Richard Cunningham

Impact of meningococcal serogroup C conjugate vaccines on carriage and herd immunity

BACKGROUND In 1999, meningococcal serogroup C conjugate (MCC) vaccines were introduced in the United Kingdom for those under 19 years of age. The impact of this intervention on asymptomatic carriage of meningococci was investigated to establish whether serogroup replacement or protection by herd immunity occurred. METHODS Multicenter surveys of carriage were conducted during vaccine introduction and on 2 successive years, resulting in a total of 48,309 samples, from which 8599 meningococci were isolated and characterized by genotyping and phenotyping. RESULTS A reduction in serogroup C carriage (rate ratio, 0.19) was observed that lasted at least 2 years with no evidence of serogroup replacement. Vaccine efficacy against carriage was 75%, and vaccination had a disproportionate impact on the carriage of sequence type (ST)-11 complex serogroup C meningococci that (rate ratio, 0.06); these meningococci also exhibited high rates of capsule expression. CONCLUSIONS The impact of vaccination with MCC vaccine on the prevalence of carriage of group C meningococci was consistent with herd immunity. The high impact on the carriage of ST-11 complex serogroup C could be attributed to high levels of capsule expression. High vaccine efficacy against disease in young children, who were not protected long-term by the schedule initially used, is attributed to the high vaccine efficacy against carriage in older age groups.

Non–Travel-Associated Hepatitis E in England and Wales: Demographic, Clinical, and Molecular Epidemiological Characteristics

Between 1996 and 2003, 186 cases of hepatitis E were serologically diagnosed. Of these, 17 (9%) were not associated with recent travel abroad. Patients were >55 years old (range, 56-82 years old) and tended to be male (76%). Two patients presented with fulminant hepatitis. A total of 129 (69%) cases were associated with recent travel to countries where hepatitis E virus (HEV) is hyperendemic. Compared with patients with travel-associated disease, patients with non-travel-associated disease were more likely to be older, living in coastal or estuarine areas, not of South Asian ethnicity, and infected by genotype 3 strains of HEV. The genotype 3 subgenomic nucleotide sequences were unique and closely related to those from British pigs. Patients infected by HEV indigenous to England and Wales tended to belong to a distinct demographic group, there were multiple sources of infection, and pigs might have been a viral reservoir.

Changes in Serogroup and Genotype Prevalence Among Carried Meningococci in the United Kingdom During Vaccine Implementation

Background. Herd immunity is important in the effectiveness of conjugate polysaccharide vaccines against encapsulated bacteria. A large multicenter study investigated the effect of meningococcal serogroup C conjugate vaccine introduction on the meningococcal population. Methods. Carried meningococci in individuals aged 15–19 years attending education establishments were investigated before and for 2 years after vaccine introduction. Isolates were characterized by multilocus sequence typing, serogroup, and capsular region genotype and changes in phenotypes and genotypes assessed. Results. A total of 8462 meningococci were isolated from 47 765 participants (17.7%). Serogroup prevalence was similar over the 3 years, except for decreases of 80% for serogroup C and 40% for serogroup 29E. Clonal complexes were associated with particular serogroups and their relative proportions fluctuated, with 12 statistically significant changes (6 up, 6 down). The reduction of ST-11 complex serogroup C meningococci was probably due to vaccine introduction. Reasons for a decrease in serogroup 29E ST-254 meningococci (from 1.8% to 0.7%) and an increase in serogroup B ST-213 complex meningococci (from 6.7% to 10.6%) were less clear. Conclusions. Natural fluctuations in carried meningococcal genotypes and phenotypes a can be affected by the use of conjugate vaccines, and not all of these changes are anticipatable in advance of vaccine introduction.

Comparison of Automated Processing of Flocked Swabs with Manual Processing of Fiber Swabs for Detection of Nasal Carriage of Staphylococcus aureus

ABSTRACT The sensitivity of automated culture of Staphylococcus aureus from flocked swabs versus that of manual culture of fiber swabs was prospectively compared using nasal swabs from 867 patients. Automated culture from flocked swabs significantly increased the detection rate, by 13.1% for direct culture and 10.2% for enrichment culture.

Improved Rate of Isolation of Neisseria meningitidis by Direct Plating of Pharyngeal Swabs

ABSTRACT Culturing of pharyngeal swabs for Neisseria meningitidis is an important clinical and epidemiological tool. Routine methods include direct plating onto solid medium or later plating in the laboratory. A comparison of these methods used with 490 high school students found a significantly higher carriage rate with direct plating (11.8 versus 6.1%; P < 0.001).

How do microbiology consultants undertake their jobs? A survey of consultant time and tasks in South West England

Aims: To measure the total consultant medical microbiologist (CMM) weekly workload, to identify time spent on different activities, and to differentiate those tasks that were viewed by a consensus of consultants as core activities from those that could be accorded a lower priority. Methods: A self administered questionnaire completed by consultant medical microbiologists in the Public Health Laboratory Service South West Group. Results: Reported hours worked by respondents ranged from 41 to 65 hours each week, excluding on call activities. Eleven of 20 respondents reported working in excess of 48 hours each week. There was no correlation between hours worked and laboratory workload as measured by numbers of specimens. Clinical liaison, result authorisation, infection control, and management activities took up most time. Working practices varied widely between individuals, partly reflecting their differing roles in the laboratory. A consensus was reached regarding the relative importance and priority of many regular CMM activities. Conclusions: Consultant microbiologists can identify, with consensus, both high and lower priority activities in their daily practice. If such clinical priorities can be more widely agreed across the profession, this would provide a rational approach to workload control.

