Emergence of dengue virus type 4 (genotype I) in India

Abstract

Dengue is an emerging arboviral disease and currently poses the greatest arboviral threat to human health. In recent decades, there has been a substantial increase in dengue outbreaks in many parts of the world including India. We performed an in-depth investigation of a major dengue outbreak in Andhra Pradesh, southern India in 2007 by serology, virus isolation, RT-PCR and genotyping. The results revealed an unusual emergence of dengue virus type 4 (DENV-4) along with the prevailing DENV-3. Phylogenetic analysis based on complete envelope gene of 182 globally diverse DENV-4 isolates demonstrated the involvement of a unique clade of genotype I of DENV-4 in the outbreak. This study also demonstrated a clear shift in the dominant serotype from DENV-3 to DENV-4 in India. This is the first report regarding the molecular characterization of Indian isolates of DENV-4, which has the potential to be involved in future outbreaks.

Genetic characterization of dengue viruses prevalent in Kerala State, India

“…4). Genotype III of DENV-3 is of Indian origin (Messer et al, 2003), and this strain has been suspected to cause more fatal infections (Dash et al, 2005). Two lineages of this genotype were recorded in the present study in Kerala.…”

“…Previously, it was reported that DENV-2 was the major serotype circulating in India (Dar et al, 1999;Kumar et al, 2001). Recently, DENV-3 has emerged as the major serotype in different parts of the country (Dash et al, 2005). Due to a lack of studies in Kerala before the 2008 outbreak on the genetic characterization of the virus, we are unable to arrive at a conclusion on the evolutionary trends of different serotypes in Kerala.…”

To study cardiac manifestations in patients presenting with dengue infection and to find out the correlation of cardiac manifestations to warning signs of dengue

“…8 Mean age group of present study is 29.3 years youngest was 18 years and oldest was 50 years and age group that is mostly affected in other studies like Gupta et al New Delhi was 5-20 years, Dash PK et al Gwalior was <15 years, and Neeraja M in Hyderabad was 20 -39 years. [9][10][11] In this study most of the patients are males (64) in comparison to females (36) and ratio is 1.7:1. In other studies like Dash PK et al, Gwalior male female ratio was 1.28:1, Neeraja M Hyderabad was 2:1, Gupta et al New Delhi, was 1.8 :1.…”

“…Difference in this may be due small number of patients taken in this study group or it may be due to because of male dominated region where male seeks more medical help in comparison to females. [9][10][11] This needs study with more numbers of patients.…”

Seroprevalence of dengue virus in a tertiary care hospital, Andhra Pradesh, South India

“…3 The largest Dengue outbreak in India which occurred in 1996, was due to DENV-2. 4 This was later replaced by 5 The subsequent outbreaks witnessed a mixed type of infection with DENV-1, 2 and 3. 6,7 We present the seroprevalence of Dengue virus referred to a tertiary care hospital from in and around Government and private hospitals and clinics of Hyderabad and Districts surrounding Hyderabad for a period of 18 months.…”