The changing epidemiology of dengue in Delhi, India

BACKGROUND: A major DHF outbreak occurred in Delhi in 1996. Following this another outbreak was reported in the year 2003. In the years 2004 and 2005, though no outbreak was reported, a definitely higher number of samples were received in the virology laboratory of A.I.I.M.S. from suspected cases of dengue infection. This study was designed to compare the serological and virological profiles of confirmed dengue cases in the years 2003, 2004 and 2005. RESULTS: Out of 1820 serum samples received from suspected cases in all three years, 811 (44.56%) were confirmed as dengue infection serologically. Out of these confirmed dengue cases maximum cases, in all three years, were seen in the age group 21–30 years. There was an increase in the number of samples received in the post monsoon period (September to November) with a peak in the second and third week of October. More samples were received from DHF cases in the year 2005 than 2004 and 2003. All four dengue serotypes were seen co-circulating in the year 2003, followed by complete predominance of dengue serotype 3 in 2005. CONCLUSION: Epidemiology of dengue is changing rapidly in Delhi. Dengue infections are seen every year thus making it an endemic disease. After co-circulation of all serotypes in 2003, now dengue serotype 3 is emerging as the predominant serotype

Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

<p>Abstract</p> <p>Background</p> <p>Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating during one outbreak.</p> <p>Results</p> <p>Acute phase sera from patients were tested for the presence of dengue virus RNA by RT-PCR assay. Of the 69 samples tested for dengue virus RNA, 48 (69.5%) were found to be positive. All the four dengue virus serotypes were found to be co-circulating in this outbreak with DENV-3 being the predominant serotype. In addition in 9 of 48 (19%) dengue virus positive samples, concurrent infection with more than one dengue virus serotype were identified.</p> <p>Conclusion</p> <p>This is the first report in which concurrent infections with different dengue virus serotypes is being reported during an outbreak from India. Delhi is now truly hyperendemic for dengue.</p

Respiratory viral infections detected by multiplex PCR among pediatric patients with lower respiratory tract infections seen at an urban hospital in Delhi from 2005 to 2007

<p>Abstract</p> <p>Background</p> <p>Acute lower respiratory tract infections (ALRI) are the major cause of morbidity and mortality in young children worldwide. Information on viral etiology in ALRI from India is limited. The aim of the present study was to develop a simple, sensitive, specific and cost effective multiplex PCR (mPCR) assay without post PCR hybridization or nested PCR steps for the detection of respiratory syncytial virus (RSV), influenza viruses, parainfluenza viruses (PIV1–3) and human metapneumovirus (hMPV). Nasopharyngeal aspirates (NPAs) were collected from children with ALRI ≤ 5 years of age. The sensitivity and specificity of mPCR was compared to virus isolation by centrifugation enhanced culture (CEC) followed by indirect immunofluorescence (IIF).</p> <p>Results</p> <p>From April 2005–March 2007, 301 NPAs were collected from children attending the outpatient department or admitted to the ward of All India Institute of Medical Sciences hospital at New Delhi, India. Multiplex PCR detected respiratory viruses in 106 (35.2%) of 301 samples with 130 viruses of which RSV was detected in 61, PIV3 in 22, PIV2 in 17, hMPV in 11, PIV1 in 10 and influenza A in 9 children. CEC-IIF detected 79 viruses only. The sensitivity of mPCR was 0.1TCID₅₀for RSV and influenza A and 1TCID₅₀for hMPV, PIV1, PIV2, PIV3 and Influenza B. Mixed infections were detected in 18.8% of the children with viral infections, none detected by CEC-IIF. Bronchiolitis was significantly associated with both total viral infections and RSV infection (p < 0.05). History of ARI in family predisposed children to acquire viral infection (p > 0.05).</p> <p>Conclusion</p> <p>Multiplex PCR offers a rapid, sensitive and reasonably priced diagnostic method for common respiratory viruses.</p

