Assoc. Prof. Dr. Trifon Valkov on the Diphtheria Outbreak in Europe and the Surge in Tick Bites

"When we talk about cases of diphtheria—i.e., epidemic data—I wouldn't say it's an exaggeration to claim there is an outbreak in Europe, because there are established criteria by which an epidemic is defined. In this case, since the end of 2022, the European Centre for Disease Prevention and Control has gradually reported an increase in the number of cases in several official communications," said Assoc. Prof. Dr. Trifon Valkov, infectious disease specialist at the Specialised Hospital for Infectious and Parasitic Diseases "Prof. Ivan Kirov," in an interview in the show “The Day Begins.”

Since then, there has been a clear rise in incidence. In 90–95% of cases, those infected are young men—migrants from Afghanistan, Pakistan, and Syria. The infection spreads through several mechanisms.

"This is a bacterial infection. Transmission occurs via airborne droplets, as well as through contact with the skin or mucous membranes. The mode of transmission determines the clinical manifestation—typically either a respiratory form, which is the most severe and often leads to complications, or a cutaneous form of the disease," he explained.

Assoc. Prof. Valkov emphasized that people who have been vaccinated are practically not at risk: "Their risk of infection is extremely low."

Regarding the measles outbreak in Romania, Dr. Valkov noted that one of the key contributing factors is the low vaccination coverage in the country—unlike Bulgaria, which, in his words, “performs very well on Europe's vaccination map.”

The professor also clarified that not every tick bite should be automatically associated with disease:

"It’s important to understand that even if the tick is a carrier of a disease, the duration of its attachment to the human body after biting plays a critical role in the likelihood of transmission," he said.