I never sad that the long-term hazards of pyriproxyfen in humans were established. What I said was that its reproductive effects had been characterized adequately to provide reasonable assurance that it is not the cause of the microencephaly cases seen in Brazil.

The long term effects of malaria and dengue are quite well characterized.

Here's a case report of an infant with dengue fever published in the BMJ:

In August 2013, a child aged 2 years and from the Tremembé ethnic group, who was previously healthy with no complaints, suddenly presented intense crying, precordial pain, and general malaise. A few minutes after these non-specific symptoms, the patient started tonic–clonic convulsions and had cyanosis, a substantial increase in body temperature to the touch, cold sudoresis, sphincter relaxation, and unconsciousness. This situation remained for 15 minutes, progressing to respiratory insufficiency, with consequent absence of peripheral pulses. Death was confirmed approximately 40 minutes after the first symptoms. An autopsy was performed using the usual techniques. Immunohistochemistry was positive for dengue, and microscopic examination indicated micro perivascular edema and cerebral hemorrhage.

About 500 people a year die of dengue in Brazil. Another 1.6 million suffer from disabling joint pain that keeps them from work for up to 2 months, a tremendous economic burden in an area in which most are subsistence farmers. Another 300K or so develop malaria.

Almost all of these cases are among the 25 million or so living in the Amazon region where pyriproxyfen was used. So perhaps you will see why people are more open there to having an antilarvicidal agent added to the water supply than they would be in say, Chicago.

Retrospective analysis of prior Zika epidemics has turned up increases in microencephaly and other neurological defects in other countries, though the magnitude of the increase appears to be lower. Its likely that a second factor, such as the widespread malnutrition found in Amazonian Brazil makes things worse.

Or Zika isn't the real culprit, I don't have a strong opinion on that. But it seems pretty clear that the problem isnt pyriproxyphen.