Co-infections with Chikungunya Virus and Dengue Virus in Delhi, India

Aedes aegypti mosquitoes are common vectors for dengue virus and chikungunya virus. In areas where both viruses cocirculate, they can be transmitted together. During a dengue outbreak in Delhi in 2006, 17 of 69 serum samples were positive for chikungunya virus by reverse transcription–PCR; 6 samples were positive for both viruses

Eugenol isolated from supercritical fluid extract of Ocimum sanctum: a potent inhibitor of DENV-2

Abstract Dengue is one of the fairly prevalent viral infections at the world level transmitted through mosquitoes (Aedes aegypti and Aedes albopictus). Due to various environmental factors, dengue cases surged rapidly at the global level in recent decades, with 193245 cases in 2021 and an increment of 110473 cases in 2022. There is no antidote available against dengue and other flaviviruses. In the absence of a dengue vaccine or specific antiviral, medicinal plants or their products can be the only choice for its effective management. Ocimum sanctum is known as ‘‘The Incomparable One,’’ ‘‘Mother Medicine of Nature’’ and ‘‘Queen of Herbs’’ in Ayurveda, and is considered an "elixir of life" supreme in both healthcare and spiritual terms. In present study eugenol was isolated in O.sanctum. Eugenol (1-hydroxy-2-methoxy-4-allylbenzene) has been substantially responsible for its therapeutic potential. High-performance thin-layer chromatography, Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy were applied to identify the compound. The Rf value of isolated compound was same in the chromatogram (0.69 + 0.05) with compare to standard. The safe dose of plant and eugenol were found as < 31.25 μg/ml and < 15.62 µg/ml. The anti-dengue activity was assessed in C6/36 cell lines, their effect was determined through Quantitative PCR. The NMR of the isolated eugenol showed similar properties as the commercial marker compound. The eugenol and SFE extract of O. sanctum showed the inhibition of 99.28% and completely against Dengue-2, respectively. Docking study exposed that the interaction of eugenol with NS1 and NS5 dengue protein showed the binding energy as − 5.33 and − 5.75 kcal/mol, respectively. The eugenol from the O. sanctum plant has the potential to be a good source of future treatment medications for dengue illness, as well as a valuable tool in its successful managemen

Genetic Variability among Group A and B Respiratory Syncytial Virus Isolates from a Large Referral Hospital in New Delhi, India

Respiratory syncytial virus (RSV) is an important childhood pathogen of acute lower respiratory infections in developed and developing countries. The molecular epidemiology of RSV in India is largely unknown. The present study was undertaken to standardize and evaluate reverse transcription-PCR (RT-PCR) for the rapid and simultaneous detection of RSV groups A and B in clinical samples and to study intragroup genetic variability. RT-PCR was evaluated by comparing the results of seminested RT-PCR with centrifugation-enhanced cultures on 200 nasopharyngeal aspirates from children with acute lower respiratory infections. RSV was isolated in 34 nasopharyngeal aspirates by centrifugation-enhanced cultures and identified in 45 samples by RT-PCR. In 15 samples RSV was identified by seminested RT-PCR alone and in four by centrifugation-enhanced cultures alone. Of the 45 samples positive for RSV by nested PCR, 15 belonged to group A, 29 to group B, and one sample suggested a mixed infection. Group B RSV predominated in both years of the 2-year study. Genetic variability within RSV groups was studied by restriction fragment analysis of 35 PCR products. Among both group A and group B RSV, two different composite patterns were observed. Thus, RSV was found to be a major pathogen of acute lower respiratory tract infections in India, as it was detected in 24.5% of children by RT-PCR. RT-PCR provides a sensitive method for detection and typing of RSV group A and B viruses in clinical samples as well as a means to study intragroup variations. However, a higher sensitivity of detection of RSV in clinical samples can be obtained by its combination with additional techniques, such as virus cultivation