Pattern of Dengue Fever in Three Centers in Three Consecutive Years: An Evaluation of 2,098 Patients

Abstract

Background: Dengue fever is the most common mosquito-borne viral disease in the world. The pattern of dengue fever varies over different years, most probably due to change in the virus for adaptation to the vector or because of the change in the vector which forces the virus to adapt to it. The presentation and severity of dengue fever also varies at different periods. Immunosuppression and bone marrow suppression with dengue fever is well documented, even though the exact mechanism is unknown.

Methods: We have assessed the pattern of dengue fever presentation, lab values, complications and the end results and so on from the data collected from three centers in two districts in Kerala State, India, over 3 years from 2017 to 2019. The total number of dengue cases were analyzed using the identity (ID) number obtained from the infectious disease control register of these hospitals. The ID number was used to retrieve all the data from the hospital information system (HIS). The discharge summary, investigations, details, complications, mode of presentation and similar data were retrieved to chart the details of 2,098 patients from the three centers.

Results: Neurotropism of dengue virus is well documented, but evaluation of 2,098 patients from three centers showed only 14 patients with encephalitis and another 14 patients with seizure at center A. Post dengue fever epidural abscess with or without spondylodiscitis were reported from center A and B. At center A, there were five cases of post dengue epidural abscess with or without spondylodiscitis in 2017 during the surge of infection between May and August. At center B, there were eight cases of epidural abscess with or without spondylodiscitis during the same period. Post dengue immunosuppression and problems related to that are not analyzed in the present study.

Conclusion: The data revealed episodic occurrence of dengue fever in these three centers, with a peak from May to August in 2017. The rest of the period showed only very few cases. There were no additional vector control measures taken in these 3 years. Co-circulation of all the serotypes of dengue virus (DENV) is shown in Kerala State (World Health Organization (WHO)). Moreover, Aedes albopictus is shown to have wide spread prevalence in the state. Even though Aedes albopictus has less vector capacity than Aedes aegypti, the virus load needed for such vector adaptation is high and there is chance of DENV undergoing crucial mutations to overcome this disadvantage. The variation in severity of the disease during outbreaks has been attributed to emergence of such new genotypes. The data showed increase in the red blood cell (RBC) count in many of these patients even when there was decrease in the white blood cell (WBC) and platelets and no evidence of capillary leak syndrome. This needs to be further investigated.

Clin Infect Immun. 2021;6(1):11-17
doi: https://doi.org/10.14740/cii119