City residents may complain about the soaring temperature, but it seems to have had one beneficial effect – according to statistics from the directorate of public health, the number of H1N1 (swine flu) cases have come down.
Joint director of public health (epidemics) S. Balasubramanian said that the number of reported cases has fallen from about 15 to 20 daily, to about one or two. “For the last two days, we have had no cases. In April, we had a total of 76 cases and one death,” he said. In January, there were 86 reported cases and eight deaths. The virus seems to have peaked in March, with 307 cases and seven deaths, but in the latter half of the month, the number of cases began to come down, said Dr. Balasubramanian.
According to the meteorological department, temperatures in the city began rising in the third week of March and were at a sweltering 35 degree Celsius for most of April and touched 36 degrees towards the end of that month. May started out scorching with the mercury levels touching 36 and 37 degree Celsius on the first two days, and then dipping slightly to 34.6 degrees on Monday.
Doctors in the city too, say they are seeing fewer cases of swine flu than before. “In April and May, there have hardly been any cases. In March, we saw the maximum number of patients largely due to panic. In January and February, there were a number of positive cases, but over the last few weeks, there has been nothing,” said Janani Shankar, senior consultant pediatrician, Kanchi Kamakoti Childs Trust Hospital. S. Thangavelu, of Dr. Mehta’s Hospital too said overall, the number of cases has come down considerably.
Subramanian Swaminathan, consultant, infectious diseases, Global Hospitals, said intense temperatures can destroy germs. “Temperature does have a role to play in killing the virus. Also, there is a possibility that since schools have closed for the vacations, there is less crowding and the transmission of the H1N1 has been interrupted. In the West too, by the end of April and May, the virus peters down,” he said.
With the temperature expected to stay high – the forecast for this week is between 35 and 37 degree Celsius – the virus may weaken further, said Dr. Balasubramanian. “It is very fragile in heat, and in temperatures above 34 degree Celsius, the transmission collapses,” he said.
However, 2015 has had the maximum number of cases and deaths in the last two years. “Every 15 to 20 years, the virus becomes pandemic. Within this, once in three years or so, it taken an epidemic form. The last time this occurred was in 2012, and now again this year,” he said. In 2009, when the virus was pandemic, affecting dozens of countries across the world, the State saw 3,057 cases and 10 deaths. Dr. Balasubramanian explained that the virus would continue to remain seasonal and in effect until all communities developed immunity towards it, after which it would probably take another form.
After two years of fewer cases, 2015 has seen a spurt in cases in the State
Year Cases Deaths
2009 3,047 10
2010 1,405 24
2011 34 4
2012 750 40
2013 48 7
2014 64 9
2015 (until May 5) 679 17
In August 2010, after the 2009 pandemic, the World Health Organisation announced that the virus had moved into the post-pandemic period but that localised outbreaks of various magnitudes were likely to continue for some years.
2015, month-wise data
Month Cases Deaths
Jan 86 8
Feb 208 1
March 307 7
April 76 1
May (till 5) 2 0
Source: Directorate of Public Health and Preventive Medicine, Tamil Nadu
) 2 0
Year-wise data of H1N1 in TN
