Immunogenicity of routine vaccination against diphtheria, tetanus, and Haemophilus influenzae type b in Asian infants born in the United Kingdom.

AIM: To determine the immunogenicity of routine vaccination against diphtheria, tetanus, and Haemophilus influenzae type b (Hib) in Asian infants born in the UK, and whether maternal antibody suppression occurs. METHODS: A cohort study with 80% power, within 95% confidence limits, to show that 80% or fewer Asian infants would respond with an anti-PRP antibody concentration >0.15 microg/ml. Infants of South Asian origin born in Berkshire were enrolled at two general practices in Reading: 41 Asian families sequentially asked to participate within 2 weeks of birth; 36 infants were enrolled and 34 completed the study. Main outcome measures were: antibody concentration against diphtheria, tetanus, and Hib expressed as geometric mean titres (GMT) and proportion of infants about a threshold protective antibody concentration. RESULTS: Median age for completing primary vaccination course was 5 months. All 34 achieved anti-PRP antibody concentration of >0.15 microg/ml, 33 were >1.0 microg/ml, and the GMT was 15.0 microg/ml. All infants developed protective antibody concentration >0.1 IU/ml for tetanus and diphtheria; the respective GMTs were 1.94 and 5.57 IU/ml. Infants with high (>0.25 IU/ml) antibody concentrations against diphtheria and tetanus at 2 months achieved lower antibody concentrations after their three dose course than those with low concentrations (<0.1 IU/ml) (p = 0.06 and 0.03, respectively). CONCLUSIONS: Despite evidence for maternal antibody suppression of the response to tetanus and diphtheria vaccination, excellent antibody responses were achieved by routine vaccination according to the accelerated schedule. High vaccine coverage should be encouraged to provide protection against the possibility of imported infection.

Cirrhosis and primary liver cancer amongst first generation migrants in England and Wales.

OBJECTIVE: To examine mortality from cirrhosis of the liver and primary liver cancer among first generation migrants to England and Wales. DESIGN: Comparison of standardised mortality ratios (SMRs) for cirrhosis of the liver and primary liver cancer in men and women aged 20-69, by country of birth for the five year period 1988-1992. SETTING: England and Wales. RESULTS: There was a statistically significant two-fold excess of mortality from cirrhosis of the liver among male migrants from East Africa (SMR 286), India (SMR 261) and Bangladesh (SMR 254) as well as men born in Scotland (SMR 253) and Ireland (SMR252). Among women, only those born in Scotland (SMR 254) and Ireland (SMR 237) showed significant excess mortality. For liver cancer, significant excess mortality occurred among men born in the Caribbean (SMR 312), Bangladesh (910) and the African Commonwealth other than East Africa (1014), with Scottish and Irish born men showing more moderate excesses (136 and 170, respectively). SMRs were elevated also in all groups of foreign-born women but, probably owing to the small numbers of deaths, none of the findings reached statistical significance. CONCLUSIONS: Of public health concern is the excess mortality from cirrhosis in first generation immigrants to England and Wales from Scotland and Ireland (men and women) and in male migrants from India, Bangladesh and East Africa. Of equal concern is increased mortality from liver cancer in all foreign-born groups of both sexes, particularly among Bangladeshis, and African-Caribbeans. As well as promoting sensible drinking among immigrant men, specific preventive measures for those of Bangladeshi, African-Caribbean origin may include selective screening for hepatitis B and C and other tumour markers. Screening for liver cancer using imaging techniques needs further investigation. The benefit/cost ratio should be assessed by the Screening Committees of the UK Departments of Health. At local level, variation in incidence and prevalence of hepatic disease and feasible prevention programmes should be assessed within developing health improvement programmes.

Efficacy of Haemophilus influenzae type b conjugate vaccine PRP-T.

Efficacy of the Haemophilus influenzae type b (Hib) conjugate vaccine PRP-T (Pasteur-Merieux) was evaluated in a controlled community intervention study in the Oxford region, UK. PRP-T was offered to infants from May 1, 1991 in three of the region's eight districts and from July 1, 1991, in a fourth district. It was given by separate injection in addition to the standard diphtheria, tetanus, and pertussis vaccine according to an accelerated 2, 3, and 4 month schedule without a booster dose in the second year of life. By October 1, 1992, more than 90% of infants in vaccine districts had received at least one dose of PRP-T. None of the infants given three doses had developed Hib infection, whereas 11 infections occurred in the control population (vaccine efficacy 100%, 95% CI 80-100%). Intention-to-treat analysis also showed a high estimate of efficacy for the vaccine (90%, 50-99%). Follow-up of study children until November 1, 1993, has shown only 1 vaccine failure in an infant, and no invasive infections in those older than 1 year (average age 22 months). PRP-T vaccine had high protective efficacy with an accelerated immunisation schedule. Furthermore, the vaccine appears to remain protective through the second year of life without a booster dose. These findings provide encouragement for use of PRP-T in the Expanded Programme of Immunisation.

An outbreak of gastrointestinal illness associated with contamination of the mains supply by river water.

In June 1992 a department of public health was informed of an outbreak of illness that was thought to be associated with contamination of the mains water supply to a farm. A field investigation identified 42 cases of acute gastrointestinal illness among 117 people potentially at risk, and found that the mains water supply to the farm was connected to an irrigation system that used water from a river. This outbreak illustrates the danger of connections between potable and non-potable water systems, and emphasises the importance of complying with existing water byelaws.

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.