Legionella pneumophila* A Cause of severe Communlty-acqulred Pneumonia VICente Falco, M.D.; 7bm4s Fem4ndez de Sevilla, M.D.; jose Alegre, M.D.; Adelaida Perm; M.D.; and]ose Manuel Martinez Vazquez, M.D.
In a prospective study ofcommunity-acquired pneumooias, 30 patients were diagnosed with LegionoaireS disease ill 15 months. Clinical, laboratory and racliologic features of these patients are reviewed and compared with those who have pneumococcal pneumonia. Alcoholism, history of smoking, previous antimicrobial therapy, gastrointestiDal and neuro logic manifestations, elevations of serum transaminases, alkaline phosphatase and creatinine levels were more fre quent ill pneumonia due to ugionells pneumoplails than in pneumococcal pneumonia. The presence of respiratory
T ofhecommunity-acquired reported incidence of Legionella sp as a cause pneumonia ranges from 1
to 30 percent of cases in various series. l -3 But despite these widely divergent data, most studies have dem onstrated the great importance of this agent in the etiology of community-acquired pneumonias, espe cially in severe cases." There are some factors that increase the frequency ofthis infection (advanced age, alcoholism, cigarette smoking, chronic disease, im munosuppression, patients receiving organ trans plants) and people with these risk factors are more likely to develop a severe disease with respiratory failure and other systemic complications. Our working team is carrying out a prospective follow-up ofcommunity-acquired pneumonias, and we have noticed a considerable increase in the incidence of pneumonia caused by L pneumophila. It is for this reason and also for the severity that usually accompa nies this disease that we conducted a prospective study of all patients admitted for community-acquired pneumonia in our hospital in order (1) to know the real incidence ofpneumonia caused by L pneu.mophila in our community, (2) to find clinical features and laboratory data that would allow us to differentiate community-acquired pneumonia caused by L pneu mophila from pneumococcal pneumonia, (3) to iden tify clinical, radiologic or laboratory data that would be suggestive ofpneumonia caused by L pneumophila and would lead to earlier thera~ and (4) to determine the utility of culture techniques in the diagnosis of pneumonia due to L pneumophila.
*From the Departments of Internal Medicine (Drs. FalceS, Sevilla, Alegre and V4zquez) and Microbiology (Dr. Ferrer), Hospital General Vall d'Hebron, Universidad Aut6noma, Barcelona, Spain. Manuscript received November 5; revision accepted February 20.
failure and racliologic progression were common 6ndings that suggested L pneumopld1lJ as the etiologic agent of a community-acquired pneumonia. Development of respira tory failure was associated with involvement of several lobes and isolation of L pneumoplails in any specimen. In 21 of 30 patients with Legionnaires' disease, L pneumoplails was isolated from respiratory specimens. Overall mortality was 10 percent, but it increased to 27 percent ill patients not treated with erythromycin ini~ (Chat 1991; 100:1007-11)
PATIENTS AND METHODS From February 1988 to May 1989 all patients with community acquired pneumonia who required hospitalization were prospec tively studied. Criteria for admission included age greater than 60 years old, underlying disease, severely ill, respiratory failure, presence of cavitation, pleural effusion or difFuse in61trates evi denced on the chest roentgenogram. For each patient we recorded clinical and routine laboratory data, chest roentgenogram and arterial blood gas value levels when there were signs of respiratory failure. Sputum specimens were cultured for bacteria only if >25 polymorphonuclear leukocytes and
In a prospective study ofcommunity-acquired pneumooias, 30 patients were diagnosed with LegionoaireS disease ill 15 months. Clinical, laboratory and racliologic features of these patients are reviewed and compared with those who have pneumococcal pneumonia. Alcoholism, history of smoking, previous antimicrobial therapy, gastrointestiDal and neuro logic manifestations, elevations of serum transaminases, alkaline phosphatase and creatinine levels were more fre quent ill pneumonia due to ugionells pneumoplails than in pneumococcal pneumonia. The presence of respiratory
T ofhecommunity-acquired reported incidence of Legionella sp as a cause pneumonia ranges from 1
to 30 percent of cases in various series. l -3 But despite these widely divergent data, most studies have dem onstrated the great importance of this agent in the etiology of community-acquired pneumonias, espe cially in severe cases." There are some factors that increase the frequency ofthis infection (advanced age, alcoholism, cigarette smoking, chronic disease, im munosuppression, patients receiving organ trans plants) and people with these risk factors are more likely to develop a severe disease with respiratory failure and other systemic complications. Our working team is carrying out a prospective follow-up ofcommunity-acquired pneumonias, and we have noticed a considerable increase in the incidence of pneumonia caused by L pneumophila. It is for this reason and also for the severity that usually accompa nies this disease that we conducted a prospective study of all patients admitted for community-acquired pneumonia in our hospital in order (1) to know the real incidence ofpneumonia caused by L pneu.mophila in our community, (2) to find clinical features and laboratory data that would allow us to differentiate community-acquired pneumonia caused by L pneu mophila from pneumococcal pneumonia, (3) to iden tify clinical, radiologic or laboratory data that would be suggestive ofpneumonia caused by L pneumophila and would lead to earlier thera~ and (4) to determine the utility of culture techniques in the diagnosis of pneumonia due to L pneumophila.
*From the Departments of Internal Medicine (Drs. FalceS, Sevilla, Alegre and V4zquez) and Microbiology (Dr. Ferrer), Hospital General Vall d'Hebron, Universidad Aut6noma, Barcelona, Spain. Manuscript received November 5; revision accepted February 20.
failure and racliologic progression were common 6ndings that suggested L pneumopld1lJ as the etiologic agent of a community-acquired pneumonia. Development of respira tory failure was associated with involvement of several lobes and isolation of L pneumoplails in any specimen. In 21 of 30 patients with Legionnaires' disease, L pneumoplails was isolated from respiratory specimens. Overall mortality was 10 percent, but it increased to 27 percent ill patients not treated with erythromycin ini~ (Chat 1991; 100:1007-11)
PATIENTS AND METHODS From February 1988 to May 1989 all patients with community acquired pneumonia who required hospitalization were prospec tively studied. Criteria for admission included age greater than 60 years old, underlying disease, severely ill, respiratory failure, presence of cavitation, pleural effusion or difFuse in61trates evi denced on the chest roentgenogram. For each patient we recorded clinical and routine laboratory data, chest roentgenogram and arterial blood gas value levels when there were signs of respiratory failure. Sputum specimens were cultured for bacteria only if >25 polymorphonuclear leukocytes and
