Can rapid dengue diagnostic kits be trusted? A comparative study of commercially available rapid kits for serodiagnosis of dengue fever.

BACKGROUND: Dengue virus infection is an important emerging disease of the tropical and subtropical regions and is mainly diagnosed by serological detection of NS1 antigen and IgM antidengue antibodies. Since enzyme-linked immunosorbent assay (ELISA) facilities are not easily available at most diagnostic centers, so most of them use various commercially available rapid diagnostic tests (RDTs) kits. AIMS AND OBJECTIVES: This study was designed to access the diagnostic accuracy of four commercially available and widely used RDTs for serodiagnosis of dengue virus infection in Indian laboratories. SUBJECTS AND METHODS: The study was conducted at Department of Microbiology, G.S.V.M Medical College, Kanpur, India, to estimate the sensitivity and specificity of following RDTs: (1) Dengue Cassette (Panbio, Australia), (2) Bioline Dengue Duo (SD Diagnostics, Korea), (3) Dengue Day 1 test (J Mitra and Co., India), and (4) Dengucheck Duo (Tulip Diagnostics, India) on 72 confirmed dengue serum samples that were positive by dengue reverse transcription-polymerase chain reaction, dengue NS1, and IgM ELISA along with 80 serum samples from nondengue febrile illness patients. RESULTS: The majority of the RDTs demonstrated low sensitivity but good specificity for detecting NS1 antigen. Detection of antidengue IgM antibodies by RDTs demonstrated low sensitivity ranging from 27.8% to 77.7%. However, specificity was generally higher (50%-86.2%) and more consistent across the assays. CONCLUSION: The study results differed markedly from the RDTs manufacturers' claimed performance characteristics. Therefore, the RDT results should be interpreted cautiously and ELISA should be performed as far as possible for serodiagnosis of dengue virus infection.

Cytomegalovirus infection in pregnant women and its association with bad obstetric outcomes in Northern India.

BACKGROUND: Cytomegalovirus (CMV) infection during pregnancy is far more complex than other infections, due to ability of the virus to be frequently reactivated during the child bearing age and may vertically transmitted to the developing fetus in spite of maternal immunity. Therefore, in the current study we determined the prevalence of CMV infection in pregnant women and tried to identify the role of maternal CMV infection in adverse pregnancy outcomes in Northern India. In this case-control study, 517 pregnant women, out of them 200 in case group and 317 in the control group. The overall 31.72% (164/517) cases were found with active CMV infection. CMV positivity (p=0.026) was significantly associated with bad obstetric history (75/200, 37.50%) compared to normal pregnancy (89/317, 28.07%). CMV infection was predominantly observed in age group 21-25 years. CMV positivity have been found to be significantly higher in women from rural area as compare to those from urban area (p=0.028). However, no significant difference has been observed in case of occupation, income, and haemoglobin level.

An outbreak of encephalitis associated with echovirus 19 in Uttar Pradesh, India, in 2011.

A sequence-independent single-primer amplification method and a modified enterovirus VP1 gene typing primer were used for identification of echovirus 19 and enterovirus 101, which remained undiagnosed by standard enterovirus molecular typing methods. Six different serotypes were identified during this study, with the predominance of ECV 19 (n = 20) followed by echovirus 21 (n = 3), EV 69 and EV 101 (n = 2 each), coxsackievirus B5 and ECV 27 (n = 1 each). To our knowledge, this is the first report of enteroviruses 69 and 101 in encephalitis cases in India.