Dr. Hector Ocaranza anticipated the arrival of measles in El Paso once it began to spread across West Texas and eastern New Mexico. The city’s location as a hub connected by highways to the epicenter of Texas’ outbreak, now accounting for 663 cases, posited a high risk. These routes are frequented by numerous families and commercial transporters journeying between Mexico and the United States daily.
“Diseases don’t respect borders,” remarked Dr. Ocaranza, El Paso’s leading public health authority. “As people become more mobile, individuals residing in Juarez may seek medical care in El Paso.” It took some time, but El Paso is now dealing with 38 measles cases, the highest number outside West Texas. Adjacent Ciudad Juarez reported 14 cases by Monday.
North America continues to witness its three largest measles outbreaks expand, with more than 2,500 documented cases. This has resulted in three fatalities in the U.S. and one in Mexico. The outbreaks originated in Canada during the fall and escalated in Texas and New Mexico by the end of January. Additionally, these outbreaks spread rapidly in Chihuahua state, reaching 786 cases since mid-February.
Certain predominantly Mennonite Christian communities with historical migrations from Canada to Mexico and Seminole, Texas, are notable in these areas. The initial outbreak in Chihuahua reportedly began with a Mennonite child who visited family in Seminole, fell ill, and subsequently spread the virus at school. Similarly, Ontario’s outbreak is believed to have began during a large gathering in New Brunswick involving Mennonite communities.
Officials from Mexico and the United States confirm that the genetic strains of measles observed in Canada align with other significant outbreaks. “This virus crossed borders,” explained Leticia Ruíz, who directs prevention and disease control in Chihuahua.
Dr. Jarbas Barbosa, director of the Pan American Health Organization, highlights the struggle across the Americas to sustain the 95% measles vaccination rate required to avert such outbreaks. A recent WHO report indicated an elevenfold increase in measles activity in the Americas compared to the previous year, marking it as “high” risk against the global “moderate” level.
Confirmed measles cases extend across six regional countries — Argentina, Belize, Brazil, Canada, the United States, and Mexico. Investigating these cases is both labor-intensive and costly, with the response to each case in the U.S. estimated at $30,000 to $50,000, according to CDC’s Dr. David Sugerman.
At the U.S.-Mexico border, Ciudad Juarez is not directly linked to the Mennonite area in Chihuahua, noted Rogelio Covarrubias, a local health official. El Paso’s first measles case involved a child from Fort Bliss, explained Dr. Ocaranza. Over half of El Paso’s cases are adults, which is unusually high, and three individuals have been hospitalized. Vaccination clinics in shopping areas and parks have seen hundreds receive free vaccinations, regardless of citizenship.
Communication between U.S. and Mexican health authorities is “informal yet effective,” according to Dr. Ocaranza, with Covarrubias’ team having been notified of a case involving someone who fell ill in El Paso before returning to Juarez. “There’s constant vigilance in Ciudad Juarez…due to global travelers passing through. Without proper precautions, measles can quickly affect many,” warned Covarrubias.
In the U.S.-Canada border region, recent outbreaks in Michigan’s Montcalm County are traced to Ontario. The state’s chief medical executive, Dr. Natasha Bagdasarian, anticipates more cases as certain areas experience lower vaccination rates, despite a general statewide rate of 95%. “Measles can ignite like a forest fire,” Bagdasarian noted, emphasizing susceptibility based on vaccination levels.
Canada reports measles cases across six out of ten provinces, with Alberta possessing 83 instances as of mid-April. Ontario’s case count climbed to 1,020, primarily in regions bordering Michigan, such as Chatham-Kent, where public exposure occurred in a Mennonite church over Easter. “We often seem one step behind, always trying to catch up to measles,” admitted Dr. Sarah Wilson of Public Health Ontario.