V L Yu

Nosocomial legionellosis in surgical patients with head-and-neck cancer: implications for epidemiological reservoir and mode of transmission.

A prospective pneumonia study was conducted simultaneously on head-and-neck surgery wards at two hospitals over 2 years; one hospital had a water supply contaminated with Legionella pneumophila but no record of having had a case of legionella pneumonia, and the other had just decontaminated its water supply because of known endemic nosocomial legionellosis. Special laboratory tests for legionella were done on all cases of nosocomial pneumonia irrespective of clinical impression. Over the first 18 months, the rate of nosocomial legionellosis was 30% at the first hospital and 0% at the second. Patients who underwent laryngectomy did not acquire the disease. Hyperchlorination at the first hospital was followed by a fall (p less than 0.01) in legionella pneumonias. Thus legionella pneumonias can be overlooked if special laboratory tests are not applied routinely, and surgical patients with head-and-neck cancer may be at high risk of nosocomial legionellosis because of the potential for pulmonary aspiration of contaminated water or orophyaryngeal microflora and/or frequent manipulation of the respiratory tract. This study demonstrates the benefits of examining the environment for legionella despite the absence of documented disease.

Community-acquired pneumonia caused by Legionella dumoffii in a patient with hairy cell leukemia

A case of community-acquired pneumonia caused byLegionella dumoffii in a patient with hairy cell leukemia is described. Diagnosis was confirmed by isolation by culture of sputum and broncho-alveolar lavage specimens, positive direct fluorescent antibody stains, and antibody seroconversion from 1 : 16 (acute) to 1 : 4096 (six months). The blue white autofluorescence of theL. dumoffii colonies when viewed under ultraviolet light was particularly useful in preliminary identification. The patient recovered from his pneumonia after administration of erythromycin and rifampin. Legionella have been shown to multiply in monocytes and cell-mediated immunity appears to be the primary mechanism of host defense in man. Hairy cell leukemia is characterized by monocyte dysfunction and such patients have a predilection for infection by microbes that are controlled by cell-mediated defenses. We review other cases of community-acquiredL. dumoffii pneumonia as well as other cases of Legionella infection in patients with hairy cell leukemia. Bei einem Patienten mit Haarzell-Leukämie wurde eine nicht nosokomialeLegionella dumoffii — Pneumonie beobachtet. Die Diagnose wurde gesichert durch kulturellen Erregernachweis aus Sputum und Bronchoalveolar-Lavageflüssigkeit, eine positive direkte Antikörper-Fluoreszenz und einen Antikörperanstieg im Serum mit einem Titer von 1 : 16 im Akutstadium auf 1 : 4096 nach sechs Monaten. Für die vorläufige Erregeridentifizierung war die weiße Autofluoreszenz derL. dumoffii-Kulturen unter ultraviolettem Licht besonders hilfreich. Nach Behandlung mit Erythromycin und Rifampicin heilte die Pneumonie ab. Es wurde nachgewiesen, daß sich Legionella in Monozyten vermehrt. Beim Menschen ist die zellvermittelte Immunität offensichtlich der primäre Abwehrmechanismus. Bei Haarzell-Leukämie besteht typischerweise eine Monozytenfunktionsstörung. Die Patienten sind besonders anfällig für Infektionen durch Erreger, die unter der Kontrolle der zellvermittelten Abwehr stehen. Wir geben eine Übersicht über andere Fälle vonL. dumoffii Pneumonie und andere Fälle von Legionella-Infektionen bei Patienten mit Haarzell-Leukämie.SummaryA case of community-acquired pneumonia caused byLegionella dumoffii in a patient with hairy cell leukemia is described. Diagnosis was confirmed by isolation by culture of sputum and broncho-alveolar lavage specimens, positive direct fluorescent antibody stains, and antibody seroconversion from 1 : 16 (acute) to 1 : 4096 (six months). The blue white autofluorescence of theL. dumoffii colonies when viewed under ultraviolet light was particularly useful in preliminary identification. The patient recovered from his pneumonia after administration of erythromycin and rifampin. Legionella have been shown to multiply in monocytes and cell-mediated immunity appears to be the primary mechanism of host defense in man. Hairy cell leukemia is characterized by monocyte dysfunction and such patients have a predilection for infection by microbes that are controlled by cell-mediated defenses. We review other cases of community-acquiredL. dumoffii pneumonia as well as other cases of Legionella infection in patients with hairy cell leukemia.ZusammenfassungBei einem Patienten mit Haarzell-Leukämie wurde eine nicht nosokomialeLegionella dumoffii — Pneumonie beobachtet. Die Diagnose wurde gesichert durch kulturellen Erregernachweis aus Sputum und Bronchoalveolar-Lavageflüssigkeit, eine positive direkte Antikörper-Fluoreszenz und einen Antikörperanstieg im Serum mit einem Titer von 1 : 16 im Akutstadium auf 1 : 4096 nach sechs Monaten. Für die vorläufige Erregeridentifizierung war die weiße Autofluoreszenz derL. dumoffii-Kulturen unter ultraviolettem Licht besonders hilfreich. Nach Behandlung mit Erythromycin und Rifampicin heilte die Pneumonie ab. Es wurde nachgewiesen, daß sich Legionella in Monozyten vermehrt. Beim Menschen ist die zellvermittelte Immunität offensichtlich der primäre Abwehrmechanismus. Bei Haarzell-Leukämie besteht typischerweise eine Monozytenfunktionsstörung. Die Patienten sind besonders anfällig für Infektionen durch Erreger, die unter der Kontrolle der zellvermittelten Abwehr stehen. Wir geben eine Übersicht über andere Fälle vonL. dumoffii Pneumonie und andere Fälle von Legionella-Infektionen bei Patienten mit Haarzell-Leukämie.

Prevention of Legionnaires' disease in transplant recipients: recommendations for a standardized approach

The risk of infection in the transplant patient is largely determined by the interaction among three factors: the presence of anatomical/technical abnormalities (usually due to surgical misadventures or vascular access issues), the nature and extent of environmental exposures, and the patient’s net state of immunosuppression. Recognizing the importance of these factors, particularly the last two of these, one can regard the transplant patient (and other immunosuppressed hosts) as a ‘sentinel chicken’; that is, any increased tra⁄c in a variety of potential pathogens will be seen ¢rst and foremost in these patientswho have been staked out in the swamps of the hospital environment. Since the ¢rst outbreaks of Legionnaires’ disease were recognized, it has been clear that transplant patients bore a greater burden of disease than the general population. In addition to L. pneumophila, type 1 (which accounts for480%of the Legionella isolates), the other species of Legionella are found more commonly among transplant patients and other immunocompromised hosts. In this editorial, Drs Singh, Stout, and Yu, who have contributed so much to our knowledge about this group of pathogens, have provided a beautifully crafted synthesis of the diagnostic, epidemiologic, and therapeutic aspects of legionellosis.We are in their debt.