Monsoon is yet to arrive in Mumbai, but mosquito borne diseases have already started gripping the city.tanakawho/Flickr

Monsoon is yet to arrive in Mumbai, but mosquito borne diseases have already started gripping the city.

While various hospitals in the city have reportedly attended to nearly 1,000 cases of malaria recently, according to the health department of BMC, nearly 2000 cases of the deadly disease have been registered in Mumbai in the past few months, DNA reported.

"If we compare the figures in the beginning of the year, the last two months (April-May) have been witnessing a rise in malaria cases. Mumbai sees malaria cases round the year and number peaks during monsoon, between August and November," Dr Pratit Samdhani, physician at Jaslok Hospital, told the newspaper.

Doctors who attended the cases also saw a notable change in the nature of the disease and warned about the risk of the disease remaining undetected. At the time of admission, most of the malaria patients were suffering from severe complications like low platelets, fever and liver complaints.

"We have unfortunately been seeing a rising number of malaria cases in this off-season. It's under reported because of the weird nature of the disease. Malaria is not picked up in the first two blood samples. This leads to such patients landing in hospitals with lung, heart, liver problems." Dr Khusrav Bhajan, intensivist at PD Hinduja Hospital, told DNA. "Doctors have to be vigilant as it looks like the parasite has undergone some kind of a mutation."

However, according to the BMC, the numbers are the same as last year and there is no need to panic as they have already taken the necessary steps to ensure safety. "We have round-the-year programmes to fight malaria," Dr Mangala Gomare, epidemiology department in-charge in BMC, told DNA. "We now aim to restrict malaria cases to the minimum and require Mumbaikars' cooperation for this."

Meanwhile, scientists at the Indian Institute of Tropical Meteorology (IITM) in Pune on Wednesday announced a 10 day delay in monsoon. Monsoon was expected to hit central India by 15 June. Number of the mosquito borne diseases is expected to go up once the monsoon hits the country.

Though malaria and dengue are very common, they are more life-threating than the swine flu, doctors say. "For one swine flu death, there are over 100 malarial deaths," Dr Vivek Sharma, senior child consultant at a private hospital in Jaipur told Times of India, in 2009.

Malaria is a disease that spreads through the bite of mosquitoes infected by a parasite known as plasmodium. After reaching the human body, the parasites get multiplied in the liver and infect red blood cells, according to the World Health Organization (WHO). It takes at least 10 to 15 days before the patient starts getting symptoms like headache, vomiting and fever. When left untreated, the disease can interrupt blood supply to important organs in the body, and can claim life.

Nearly 207 million cases of malaria were reported in 2012 and the disease claimed 6,27,000 lives, according to a WHO report.