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Biomedical subjects

M M Hannan

Publications and source records attributed to M M Hannan.

11 recordsLinked to original sources

Investigation and control of a large outbreak of multi-drug resistant tuberculosis at a central Lisbon hospital.

An increase in the number of new cases of tuberculosis (TB) combined with poor clinical outcome was identified among HIV-infected injecting drug users attending a large HIV unit in central Lisbon. A retrospective epidemiological and laboratory study was conducted to review all newly diagnosed cases of TB from 1995 to 1996 in the HIV unit. Results showed that from 1995 to 1996, 63% (109/173) of the Mycobacterium tuberculosis isolates from HIV-infected patients were resistant to one or more anti-tuberculosis drugs; 89% (95) of these were multidrug-resistant, i.e., resistant to at least isoniazid and rifampicin. Eighty percent of the multidrug-resistant strains (MDR) available for restriction fragment length polymorphism (RFLP) DNA fingerprinting clustered into one of two large clusters. Epidemiological data support the conclusion that the transmission of MDR-TB occurred among HIV-infected injecting drug users exposed to infectious TB cases on open wards in the HIV unit. Improved infection control measures on the HIV unit and the use of empirical therapy with six drugs once patients were suspected to have TB, reduced the incidence of MDR-TB from 42% of TB cases in 1996 to 11% in 1999.

AIDS-Related Opportunistic Infections↗

Pyrazinamide-monoresistant Mycobacterium tuberculosis in the United States.

Mycobacterium bovis is naturally resistant to the antituberculosis drug pyrazinamide (PZA). To determine whether all Mycobacterium tuberculosis complex isolates demonstrating PZA monoresistance were truly M. bovis, we examined the phenotype and genotype of isolates reported as PZA monoresistant in five counties in California from January 1996 through June 1999. Isolates reported by local laboratories to be PZA monoresistant were sent to the state reference laboratory for repeat susceptibility testing using the BACTEC radiometric method and to the Centers for Disease Control and Prevention for pncA sequencing and PCR-restriction fragment length polymorphism (RFLP) analysis of the oxyR gene. Of 1,916 isolates, 14 were reported as PZA monoresistant and 11 were available for retesting. On repeat testing, 6 of the 11 isolates were identified as PZA-susceptible M. tuberculosis, 1 was identified as PZA-monoresistant M. bovis, and 1 was identified as M. bovis BCG. The three remaining isolates were identified as PZA-monoresistant M. tuberculosis. Sequencing of the pncA and oxyR genes genotypically confirmed the two M. bovis and the six susceptible M. tuberculosis species. Each of the three PZA-monoresistant M. tuberculosis isolates had different, previously unreported, pncA gene mutations: a 24-bp deletion in frame after codon 88, a base substitution at codon 104 (Ser104Cys), and a base substitution at codon 90 (Ile90Ser). This study demonstrates that PZA monoresistance is not an absolute marker of M. bovis species but may also occur in M. tuberculosis, associated with a number of different mutational events in the pncA gene. It is the first report of PZA-monoresistant M. tuberculosis in the United States.

Amidohydrolases↗

Hospital infection control in an era of HIV infection and multi-drug resistant tuberculosis.

Tuberculosis infection control in hospitals has received renewed interest after decades of low prominence following the occurrence of multiply drug-resistant strains in populations of patients with immune systems affected by HIV. This paper examines the history of tuberculosis infection control in hospitals and how recent outbreaks have influenced contemporary measures. The principal infection control measure must always be early recognition and isolation of patients in HIV-care situations who may be dispersing Mycobacterium tuberculosis, in both ward and outpatient areas. If there is either a high degree of suspicion or proven TB, patients should be housed in negative pressure isolation rooms whilst undergoing treatment and investigation. Procedures which may generate infectious aerosols should be carried out in similarly ventilated rooms. The quality assurance in such infection control is through the administrative systems put in place, staff training and the engineering controls of isolation room ventilation.

AIDS-Related Opportunistic Infections↗

Acid-alcohol fast bacilli in sputa of HIV-infected patients.

