KARACHI, Dec 5: Contrary to the trend of dengue fever cases reported in 2011, the month of November has witnessed the highest number of cases reported so far this year, including a death, from various city hospitals.
The situation is alarming while keeping in view the belief that the growth of the mosquito responsible for the spread of dengue virus is reduced during winter.
According to data obtained from the provincial government dengue surveillance cell, as many as 652 positive cases of mosquito-borne dengue fever, including 262 cases reported in November, have been reported so far this year.
Karachi had reported 858 dengue positive cases and 16 related deaths in 2011. Health authorities this year have confirmed two deaths of dengue positive patients in the city.
A month-wise breakdown of dengue positive cases reported this year shows: January (11) cases, February (14), March (eight), April (12), May (16), June (28), July (39), August (40), September (61), October (141) and November (262).
The dengue positive cases for 2011 were: January (18) cases, February (five), March (eight), April (seven), May (14), June (eight), July (24), August (48), September (393), October (377), November (142) and December (40).
So far this month (December), Karachi has reported 31 dengue positive cases, including five admitted to hospitals on Wednesday.
KMC-run Abbasi Shaheed Hospital, which had reported a large number of dengue positive cases last year, reported only two cases this year and that too on Wednesday.
Lack of oil for fumigation
While some citizens linked the change in the trend of dengue cases reported this year, particularly in October and November, to inadequate fumigation and overall relaxed attitude of public health workers in the city, a sources in the KMC municipal services department told Dawn that spray of insecticides through vehicle-mounted machines had been postponed because of non-availability of fuel needed for the vehicles and oil for the purpose of dilution of the chemicals used in the fumigation.
The department had started fumigation under a schedule, but that had to be stopped for want of fuel about 10 days ago, the source said.
They said that only four of the 18 towns in the city could run fumigation campaigns as per schedule so far, while authorities were waiting for supply of the needed fuel and oil for remaining 14 towns.
Speaking to Dawn on Wednesday, an infectious diseases expert in the city, Dr Afia Zafar, maintained that due to late commencement of monsoon in the city, the peak season of transmission of virus had shifted to November.
She said that although rains had been less, the rainy season delayed this year.
“Clean and stagnant water provides an ideal location for breeding of virus spreading mosquitoes, ie Aedes aegypti, and that needs to be checked and destroyed,” she said.
She advised the people to use mosquito repellents, wear clothes which covered most parts of their bodies, cover windows with nets and frequently use insecticides, in addition to avoiding staying outdoors for long at the time of sunset.