CONCORD, N.H. – State health officials announced new evidence Monday of the spread of a dangerous virus and again urged people to take steps to avoid being bitten by mosquitoes.

The state public health laboratory found the mosquito-borne Eastern equine encephalitis virus, known as Triple E, in four more birds, a horse and two pools of water, officials said.

“We are continuing to identify Triple E in new communities across the state,” health Commissioner John Stephen said in a statement. He recommended that all residents take precautions, even in communities where the virus has not been found.

In Massachusetts, a 3-month-old baby girl has been diagnosed with the mosquito-borne disease, bringing the number of human EEE cases in Massachusetts this year to four.

The girl, who remains hospitalized, became ill Aug. 25, public health officials said. The case was confirmed as EEE on Sunday. A state official described the girl as “improving.”

N.H. health Commissioner Stephen advises people to use repellants, wear long sleeves and pants outside, and drain standing water near homes.

The infected birds, found in Hopkinton, Salem, Nottingham and Plaistow, bring the statewide total this year to 32. The horse, in Kingston, was the sixth found to have the virus.

Both pools of water were in Andover.

Five people have contracted Triple E in the state, including a 20-year-old Newton woman who died Friday at a Boston hospital. Newton is just north of Haverhill, Mass.

Kelly Labell was the daughter of former Newton Police Chief Richard Labell, who said he plans to campaign for mandatory vaccinations of horses against the disease. There is no human vaccine.

Experts say vaccinating horses would not help prevent human cases of the disease, however. Dr. Jose Montero, the state epidemiologist, says both humans and horses are “dead ends” in the transmission of Triple E, apparently because they do not develop high enough levels of the virus to pass it on.

The state already encourages the vaccination of horses for their own protection, he said.

Labell, now a part-time police detective in Raymond, said his daughter stayed home on Sept. 2 from work with flulike symptoms, including pain in her lower back, neck and left ear. When she developed a fever, she went to a hospital where she was diagnosed with an inner-ear infection and the flu. She was sent home with antibiotics.