The High Council of Public Health recommends not to give up too quickly the insecticide malathion as a tool to fight against mosquitoes spreading chikungunya.
Malathion is an insecticide classified since March as “probably carcinogenic” by the World Health Organization (WHO). This is why the President of the General Council of Guyana recently announced the “suspension of malathion sprays” in his region. Alain Tien-Liong had specified that “the principle of responsibility and precaution obliges us to suspend spraying of this product until we have the State’s decision on this file. “
A unilateral decision since the insecticide malathion enjoyed a derogatory use in Guyana since an order of August 2014 taken by Marisol Touraine (Minister of Health) with the aim of stemming the progression of the chikungunya epidemic. But in this case, a new twist, the High Council of Public Health (HCSP) recommends this Thursday “not to give up too quickly this tool to fight against mosquitoes that spread the virus. “
Strict spraying conditions
In its opinion, the HCSP recalls that “if the spraying precautions that it recommended are applied, the exposure of the population to malathion remains at very low levels. »This must therefore be strictly local, in the immediate vicinity of places frequented by people with the disease, away from surface water, exclusively in the space outside homes (only deltamethrin can be used in premises).
In addition, residents must be informed of the intervention and its schedule; spreading must be done away from any display of food products; the personnel in charge of spraying must wear personal protective equipment, etc.
The High Council considers that if this procedure is scrupulously respected “these exposures are therefore unlikely to be associated with measurable risks. “He even writes that” once these strict conditions are implemented, the exposure of populations to the product is low enough for the recent classification of malathion as a probable carcinogen by the IARC (1) does not modify the assessment of risks already taken into account. ”
In addition to other techniques
Conclusion of the High Council, malathion should only be used in addition to other techniques (elimination of larvae, mosquito nets, repellents, etc.), but, because of its efficacy shown on the adult forms of the mosquito during tests carried out in 2014 , there must remain in the arsenal of means to fight the chikungunya epidemic in Guyana.
A review in the coming months
However, the HCSP recommends that, with a view to deciding on its possible future use, an assessment be made of the efficacy of malathion and the resistance acquired after 5 months of use, and an evaluation in the field of the protective measures of malathion. the population and the environment during spraying.
As a reminder, according to the latest figures published by InVS and CIRE Antilles Guyane, the number of clinically suggestive cases of chikungunya was estimated at 13,751 as of March 22, 2015, with nearly 7,000 confirmed or probable cases; 2 deaths are attributable to him. A significant fraction of those affected suffer from sequelae which can be disabling, the bulletin concludes.
(1) International Agency for Research on Cancer
.
