Dengue control: ‘Try fish and sand instead of insecticide’

Trained officers recommend alternatives to insecticide, strong public awareness campaign.

LAHORE:

The government should replace large-scale spraying of insecticides with biological methods for curbing the population of the dengue mosquito and larvae, said government officers at a seminar on Tuesday.

A total of 112 officers of the Environmental Protection and Health Departments and public sector doctors visited Sri Lanka and Thailand in December to learn how these countries handle outbreaks of the seasonal disease. Some of these officers shared their findings at the seminar, which was organised by the EPD.

Younas Zahid, the deputy district officer (environment), said the most dangerous form of the disease, dengue haemorrhagic fever (DHF), occurred among people who had been infected with dengue before. He said just two of 64 mosquito species could spread dengue, and only one could transfer the virus from a dengue patient to a healthy person.

He said papaya leaf extract was not a suitable remedy. “It is a big misconception that it has curative properties. There is no scientific evidence suggesting any remedial properties in papaya leaves,” he said.

Zahid said dengue larvae could survive in dirty water, as long as there was a certain minimum level of oxygen in it. The disease has spread to 102 countries worldwide, he said.

Mahmood Masood Tamanna, the executive district officer (environment), suggested alternative methods to insecticide for controlling the vector population. Fish such as the guppy fish and tadpoles, which feed on larvae, should be introduced in fresh water bodies. In Thailand, large quantities of sand are dumped in small puddles and ponds to kill off larvae. “This practice should also be implemented here at fresh water bodies, as mosquitoes are gradually becoming more resistant to insecticides,” he said.

He said garlic water made a good natural mosquito repellent. “We should also use fumigation spray with less active ingredients as they are likely to cause less damage to the environment,” he said.

Tamanna also emphasised the need for community participation in dengue control efforts. In Thailand, two or three volunteers from each community collect data about patient numbers and areas with mosquitoes, he said. They educate locals about preventive measures. Every month, they meet with district officers so both sides can keep each other informed. Hospitals compile data on dengue and DHF patients and provide the information to the public and the health ministry. “Such cooperative measures could help us better analyse the situation here,” he said.

A Shadbagh resident, who volunteers to drain water puddles in his street and educate his community about preventive measures, suggested that a 30-minute session about dengue control be held in each primary school in his area. “Most of the parents have no schooling. The children would be able to pass on safety measures to their families if the EPD initiated such a programme,” he said.

Tamanna said he would propose such an initiative.

Tahira Mariam, the education officer at the EDO (health) office, said successful ‘marketing’ was a key part of getting health messages across to the public. In Thailand, a logo for one public health campaign had become very popular, she said. “If they breed, you’ll bleed,” was printed on a billboard and received a positive response. It was then plastered on buses and trains and made part of television advertisements, she said.

She said another message calling on people to turn over empty containers had also been very successful in Thailand. The disease could be reduced by a great extent by raising awareness, she said. “We just need to have target-specific messages,” she said.

Dr Somia Iqtidar of Mayo Hospital and Professor Muhammad Ali Khan of Services Hospital gave a presentation on clinical management of dengue patients. Prof Khan said that most of the deaths during last year’s dengue outbreak occurred because of improper treatment techniques. He said he had trained 5,000 private practitioners since returning from Thailand. He said people should check with their doctors if they had been trained.

Published in The Express Tribune, February 1^st, 2012.