and phylogenetic studies are needed to understand disease transmission in the area. An early warning and response system and an effective health policy are crucial for preventing and controlling arboviruses in Sudan.

We report an outbreak of dengue in Darfur, western Sudan, during September 2014–April 2015. Dengue virus–specific PCR testing of 50 samples from nonmalaria febrile illness case-patients confirmed 35 dengue cases. We detected 7 cases of dengue shock syndrome and 24 cases of dengue hemorrhagic fever.

The goal of this study was to systematically review the published data on dengue virus (DENV) seroprevalence in Sudan and to estimate disease burden through meta-analysis. We searched, reviewed, and extracted online available reports on DENV in Sudan. Among 168 identified records, 19 were selected. Dengue infections were documented in 11/18 states. The overall seroprevalence of DENV in Sudan was estimated to be 27%, while the prevalence of dengue IgM was 22% and IgG was 38%. The prevalence of dengue estimated from community and hospital-based cross-sectional studies were 26% and 30% respectively. Additionally, one cohort study and a single PCR-based study reported a prevalence of 1% and 4%, respectively. Regional analysis revealed that the variation in seroprevalence in East, North, West, and Central Sudan was 23%, 24%, 36% and 43%, respectively. Interestingly, we found that DENV is circulating countrywide with a significant spatiotemporal variation in the disease seroprevalence. Furthermore, publications on dengue prevalence are temporally and geographically fragmented, perhaps due to limited resources. However, this gap in data and knowledge highlights the urgent need for a country-wide surveillance system and continued study of dengue burden in Sudan to accurately estimate the disease prevalence and determine the associated risk factors.