A survey of time management and particular tasks undertaken by consultant microbiologists in the UK

Background: Medical microbiology practice encompasses a diverse range of activities. Consultant medical microbiologists (CMMs) attribute widely differing priorities to, and spend differing proportions of time on various components of the job. Aim: To obtain a professional consensus on what are high-priority and low-priority activities, and to identify the time spent on low-priority activities. Method: National survey. Results: Many respondents felt that time spent on report authorisation and telephoning of results was excessive, whereas time spent on ward-based work was inadequate. Timesaving could also be achieved through better prioritisation of infection-control activities. Conclusion: CMMs should apportion their time at work focusing on high-priority activities identified through professional consensus.

Detection of hepatitis b virus DNA in the blood of a stem cell donor after granulocyte colony‐stimulating factor treatment

Occult hepatitis B virus (HBV) infections have gained much attention in terms of transmissibility and reactivation. Here, we report the case of a healthy stem cell donor with serological evidence of a resolved HBV infection who became temporarily HBV DNA–positive in the blood after stimulation with granulocyte colony-stimulating factor (G-CSF). A 51-year-old man from the German Bone Marrow Donor Center was identified as human leukocyte antigen matching (10/10) stem cell donor for a 44-year-old female patient diagnosed with precursor B-cell acute lymphoblastic leukemia in the United Kingdom. This donor was a well-known blood donor since 2009 and was previously tested positive for antibody to hepatitis B core antigen, antibody to hepatitis B e antigen, and antibody to hepatitis B surface antigen (anti-HBs). During the diagnostic workup the serological findings could be confirmed and HBV DNA was not detected. Thus, in accordance with German regulations, this donor was considered eligible for stem cell donation. The donor started G-CSF treatment, and at day 5 cluster of differentiation 34 (CD34)–positive stem and progenitor cells were collected. At this time HBV DNA (pooled tested, detection limit 257 IU/mL) tested negative. The product was shipped from the German apheresis center to the UK transplantation center and infused after myeloablative conditioning of the patient had been completed. Six days after transplantation, testing of the product at the transplantation center revealed the presence of 26 IU/mL HBV DNA, which could be confirmed by testing backup samples (product and blood) (Table 1; Supporting Information). Therefore, the stem cell recipient immediately started lamivudine treatment and has tested negative for HBV DNA (last test day 1130) ever since. AntiHBs of the recipient was negative before transplantation but temporarily positive after transplantation (Supporting Information). HBV DNA testing of the donor was again negative at day 16 after apheresis. Anti-HBs titration and neutralizing experiments using hepatitis B surface antigen (HBsAg) from different genotypes specified the presence 3,300 IU/L anti-HBs in the blood of the donor highly capable of neutralizing HBsAg from different genotypes. Parts of the HBV DNA detected in the

Detection of HBV DNA in the blood of a stem cell donor after G‐CSF treatment

Occult hepatitis B virus (HBV) infections have gained much attention in terms of transmissibility and reactivation. Here, we report the case of a healthy stem cell donor with serological evidence of a resolved HBV infection who became temporarily HBV DNA–positive in the blood after stimulation with granulocyte colony-stimulating factor (G-CSF). A 51-year-old man from the German Bone Marrow Donor Center was identified as human leukocyte antigen matching (10/10) stem cell donor for a 44-year-old female patient diagnosed with precursor B-cell acute lymphoblastic leukemia in the United Kingdom. This donor was a well-known blood donor since 2009 and was previously tested positive for antibody to hepatitis B core antigen, antibody to hepatitis B e antigen, and antibody to hepatitis B surface antigen (anti-HBs). During the diagnostic workup the serological findings could be confirmed and HBV DNA was not detected. Thus, in accordance with German regulations, this donor was considered eligible for stem cell donation. The donor started G-CSF treatment, and at day 5 cluster of differentiation 34 (CD34)–positive stem and progenitor cells were collected. At this time HBV DNA (pooled tested, detection limit 257 IU/mL) tested negative. The product was shipped from the German apheresis center to the UK transplantation center and infused after myeloablative conditioning of the patient had been completed. Six days after transplantation, testing of the product at the transplantation center revealed the presence of 26 IU/mL HBV DNA, which could be confirmed by testing backup samples (product and blood) (Table 1; Supporting Information). Therefore, the stem cell recipient immediately started lamivudine treatment and has tested negative for HBV DNA (last test day 1130) ever since. AntiHBs of the recipient was negative before transplantation but temporarily positive after transplantation (Supporting Information). HBV DNA testing of the donor was again negative at day 16 after apheresis. Anti-HBs titration and neutralizing experiments using hepatitis B surface antigen (HBsAg) from different genotypes specified the presence 3,300 IU/L anti-HBs in the blood of the donor highly capable of neutralizing HBsAg from different genotypes. Parts of the HBV DNA detected in the