Kathmandu, Dec. 12: The number of people infected with dengue in the Nepal has increased this year, due to the unplanned and fast urbanisation.
According to the Epidemiology and Disease Control Division (EDCD), under the Department of Health Services, over 1,500 people have been living with dengue positive till the date in 2016.
Dengue cases have not been increasing steadily, however. In 2009, a total of 917 people affected by the disease had reached health institutions and of them, five had died due to the disease. In 2015, 35 people were clinically proved as dengue positive and one had died.
The first case of dengue was detected in Nepal in 2004 in a foreigner traveling to Chitwan. Then after, the epidemic spread in Chitwan since 2005, and by now it is the worst hit district.
Although the period between mid-October and mid-November is the most favourable for dengue, viruses to the spread, the disease is recorded even in December, health officials said.
A total of 30 districts, almost all Terai districts and some hilly districts seem to be prone to dengue epidemic, said Dr. Guna Nidhi Sharma, chief of the epidemiology and disease control programme under the EDCD.
Majority of the infections have been reported from Ratnanagar and Tandi, located in the eastern part of Chitwan district, he added.
Chitwan is highly prone to the spread of vector-borne diseases such as dengue. But the government did not launch any effective programme in the area before the epidemic started, senior virologist Dr. Basudev Pandey said.
Normally, dengue and other viral diseases increase sharply in a gap of every 2 to 3 years. This means, periodic increase may be the cause of unexpected rise of dengue cases this year, he said.
On the other hand, existing immunity power of the human body also decreases in the second time infection. The immunity power of the whole community to fight against the disease goes lower with the frequency of the infection, he said.
The period from October to December is a favourable time for the growth of the Aedes aegypti mosquito, which is responsible for transmitting dengue.
High fever, pain in the joints and muscles, rashes on the body and bleeding of the gums are the major symptoms of dengue.
In terms of density of the mosquito population, the people of Chitwan are highly prone to being infected with dengue, where a number of people die of it every year.
Unplanned and fast urbanisation and high temperature are blamed for the rise in dengue cases in Terai districts including Chitwan.
Lack of investigation over the cause of spread of dengue and effective programme to control the disease before the spread of epidemic led to the high burden of disease and numbers of death, said Dr. Sher Bahadur Pun, an expert on viral and vector borne diseases at the Shukra Raj Tropical and Infectious Disease Hospital,Teku.