Prevalence of moderate penicillin resistant invasive Neisseria meningitidis infection in Scotland, 1994–9

Abstract

We examined the serological characteristics of 774 invasive meningococcal isolates collected through an active laboratory-based surveillance system in Scotland from 1994 to 1999. Of these, 72–73% of isolates were tested for susceptibility to several antimicrobial agents. Meningococci with high-level resistance to sulphadiazine had a prevalence of 10% and incidence of 0·22 per 100000 population. High-level resistance to penicillin and other antibiotics was not detected. The prevalence of moderate penicillin resistant meningococci was 8·3%. There was no increase in moderate penicillin resistant meningococcal isolates during the study period, but there were temporal and geographic variations. The estimated incidence of moderate penicillin resistant meningococci was 0·15 per 100000 population. High and low incidence of moderate penicillin resistant meningococci appeared to correlate with the number of doses of penicillin prescribed in some geographic locations. The majority of moderate penicillin resistant isolates belonged to serogroups B (52·2%) and C (39·2%). However, the prevalence of moderate penicillin resistance in serogroup W135 was substantially higher (51·7%) than serogroups B (7·8%) and C (7·6%). Serogroup W135 accounted for a higher proportion of moderate penicillin resistance (8·7%) than disease (1%). There was no predominant penicillin resistant serotype/subtype within any serogroup. Constant surveillance is necessary to monitor the emergence and spread of resistance and to guide appropriate public health interventions in preventing drug resistant meningococci.

Prospective Study of a Real-Time PCR That Is Highly Sensitive, Specific, and Clinically Useful for Diagnosis of Meningococcal Disease in Children

“…In addition, culturing allows for complete antimicrobial susceptibility testing of isolates, whereas the utility of PCR for predicting susceptibility profiles has yet to be widely validated (3). Although in Australia there has yet to be an isolate of N. meningitidis resistant to penicillin, increasing penicillin MICs and the emergence of beta-lactamase-producing organisms have been documented elsewhere, highlighting the need for ongoing surveillance (2,22).…”

Response from NICE

“…2,3 On an individual level a person on methadone is less likely to die, commit crimes, or get blood-borne viruses. 4 In contrast, Fitzpatrick's piece is largely rhetorical and it is flawed rhetoric at that. He argues that because there are people who have been on methadone for many years, this 'confirms the spectacular ineffectiveness of the (methadone) treatment'.…”

“…With regard to the moderate penicillin resistance that the authors note was documented by Kyaw et al 4 (and elsewhere), it is important to monitor through good surveillance (best achieved by obtaining blood and cerebrospinal fluid cultures in hospital) but, as Kyaw et al say in their paper, the clinical significance of moderate resistance among meningococci remains unknown. 4 Meeting a case of meningococcal disease is thankfully a once in a lifetime experience for most GPs and, carriage of ceftriaxone over a GPs' career is unnecessary and wasteful, especially as we are still uncertain whether antibiotic therapy outside a hospital environment even helps. We recommend that GPs continue to carry benzylpenicillin, at minimal cost, and to administer it if its use will not delay hospital admission.…”

‘One for all’ concerns regarding NICE antibiotic guidelines on suspected bacterial meningitis!

“…[6][7][8] Penicillin resistant rates among UK Haemophillus species isolates is 17.7% and penicillin intermediate S. pneumoniae is 10.8%. In a Scottish study the prevalence of moderate penicillin resistant meningococci was 8.3%, the majority of isolates (52.2%) belonged to serogroup B, 3,4 and according to the same NICE guidelines the prevalence of Haemophillus resistance to third generation cephalosporins is almost zero. There is currently a low prevalence of pneumococcal cefotaxime/ceftriaxone resistance in the UK, with only 1.7% of strains…”