Early Dengue infection and outcome study (EDEN) - study design and preliminary findings.
BACKGROUND
Dengue is a major public health problem in Singapore. Age-specific dengue morbidity rates are highest in the young adult population, unlike in many other Southeast Asian countries where dengue is mainly a paediatric disease. Hence, the World Health Organization (WHO) guidelines on dengue diagnosis and management which were developed using the paediatric experiences, may not be suitable for the management of adult dengue infections.


METHODS
The Early DENgue (EDEN) infection and outcome study is a collaborative longitudinal study to investigate epidemiological, clinical, viral and host-specific features of early dengue-infected adults, in an effort to identify new early markers for prognostication. Patients presenting with early undifferentiated fever were included in the study. We carried out an interim analysis to look for early indicators of severe disease.


RESULTS
During the period of this interim study analysis, 455 febrile patients were recruited. Of these, 133 were confirmed as acute dengue cases based on dengue-specific polymerase chain reaction (PCR) results. There were significant clinical and epidemiological differences between dengue and febrile non-dengue cases. Nine per cent of the dengue cases experienced persistent tiredness, drowsiness and loss of appetite beyond 3 weeks of illness. Quantitation of viral loads using the crossover (Ct) value of real-time RT-PCR correlated with the duration of symptoms. More than half of both primary and secondary dengue cases were hospitalised. There was no dengue-related mortality in this study.


CONCLUSIONS
The duration of illness and prolonged symptom duration in 9% of the subjects indicate that the burden of dengue illness is substantially different from other non-dengue febrile illness in our study cohort. Our study also highlights the paucity of early prognostic markers for dengue fever in adults.
Low
Jenny G H
JG
Department of Infectious Diseases, Communicable Disease Centre, Tock Seng Hospital, Singapore. jenny.low@sgh.com.sg
Ooi
Eng-Eong
EE
Tolfvenstam
Thomas
T
Leo
Yee-Sin
YS
Hibberd
Martin L
ML
Ng
Lee-Ching
LC
Lai
Yee-Ling
YL
Yap
Grace S L
GS
Li
Chenny S C
CS
Vasudevan
Subhash G
SG
Ong
Adrian
A
D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis*; D003715:Dengue / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D003716:Dengue Virus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009017:Morbidity / Q000639:trends; D011379:Prognosis; D012367:RNA, Viral / Q000032:analysis*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012846:Singapore / Q000453:epidemiology
D000914:Antibodies, Viral; D012367:RNA, Viral