Over the past couple of days a report from the Argentine environmental activist website Red Universitaria de Ambiente y Salud – Medicos de pueblos fumigados called REPORT from Physicians in the Crop-Sprayed Town regarding Dengue-Zika, microcephaly, and massive spraying with chemical poisons has been making huge waves, with many activist websites promoting the document.
The gist of it is the authors believe the larvacide Pyriproxyfen, which has been used on some drinking water supplies in Brazil, is a more likely cause of microcephaly than the Zika virus.
You can read it for yourself, but other than its introduction to Northeastern Brazil in 2014 - about the same time as the Zika virus arrived - the evidence for causation seems pretty thin. One does hope that all reasonable possibilities are being looked at - not just Zika - but whether this qualifies . . . I've no idea.
It does, however, tap into a very popular sentiment - the growing distrust of the agro-chemical industry - and is therefore getting a lot of play.
Enough that today, the Minister of Health for the southern state of Rio Grande De Sol ordered the temporary suspension of the use of the larvacide for use on drinking waster pending an investigation.
A fairly easy decision for Rio Grande De Sol, as they reportedly rarely use the chemical. They also only have one microcephalic birth reported, for whatever that is worth.
First the official (translated) statement, followed by the Brazilian MOH's response.
Secretary announced the suspension of larvicidal in water for human consumption during d-day to combat Aedes aegypti MosquitoIs temporarily suspended in Rio Grande do Sul the use in drinking water of Pyriproxyfen larvicidal, used to stop the development of larvae of the Aedes aegypti mosquito. This was announced this Saturday (13) by the Secretary John Gabbardo of Kings, at the opening of d-day to combat Mosquito. The decision is due to the assumption that the substance may enhance the brain malformation caused by zika virus, raised by argentina medical Physicians in the Crop-Sprayed Towns. The suspension has already been communicated to the 19 regional Health company departments of the State, which shall inform the Municipal Surveillance.The larvicidal was used on a small scale in Rio Grande do Sul, only in specific cases, when it is not possible to avoid the accumulation of water or remove the containers, such as fountains and cement pots in cemeteries. "We decided to suspend the use of the product in water for human consumption until it has a position of the Ministry of health and therefore strengthen further the appeal to the population to that eliminates any possible outbreak of the mosquito," explained the Secretary. According to the data from environmental monitoring, 75% of the foci are located in residential or domestic environments.
Within minutes of this announcement, many advocates of the theory were declaring victory on Twitter, calling Zika a hoax and blaming the government. The Brazilian MOH responded to the RS MOH's decision, with the following statement.
Registration Date: 02/13/2016 15:02:14 the change in the 02/13/2016 16:02:23There is no epidemiological studies showing the association between use of pyriproxifen and microcephaly. The Ministry of Health only uses larvicides recommended by the World Health Organization (WHO). Products undergo a rigorous evaluation process of the World Health Organization Pesticed Evaluation Scheme (WHOPES). The pyriproxifen is among the products approved by that committee and also is certified by ANVISA (National Health Surveillance Agency), which assesses the safety of the larvicide in Brazil.
Unlike the relationship between the Zika virus and microcephaly, which has had its confirmation attested in tests that indicated the presence of the virus in samples of blood, tissue and amniotic fluid, the association between the use of pyriproxifen and microcephaly has no scientific basis. Importantly, some localities that do not use pyriproxifen were also reported cases of microcephaly.
The Secretary of State of Rio Grande do Sul Health (SES / RS), as the local health authority, is empowered to use the product purchased and distributed the Ministry of Health or develop alternative strategies.
It is noteworthy that the Ministry of Health recommends only the use of larvicides in special situations where there is water storage need and deposits may not be physically protected.
It is important to remember that to eradicate the Aedes aegypti and all its potential breeding, the adoption of a routine is necessary with simple steps to eliminate containers that hold standing water. Fifteen minutes of inspection are enough to keep the environment clean. Little plates with plant pots, garbage cans, buckets, drains, gutters, bottles, tires and even toys can be the villains and serve as breeding grounds for mosquito larvae. Other individual protection initiatives can also complement the prevention of diseases such as the use of repellents and insecticides to the environment.
Check WHO report on the use of pyriproxifen:
Although the evidence for Zika being the cause of microcephaly in Brazil continues to grow, the notion that this larvacide may be a factor is probably not going away anytime soon.