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Biomedical subjects

R Booy

Publications and source records attributed to R Booy.

71 records · Page 4Linked to original sources
PubMed1993

Is the cold chain for vaccines maintained in general practice?

OBJECTIVE: To investigate the cold chain for vaccines and compliance with the local code of practice for storage. DESIGN: In a random sample of general practices orders for live vaccines (oral polio and measles, mumps, and rubella) were accompanied by a cold chain monitor which was activated on leaving the supplying pharmacy. The monitors were read at specified intervals and when all vaccines in the order had been used. Structured interview was used to check compliance with the local code of practice on storage. SETTING: West Berkshire and Aylesbury Vale district health authorities. SUBJECTS: 16 (25%) general practices in West Berkshire, and 13 (50%) in Aylesbury Vale. MAIN OUTCOME MEASURES: Compliance with code of practice. Changes in the cold chain monitor. RESULTS: For six key requirements within the code of practice compliance varied from 70% to 0%. Only 16 of 29 practices had a named person responsible for vaccine storage and only four were aware of the local code of practice. Vaccine was stored for longer and more breaks in the cold chain occurred in West Berkshire than in Aylesbury Vale. The potency of some vaccines in 10 of 26 orders became suspect before use. CONCLUSIONS: Knowledge of appropriate management of the cold chain in two districts was poor. Breaks in the chain were more frequent and compromised potency more likely when vaccine had been stored for more than eight weeks. Problems in maintaining the cold chain indicate the need for continuing audit, which should become a prerequisite for payments to general practitioners for immunisation.

Cold Temperature↗
PubMed1993

Comparison of the epidemiology and cost of Haemophilus influenzae type b disease in five western countries.

To determine and compare the cost of Haemophilus influenzae type b (Hib) disease in Australia, Finland, Israel, Switzerland and the United Kingdom a collaborative study was undertaken. The incidence of Hib disease varies in these 5 countries from 34 to 58.5 cases per 100,000 children less than 5 years of age. Although the incidence of meningitis in this age group is similar (between 18 and 26/100,000) in these countries, the incidence of epiglottitis varies from 0 to 22.7/100,000. The cost of hospitalization and the frequency of sequelae are similar for 4 of the 5 countries; however, the break even cost of a vaccination program to prevent 90% of Hib disease is estimated to vary from $22 to $84 per child (US$). Because of a lower incidence of Hib disease and lower cost for hospitalization, these costs are considerably less than those for the United States ($301.64 using similar calculations).

Australia↗
PubMed1993

Haemophilus influenzae type b carriage and immunity four years after receiving the Haemophilus influenzae oligosaccharide-CRM197 (HbOC) conjugate vaccine.

Late in 1991, before the implementation of a national immunization program against Haemophilus influenzae type b (Hib) in the United Kingdom, we performed a 4-year follow-up of 120 children who in 1987 had been enrolled in an immunogenicity trial in which 60 of them (vaccinees) received an Hib conjugate vaccine (HbOC) at the same time as diphtheria-tetanus toxoid-pertussis vaccine at the ages of 3, 5 and 9 months. Sixty others (controls) received only diphtheria-tetanus toxoid-pertussis vaccine at the same ages and were not subsequently immunized against Hib. We investigated Hib pharyngeal colonization using the antiserum agar method and the concentrations of serum IgG antibody to the type b capsule by enzyme-linked immunosorbent assay. At 4 years of age the Hib colonization rates in vaccinees and controls were 8% (5 of 60) and 5% (3 of 60), respectively. The children colonized with Hib had greater serum anti-capsular IgG concentrations than did noncolonized children (P < 0.001), and colonized vaccinees tended to have higher concentrations than colonized controls (P = 0.053). Regardless of Hib colonization status vaccinees had greater antibody concentrations than controls (P < 0.001). Forty-nine percent of vaccinees had an antibody concentration > 1 microgram/ml. There was an inverse relationship between the Hib colony count on culture and the serum IgG concentration. These data indicate that the increase in serum antibody concentration after immunization with an Hib conjugate vaccine is sustained and that immunization primes for a booster response on exposure to Hib. There may be a relationship between previous Hib conjugate immunization and the density of Hib colonization in children.

Antibodies, Bacterial↗
PubMed1993

Prospective surveillance of neonatal meningitis.

Neonatal meningitis is a serious problem with a high mortality and frequent neurological sequelae. The incidence of neonatal meningitis was calculated and the aetiology, clinical and laboratory features, and the treatment of cases recorded prospectively over a 7 year 8 month period was documented. It was further investigated whether secondary meningitis had occurred after lumbar puncture. The estimated incidence of bacterial, viral, and fungal meningitis was 0.25, 0.11, and 0.02 per 1000 live births respectively. There were eight cases of early onset meningitis (seven definite, one probable) and group B streptococci accounted for six (75%) of these. Blood cultures were negative in only one of seven cases of definite early bacterial meningitis. Of the 15 late onset cases, Gram negative organisms accounted for six of the seven bacterial cases. The overall mortality was 26%. Of the 11 survivors of bacterial meningitis, three (27%) had significant neurological sequelae at follow up (between three months to three years later). As in the first 48 hours after birth an initial blood culture is unlikely to be negative if bacterial meningitis is present, lumbar puncture can be deferred if the procedure might exacerbate respiratory distress. Although approximately 1880 infants had a lumbar puncture during the review period, only one case of meningitis was found where it was possible that lumbar puncture in a bacteraemic infant may have caused meningeal infection. The incidence of this potential complication must therefore be low.

