The number of dengue fever cases dropped in 2003 from the previous year, following the launch of a prevention campaign after an unexpected outbreak in January, World Health Organization officials said.
Dengue cases spiked in the dry season between January and March, prompting fears among health officials the disease would be widespread during the peak season between May and August, said Dr Chang Mohseng, WHO adviser on dengue vector control.
In response, the WHO in April launched a $200,000 campaign, funded by the World Bank, in which 2.8 million samples of a water-treatment chemical to ward off mosquitoes were distributed to about 200,000 families, Chang Mohseng said. “If we didn’t do anything, I’m sure the cases would have been more,” the doctor said Monday.
There were 12,081 reported cases of dengue fever nationwide in 2003, down from 12,441 in 2002, said Dr Ngan Chantha, director of the National Dengue Control Program at the National Malaria Center. Of these, 188 people died, he said.
Hardest hit was Siem Reap province, with 2,493 cases and nine deaths, followed by Kompong Cham, Phnom Penh, Kandal and Banteay Meanchey, he said. The mortality rate for the virus was higher in rural areas, he said.
He attributed the outbreak in the early part of the year to unusually high temperatures and rainfall, and to an increasingly mobile population.
When people travel within the country, “they bring the virus in their bodies,” Ngan Chantha said. Cars, airplanes and other vehicles can harbor infected mosquitoes, he added.
Mobility contributed to the spike in cases in Siem Reap town, where large numbers of people travel for jobs in the tourism sector, Chang Mohseng said.
The number and severity of cases in Siem Reap province increased in 2003, said Dr Ngoun Chan Theaktra, senior doctor at Angkor Hospital for Children. It was the worst year for dengue fever in two or three years, he said.
“It was pretty intense. It was a pretty sad time here,” said Jon Morgan, executive director of Angkor Hospital for Children.
The WHO plans to distribute another $200,000 worth of water-treatment chemicals in March, before this year’s rainy season, Chang Mohseng said.