The measles outbreak is developing in the northwestern United States, 30 reported cases

by GILLIAN FLACCUS, Associated Press

PORTLAND, Oregon (AP) – The number of confirmed cases of measles near Portland has dropped from 25 to 30 on Friday, and nine new cases are suspected – an epidemic reinforced by lower-than-normal vaccination rates in what has been identified as a vaccine vaccination US "hot spot".

Public health officials in southwestern Washington, just across the Columbia River and from Portland, Oregon, said people may have been exposed to dangerous disease in more than three dozen localities , including the Portland International Airport, a Portland Trail Blazers match, a location located at stores such as Costco and Ikea.

Twenty-six of the confirmed patients had not been vaccinated against measles and the immunization status of four other infected persons is unknown. A person was hospitalized.

Most cases involved children under the age of 10, the Clark County Public Health Department said in a statement. An adult is infected and the others are teenagers.

Washington Governor Jay Inslee, a Democrat, on Friday declared an urgent state of health for his country, and neighboring Oregon and Idaho authorities issued warnings to residents.

According to Inslee, the number of cases "creates an extreme risk to public health that could quickly spread to other counties".

Clark County, which includes the Portland community in Vancouver's bedroom, has a measles immunization rate of 78%, well below the 92-94% required for so-called "herd immunity." "said Marissa Armstrong, spokesman for the ministry.

Group immunity occurs when unvaccinated people are protected from infection because almost everyone around them has been vaccinated and is immunized against a disease.

The vaccination rate against measles in 2-year-olds in Multnomah County, where Portland resides, was 87% in 2017, according to state data. The measles vaccine includes two injections, one administered at the age of 2 years and the other between 4 and 6 years in general.

Data on the vaccination rate of Portland for the two vaccines were not immediately available.

Two doses of the vaccine in childhood have an effectiveness of 97% and confer immunity for life. One dose is effective at about 93%.

Washington and Oregon both allow vaccine exemptions for personal and philosophical reasons. Armstrong said the vaccine exemption rate in Clark County for non-medical reasons was high at 7.5%.

People with measles can be contagious for four days before they develop symptoms.

The virus, spread by coughing or sneezing, can stay in the air for up to two hours in an isolated area. Ninety percent of people exposed to measles who have not been vaccinated will be vaccinated, public health officials said.

Whenever an unvaccinated person who has been exposed to measles goes out in public, "it starts all over again," Armstrong said. "It's the fear."

Earlier this week, the authorities managed to identify several people who had been exposed but were not yet sick. These people stayed home and then became ill, Armstrong said.

"We see this as a victory, so we can slow down the process by preventing these people from going in public," she said. "People help us and stay at home."

Officials still do not know where the outbreak began.

The first known patient sought medical attention on December 31, but it is not known if other people have ever been sick and have not sought treatment.

Those who may have been exposed must watch for the onset of the first symptoms of fever and discomfort, as well as a rash beginning on the head and descending into the body. Serious complications such as pneumonia and brain infections can occur in some cases.

People who think they have measles should contact their health care provider before they visit to avoid exposing others.