The measles outbreak that plagued northern Mexico is now a national issue. Infections have continued to rise since the first warning was issued on March 13 and have now spread to 18 of the 32 states. In total, there are 5,410 probable cases of the disease throughout the country, more than double the 2,597 confirmed cases. This increase experts are calling an “emergency,” as infections are advancing faster than immunizations. The situation is especially alarming in Chihuahua, on the northern border, where the vast majority of confirmed cases are concentrated—2,417 as of Tuesday—and where there have already been eight deaths from complications arising from the disease, mostly children but also three adults aged 27, 31, and 45. The ninth death was recorded in neighboring Sonora, where there are 78 confirmed infections, five in the last 24 hours.
The disparity between the numbers of confirmed and probable cases doesn’t prevent specialists from speaking of a national outbreak. In most states, the number of confirmed patients doesn’t exceed twenty, leading them to suspect that poor or late detection is preventing these cases from being confirmed. “It’s hard to believe that Coahuila has only 13 cases [with 116 probable cases], when it’s neighboring Chihuahua. Chihuahua is probably doing things well, while the other states aren’t doing so well,” notes epidemiologist Óscar Sosa. The expert offers a key to understanding the gap: “The characteristics of the virus inside the body last for a certain time, between one and two weeks. If I detect a case too late, I won’t be able to send samples for confirmation; it will remain a probable case.”
Guanajuato is the paradigmatic example in this regard. The state has 365 probable cases, but only two confirmed cases, a contrast that, to a lesser extent, is also observed in Zacatecas, Coahuila, Durango, and Michoacán. “When we talk about the precariousness of health systems, we’re talking about this,” says Samuel Ponce de León, coordinator of the Program on Epidemiological and Emerging Risks at UNAM: “There is no material or personnel to take a sample, take it to the laboratory, and have it processed properly.” The federal Ministry of Health disagrees with this analysis and rejects the idea that the gap between the two figures is “strange”: “Epidemiological surveillance operates throughout the country.”
The current outbreak, the largest so far this century, originated on the border between Mexico and the United States, in a Mennonite community opposed to vaccination that travels between both sides of the border. Three months later, the situation is different. “That was the first act. This second act we’re experiencing far exceeds the limitations of religious beliefs. It’s possibly due to agricultural workers, day laborers who travel from one state to another to work. And the problem is that they’re not vaccinated,” Ponce de León points out.
Dr. Leticia Ruiz, head of the Undersecretariat of Prevention and Health Promotion in Chihuahua, confirms: “There are intense outbreaks in this population group, and it’s even affecting the time it takes to take them to the hospital due to Chihuahua’s geographic location and dispersion. We have to travel 18 hours to reach these communities; we can reach some, but not others.” It’s this sector they’re now primarily focusing their efforts on, through people who come to work in areas near cities.
All roads lead to the low coverage rates of recent years. Measles is the most contagious infectious disease in the world; up to 18 new cases can arise from each case, which is why immunization rates above 95% are recommended to protect against transmission, a goal still distant in North America, where almost all of the continent’s cases are concentrated. In Canada, there are nearly 3,000 confirmed cases, and in the United States, 1,200, far from the 33 in Argentina, the next on the list of affected American countries, according to the latest report from the Ministry of Health. “The speed at which you can vaccinate is much slower than the speed at which the disease is transmitted. Very rarely will you be able to achieve the necessary vaccination” once an outbreak has begun, says Óscar Sosa.
Mexico has attempted to overcome its backlog in the first half of the year. Between January and March, it vaccinated 715,000 people and resumed National Vaccination Week in April, an intensive program that had not been used, at least in this format, practically since the pandemic began. During that period, 2.2 million doses of up to 14 different vaccines were administered, 120% of the target set. Between April 1 and June 20, it also administered 1.88 million doses specifically against this infection, according to data provided by the Federal Secretariat to this newspaper on Tuesday. The agency has also confirmed the acquisition of 23.5 million doses of the double viral vaccine (MR), intended primarily for adults, and 3.5 million doses of the MMR vaccine (MMR), for children under 10 years of age.
Despite these efforts, experts believe the response is insufficient. “Given the numbers we have today and the short-term outlook, this should be addressed urgently. It is truly an emergency,” says Samuel Ponce de León, who believes the underlying cause is a “budgetary insufficiency” to address the ongoing vaccination campaign required. “The speed of transmission will increase when cases begin to appear in states like Nuevo León, Jalisco, the State of Mexico, or the capital, because the population density is much higher,” he adds, although he also clarifies that vaccination rates are generally higher in those territories.
The two specialists agree that one of the factors that is not receiving the necessary attention is adult vaccination. Although younger children are the most vulnerable to exposure to infection, young people also account for a significant portion of cases, but not for vaccines, despite the fact that there have been three deaths between the ages of 27 and 45: a member of the Mennonite community, a Rarámuri Indigenous person, and another Tarahumara Indigenous person. Of the 600,000 doses administered by the federal government between April and May, 443,500 were triple-viral and 156,000 were double-viral.
Chihuahua authorities have been working hard to contain the outbreak in the state, which is particularly difficult to contain due to the terrain. In the three months since the first cases were first reported, they have recovered the necessary vaccination rates for children aged six months, one year, and 18 months, explains Leticia Ruiz, of the state’s Undersecretary of Health. “Our staff has been doubling their work hours to address all of this,” she says. Between 60,000 and 70,000 doses of the MMR vaccine were administered in the state each year. In these six months, they have already administered 169,000.
“The working population who were not vaccinated as children are transmitting the disease, and it reaches children under five, who are the most vulnerable because it causes pneumonia, the leading cause of hospitalization,” notes the official, who details that they have administered 118,000 doses of the MMR vaccine, the one for adults, so far this year.
The state has expanded its large vaccination centers with the support of universities and volunteers to reach the entire population, a task in which the federal government is also participating. “They’ve been moving vaccines to try to supply us with as many as possible, even taking them from other states,” says Ruiz. Currently, between those supplied by the federal secretariat and those from the state itself, they have approximately half a million doses, of which more than half have already been administered. However, the expert places the containment horizon at the end of this year. “We managed to contain an exponential increase; now we have sustained transmission at low levels,” she explains. “What we’re looking for is to lower it even further until it disappears.”
Source: elpais
