Co-circulation of Chikungunya and Dengue viruses in Dengue endemic region of New Delhi, India during 2016.

Co-circulation of Chikungunya and Dengue viral infections (CHIKV and DENV) have been reported mainly due to transmission by common Aedes vector. The purpose of the study was to identify and characterise the circulating strains of CHIKV and DENV in DENV endemic region of New Delhi during 2016. CHIKV and DENV were identified in the blood samples (n = 130) collected from suspected patients by RT-PCR. CHIKV was identified in 26 of 65 samples (40%). Similarly, DENV was detected in 48 of 120 samples (40%). Co-infection with both the viruses was identified in five (9%) of the samples. Interestingly, concurrent infection with DENV, CHIKV and Plasmodium vivax was detected in two samples. CHIKV strains (n = 11) belonged to the ECSA genotype whereas DENV-3 sequences (n = eight) clustered in Genotype III by phylogenetic analysis. Selection pressure of E1 protein of CHIKV and CprM protein of DENV-3 revealed purifying selection with four and two positive sites, respectively. Four amino acids of the CHIKV were positively selected and had high entropy suggesting probable variations. Co-circulation of both viruses in DENV endemic regions warrants effective monitoring of these emerging pathogens via comprehensive surveillance for implementation of effective control measures.

Occurrence of co-infection with dengue viruses during 2014 in New Delhi, India.

Dengue fever is an arthropod-borne viral infection that has become endemic in several parts of India including Delhi. We studied occurrence of co-infection with dengue viruses during an outbreak in New Delhi, India in 2014. For the present study, blood samples collected from symptomatic patients were analysed by RT-PCR. Eighty percent of the samples were positive for dengue virus. The result showed that DENV-1 (77%) was the predominant serotype followed by DENV-2 (60%). Concurrent infection with more than one serotype was identified in 43% of the positive samples. Phylogenetic analysis clustered DENV-1 strains with the American African and DENV-2 strains in Cosmopolitan genotypes. Four common amino-acid mutations were identified in the envelope gene of DENV-1 sequences (F337I, A369T, V380I and L402F) and one common mutation (N390S) in the DENV-2 sequences. Further analysis revealed purifying selection in both the serotypes. A significant number of patients were co-infected with DENV-1 and DENV-2 serotypes. Although we do not have direct evidence to demonstrate co-evolution of these two stereotypes, nonetheless their simultaneous occurrence does indicate that they are favoured by evolutionary forces. An ongoing surveillance and careful analysis of future outbreaks will strengthen the concept of co-evolution or otherwise. Whether the concurrent dengue viral infection is correlated with disease severity in a given population is another aspect to be pursued. This study is envisaged to be useful for future reference in the context of overall epidemiology.

Clinical course and outcome of snake envenomation at a hospital in Karachi.

INTRODUCTION: Snake envenomation is a frequently reported medical emergency at the Civil Hospital Karachi, Pakistan, [corrected] thus obviating the need to assess the patterns of the clinical course and outcome of snake envenomation cases. METHODS: The demographic characteristics, clinical signs and symptoms, laboratory findings, treatment and outcome of 80 victims of snake bite were recorded. These patients were admitted to the Civil Hospital Karachi between January 2006 and September 2007. The data of all the cases was analysed statistically using the Statistical Package for the Social Sciences version 11.0. RESULTS: The majority of the 80 victims of snake bite were male (80 percent) and 20 percent were female. The mean age of the patients was 33.3 years. The main type of envenomation was vasculotoxic (92.5 percent), and none were neurotoxic or myotoxic. Both local and systemic clinical features of envenomation were present. Bleeding was reported in 43.8 percent of the patients. 71.3 percent of the patients showed coagulopathy of defibrination and the anti-coagulant type. All patients received anti-snake venom. Five (6.3 percent) patients in the study died. CONCLUSION: The most common type of snake envenomation in this part of the province of Sindh is vasculotoxic due to the high inhabitancy of Viperidae. High morbidity and mortality rates can be reduced significantly through patient education on the precautions that need to be taken by farmers and field workers against snake bite. Early referral to a well-equipped health facility is necessary, as the mortality rate was high among those patients who arrived late.