Can Southern Nevada expect a measles outbreak?

Not a single case of measles has been detected in Southern Nevada this year, despite infections across the country reaching their highest level in more than three decades, the head of the Southern Nevada Health District said on Thursday.

Nevada is one of only a dozen states where cases have not been reported since infections exploded in western Texas earlier this year. The Centers for Disease Control reported 1,288 confirmed cases in the U.S. as of Wednesday, the most recent total on its website. There have been 162 hospitalizations and three deaths.

Although the worst in decades, the number of cases remains a far cry from 1991, when the CDC reported 9,643 cases.

Southern Nevada health officials are using multiple methods to detect possible measles cases, including wastewater surveillance, which serves as an early-warning system, said District Health Officer Cassius Lockett.

Within wastewater are viruses shed by infected people through saliva, urine and feces, which enter the wastewater system via sinks, shower drains and toilets. Wastewater surveillance, embraced during the COVID-19 era, can provide an early picture of infection levels.

The measles virus has not been detected in local wastewater, Lockett said, giving him “a whole lot more confidence that right here today we have no measles cases in Clark County.”

Not that Southern Nevada is in the clear.

“It doesn’t mean that we’ve avoided measles,” said Brian Labus, an associate professor of epidemiology and biostatistics at UNLV’s School of Public Health. “It just means we haven’t had it yet.”

‘Not enough to stop an outbreak’

In 2000, measles was declared eliminated in the United States, a status threatened by the ongoing spread of the disease this year.

In January, an outbreak in west Texas began in a Mennonite community with low vaccination rates and many children schooled at home outside of school-immunization requirements, according to a report by the Johns Hopkins Bloomberg School of Public Health. The Texas Department of State Health Services has reported 753 cases this year, including two deaths of school-age, unvaccinated children with no known underlying health conditions.

Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University, said he is “distressed and disheartened” by ongoing cases of a disease that can be prevented by vaccination. Two doses of measles, mumps and rubella (MMR) vaccine will provide lifetime immunity in 97 percent of the population, the CDC states.

“If every susceptible child were to receive their measles vaccine this afternoon, in two weeks we could bring all these outbreaks to a complete close,” said Schaffner, a national authority on vaccination. “I think these outbreaks are going to continue, or to smolder along.”

Vaccination rates have dipped in Nevada as in the rest of the country. Nevada Division of Public and Behavioral Health data shows that MMR vaccination rates in children ages 5 to 12 have declined over the past decade, dropping in Clark County from 94.5 percent in 2016 to 92.4 percent this year. Most of the decrease has taken place since the pandemic, as vaccination skepticism got a stronger foothold.

“People developed strong feelings about mandates, masks and politics” that contributed to vaccination skepticism, according to Labus.

“I don’t think it’s a permanent thing,” he added.

Signals by U.S. Secretary of Health and Human Services Robert F. Kennedy Jr., including the recent firing of an expert federal advisory committee on vaccination, also are sowing doubt, some vaccination authorities say. Kennedy said he replaced committee members to increase public confidence.

Although not at the 95 percent level that would provide the so-called herd immunity that stops the spread of measles, Labus said Southern Nevada’s vaccination rates are high enough to prevent case numbers like those in Texas, though unvaccinated pockets of the community could be affected.

“Our vaccination rates are not enough to stop an outbreak but enough to stop it from being a catastrophe,” he said.

‘Tip of the spear’

Measles is spread through coughing, sneezing and even breathing, with the virus lingering in the air for hours.

Symptoms, which appear one to two weeks after contact with the virus, include a high fever, cough, runny nose, red and watery eyes, and, after a few days, a telltale rash. Measles can cause serious complications, especially in young children, such as pneumonia and encephalitis — swelling of the brain — that can result in disability or death.

Measles is among the most contagious diseases in the world and, as such, has been the first of vaccination-preventable diseases to re-emerge, Schaffner said.

“Measles is the harbinger, the tip of the spear, because it is so highly contagious,” Schaffner said. He fears that other diseases quelled by vaccination also will have a comeback in the face of declining vaccination rates: bacterial meningitis, polio, diphtheria, tetanus.

“These are diseases that medical students and young physicians would have to run to their textbooks — their electronic textbooks — to read about,” he said.

Contact Mary Hynes at mhynes@reviewjournal.com or at 702-383-0336. Follow @MaryHynes1 on X.