A Surveillance Study of Cooling Tower Water of Large Buildings in Seoul City for Legionella Species with Molecular Analysis / 감염

BACKGROUND: To prevent and control legionellosis outbreaks, it is important to monitor cooling towers for Legionella and establish epidemiological markers. We determined level of contamination with Legionella of cooling tower in Seoul city, analyzed the distribution of Legionella subtypes, and evaluated molecular typing methods for discrimination power and feasibility. METHODS: Water samples from 120 cooling towers in 25 areas(Gu) of Seoul city were collected during June, 1997. Culture and duplex-PCR(polymerase chain reaction) with Southern hybridization probed with Legionella-specific genes were performed with filtered samples. Twenty-two Legionella isolates were analyzed comparatively by pulsed-field gel electrophoresis(PFGE) and arbitrarily primed(AP)-PCR using a M13 reverse primer. RESULTS: Culture and duplex-PCR with Southern hybridization were positive for Legionella in 22(18.3%) and 106(88.3%) of 120 samples, respectively, resulting in 90.8%(109/120) of contamination level. Out of 22 Legionella isolates, 17 were identified as Legionella pneumophila serogroup 1, 4 as L. pneumophila serogroup 6 and 1 as an unknown. Molecular analysis of 17 isolates of L. pneumophila serogroup 1 showed 7 subtypes by PFGE(A0 in 9 isolates; A1, 2; A2, 1; A3, 2; B, 1; C, 1; D, 1) and 5 subtypes by AP-PCR(Ia in 11 isolates; Ib, 2; Ic, 2; II, 1; III, 1). The agreement of results of both methods was 76.5%(13/17) of L. pneumophila serogroup 1 and 81.8%(18/22) of all isolates, respectively. CONCLUSION: Most of cooling towers in Seoul city were already contaminated with Legionella just before summer, requiring decontamination measures and continuous surveillance. L. pneumophila serogroup 1 was the predominant isolate with variable subtypes. The AP-PCR can be used as a rapid and reproducible screening tool in tracking legionellosis outbreak.

Clinical Features and Prognostic Factors of Infections in Patients with Acute Leukemia(1988~1995) / 감염

BACKGROUND: Infection is one of the most important and fatal complications in patients with acute leukemia. The characteristics of infection in acute leukemic patients are different from those in other diseases by the lack of normal inflammatory responses or distinct clinical evidence except fever. To improve the outcome of acute leukemia, it is very important to recognize the risk factors, patterns and prognostic factors of acute leukemia. METHODS: We analyzed retrospectively the patterns of infection from 113 febrile patients with acute leukemia from January, 1988 to December, 1995. To determine the prognostic factors and the outcome of infection, the following variables were analyzed: the presence of neutropenia, use of chemotherapeutic agents, type and site of infections, isolated organisms, gastrointestinal decontamination, duration of neutropenia, and bone marrow recovery. RESULTS: Out of 113 febrile patients with acute leukemia, 84 infection episodes(74%) occurred after chemotherapy. The mean duration of neutropenia was 18+/-13 days. The incidence of microbiologically-documented infection(MDI) was 35%(40/113). Pneumonia was the most common infection(26%), followed by primary sepsis(24%), catheter-related infection(9%). In cases of MDI, 63% were caused by gram-negative bacteria, followed by gram-positive bacteria(28%), and fungi(10%). Escherichia coli(25%) was the most common isolated in MDI. Regarding the prognostic factors in cases with infections, the recovery of bone marrow function was the only statistically significant factor(P=0.01). CONCLUSION: Infection has been a major cause of morbidity and mortality in acute leukemic patients. To prevent infection and thereby improve the prognosis of acute leukemia, restoration of bone marrow function at early stage is important.

A Case of Fatal Nosocomial Legionnaires' Disease by Legionella pneumophila Serogroup 1 / 감염

Nosocomial Legionnaires' disease has often been documented to occur in immunocompromised patients and to be severe, potentially fatal, pneumonia. We report a case of fatal nosocomial Legionnaires' disease developed shortly after steroid pulse therapy. A 39-year old woman with systemic lupus erythematosus was admitted via emergency room due to generalized edema and gross hematuria. Under the diagnosis of lupus nephritis, she was given intravenous steroid pulse therapy for 3 days and then maintained with oral prednisolone. On the 7th day of admission the patient's conditions got worse with progression to acute renal failure and respiratory difficulty. On the 10th day of admission when she was started on hemodialysis, chestradiograph showed newly developed multifocal mass-like consolidations on both lung fields. In spite of empirical therapy with roxithromycin and rifampin, the consolidations were aggravated and rapidly extended to both whole lung fields. On the 15th day of admission she was mechanically ventilated due to respiratory failure, but died of hypoxia and shock on the 19th day. Later, a legionella species was isolated from the tracheal aspirates and identified as L. pneumophila serogroup 1. We also detected L. pneumophila from the tracheal aspirates by duplex PCR which amplified both 5S rRNA and mip genes of L. pneumophila.

Retinal Hemorrhage in an Adult with P. vivax Malaria / 감염

Malaria is a worldwide febrile illness with high morbidity and mortality. High fever, jaundice, hemolysis, and hepatosplenomegaly are usual symptoms and signs of malaria, whereas retinal hemorrhage is an unusual finding. Retinal hemorrhage has been known to be one of the clinical manifestations in severe Plasmodium falciparum infection, especially in children developing cerebral malaria. However, retinal hemorrhage can occur in adult patients with severe parasitemia, shizontemia, anemia and may occur in malaria infections caused by other Plasmodium species, because it is due to dense parasitemia in deep vascular beds. A case of Plasmodium vivax malaria with retinal hemorrhage has not been reported as yet. We report a Plasmodium vivax malaria patient with retinal hemorrhage, who presented with severe schizontemia and anemia.