Journal of Mosquito Research 2015, Vol.5, No.17, 1-10
2
variation between countries and within each country.
In 2010, World Health Organization (WHO) stratified
the current situation of Dengue/DHF in India under
category A (earlier it was under category B up to
2009), which means a major public health problem, a
leading cause of hospitalization and death among
children, shows cyclical epidemics in urban centers
spreading to rural areas with multiple virus serotypes
circulating. In India, National Vector Borne Disease
Control Program (NVBDCP) reported 28292
laboratory-confirmed dengue cases in 2010 from 31
out of 35 states in India (highest ever in a year). In
2011, 18,860 confirmed dengue cases were reported
and 169 deaths and in 2012, total 37,070 cases and
227 deaths were attributable to dengue in India
(NVBDCP 2012).
The northern states of India are badly affected by
dengue, although the intensity of transmission varies
every 2-4 years. Uttarakhand is one of the dengue
prone states in northern India, which has a history of
dengue epidemics since long with a heavy epidemic of
dengue/DHF in 2010. Moreover, Uttarakhand (India)
is the prime destination of tourists from all over the
world. This also increases the traveler’s health risk.
Cultural tradition, socio-environmental conditions,
and household circumstances often result in the
absence or in the irregularity of water supply for a
significant part of the population in Uttarakhand,
causing the need to store water in reservoirs (Singh et
al
.
2010). Moreover, due to a relatively dry climate in
summer seasons, people use water coolers (a cooling
device made up of metal/plastic having a water tank)
in their houses. These coolers are the potential place
for
Aedes
mosquito breeding. Furthermore, because of
irregular garbage collection in many areas, other
breeding sites like plastic container, tin containers,
bottles, water storage tanks, tire, and many unusual
breeding sites.
In this study, epidemiological characteristics of
dengue/DHF and the entomological parameters were
assessed during the epidemic of dengue in 2010 to
determine the epidemic risk of dengue in Uttarakhand,
India with the aim to establish better policies to
control the dengue epidemics in these areas (e.g.,
improvement of water supply to minimize the
requirement of storage water, which are found to the
breeding place of
Aedes aegypti
; establish a local
threshold of HI, BI & CI for forecast the outbreak
etc.). The results of above study are presented in this
manuscript.
Methods
Study Area and its eco-environmental settings
Initially, the study was conducted in different parts of
Uttarakhand, however, finally, we focused our
epidemiological and entomological surveillance in
Nainital and Dehradun, the two districts badly hit by
dengue epidemics in 2010. We analyzed the
epidemiological history of dengue in the entire
Uttarakhand state, and selected Nainital (exhibited a
low-middle epidemics in September 2009 with 51
confirmed dengue cases) and Dehradun (exhibited an
early signal of epidemics on August 2010 with 19
confirmed dengue cases) districts for investigations of
entomological measures of risk of dengue. The
localities within these two districts for the
entomological survey were picked out based on
dengue suspected cases reported during 2009-2010.
Total 11 localities each in Nainital (viz. Forest
compound, Kotdwar Rd., Khatyari, Gular Ghati,
Perumdara, 25 acres Colony, CCPM colony, Nageena
Colony, bungalow colony, Bindukhatta, Indiranagar)
and Dehradun (viz. Patel Nagar, Vikas Nagar,
Chandreshwar Nagar, Kailash gate, Shyampur,
Aadarsh gram, Rani Pokhari, Reetha Mandi, Deep
Nagar, Kedar Purum, Indra colony) districts were
chosen.
Topography:
Uttarakhand lies within the Himalayan
region, with three distinct topographical belts - the
Shivaliks within the sub Himalayan tract [300-600 m
Above Mean Sea Level, (AMSL)], the Himachal
ranges within the lower Himalayan region (1,500-2,700
m AMSL), and the Himadri ranges within the upper
Himalayan region (4,800-6,000 m AMSL). The lower
hilly region, ranging between 600 m-1,800 m, and it is
within the region where the majority of the human
populations live. Major parts of our study sites are
located in this region.
General Climate:
The climatic conditions change
with the increase of altitude, extending from sub-zero
temperatures at high altitudes in winter to moderate
temperatures in the lower tracts in summer. The
territory has three distinct seasons - monsoon (June -
September), winter (October- February) and summer
