A July 3 editorial was titled “Stop stalling, fund Zika fight.” I applaud more funding for Zika virus with its possible link to microencephaly (small brain) and other birth defects.

However, I am concerned that such funding may ignore known causes of microencephaly (such as viruses, including rubella, cytomegalovirus and herpes, bacteria, parasites, pesticides, poverty and malnutrition) and could promote mass spraying for pesticides that could do more harm than good.

In Brazil the surge in cases of both Zika infected pregnant women and children born with microencephaly since May 2015 has been linked to exposure to the Zika virus with damage to nerve cells.

However, in Colombia a huge increase in Zika infections among pregnant women since August 2015 has not been accompanied by a surge in microencephaly.

Not one case of microencephaly was seen among 1,850 Colombia mothers infected with Zika during the third trimester of pregnancy in 2016.

If the Zika virus were the cause, how come there is no epidemic of microcephaly among infected pregnant women in Columbia?

Some researchers have suggested that one reason there may be a greater incidence of microcephaly in Brazil as compared to Colombia is that the mosquito larvacide pyriproxyfen is regularly added to drinking water and drinking water supplies in Brazil but not Colombia.

I would urge caution in the use of pesticides to control the Aedes aegypti mosquito which spreads the Zika virus.

Integrated pest management offers promise in controlling mosquitoes. Use of repellents like oral vitamin B1 and garlic may also be somewhat helpful in repelling mosquitoes.

Luke Curtis, M.D.

Research and Development

Medical Technical Writer

Preventive and Personalized Health Care

Northforest Drive

North Charleston