February 06, 2019, 05:30 pm Chris Crawford – (Editor's note: This story has been updated with the number of measles cases in Washington as of Feb. 6 and details of cases in Clark County.)
As of Feb. 6, the state of Washington has confirmed 51 cases of measles during what has become another vaccine-preventable outbreak in the United States.
Of course, these outbreaks could be curbed if parents vaccinated their children with the measles, mumps and rubella (MMR), or measles, mumps, rubella and varicella/chickenpox (MMRV) vaccine.
Fifty of the 51 cases of measles occurred in Clark County, Washington, and of these 50 cases, 43 patients were unimmunized, six had unverified immunization status and one had received one dose of the MMR vaccine; 35 were age 10 or younger.
Clark County has an additional 11 suspected cases, as well.
Most of these cases are in Vancouver, Wash., which is just north of the Columbia River and Portland, Ore.
A man in his 50s from Seattle in King County, Wash., also was confirmed as having measles, and it's known that he traveled to the epicenter of the outbreak in Vancouver.
As of Feb. 4, Multnomah County, home to Portland, had one case of measles of its own, also from exposure in Clark County.
This is according to the family physician in charge of controlling the measles outbreak, Public Health Director for Clark County Alan Melnick, M.D., M.P.H., C.P.H.
"This has really been a nightmare, and a preventable nightmare at that," Melnick told AAFP News. "We are seeing this outbreak especially in an unvaccinated population."
Melnick said exposures occurred up until Jan. 24. The incubation period for measles is seven to 21 days after an exposure, he added.
"So even if we have no future sites, we're likely to see cases at least until mid-February," he said.
Melnick said when a measles case is introduced in a large unvaccinated population, "the illness can spread like wildfire."
To limit exposures to the measles outbreak in Clark County, Melnick recommended that any unvaccinated individual who had been at any of the exposure sites (reported on the public health department's website) and developed symptoms not go to their primary care office or emergency department, but to call these places first so facility personnel can prepare for the visit.
Additionally, the regional public health departments have been sending advisories to health care professionals, such as one on Jan. 25 that provided guidance on how to see infected patients safely without exposing other patients -- especially infants, pregnant women and those who are immunosuppressed.
For health care facilities, exposure isn't defined by whether the patient was masked, but whether proper infection control measures were in place, the health advisory said.
For example, the advisory said if a facility can validate that the patient was masked before entering the facility, taken through a back entrance, escorted through a hallway not shared by other patients and taken straight into a negative air-pressure room, then remasked and escorted out by the same route, the regional public health departments didn't consider that to be exposure to other patients, but still wanted a list of exposed staff members.
"However, if a patient was masked but in the waiting area or walked down a hallway that other patients used, that would be considered an exposure at the health care facility," the advisory said.
The advisory also explained that unimmunized contacts of infected patients should avoid all public settings from seven days after the first date of exposure until 21 days after the last day of exposure, regardless of whether they received the vaccine within 72 hours or immunoglobulin (IG) within six days of exposure.
For most people who were exposed in public settings, more than 72 hours has passed, the advisory said.
"Therefore, they are still at risk of getting measles during the incubation period," it noted. "If they receive the vaccine more than 72 hours after the exposure and then develop a rash and fever, it would be difficult to determine if they have measles or a mild reaction to the vaccine."
For collecting specimens, the health advisory recommended a nasopharyngeal swab for rubeola polymerase chain reaction (PCR) and culture (the preferred respiratory specimen); urine for rubeola PCR and culture; and serum for rubeola IgM and IgG testing.
Melnick said if the exposure to measles occurs at a school, unvaccinated children and staff should be excluded from the school during the full incubation period.
"If exposure occurs in a doctor's office, we have been identifying who might have been in the clinic at the time ranging from a half hour before to two hours after the person with measles was in the office," he said. "If any of these people haven't been vaccinated or aren't immune to measles, we will actively call them every day and make sure they don't go into public settings if they develop symptoms."
When the Clark County public health department has identified high-risk exposures quickly enough, Melnick said it's getting IG within six days to exposed and susceptible infants and pregnant women.
The public health department has been working with two hospitals in the county to administer the IG in their emergency departments, including to 15 infants who were sent for immunization the day Melnick spoke to AAFP News.
"The hospitals know they're coming, and they aren't sick yet," Melnick said. "These are people in which we are trying to prevent infection."
Melnick also noted that IG tends to be in short supply. The state health department has been helping procure some and hospitals are working themselves to acquire more.
"The time crunch is critical because by the time someone gets diagnosed, they have several days of respiratory symptoms before the rash begins," Melnick said, "so identifying whether someone is a case -- getting the lab results back -- by that time, you are near the end of that six-day window to give immunoglobulin," he said. "It's a race against time to get the IG to infants and pregnant women."
The public health department also is promoting MMR clinics that its health care partners have set up.
"We are procuring additional vaccine supplies from the state and the hospitals, and one of our large clinics in town is foregoing the administration fee for people who don't have insurance," Melnick said.
Because the governor of Washington declared a state of emergency related to the measles outbreak, Melnick said the public health department should be able to seek reimbursement from the Federal Emergency Management Agency for costs associated with the outbreak.
"Family physicians in the community also are busy immunizing patients with MMR during this outbreak," he said. "It's all hands on deck."
The Feb. 3 health advisory offered immunization recommendations for patients during the measles outbreak.
Infants younger than age 6 months should not receive MMR but should receive intramuscular IG (IMIG) if they are within six days of exposure.
Infants ages 6-11 months, if identified within 72 hours, should receive MMR. However, this dose should not count toward their MMR series administered at ages 12-15 months and 4-6 years.
Infants ages 6-11 months, if identified more than 72 hours but within six days of exposure, should receive IMIG. But note that IG and MMR should not be given together.
Dosing of IMIG is 0.5 mL/kg of body weight (max dose 15 mL).
Administration of MMR or varicella vaccines must be delayed by six months after administration of IG.
IG prolongs the incubation period (and consequent recommendations for home quarantine) from 21 to 28 days, the advisory said.
Unless exposed as previously described, the regional public health departments didn't recommend expanding MMR immunization for infants younger than age 12 months.
"Some evidence has shown that administering a dose of MMR to infants 6 to 11 months results in a blunted response to subsequent doses of MMR," the health advisory said.
Melnick said he really hopes family physicians across the country, and the AAFP, use the Washington measles outbreak to combat misinformation about vaccines, including MMR, that has been shared on social media.
"What we tell people is, 'If you want to learn about measles and the measles vaccine, talk to your family physician,'" he said. "Physicians have a lot of credibility, and if you are a practice that has folks with vaccine hesitancy, getting the right information to them is really critical."
Melnick also encouraged the AAFP to advocate for policy change to lead to higher vaccination rates and for adequate funding of the public health system to support public health departments in situations like the current measles outbreak.
"And we could be putting more resources into working with schools to get those vaccination rates up," he added. "It's also important to work with schools to reduce the number of philosophic exemptions, working with parents but also making sure the schools have adequate access to vaccination registries."
Finally, Melnick suggested family physicians take leadership roles in their communities, such as on the school board or as a team physician, advocating to improve immunization rates in student populations.
"That's what's great about being a family doc: You have a lot of credibility and influence with different groups and organizations that could really help," he concluded.
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