WHO warns of ‘unusual’ rise in Legionella cases in Poland, total 166 cases, 23 deaths

The World Health Organization (WHO) warns that as of September 11, 2023, Poland has reported 166 cases of Legionnaires’ disease, including 23 deaths; taking into account reports from 2016, confirmed cases, hospitalizations and The increase in related deaths is “unusual.” Legionnaires’ disease, commonly called Legionnaires’ disease, is a pneumonia-like illness caused by bacteria. Its severity ranges from mild to severe and sometimes fatal pneumonia. Most people get Legionnaires’ disease by breathing in bacteria found in water or soil. To date, no direct human-to-human transmission has been reported. Polish health authorities are coordinating group investigation activities, active case finding to identify additional cases, and public health activities to prevent transmission and limit the emergence of new cases through preventive control measures. Since September 7, no new cases have been reported, although the source of infection has not yet been determined. Investigations continue to determine the origin of the outbreak. Preliminary results of the ongoing epidemiological investigation show that the first case developed symptoms on July 30, while most cases developed symptoms between August 12 and 16. Adults aged 60 to 90 are the most affected age group. The most recent reported case date is August 29. All 23 related deaths had underlying comorbidities and ranged in age from 53 to 98 years (11 women and 12 men). Legionella, symptoms and treatment Legionnaires’ disease is a form of pneumonia with an incubation period of 2 to 10 days (but up to 16 days has been recorded in some outbreaks). It is an important cause of community- and hospital-acquired pneumonia, and although rare, Legionnaires’ disease can cause outbreaks of public health importance. The initial symptoms are fever, mild cough, loss of appetite, headache, malaise and lethargy, and some patients also experience muscle aches, diarrhea and confusion. The severity of Legionnaires’ disease ranges from a mild cough to rapidly fatal pneumonia. Untreated Legionnaires’ disease usually gets worse within the first week. Mortality from Legionnaires’ disease depends on the severity of the disease, the use of antibiotic treatment, the environment in which Legionella was acquired, and whether the patient has underlying medical conditions, including immunosuppression. Mortality in untreated immunosuppressed patients can reach 40-80%, and can be reduced to 5-30% with appropriate case management, depending on the severity of clinical signs and symptoms. Generally speaking, the mortality rate is usually between 5% and 10%.