Discussion:
Here we report a case of malaria and RVF co-infection that was presented with mild symptoms without involvement of the main characteristics of RVFV infections, namely hemorrhage or neurological syndromes [28]. This none severe presentation of RVF infection has been observed during a recent outbreak in the northern side of the country (Fig. 1) [1]. However, during another outbreak of RVF in the southeastern side of the country during the same year, cases were presented with severe manifestation (Fig. 1) [13]. This difference in the overall manifestation of several patients could be attributed to the sensitivity of the surveillance system and it is capacity to identify and detect none severe cases during the outbreak [3,27]. Therefore, healthcare providers in countries endemic with several causes of febrile illness should pay extra attention during the differential diagnosis and the possibility of co-infection should be high expected in such settings [3,6,7, 29 -31]. Particularly, that recently there is a growing evidence about diseases emergence and unusual presentation of endemic diseases [24, 31 - 33]. Alternatively, this difference in the clinical manifestation of RVF infection could be attributed to variation in the virus strains some clads of viruses are more associated with severe clinical presentations of the disease [34 - 36]. Similar situation has been observed during the currently ongoing Mpox outbreak of global concern [37]. Clade IIb of the Mpox virus that diverged from the West African lineage is associated with globally expanded transmission outside the endemic areas with none severe clinical presentation. While on the other hand, the Democratic Republic of Congo/Central African lineage (clade I) is associated with local transmission in Africa and a higher Case Fatality Rate [37].
Interestingly, a substantial increase in outbreaks frequency of endemic and emerging infectious diseases has been observed throughout the country. Several outbreaks of vector-borne diseases including malaria [17], CCHF [11], Chikungunya [10], dengue [29], RVF [1], Leishmaniasis [16], and other zoonotic emerging infectious diseases such as Cholera [38], COVID-19 [39], and hepatitis E [40] were reported in Sudan. These outbreaks were associated with climate change and sudden forcible displacement of human and animals populations as well as international travel and unplanned urbanization [25, 41].
Considering the lack of effective treatment and zoonotic nature of arboviral diseases, their prevention and control rely on the implementation of a transdisciplinary One Health strategy [13,42] including the integration of diseases control programs [43], enhanced surveillance and control of diseases vectors [18, 43,44], improving the water sanitation and hygiene [45], and the use of vaccines [38].
In conclusion, in areas endemic with several infectious diseases like Sudan, co-infection should always be expected and investigated to improve the case management and the clinical outcome. Therefore, investment should be done on training clinical epidemiologists and improving the diagnostic capacity and surveillance system. Additionally, further studies are needed to investigate diseases progress and clinical outcome in case of co-infection with two or more infectious diseases.