Feb. 5 (UPI) -- Five new cases of measles have been diagnosed in the Houston area, part of a national trend that's seeing a return of the once-eradicated disease.
The cases involve four children under 2 years old and a woman.
Officials say vaccinations levels are falling in several Texas counties, and anything below a 95 percent vaccination rate is considered dangerous.
The Texas cases follow dozens in Washington state, where 49 confirmed cases turned up last month. Only seven had been vaccinated.
Washington state epidemiologist Dr. Scott Lindquist said he's seeing new cases every day.
Some people are self-treating with vitamin A, prompting the Washington State Department of Health to warn the public that doing so has no effect on measles.
In Texas, officials said several counties in the Dallas-Fort Worth, Austin and Houston areas saw a high number of parents requesting non-medical exemptions to vaccinations rules last summer.
"This is a reminder for people to be on guard and be up to date on their vaccinations," said Dr. Umair A. Shah, executive director for Harris County Public Health. "Measles, a serious disease, is in our community."
He added that it's too early to tell if the five new cases could be the beginning of a local outbreak.
Dr. Peter Hotez, an infectious disease specialist at Baylor College of Medicine and Texas Children's Hospital, said measles peaks in the late winter or early spring.
"2019 might be the year we really see the public health consequences of anti-vaxxers," Hotez said. "In a sense, we already saw that in 2018, but it looks like cases may pick up more in 2019."
Other anti-vaccination hot spots include New York, Hawaii, Oregon, Pennsylvania, Connecticut, Colorado, California and Georgia.