Comparative performance of the probable case definitions of dengue by WHO (2009) and the WHO-SEAR expert group (2011)

Abstract

Background The primary objective of this study was to find the performance of the 2009 probable case definition of dengue and compare it with the definition given by the WHO-SEAR expert group in 2011. Methods A cross-sectional study was conducted in Thiruvananthapuram district of Kerala, which is hyperendemic for dengue. A consecutive series of 851 participants defined by the selection criteria were recruited from the primary, secondary, and tertiary health care settings. Sensitivity, specificity, predictive values, and likelihood ratios of the clinical case definitions were calculated using reverse transcriptasepolymerized chain reaction (RT-PCR) as gold standard in case of fever less than or equal to 5 days and serology (IgM positivity) for fever .5 days. Diagnostic odds ratio (DOR) was also calculated as a single indicator of performance of the case definition. Results The 2009 World Health Organization (WHO) case definition had a sensitivity of 76.4% (69.6-82.1) and negative predictive value of 87.5%. The 2011 WHO-SEAR expert group case definition had a higher sensitivity of 87.9% (82.2-91.9) but lower negative predictive value of 86.6%. The three independent criteria which were significantly associated with dengue were thrombocytopenia less than 150 000 (OR 2.80), leukopenia (OR 2.28), and absence of backache (OR 2.68). The performance of 2009 case definition was better (DOR 2.4) than the 2011 WHO-SEAR expert group case definition. This was further enhanced when thrombocytopenia was specified as platelet count less than 150 000 (DOR2.7). When 'no backahe' was added as an additional criteria, the performance of both definitions improved. Conclusions The 2009 WHO case definition has better discriminatory power than the 2011 WHO-SEAR expert group case definition. The performance of 2009 WHO case definition is enhanced by specifying thrombocytopenia as platelet count less than 150 000. The inclusion of 'no backache' further improves the discriminatory power. This may be more useful in primary care settings, to rule out dengue.

Re-Model the Relation of Vector Indices, Meteorological Factors and Dengue Fever

“…Dengue is the most rapidly expanding and spreading mosquitoborne viral disease in tropical and subtropical countries [1]. This disease is mainly transmitted by Aedes aegypti and Aedes albopictus [2].…”

“…This disease is mainly transmitted by Aedes aegypti and Aedes albopictus [2]. The incidence of dengue has increased by 30-fold in the past 50 years [1]. Approximately 2.5 billion people in more than 100 countries are currently under the risk of dengue viral infection, with the majority living in the Asia-Pacific region [3].…”

Utility of dengue NS1 antigen rapid diagnostic test for use in difficult to reach areas and its comparison with dengue NS1 ELISA and qRT‐PCR

“…In a recent study, that used WHO case definition of DEN as the standard and evaluated the same RDT that we have evaluated the sensitivity and specificity was reported very low, probably because of using the clinical criteria as reference marker, that itself is debatable . Moreover, it is reported that the RDTs have different sensitivity and specificity in primary and secondary infection, Timing and storage of specimen, and to the infection by different serotypes .…”

Accuracy of clinical criteria and an immunochromatographic strip test for dengue diagnosis in a DENV-4 epidemic

“…We were also not able to reevaluate the patients in the convalescent period due to the pragmatic diagnostic study outline and the dynamics of the Rio de Janeiro city’s health care system. Although the gold standard for dengue diagnosis would be pairing specific dengue IgM in acute and convalescent period, as proposed by WHO [ 11 ], recent studies have also exclusively used PCR as the reference test to evaluate early phase dengue [ 45 ], to evaluate clinical algorithms [ 46 ] or ELISA and NS1 tests [ 15 ].…”