Fatal cases associated with secondary dengue infection

      Background: Dengue is one of the most important mosquito-borne diseases. The disease can manifests as mild dengue fever (DF) or severe and life-threatening dengue hemorrhagic fever (DHF)/ dengue shock syndromes (DSS). The dramatic rise in dengue incidence globally in the recent years is accompanied with increasing number of fatal infections especially in the hyperendmic regions where there are more than one dengue virus genotypes co-circulating. There are also reports of possible increasingly more frequent atypical clinical presentation of severe dengue. In the present study, we examined the clinical presentations of several dengue-associated deaths recorded in our hospital from year 2006 and 2007.
      Methods: A retrospective study was performed following approval of the University of Malaya Medical Centre Ethics Committee. Ten fatal dengue cases recorded at the UMMC from year 2006 to 2007 were identified, and the relevant clinical and laboratory records were examined. Serological tests to detect dengue-specific IgM and IgG and dengue-specific NS1 antigen were performed.
      Results: Of the 10 fatal dengue cases reviewed, 9 were female. Eight of the patients had evidence of secondary dengue infection. Deaths occurred at an average of 2.4 day post admission except for 2 patients who were brought dead to the hospital. The mean illness duration prior to hospitalization was 4.7 days. The common presentation recorded include persistent vomiting (n=9), body ache (n=8), bleeding manifestations (n=7), abdominal pain (n=6) and diarrhea (n=6). Shock complicated with septicemia, massive multiple bleeding, multi-organ failure, and coagulopathy were the common causes of deaths.
      Conclusion: Findings from the study suggest that there is no significant atypical clinical presentation amongst the recent fatal cases seen here in comparison to those previously reported. All patients who succumbed to dengue had secondary dengue infection even though they may have slightly different clinical presentation. This suggests the relevance of secondary infection to the immunopathology of dengue. Early recognition and diagnosis of severe dengue is crucial in order to provide proper and efficient patient management and treatment.