Delhi Gripped by Chikungunya and Dengue Viruses

More than 1,000 cases of chikungunya have been registered in India's capital city. Delhi is reporting one of its worst outbreaks of the mosquito-borne chikungunya virus in India.

The name chikungunya derives from a word meaning "to become contorted" from the African Kimakonde language.

The illness is largely non-lethal although the World Health Organization (WHO) and India's health minister JP Nadda told reporters, “that the government was investigating to see if the virus could be linked to the deaths, as many of those who died were already suffering from other illnesses such as kidney disease and high blood pressure.”

"The Health committee went through all the documents and concluded that most patients have died due to comorbidities they already suffered from. Chikungunya virus did not kill them.

In the case of dengue deaths, supportive documents were missing in at least four cases," said Dr Raheja head of the dengue control cell.

It is unclear why Delhi has been so severely affected this year, but heavier than usual rainfall coupled with the large number of construction projects in the city could be a factor, as this can create many stagnant pools of water where mosquitoes can breed.

The city of Delhi also has a large number of open drains.

Officials have been fumigating densely populated areas of Delhi. These diseases are spread by mosquitoes that bite and pass on the viruses.

Two of the mosquito species most commonly involved in spreading the virus are Aedes aegypti and Aedes albopictus, which can also transmit other mosquito-borne viruses, including dengue.

Chikungunya is a viral disease spread by mosquitoes that bite during daylight hours. It cannot be transmitted from person to person.

Chikungunya severely affects the quality of life of those who contract it - in many cases severe joint pains persist even after the fever has subsided.

Symptoms include the sudden onset of fever and joint pain, particularly affecting the hands, wrists, ankles and feet. Most patients recover after a few days but in some cases the joint pain may persist for weeks, months or even longer.

Dengue is a disease caused by any one of four closely related dengue viruses (DENV 1, DENV 2, DENV 3, or DENV 4). The viruses are transmitted to humans by the bite of an infected mosquito. Delhi has been experiencing a larger than normal number of cases of Dengue as well.

The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.

Dengue hemorrhagic fever is characterized by a fever that lasts from 2 to 7 days, with general signs and symptoms consistent with dengue fever. When the fever declines, symptoms including persistent vomiting, severe abdominal pain, and difficulty breathing, may develop. This marks the beginning of a 24- to 48-hour period when the smallest blood vessels (capillaries) become excessively permeable (“leaky”), allowing the fluid component to escape from the blood vessels into the peritoneum (causing ascites) and pleural cavity (leading to pleural effusions).

This may lead to failure of the circulatory system and shock, followed by death, if circulatory failure is not corrected.

There is no vaccine available for Chikungunya today. Three vaccines have made it to clinical trials, but none have been licensed for distribution.

However, there is a dengue vaccine, Dengvaxia (CYD-TDV), developed by Sanofi Pasteur. Approximately five additional dengue vaccine candidates are in clinical development.

Health officials advise wearing long-sleeved clothing and trousers that minimizes skin exposure, and to wear insect repellent at all times in areas where the mosquitoes involved are found.