Sri Lanka dengue epidemic easing; data may understate extent
Aug 17, 2017 06:57 AM GMT+0530 | 0 Comment(s)
PEAK EPIDEMIC: Sri Lanka dengue infections usually peak in June/July and November/December. Date source: epidemiology unit Ministry of Health
ECONOMYNEXT - Sri Lanka's 2017 dengue epidemic has started to wane, with hospital admissions sharply down, Health Minister Rajitha Senaratne said, while questions remain over reported data and mortality rates.
"Dengue cases have dropped in August and special dengue wards in hospitals are closing," Minister Senaratne said.
According to the epidemiological unit of the Health Ministry, 136,468 dengue cases have been reported up to the second week of August 2017 compared to 55,150 for the whole of 2016.
However, the true extent of the epidemic may be understated. A check at some of Sri Lanka's private hospitals where dengue antigen tests are performed showed that there is currently no requirement to report positive results to the health ministry.
"I will check on that," Minister Senaratne said. "In the past also, many people did not even know that they had dengue."
Hospitals, however, report admissions to the ministry, and public health officials who will visit homes to fumigate.
The 'dengue antigen test' or NS1 that is routinely performed now was not available over a decade ago, and doctors usually diagnosed dengue from clinical symptoms, when there was continued fever.
During the 2017 epidemic, due to the lack of space in both state and private hospitals, only patients whose platelet count fell below 130,000 were admitted to hospitals. As a result, a large number of patients were treated at home. Many were also at smaller nursing homes as larger hospitals were full.
If the total positive cases are understated, the mortality rate may be overstated, Minister Senaratne said.
According to available data, an outbreak of a virulent form of dengue (believed to be a mutant DEN-3 serotype) in 1989 and 1990 led to dengue haemorrhagic fever, and a high mortality rate of around 9 percent based on reported cases.
Since then, the mortality rate has been around 0.4 percent.
In the 2017 epidemic, 44 percent of the cases were reported form the densely populated Western Province, when the area experienced the South-West monsoon rains. Dengue is spread by a mosquito. The disease also spikes in November and December during the North-East monsoon rains.
In 2016, total cases almost doubled from 29,000 reported in 2015 and the disease was already at a historic high in December and January.
The Meethotamulla garbage disaster, which hit garbage collection in the Western province, is believed to have helped worsen the disaster.
Following an earlier epidemic, the government started fining plastic and metal collectors who stored old metal tin cans until they were compacted and mostly exported, which halted metal tins from being collected by individuals who usually collected them from homes and the roadside.
During the current epidemic, 39,822 cases were reported in July, up four-fold from 10,715 in 2016 and 2,125 in 2015, though questions remain over data.
Reported cases rose steadily from 5,685 in the fourth week of June (week 26) to 10,146 in second week of July and 10,251 in the third week. In the fourth week, cases eased to 9,441.
In the week to August 04, cases dropped to 6,440 and in the week to August 11, 3,260 cases were reported, which is still the highest reported ever for week 32.
Minister Senaratne says stepped up garbage collection and community efforts helped to reduce the epidemic. (Colombo/Aug17/2017)