To disclose risk factors for active tuberculosis transmission in the Netherlands, restriction fragment length polymorphism (RFLP) patterns of 78% of the Mycobacterium tuberculosis isolates, from the period 1993-1997, were analyzed. Of the respective 4266 cases, 46% were found in clusters of isolates with identical RFLPs, and 35% were attributed to active transmission. The clustering percentage increased strongly with the number of isolates; taking this into account, fewer cases were clustered than has been reported in other studies. Contact investigations in the five largest clusters of 23-47 patients suggested epidemiological linkage between cases. Of patients identified through contact tracing, 91% were clustered. Demographic risk factors for active transmission of tuberculosis included male sex, urban residence, Dutch and Surinamese nationality, and long-term residence in the Netherlands. Human immunodeficiency virus infection was not an independent risk factor for active transmission. Isoniazid-resistant strains were relatively less frequently clustered, suggesting that these generated fewer secondary cases.

False-positive Mycobacterium tuberculosis cultures are a benchmark for the quality of laboratory processes and patient care. We studied the incidence of false-positive cultures, risk factors, and consequences for patients during the period from 1993 to 2000 in 44 peripheral laboratories in The Netherlands. The national reference laboratory tested 8,889 M. tuberculosis isolates submitted by these laboratories. By definition, a culture was false positive (i) if the DNA fingerprint of the isolate was identical to that of an isolate from another patient processed within 7 days in the same laboratory, (ii) if the isolate was taken from a patient without clinical signs of tuberculosis, and/or (iii) if the false-positive test result was confirmed by the peripheral laboratory and/or the public health tuberculosis officer. We identified 213 false-positive cultures (2.4%). The overall incidence of false-positive cultures decreased over the years, from 3.9% in 1993 to 1.1% in 2000. Laboratories with falsepositive cultures more often processed less than 3,000 samples per year (P < 0.05). Among 110 patients for whom a false-positive culture was identified from 1995 to 1999, we found that for 36% of the patients an official tuberculosis notification had been provided to the appropriate public health services, 31% of the patients were treated, 14% of the patients were hospitalized, and a contact investigation had been initiated for 16% of the patients. The application of DNA fingerprinting to identify false-positive M. tuberculosis cultures and the provision of feedback to peripheral laboratories are useful instruments to improve the quality of laboratory processes and the quality of medical care.

Objective: To evaluate the prevalence and epidemiology of penicillinase producing Neisseria gonorrhoeae (PPNG) and tetracycline resistant Ngonorrhoeae (TRNG) (Genitourin Med 1997;73:510-517)

Mycobacterium heckeshornense is a rare isolate in clinical specimens. We performed simultaneous 16S rRNA sequence analysis of a mycobacterium culture and a histopathology specimen to determine the relevance of M. heckeshornense infection in an immunocompetent patient initially presenting with pneumothorax.

Respiratory infections with penicillin resistant pneumococci constitute an increasing health care problem. This paper describes the nosocomial spread of penicillin resistant pneumococci (PRP) on a pulmonary ward.During an eight-month period, minimal inhibitory concentrations (MICs) for penicillin and several other antibiotics were performed on all Streptococcus pneumoniae isolates that were shown to be penicillin resistant by a screening assay. The personal data and case history of all patients with penicillin resistant pneumococci were evaluated.Penicillin Resistant Pneumococci were cultured from 18 patients, 16 men (mean age 74±8 yrs) and 2 women (aged 54 and 60 yrs). Chronic obstructive pulmonary disease was diagnosed in 16 patients, 10 of which had an additional underlying disease (2 diabetes mellitus, 2 heart failure, 2 malignancy).Prior to culture of Penicillin Resistant Pneumococci, 11 out of 18 patients were treated with antibiotics, a β-lactam in most instances. Ten out of 18 patients died during or shortly after hospitalization. The death of one patient seems to be directly related to infection with Pencillin Resistant Pneumococci. The five Penicillin Resistant Pneumococci isolates available for serotyping were all type 9. The minimal inhibitory concentrations for penicillin varied from 0.5 to 2.0 mg·l -1 . High minimal inhibitory concentrations were also noted for cefixime (all over 4.0 mg·l -1 ) and ceftriaxone (0.5-1.0 mg·l -1 ).It is concluded that penicillin resistant pneumococci can spread rapidly among old and debilitated patients. Thus, patients with this infection should be barrier nursed.