Mycoplasma pneumoniae, a small bacterium, has been diagnosed more frequently in the last few months in Iceland. Mycoplasma infection is characterized by symptoms like tracheo-bronchitis and occasionally pneumonia. Often referred to as "atypical" or "cold" pneumonia, Mycoplasma infections are generally milder than typical bacterial pneumonia, featuring a low-grade fever and a persistent cough. While prevalent in school-age children and young people, individuals of all ages can be affected. Epidemics of Mycoplasma infections emerge every few years in the community.

Notably, the Chief Epidemiologist in Iceland doesn't publish statistics on Mycoplasma infections due to the disease not being a notifiable disease by law. Despite the typical rise in respiratory infections during winter, mainly viruses, recent weeks have witnessed an unusually high number of new Mycoplasma pneumoniae diagnoses, with ten cases detected in 2024 so far. This contrasts with 38 cases diagnosed in the entire 2023 (from July onward) and only one in 2022.

This winter, an increase in Mycoplasma cases has also been observed in several other European countries and beyond. Denmark, for instance, has been experiencing an ongoing and unusually large Mycoplasma epidemic since late October 2023, primarily affecting school-aged children, with approximately 14% of cases, predominantly among adults, requiring hospitalization.

The reduction in Mycoplasma infections during the peak of the COVID-19 epidemic and subsequent diminished herd immunity might have contributed to the current surge in cases. It's crucial for doctors to consider laboratory testing for Mycoplasma when symptoms suggest "atypical" pneumonia, as timely and accurate diagnosis facilitates proper treatment. Lower respiratory tract samples, such as a good sputum sample, for PCR testing, are recommended.

In cases requiring antibiotic treatment, macrolide antibiotics are the standard choice for Mycoplasma pneumonia, while beta-lactam antibiotics are not recommended. The inappropriate use of antibiotics can lead to complications and increased antibiotic resistance, underscoring the importance of accurate diagnoses and targeted treatments.

Addition: We would like to clarify that there is no conclusive evidence indicating that treatment with antibiotics significantly changes the course of Mycoplasma infection and mild infections usually self-resolve. Importantly we want to avoid unnecessary antibiotic use, particularly in children. The announcement is primarily to alert healthcare professionals to the observed increase in this infection in neighboring countries, and indications suggest a similar situation here this winter. Primary healthcare and hospitals will continue to assess the need for testing and treatment on a case-by-case basis, which especially applies to older people and immunocompromised individuals.

The Chief Epidemiologist