Dhaka: Amid the spread of Chikungunya, a viral disease transmitted to humans through infected mosquitoes, in the capital Dhaka, another mosquito-borne disease dengue has silently struck the city amid the variation in rainfall pattern.

Dengue is a seasonal fever. Generally, people in the capital get infected with dengue virus when monsoon begins since mosquitoes find a suitable atmosphere and spread the virus.

Official data reveals that only 68 people got infected with dengue virus in first four months of 2016. On the other hand, a total of 254 people suffered from dengue during the same period this year (2017).

A large number (91) of people were infected with dengue virus in the city in January this year while 58 cases were reported in February, followed by 33 in March and 72 in April this year, according to the data provided by the National Health Crisis Management Centre and Control Room of the Director General of Health Services (DGHS).

Dengue fever, also known as breakbone fever, is a mosquito-borne tropical disease caused by the dengue virus. Dengue is spread by two mosquito species-Aedes aegypti and to a lesser extent Aedes albopictus-both of which breed in stagnant water pools.

According to experts, global climate change contributes to variation of rainfall pattern in the South Asia, including Bangladesh, resulting in early outbreak of viral diseases like dengue fever.

"We first identified infections of dengue virus in the capital Dhaka in early January last since rain started early this time and helped mosquitoes spread the virus fast," in-charge of the National Health Crisis Management Centre and Control Room Dr Ayesha Akhter told UNB.

The June-September period is the season of dengue fever in Bangladesh. But, the season for the dengue virus is prolonging here as it starts early and continues even after winter sets in.

Official data shows that so far over 660 dengue cases with two fatalities have been reported this year in the capital. Of them, 121 dengue cases were reported in May, followed by 202 in June and 84 up to July 16, 2017.

In 2016, some 6,060 dengue cases with 14 fatalities were found in the city. Maximum 1,544 people suffered from dengue in September last year while 1,451 cases were found in August, followed by 1,077 in October, 928 in July, 522 in November, 254 in June and 145 in December.

Analysing these official data, it has been found that the prime period of dengue outbreak is still ahead and it may hit the capital hard in the coming days. "If the monsoon prolongs, obviously more people will be infected by dengue this year," Dr Ayesha said.

Dengue cases are increasing in the country, especially Dhaka and its adjoining areas, day by day. But, it gets less focus due to Chikungunya prevalence. So far, around 17 patients affected with dengue get admitted to different hospitals while 642 got released after taking treatment from hospitals this year.

The symptoms of the dengue are sudden high fever, severe headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into the life-threatening dengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs.