Disseminated Legionella pneumophila infection in an infant with severe combined immunodeficiency

The mysterious illness that drove them to their knees - Ah, that Legionnaires' disease - A historical reflection of the work in Legionnaires' disease in New Zealand (1978 to mid-1990s) and the 'One Health' paradigm

And so, formed the basis for the song Legionnaires' disease (LD) composed by the legendry musician Bob Dylan shortly after this mysterious illness dramatically entered the clinical and epidemiological scene in July 1976 at an American hotel. Now more than forty years have passed since Legionella pneumophila, the causative agent of LD, was formally identified in 1977. Once the publicity associated with the outbreak subsided, there was the challenge to science and health professionals of what was an extremely complex and intriguing health concern. In the United States, the outbreak investigation that eventually solved the mystery had taken an array of surprising twists and turns. Globally, it revealed the strengths and weakness of countries' health systems in response to the outbreak from an unknown agent. Extensive international coverage of the outbreak also marked a turning point in journalism's efforts to hold officials accountable for their response to epidemics that had the potential to threaten the lives of hundreds of people. In 1979, New Zealand became an active participant in the international efforts towards increasing the understanding of infection caused by Legionella species and set up a centralized laboratory diagnostic service. By 1980 LD had become a notifiable disease making New Zealand one of the first countries globally to do so. This historical narrative in the decade or so from its recognition, provides a unique insight into how the One Health paradigm was instrumental in New Zealand's early response to LD in tandem with control strategies. The findings show that from 1979 the distribution of the Legionella species in New Zealand did not follow patterns observed in studies carried out globally.

Legionella micdadei brain abscess

We describe an immunocompromised patient who developed a large frontal brain abscess caused by Legionella micdadei. This is, to our knowledge, a rare case of culture-proven Legionella central nervous system infection.

Problem pathogens: paediatric legionellosis—implications for improved diagnosis

Legionnaires' disease is an established and frequent cause of pneumonia in adults but is thought to be a rare cause in children. We reviewed the medical literature for cases of Legionnaires' disease in children and analysed the epidemiology, clinical characteristics, and treatment. 76 cases of legionella infection in children were identified. In 56%, diagnosis was made with culture methodology. 46% were community-acquired infections. 51.5% were under 2 years of age. 78% of the patients had an underlying condition such as malignancy. Fever, cough, and tachypnoea were the most common symptoms. The overall mortality rate was 33% and was higher in immunosuppressed children and in children younger than the age of 1 year. Patients who were treated empirically with anti-legionella therapy had a notably lower mortality rate compared with patients on inappropriate therapy (23%vs 70%). In 88% of hospital-acquired cases, an environmental link to potable water colonised with legionella was identified. We found no clinical features unique to Legionnaires' disease in children that would allow differentiation from pneumonia due to other respiratory pathogens. Awareness of legionella as a potential cause of paediatric pneumonia is particularly important because infection can be severe and life threatening and antimicrobial therapy often used for empirical therapy in children is not effective against legionella. In any case of pneumonia unresponsive to antibiotics, Legionnaires' disease should be considered and specific diagnostic tests to verify this diagnosis should be done. As legionella diagnostic tests become more widely applied, we predict that legionellosis may appear as an emerging infectious disease in children.

Pneumonia and Osteomyelitis Due to Legionella longbeachae in a Woman with Systemic Lupus Erythematosus

A patient with risk factors of systemic lupus erythematosus, corticosteroid use, and malignancy received a diagnosis of concomitant pneumonia and osteomyelitis caused by Legionella longbeachae. In this report, the first description of Legionella osteomyelitis, previous cases of extrapulmonary Legionella infection are detailed.

Cerebellar Involvement in Legionellosis

The involvement of the cerebellum in Legionnaires' disease has been noted in occasional case reports, but there have been no reviews on this subject to date. We report a previously healthy patient who contracted Legionella pneumonia and developed profound cerebellar dysfunction during his illness. He was treated with antibiotics with improvement of his pneumonia, but his cerebellar symptoms persisted. We review 29 case reports of cerebellar dysfunction in Legionnaires' disease and summarize the clinical course, cultures, cerebrospinal fluid analyses, and neuroimaging. Finally, possible methods of pathogenicity are discussed including data regarding direct bacterial invasion, toxin production, and immune-mediated mechanisms.

Nosocomial Legionnaire's disease in a children's hospital

BACKGROUND

Only a few cases of nosocomial Legionella sp. infection have been reported in children. We report the clinical and epidemiologic data of five nosocomial legionellosis cases that occurred in the Pediatric Nephrology Service between August, 1994, and December, 1998, and the control measures adopted.

METHODS

The Hospital Materno-Infantil Vall d'Hebron, Barcelona, is a 407-bed tertiary care hospital. The pediatric kidney transplant unit has three isolated beds in the same ward within the Pediatric Nephrology Service. Diagnostic workup to establish Legionella pneumophila infection included culture, fluorescent antibody and serologic studies. Macrorestriction analysis of genomic DNA was used as epidemiologic markers of the isolated strains.

