Alan Gaylard Shattock

Increased severity and morbidity of acute hepatitis in drug abusers with simultaneously acquired hepatitis B and hepatitis D virus infections

Hepatitis D virus (delta agent) markers were present in 111 (36%) of 308 intravenous drug abusers who were positive for hepatitis B surface antigen (HBsAg), 52 of these having hepatitis D virus antigenaemia. IgM antibody to hepatitis B core antigen (anti-HBc IgM) was present in 92 out of 95 subjects tested, indicating that hepatitis D virus and hepatitis B virus infections had been acquired simultaneously. Hepatitis D virus markers were present in three out of four patients with fulminant hepatitis, and in 80 of 223 (36%) with mild or moderate hepatitis compared with four of 29 (14%) of those who were asymptomatic. These proportional differences were significant (p less than 0.001). Hepatitis D virus markers were present in twice as many patients positive for anti-HBc IgM requiring admission to hospital with acute hepatitis compared with outpatients attending a drug treatment centre. Tests on one patient showed complete disappearance of HBsAg, but hepatitis D antigen (HDAg or delta antigen) and hepatitis B e antigen (HBeAg) were still present in serum samples. All five patients with chronic active hepatitis had hepatitis D antibody (anti-HD) compared with seven of 24 (29%) with chronic persistent hepatitis (p = 0.008). Blocking anti-HD persisted for long periods after simultaneous infections with hepatitis B virus and hepatitis D virus but at lower titres than in patients with chronic liver disease.

Cost-effective analysis of hepatitis A prevention in Ireland.

OBJECTIVE:The purpose of this study was to determine the most cost-effective prevention strategy against hepatitis A virus (HAV) infection for healthcare workers and the general population at risk in Ireland.METHODS:Four prevention strategies were compared: active immunization with Havrix Monodose (1440E.U); screening for anti-HAV antibody and then vaccinating; passive immunization; screening for anti-HAV antibody and then passive immunization. The cost-effective ratio was calculated for each prevention strategy. Threshold analysis, sensitivity analysis, and model extension to include indirect cost from work days lost and secondary attack rates through horizontal transmission were also derived.RESULTS:The medical costs were lowest and the infection rate highest when no preventive action was taken. Vaccination was most cost effective when the prevalence of immunity was 45% or less, reducing the infection rate by 98% when compared to nonprevention. Screening before vaccination was most cost effective when the prevalence of immunity was greater than 45%. Passive immunization and screening before passive immunization were not comparable to the other strategies in cost effectiveness. Sensitivity analysis showed that the cost-effective ratio for vaccination was dependent on vaccine price, incidence of HAV, and prevalence of immunity in the target group. Extending the model to include indirect costs further increased the cost effectiveness of vaccination.CONCLUSION:The best cost-effective strategy relates to target group immunity. Where HAV immunity is 45% or less, vaccination is the strategy of choice and when immunity is greater than 45%, then screening followed by vaccination should be used. This study can be used to provide a framework within which choices can be made to achieve better health for less cost.

Capture immunoassay for the diagnosis of bovine mastitis using a monoclonal antibody to polymorphonuclear granulocytes

A direct capture enzyme-linked immunosorbent assay (ELISA) was developed to measure elevated polymorphonuclear granulocyte (PMN) antigens using horseradish peroxidase (EC 1.11.1.7) conjugated rabbit polyclonal anti-PMN antisera and a monoclonal antibody specific for PMN cells. Optical densities obtained in the ELISA were used to predict the cell counts of milk samples. Predicted counts were not significantly different from actual somatic cell counts (SCC). In a total of 156 bovine milk samples the correlation coefficient between somatic cell counting, taking greater than 500,000 cells/ml as being indicative of mastitis, and the assay was 0.94, yielding an assay sensitivity of 95.2% and a specificity of 97.3%. In further trials the ELISA could detect elevated PMN antigens in milk with SCC as low as 100,000 cells/ml. The results indicate that the monoclonal antibody based direct ELISA has excellent potential in the detection and determination of bovine mastitis.

Possible reactivation of hepatitis D with chronic delta antigenaemia by human immunodeficiency virus.

This very short paper reported on a case study of reactivation of infection with hepatitis D virus in an intravenous drug abuser, who was a carrier of hepatitis B surface antigen (HBsAg).

