Barbara Altman helps her son Andrew, 53, who has microcephaly, as they a walk near her home in Rockville, Md. (Jabin Botsford/The Washington Post)

So far, the financial cost of the Zika virus and the birth defects caused by it is unclear. The care for one child with birth defects can cost $10 million or more, Tom Frieden, the director of the Centers for Disease Control and Prevention, said at a press briefing in April.

When our son Andy was born with microcephaly 53 years ago, a doctor advised me and my husband to put him in an institution. We were determined to keep him at home, but if we had put him in an institution at 2 months of age, I estimate his care would have cost Medicaid almost $21 million (in 2013 dollars) over the past 53 years. That’s $1,084 a day, or $395,660 a year.

Because we did not send Andy to an institution, his care has cost far less than that over the years.

My husband and I were lucky to have good health insurance, which paid for Andy’s surgery and normal doctor’s visits. When I turned 65 and began collecting Social Security, Andy, who was 38, became eligible for half the amount of my payment because he had been disabled from birth. He had to wait two years to qualify for Medicare. At that point, his Blue Cross Blue Shield became his secondary insurance.

Here’s how I calculate the costs, which do not include public school special education programs he attended from age 16 to 21:

Private schools ages 5 to 16: $5,000 a year for total of $50,000, paid by me and my husband.

Medicaid payment of post-hip-surgery stay at Great Oaks: $197,288 (estimated, in 2013 dollars).

Caregiving from ages 21 to 26: 5 years at $11,200 a year for total of $56,000, paid by me and my husband.

Institutional care at Great Oaks for 12 months (I had hip surgery and needed recovery time when he was 25-26): $395,660 in 2013 dollars paid by Medicaid.

Supported living and day programs for 27 years at $143,000 annually: $3,861,000 in 2015 dollars, paid by Medicaid.

Caregiving for a serious bout of pneumonia in the past two years: $12,000 paid by my husband and myself.

Total expenditures: about $4.6 million.

Barbara Altman