RESULTS

In May, 1996, a case of L. pneumophila serogroup 6 pneumonia was identified in a 19-year-old youth who had received a kidney transplant 16 days earlier. Retrospective and prospective analysis of legionellosis cases diagnosed at our center up to August, 1994, yielded four additional cases. Four patients had had a kidney transplant and were receiving immunosuppressive therapy, and the fifth had been diagnosed with systemic lupus erythematosus with renal involvement. L. pneumophila serogroup 6 was isolated in bronchial secretions in four cases; in the fifth patient the diagnosis was made by serology. L. pneumophila serogroup 6 was isolated from potable water of the hospital. Molecular epidemiologic methods revealed the identity of the environmental and clinical isolates. Showering was implicated as the most feasible means of exposure to contaminated water.

CONCLUSIONS

Nosocomial legionellosis, albeit rare in children, should be considered in the differential diagnosis of pneumonias, particularly in immunosuppressed children, because the fatality rate may be high without early diagnosis and treatment.

Legionella pneumophila peritonitis in a kidney transplant patient

Legionella pneumophila serotype 6 was isolated from the peritoneal fluid of a 59-year-old immunosuppressed patient who developed peritonitis shortly after kidney transplantation. Clinical and radiological examination did not show pulmonary abnormalities until shortly before his death when multiple organ failure developed with adult respiratory distress syndrome (ARDS). Post mortem examination showed L. pneumophila in the peritoneum and in a small pulmonary infiltrate, confirmed by positive cultures. A primary peritoneal inoculation via an indwelling Tenckoff catheter seems to have been the most likely route of infection. Positive L. pneumophila type 6 cultures were obtained from the shower and hot water tap in the room of the patient. L. pneumophila must be considered as a potential cause of peritonitis in which routine microbiological cultures remain negative.

Nosocomial infection with Legionella pneumophila serogroup 1 and 8 in a neonate

A case of pneumonia related to 2 serogroups (1 and 8) of Legionella pneumophila (Lp) in a 10-day-old boy is described together with the epidemiological survey in the maternity ward which made it possible to establish its nosocomial origin. Rodshaped bacteria reacting with an Lp genus-specific monoclonal antibody and serogroup 1 and 8 polyclonal sera were detected in bronchoalveolar lavages (BAL) collected on day 13. Serogroups 1 and 8 were recovered from cultures of BAL collected on days 12 and 13. Fourfold or more antibody rises to serogroups 1, 5, 8 and 10 of Lp were observed in sequential serum specimens. Water samples collected from the tank and mixer of the maternity ward grew serogroups 1 and 8 of Lp. Serogroup 1 was detected in large amounts in water samples taken at several points of the hot water supply system and from the oxygen nebulizers and the feeding-bottle heater. Analysis of the Lp serogroup 1 strains isolated from the water by subgroup-specific monoclonal antibodies revealed the presence of 4 different subgroups, one of which was identical to the Lp 1 subgroup isolated from the neonate's BAL. This latter subgroup, reactive with McKinney monoclonal antibody Mab 2, has been described as highly virulent. No other case of legionellosis was recorded in the maternity ward.

Nosocomial legionnaires disease in a children's hospital

Between August 1982 and December 1985, seven patients at a children's hospital developed hospital-acquired pneumonia caused by Legionella pneumophila. Demographic data included the following: mean age 12.3 years (range 9 months to 20.5 years); male/female ratio 5:2; all patients were white. Some previously identified risk factors present in our patients included high-dose corticosteroid therapy (five patients), other immunosuppressive therapy (four), and chronic lung (five) or kidney (three) disease. Symptoms and signs included rapid onset, fever, cough, pleuritic chest pain, dyspnea, abdominal pain, diarrhea, and headache. Rhinitis, myalgia, and neurologic abnormalities were not noted. Chest roentgenograms revealed single-lobe consolidation in three patients, diffuse bilateral alveolar infiltrates in three, and pleural effusion in three. All patients were treated with erythromycin; three patients also received rifampin. Tracheal intubation and mechanical ventilation were required by four patients. Six patients improved after therapy. One child died of persistent lung disease 1 month after the onset of legionnaires disease. L. pneumophila was isolated from potable water in the hospital. Aerosol equipment cleansed with tap water and the showers were implicated as means of exposure by patients to contaminated potable water. No new nosocomial cases were seen after immunocompromised children were prohibited from taking showers, and sterile water was used to cleanse equipment for administering aerosol medications.

