Three Outbreaks in the Basque Country, Málaga, and Melilla Spike Measles Cases

The number of measles cases is once again surging in Spain. In January, the Ministry of Health reported 64 infections of this disease, primarily caused by three outbreaks: one in the Basque Country, another in Melilla, and another in Málaga. Only Romania, a country where this disease remains widespread, recorded more infections in Europe in the first month of the year, with 918 cases and two deaths.

The most concerning situation is in the Basque Country, where 38 infections have already been detected, 18 of which are healthcare workers. Of these infections, 36 stem from an outbreak detected in November in Vizcaya from an imported case, and the other two cases, unrelated to each other, have been found in Guipúzcoa.

Meanwhile, in the province of Málaga, six children are infected following an outbreak in a nursery. In Melilla, the Ministry of Health, which holds health responsibilities in the autonomous cities, has activated a special response due to the increase in cases and, particularly, after the hospitalization of four people, three children and one adult. In Melilla, health authorities have specifically urged everyone born after 1978 to receive the two doses of the measles vaccine if they have not previously done so.

Vaccination against measles (with the Beckenham 31 strain) was first introduced in Spain in 1968, although it was soon abandoned due to its high reactogenicity. A new monovalent vaccine (with the Schwarz strain) was included in the vaccination schedule in 1977 and began to be administered in 1978 at nine months of age. By 1981, it was replaced by the MMR vaccine, against measles, rubella, and mumps, which consists of two doses.

Spain achieves a vaccination coverage of over 90% with two doses and 95% with one, although not all regions reach this level. The Balearic Islands record the lowest figure, with 75.85% for two doses. "Vaccination against measles is very important, as it is one of the diseases with the highest contagion rates. The basic reproduction number (R0), meaning the number of people infected from one case in a non-immune population, ranges between 12 and 18," emphasizes pediatrician and spokesperson for the Spanish Association of Vaccinology, Fernando Moraga-Llop.

Of the 64 cases reported in January, 25 are imported and another 32 are linked to imports (the origin of the rest is yet to be confirmed), meaning the vast majority would directly or indirectly originate from other countries. The total already accounts for nearly a third of the 211 recorded throughout 2024, according to data from the Carlos III Institute, which shows a progressive resurgence of measles after the pandemic, when the disease was nearly eradicated. Thus, 88 cases were detected in 2020; two in 2021; only one in 2022; and fourteen in 2023. In the years before COVID-19, the figures were higher: 287 in 2019; 223 in 2018; 157 in 2017; 35 in 2016; 33 in 2015; and 151 in 2014.

"We need to be careful. We are not facing an extreme situation, but we must increase vigilance and protection. For example, if we are in a hospital waiting room and see someone with symptoms, we should wear a mask," explains Dr. Gema Fernández Rivas, a microbiologist at the Germans Trías Hospital in Badalona. Fernández Rivas warns that there is a group of the population that may be at higher risk of infection. "The older ones acquired immunity because they had measles, and the younger ones are well vaccinated, but those born between the late 60s and mid-80s may not have been fully vaccinated," she adds.

In its latest report on measles, published last June, the Centre for Coordination of Health Alerts and Emergencies (CCAES), led by Fernando Simón, noted "the possibility of transmission in susceptible population groups where adequate vaccination coverage has not been achieved nor have they previously contracted the disease." Although it indicated that the risk of infection in the general population was low due to high vaccination coverage, it did warn that "as long as the situation of high incidence in some neighbouring countries persists, it is expected that cases and outbreaks will continue to appear in populations that are not immune to the disease."

In this regard, the European Centre for Disease Prevention and Control (ECDC) has warned that "Morocco is experiencing a significant measles outbreak that began in October 2023 and has spread throughout the country," with 3,631 infections and five deaths during January 2025.