Birth Weight↗
PubMed1993

Invasive Haemophilus influenzae type b disease in the Oxford region (1985-91).

For a seven year period (1985-91) clinical and epidemiological data were prospectively collected on children aged < 10 years with microbiologically confirmed invasive Haemophilus influenzae type b infection in the Oxford region to study the epidemiology of the disease and determine the potential impact of early primary immunisation in infants. Computer records of primary immunisations given to these cases were retrospectively analysed and, where necessary, hospital and general practitioner records were searched to determine the immunisation history. Over the seven year period, 416 cases of invasive H influenzae type b disease were reported. Widescale immunisation against H influenzae type b began in 1991 as part of a regional trial. The estimated annual incidence for invasive disease between 1985 and 1990 was 35.5 cases per 100,000 children aged less than 5 years; for H influenzae type b meningitis it was 25.1 per 100,000 children aged less than 5 years. The cumulative risks for invasive disease and meningitis by the fifth birthday were one in 560 and one in 800 respectively. The majority of disease (71%) occurred in children less than 2 years of age with the peak monthly incidences at 6 and 7 months of age. The overall mortality was 4.3% and 50% of these deaths occurred suddenly. Most (91%) of the children had received at least one primary immunisation against diphtheria, tetanus, and pertussis before H influenzae type b infection and there was only one case of parental refusal of immunisation. None had received H influenzae type b immunisation. Given a vaccine uptake of 90% by 5 months of age it is estimated that at least 82% of the H influenzae type b infections could have been prevented. Extrapolated nationally, 1150 cases of infection and 50 deaths could be prevented each year by routine primary immunisation.

Age Factors↗
PubMed1993

Value of cerebrospinal fluid examination in the diagnosis of meningitis in the newborn.

Between 1 October 1988 and 30 September 1991 the results of all 896 cerebrospinal fluid examinations from 736 neonates were correlated with clinical diagnosis, treatment, and outcome. The prevalence of fungal or bacterial meningitis in babies requiring lumbar puncture was only 0.95%. Gram staining had a sensitivity of 68% and a positive predictive value of only 46% for the diagnosis of meningitis. Primary cultures directly onto agar plates had a sensitivity of 81% and positive predictive value of 46%. Broth enrichment cultures did not improve sensitivity and were frequently found to be false positive. Empirical treatment should not be altered unless more than a few organisms are seen on Gram staining. Primary cultures are adequate for the diagnosis of fungal and bacterial meningitis. Enrichment cultures should be performed only when the Gram stain and/or cell count suggests meningitis is likely. Clinicians should be aware that diagnostic tests performed in populations with a low prevalence of disease are likely to generate many false positive results and have a low positive predictive value.

Bacteriological Techniques↗
PubMed1992

Immunogenicity of combined diphtheria, tetanus, and pertussis vaccine given at 2, 3, and 4 months versus 3, 5, and 9 months of age.

In the UK an accelerated schedule for immunisation against diphtheria, tetanus, and pertussis (injections at 2, 3, and 4 months of age) was introduced in 1990 to replace the more widely spaced schedule of 3, 5, and 9 months. There is concern, however, that the new schedule may be less immunogenic and therefore less protective than the old schedule. We have measured serum concentrations of antibodies against diphtheria, pertussis, and tetanus in infants immunised according to the two regimens. Both schedules resulted in protective concentrations of antibody against tetanus and diphtheria and in satisfactory antibody responses to three pertussis antigens (filamentous haemagglutinin, pertussis toxin, fimbriae). However, immunisation by the old schedule led to significantly higher antibody concentrations against both diphtheria and tetanus than did immunisation by the new schedule (p less than 0.01). In infants immunised with the new schedule, postimmunisation antibody concentrations against tetanus toxoid and against two pertussis antigens (pertussis toxin and fimbriae) were significantly lower in infants in whom preimmunisation (maternally derived) antibody concentrations were high (p less than 0.02). The findings suggest that with an accelerated immunisation schedule maternal antibodies can have an inhibitory effect on the responses to immunisation against tetanus and pertussis.

Antibodies, Bacterial↗
PubMed1992

Immunogenicity and safety of PRP-T conjugate vaccine given according to the British accelerated immunisation schedule.

The immunogenicity and safety of a new Haemophilus influenzae type b conjugate vaccine, PRP-T, was studied in 107 infants from the Oxford district. The vaccine was given concurrently with diphtheria, pertussis, tetanus, and polio vaccines at 2, 3, and 4 months of age. Symptoms after immunisation were recorded by a parent. Sera were obtained before the first immunisation and at 5 months of age and the antibodies were measured by both radioimmunoassay and enzyme linked immunosorbent assay (ELISA). No serious adverse reactions were observed and there was no increase in the incidence of expected minor side effects. By radioimmunoassay, the geometric mean titre of serum anticapsular antibody increased from 0.09 micrograms/ml before immunisation to 5.01 micrograms/ml after three immunisations. Ninety eight per cent of children had antibody concentrations consistent with protection (greater than or equal to 0.15 micrograms/ml). IgG antibody concentrations measured by ELISA correlated well with total antibody concentrations measured by radioimmunoassay (r = 0.864). These results provide encouragement that routine immunisation against H influenzae type b at 2, 3, and 4 months of age, could prevent most cases of disease in children in the UK.

Age Factors↗