Hepatitis a in urban Ireland

Aims: To determine the prevalence of immunity to hepatitis A virus (HAV) infection in urban Ireland and to categorize the region into low, intermediate or high HAV endemicity, and to analyse the significance of certain commonly associated risk factors.Methods: Two hundred and thirty three volunteers were recruited from 6 general practices in Dublin, Ireland. There were 44 volunteers in the 10 to 19 yr age group, 40 in the 20 to 29, 42 in the 30 to 39, 43 in the 40 to 49 and 64 in the over 50 age groups. Each participant completed a detailed questionnaire and was tested for anti-HAV total antibody (primarily IgG) using a competitive ELISA assay. Urban Ireland was classified into the appropriate area of HAV endemicity according to the prevalence of immunity by age group. Risk factor differences were analysed for significance using the chi square test and Fisher’s exact test.Results: One hundred and fifty seven (67 per cent) volunteers were immune, of whom 20 (45 per cent) were in the 10 to 19 yr age group, 17 (43 per cent) in the 20 to 29, 30 (71 per cent) in the 30 to 39, 34 (79 per cent) in the 40 to 49 and 59 (92 per cent) in the over 50 age groups. Fifty-five per cent of the individuals studied below the age of 20 yr were non-immune. The immune rates over the age of 30 were significantly greater (p>0.01) than those in the 10 to 29 age groups. Socioeconomic pattern in the total and 10 to 19 yr age group was a significant (p>0.0002, p>0.004 respectively) risk factor for infection.Conclusion: This study concludes that urban Ireland is an area of low HAV endemicity with age and socioeconomic status as the significant influences on seropositivity. This survey provides an insight into the changing epidemiology of HAV infection in Ireland and serves as a guide for immunisation of at risk population groups.

DELTA INFECTION WITHOUT INCREASE IN SEVERITY OF HEPATITIS

The findings of increased morbidity of HbsAG positive hepatitis with delta infection in a study by Dr. Smedile et al were contrary to those of studies performed by the authors. A group of 27 and a group of 41 drug abusers were examined serologically and had liver biopsies performed. There was no significant difference in histological findings between delta positive and delta negative patients in the 27 member group. None of the 41 member group showed any increase in severity of illness. Ethnic origin may be an important factor in the pathogenicity of the delta agent.

Changes in incidence of hepatitis B in Ireland from 1970–1987

SummaryThis paper analyses data on 2,226 cases of Hepatitis B virus (HBV) infection detected during the years 1970 to 1987. Of those where information on risk-group was available (1,301), infection among intravenous drug-abusers accounted for the largest proportion (49%). Most became infected during and since an outbreak of hepatitis B and Delta hepatitis which originated in this group in 1980. A comparison of the data before and after the start of the outbreak among drug-abusers shows a marked increase in the number of HBV infections in nondrug users, including haemophiliacs, homosexuals and health-care staff, and a dramatic decrease in hepatitis B following blood transfusion. A larger group (165 cases), many of whom are long-term healthy hepatitis B surface antigen carriers, were patients in institutions for the mentally handicapped (IMH). Most were detected recently during pre-vaccination sampling programmes. Others affected included visitors to and from high-incidence areas, tattooed persons, dialysis patients, persons born to infected mothers, and members of the security forces dealing with drug-abusers.In all, 8.4% of the hepatitis B cases detected were found to be carriers and 67% of these remained carriers in 1987. The mean duration of carriage was 3.25 years. Intravenous drug-abusers and IMH patients constituted the two largest groups of carriers.The running-three-yearly mean incidence of new cases of hepatitis B has levelled off below the peak of 1981. Although the number of cases among drug-abusers has apparently decreased, the number of cases among non drugabusing groups has increased by 50%. The use of recently introduced vaccines in some risk groups should help to reverse this upward trend.

Chronic active hepatitis in intravenous drug abusers may be delta agent infection associated

SummaryTwenty-Seven parenteral drug abusers had serum tested for delta antigen and antidelta antibody and had liver biopsies performed. All four patients with chronic active hepatitis were delta positive. This study suggests that delta agent infection increases the risk of progression of intravenous drug abuse associated liver disease to chronic active hepatitis.