Dengue cases cross 1,000 mark in Delhi
With 190 new cases reported in the week ending October 20, the total number of infections reported by the Municipal Corporations of Delhi has gone up to 1,020 cases. Five more suspected dengue deaths were reported by Delhi hospitals and are waiting to be confirmed.Updated: Oct 24, 2018 09:03 IST
Even with a milder dengue strain doing the rounds this year, the mosquito-borne viral infection has hit over 1,000 people so far this year in Delhi and resulted in the death of a 12-year-old girl.
With 190 new cases reported in the week ending October 20, the total number of infections reported by the Municipal Corporations of Delhi (MCDs) has gone up to 1,020 cases. Five more suspected dengue deaths were reported by Delhi hospitals and are waiting to be confirmed.
October and November are usually the months when the disease peaks in the national capital.
The numbers start decreasing once the temperature dips and the winter sets in.So, even though the numbers started spiking mid-September, fewer cases are likely to be reported this year as compared to the two previous years.
The 1,020 cases reported this year is still lesser than half the number of cases that were reported during the same period in the past two years — 2,884 in 2017, and 2,099 in 2016.
The numbers and hospitalisations are fewer this year as the dengue strain in circulation is Type-3, which is known to be less virulent. Dengue has four strains and Type-2 and 4 are known to have severe disease manifestation and, normally, require hospitalisation.
Dengue strain Type-1 and Type-3 are less potent.
“Also, this year, fewer cases were reported as the rainfall was heavy and continuous and washed away mosquito breeding sites,” Dr PL Joshi, former director of National Vector Borne Disease Control Programme, said.
There are several factors that determine the spread of dengue – the temperature, rainfall, breeding control measures, the herd immunity and the strain of the virus. However, the most effective way to manage the spread of the disease is to effectively control mosquito breeding.
“Rain and temperature are good predictors of whether there could be an outbreak. However, those factors cannot be manipulated. To effectively control the vector, a holistic approach is needed— from better hygiene and sanitation to wiping away breeding grounds and control measures such as fogging if there is a huge population of adult mosquitoes,” Dr Sujatha Sunil, group leader, Vector Borne Diseases Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), said.
The numbers that are reported with the civic agencies are still far fewer than the actual numbers, primarily due to underreporting of cases.
In a study, published in The American Journal of Tropical Medicine and Hygiene, titled Economic and Disease Burden of Dengue Illness in India, it was found that between 2006 and 2012, the actual number of clinically diagnosed dengue cases was 282 times higher than the reported numbers.
And, 80% of the treatment expenditure went to the private sector.
“This is a fraction of the actual number of cases in the country. The data mostly comes from the government sentinel surveillance hospitals, which are like the watchtowers that keep checking for the disease even between dengue seasons to pre-empt an outbreak,” Joshi said.
“In Delhi, where there are so many sentinel surveillance hospitals, the reporting of cases takes at least a week or two and, in the case of deaths, like this year, it took over a month to confirm. Surely, in places where there are fewer such hospitals, the reporting of cases would take longer,” an official from the municipal corporation, on condition of anonymity, said.
“Long-term changes such as creating better water supply so that people need not store water in open containers to planned urbanisation can help reduce the spread of the disease,” Joshi said.
“Another positive thing in Delhi is that the number of water coolers has reduced. Now, water coolers are hardly spotted, and that means there is a decrease in breeding grounds of mosquitoes,” Joshi said.
First Published: Oct 24, 2018 09:00 IST