Legionnaires disease: historical perspective

In the summer of 1976, a mysterious epidemic of fatal respiratory disease in Philadelphia launched an intensive investigation that resulted in the definition of a new family of pathogenic bacteria, the Legionellaceae. In retrospect, members of the family had been isolated from clinical specimens as early as 1943. Unsolved epidemics of acute respiratory disease dating to the 1950s were subsequently attributed to the newly described pathogens. In the intervening years, the Legionellaceae have been firmly established as important causes of sporadic and epidemic respiratory disease. The sources of the infecting bacteria are environmental, and geographic variation in the frequency of infection has been documented. Airborne dissemination of bacteria from cooling towers and evaporative condensers has been responsible for some epidemics, but potable water systems are perhaps more important sources. The mode of transmission from drinking water is unclear. The Legionellaceae are gram-negative, facultative, intracellular pathogens. The resident alveolar macrophage, usually an effective antibacterial defense, is the primary site of growth. Cell-mediated immunity appears to be the most important immunological defense; the role of humoral immunity is less clear. Erythromycin remains the antibiotic of choice for therapy of infected patients, but identification and eradication of environmental sources are also essential for the control of infection.

Legionella pneumophila immunity and immunomodulation: nature and mechanisms

L. pneumophila is a facultative intracellular opportunistic pathogen ubiquitously present in the environment. Much is now known concerning the ecological niche of this organism as well as many other characteristics of these bacteria, including physiology and biochemistry. However, much less is known about immune mechanisms responsible for host resistance vs susceptibility. Not only outer membrane protein rich fractions but also LPS-rich components are potent immunogens, both in experimental animals such as susceptible guinea pigs and more resistant rodent species like rats and mice. Immunity to these organisms can be readily observed by a variety of serologic techniques. Antibody titers increase rapidly after exposure of individuals to these bacteria either by infection or immunization. However, such antibody does not appear to play an important role in host resistance. Serum antibody plus complement is not lytic for the bacteria in vitro. Furthermore, antibody appears to promote the phagocytosis of the bacteria by monocytes and/or macrophages in culture but such phagocytosis does not result in killing of the bacteria, merely an enhanced uptake and subsequent replication of the organisms. Studies on cellular immunity have focused attention on the role of T lymphocytes, monocytes and macrophages. In addition, cutaneous hypersensitivity is readily induced by infection or immunization of experimental animals with Legionella or antigenic components. In vitro correlates of hypersensitivity is also readily evident after infection or immunization. Although lymphoid cells from guinea pigs only show evidence of responsiveness to Legionella antigens by the lymphocyte blastogenic reaction after animals have been sensitized, peripheral blood monocytes from man as well as splenocytes from mice show evidence of responsiveness to Legionella even before known infection or sensitization. However, higher blastogenic responses become evident after sensitization or infection. In addition, interleukins, such as interleukin 1 and 2, as well as interferon and tumor necrotizing factor, appear in response to Legionella antigens and seem to play a role in resistance mechanisms. Cellular replication of Legionella in monocytes from man as well as macrophages from susceptible animals seems related to susceptibility or resistance to these organisms. Further analyses of the nature and mechanism of humoral vs cellular immune responses to Legionella antigens will provide valuable information about immunity and resistance to these intracellular pathogens in susceptible individuals.

Legionella and Legionnaires' disease: a review with emphasis on environmental studies and laboratory diagnosis

Legionella pneumophila and related species are important causes of epidemic bacterial pneumonia and nosocomial infection. This review will discuss this new family of bacteria and the diseases they produce. The classification, general microbiologic characteristics, and ecology of the bacteria will be reviewed and the epidemiology and clinical aspects of the infection will be discussed. More emphasis will be given to issues that are more directly related to laboratory workers and with which the author has had more direct experience: pathology, laboratory diagnosis of human infection, pathogenesis of the infection, and virulence mechanisms of the bacterium. Therapy and prevention of the infection will be discussed more briefly.

Symposium on infectious complications of neoplastic disease (Part II). Legionnaires' disease. Aspects of nosocomial infection

Tremendous progress has been made recently in characterization of Legionella pneumophila and infections caused by it. Certain areas that are particularly germane to immunosuppressed patients, who are affected more frequently than other patients, and areas that are controversial and merit particular consideration are considered herein. These include pathogenesis and correlation of experimental and clinical evidence, nosocomial outbreaks and almost ubiquitous distribution of L. pneumophila in water despite only a limited number of studies linking the two by aerosols, prevalence and possible reasons for the apparent spotty distribution, protean clinical manifestations, difficulties in diagnosis, certain aspects of therapy, and control by environmental changes.

Unusual progression of a Legionella pneumophila infection in a young child

A 2 8/12-year-old boy showed an unusual course of a Legionella pneumophila infection with severe dyspnea, longterm loss of conscience (5 days) and permanent persistence of pulmonary obstruction.

Legionella pneumophila pericarditis proved by culture of pericardial fluid

Serogroup 1 Legionella pneumophila was isolated from the pericardial fluid of a nonimmunosuppressed patient with pulmonary infiltrates, cardiac tamponade, and histologic evidence of pericarditis. This is the first reported case in which the association of L. pneumophila infection and pericarditis has been proved by growth of the organism from pericardial fluid. Physicians caring for patients with pericarditis of unknown cause should consider L. pneumophila in their differential diagnosis because special diagnostic efforts and relatively specific therapy are required for its optimal management.