Dengue Outbreak in a Hilly State of Arunachal Pradesh in Northeast India

Abstract

Dengue has been reported from plains as well as hilly regions of India including some parts of Northeast India. In July-August 2012, outbreak of fever with unknown origin (FUO) indicative of Dengue was reported in Pasighat, East Siang district of Arunachal Pradesh (AP) state. Serum samples (n = 164) collected from patients from Health Training and Research Centre General Hospital, Pasighat, were tested for NS1 antigen and IgM antibodies. NS1-positive samples were analyzed by RT-PCR assay and entomological surveys were carried out. The majority of suspected cases reported NS1 antigen positivity. Females and young adults were mostly affected. The majority of the amplified NS1-positive samples showed Dengue serotype 3 infection. Aedes (Stegomyia) albopictus, known as semiurban breeding mosquitoes, was the only potential vector species identified from the affected areas of Pasighat which single handedly contributed to the outbreak. Thus, the present work identifies Dengue as an emerging arboviral infection in hilly state of AP along with a looming risk of its spread to neighbouring areas.

Serological and Epidemiological Picture of Dengue during the Year 2014: An Exclusive Study of Kutch District, Gujarat, India

“….67%) were slightly higher than the rural (362, 46.65%) areas. Although previous studies from Gujarat & India showed that prevalence of dengue cases were much higher in urban areas; difference here in the present study is much less Madhulika Mistry et al, 2015;Durani et al, 2014;Patankar et al, 2014;Dutta et al, 2012;Khan et al, 2014. One reason for this can be natural demography of Kutch region where majority of population lives in rural areas as per Census 2011 data (Government of India, 2011 Census).…”

Vigilance to Limit the Bidirectional Introduction and Co-circulation of Virus Serotypes Aims to Reduce Risk of Severe Dengue Disease in North East India

“…This physiographical region was hypoendemic for dengue, despite being surrounded by dengue-endemic countries and so represented a bottleneck to the spread of dengue across the Asian continent [33]. However, of public health concern North East India is now reporting outbreaks of dengue [34][35][36]. This is occurring in a region in which the incidence of disease was hitherto sufficiently low that the population has limited or no immunity to any DENV serotype.…”

“…Although Manipur was noted to have a porous border with Myanmar, there was no suggestion that the outbreak originated in Myanmar, so it is probable that it was introduced there by an infectious traveller from Cambodia or elsewhere [34]. Further outbreaks followed in Assam in 2010, 2012 and 2013 [35], and in Arunachal Pradesh in 2012 [36]. The number of confirmed dengue cases in Assam increased markedly from 237 in 2010 to 1058 in 2012 and then to 4526 in 2013 [35].…”

“…aegypti during the 2013 outbreak identified the presence of serotype DENV-2 [41]. Of 164 suspected cases in Arunachal Pradesh, 107 were confirmed by serology [36]. Of these, 89 were tested by RT-PCR and dengue was detected in 35: 27 instances of single serotype infection of DENV-3; 7 dual infections of DENV-1 and DENV-3; and one case of DENV-2 and DENV-3 mixed infection [36].…”

“…Of 164 suspected cases in Arunachal Pradesh, 107 were confirmed by serology [36]. Of these, 89 were tested by RT-PCR and dengue was detected in 35: 27 instances of single serotype infection of DENV-3; 7 dual infections of DENV-1 and DENV-3; and one case of DENV-2 and DENV-3 mixed infection [36]. A retrospective surveillance study of 430 suspected dengue cases during 2009-2011 found 143 to be dengue positive (92 by IgM-capture ELISA and 51 by RT-PCR); these were collected from Assam (82), Meghalaya (35), Nagaland (15), Manipur (8) and Arunachal Pradesh (3) [42].…”