A 3-year-old from the midcoast area of Maine is recovering from a serious case of meningitis and blood infection caused by the bacterium Haemophilus influenzae type B, or Hib. According to a health alert issued Monday by the Maine Center for Disease Control and Prevention, the child had not undergone the full four-injection series of Hib vaccines recommended by the federal CDC and became ill in late February.

“It’s not so much about this one case as it is about the fact that with declining vaccine rates we can expect to see more cases like this,” said Dr. Dora Anne Mills, director of the Maine CDC. Mills said a recent survey in Maine found that more parents are choosing not to immunize their youngsters, citing fears of autism and other disorders. She said these concerns are based on “misinformation” and that young parents don’t realize how serious vaccine-preventable illnesses can be.

“They’re more afraid of the vaccine than of the disease,” Mills said.

Parents surveyed also indicated that they rely on “herd immunity” to protect their children — the notion that because most other children do receive immunizations, their own youngsters are unlikely to become ill. But the Hib organism exists naturally in the human body, Mills said, and without adequate immunization it can trigger a life-threatening infection with no warning.

Mills would not comment on whether the sick child’s parents had decided not to complete the Hib series or whether other factors contributed to the situation.

Hib is spread through coughing and sneezing.

Mills, a pediatrician, said cases of meningitis caused by Hib were frighteningly common as recently as the 1980s and a leading cause of death and mental retardation in babies and young children.

“It was like a miracle when the vaccine became available,” she recalled. “We saw this terrible disease just melt away.”

The critically ill midcoast youngster was hospitalized at Eastern Maine Medical Center in Bangor for about two weeks, including a period in the pediatric intensive care unit. The child was discharged home last weekend. Mills said a full recovery is not certain.

Maine’s last confirmed case of Hib meningitis was reported in 1989.