We identified 34 HIV-infected patients with sputum smear positive for acid-alcohol fast bacilli (AAFB) to determine any factors predictive of subsequent species identification. There were 20 cases of Mycobacterium tuberculosis (MTB), 9 cases of Mycobacterium avium-intracellulare (MAI), 3 cases of Mycobacterium kansasii and one each of Mycobacterium malmoense and Mycobacterium fortuitum. Factors associated with isolation of MAI were lower CD4 cell count, a higher incidence of previous AIDS diagnosis, a history of dyspnoea and a normal chest X-ray. The organism was isolated from blood cultures in 58% of patients with MTB and 78% of patients with MAI infection. Disseminated disease was diagnosed in 45% of MTB patients and 33% of MAI patients.

AIDS-Related Opportunistic Infections↗

An outbreak of Salmonella enteritidis in a maternity and neonatal intensive care unit.

An outbreak of Salmonella enteritidis in a maternity and neonatal intensive care unit is described. The outbreak involved six babies and three mothers over a period of 23 days. The index case presented with premature labour with chorioamnionitis caused by S. enteritidis. There was no history of diarrhoea at the time of her admission of during her pregnancy. The absence of illness led to a delay in instituting standard isolation procedures until S. enteritidis had been isolated from the placenta four days after delivery. It appeared that the resuscitator in the labour ward operating theatre acted as a reservoir for the initial transmission with secondary person-to-person spread. Early introduction of universal infection control measures including handwashing and appropriate disinfection of equipment would have prevented the outbreak.

Adult↗

Safety and efficacy of monoclonal antibody purified factor IX concentrate in previously untreated patients with hemophilia B.

The safety and efficacy of a monoclonal antibody purified factor IX concentrate were evaluated in two continuing trials of 32 previously untreated patients with mild, moderate, or severe hemophilia B. Patients were evaluated every 2 weeks for 24 weeks and every 3 months thereafter for at least 1 year. No patients became positive for human immunodeficiency virus antibody or hepatitis C virus antibody during the trial. Two patients developed a false-positive hepatitis B core antibody, one transiently, but neither had elevated levels of alanine aminotransferase (ALT). None of the 25 patients evaluable for non-A, non-B, non-C hepatitis by strict International Society of Thrombosis and Hemostasis criteria developed elevated levels of ALT indicative of posttransfusion infection. Anaphylaxis occurred in one subject who also developed an inhibitor to factor IX (19.3 Bethesda units). Five of the eight adverse events reported (63%) were mild in severity, and the relationship of three of these to therapy was considered remote. Hemostasis with monoclonal antibody purified factor IX concentrate was excellent in all patients.

Adolescent↗

Concomitant treatment with factor IX concentrates and antifibrinolytics in hemophilia B.

Concomitant use of the monoclonal antibody-purified factor IX concentrate (Mononine, Armour Pharmaceutical Company, Collegeville, Pa.) and two antifibrinolytic agents, epsilon-aminocaproic acid (EACA; Amicar, Immunex, Seattle, Wash.) or tranexamic acid (AMCA; Cyklokapron, Kabi Pharmacia, Piscataway, N.J.) was examined for safety and efficacy in patients with hemophilia B. In a retrospective review of 19 patients treated with monoclonal antibody-purified factor IX and EACA on 35 occasions, bleeding was successfully controlled and no instances of clinical thrombotic complications were reported; one instance of urticaria resolved without additional treatment. The use of EACA or AMCA in combination with monoclonal antibody-purified factor IX was also examined prospectively in a study of 9 patients. Bleeding was effectively controlled and no thrombotic events were detected clinically with either antifibrinolytic agent. No significant changes in hematocrit or hemoglobin were detected, and there was no evidence of thrombosis as evaluated clinically and by sensitive molecular markers. It was concluded from both the retrospective and prospective data that monoclonal antibody-purified factor IX concentrate in combination with an antifibrinolytic agent does not activate the coagulation cascade and is a safe and effective treatment for prevention and control of oral bleeding in hemophilia B patients.

Aminocaproates↗