Viral hepatitis in Danish children. Disappearance of an infection from its previous reservoir

Twenty-year survey of the epidemiology of hepatitis B in Denmark: effect of immigration

Implementation of hepatitis B virus (HBV) vaccination is being considered in Denmark. Therefore, a 20 y survey on the epidemiology of HBV infection was performed. All notified cases of acute HBV infection in Denmark from 1982 to 2002 were reviewed retrospectively and all available data from 1970 to 2001 on the prevalence of hepatitis B surface antigen (HBsAg) in different groups of the Danish population were studied. The notified annual incidence of acute HBV infection has declined from more than 200 cases to fewer than 50 cases in 2001. In the indigenous population there has been a similar decline in prevalence of HBsAg carriers, from 0.15 to 0.03%, but owing to immigration of new HBsAg carriers from developing countries the overall number of carriers has not changed. The small effect of immigration on the incidence of acute HBV infections as well as the decreasing prevalence of HBsAg carriers among Danes should be taken into account when planning new vaccination strategies in Denmark.

Low hepatitis B prevalence among pre-school children in Denmark: saliva anti-HBc screening in day care centres

Although Denmark has a low hepatitis B virus (HBV) prevalence, HBV transmission has been reported in Danish day-care centres. The aim of this study was to validate saliva anti-HBc testing as a method for HBV screening, the applicability of saliva sampling to pre-school children, and to determine the HBV prevalence in Danish day-care centres with a high proportion of immigrants. For validation, paired saliva and plasma samples were obtained from blood donors and injecting drug users. Employees and children in day-care centres with a high proportion of immigrant children were offered saliva screening followed by blood test if positive. The specificity and sensitivity of anti-HBc tests on saliva was 100% (102 blood donors and four injecting drug users) and 85.9% (61 of 71 anti-HBc-positive injecting drug users), respectively. In all samples from HBsAg (n = 7) or anti-HBc IgM-positives (n = 9), anti-HBc was detected in saliva. Adequate saliva samples were obtained from 93% (588/634) of children and 100% (166/166) of employees participating in the day-care centre survey. Among children 55% were of non-Scandinavian origin and only one (0.2%, 95% CI [0.0; 1.0]) was HBV positive. Among employees the corresponding values were 22% and 7 (4.2%). The positive predictive value of the saliva test was 25% (1/4) among children and 88% (7/8) among adults. In conclusion, saliva testing is feasible for HBV screening among children in low prevalence populations, but any anti-HBc reactivity should be confirmed by plasma analysis. The HBV prevalence in pre-school children in Denmark is low even among immigrants from endemic areas.

Duality of patterns in hepatitis A epidemiology: a study involving two socioeconomically distinct populations in Campinas, São Paulo State, Brazil

To evaluate the prevalence of antibodies against hepatitis A in two socioeconomically distinct populations, 101 and 82 serum samples from high and low socioeconomic groups, respectively, were analysed for the presence of IgG anti-HAV using a commercial ELISA. The prevalence in low socioeconomic level subjects was 95.0%, whereas in high socioeconomic subjects was only 19.6% (p < 0.001). These data show a duality in Brazil: anti-HAV prevalence in low socioeconomic subjects is similar to that of developing countries, while in high socioeconomic subjects, a pattern typical of developed countries is found. The control of this infection in our country is primarily related to the improvement of sanitation, but especially for high socioeconomic level populations, the use of vaccination against hepatitis A is strongly advisable to avoid the occasional appearance of this disease in adults.

Chronic hepatitis B in children. Natural history and treatment

Hepatitis B virus (HBV) infection in children is worldwide in distribution, but the features of HBV-associated liver disease differ depending on the route of transmission and the time of acquisition of the infection. The degree of liver injury varies from a mild disease to the development of cirrhosis and hepatocellular carcinoma, and depends on the replicative status of the viral genome. It is believed that the immune function plays a key role in the severity of HBV disease, and the impact of HBV mutants needs to be assessed. The goals of antiviral therapy in children are therefore, the clearance of viremia and HBV sequences from infected tissues, together with an improvement in the liver disease. Administration of 10 MU/m2 b.s. 3 times weekly over 6 months resulted in a significantly higher clearance of viremia, with normalization of ALT values and greater improvement in liver histology in treated than in untreated patients. Long-term follow-up of these cases reveals the presence of the viral genome in serum and liver by PCR without clearance of HBsAg. Complete eradication of HBV might need more years of evolution as for adult patients. The combination of more than one antiviral agent, as well as the potentiation of the immune system, needs to be assessed to improve the actual response rate obtained with interferon-alpha.

The etiology of acute hepatitis in hospitalized children in Cairo Egypt

Seromarkers for hepatitis A, B and D were used to determine the cause of acute hepatitis in 94 children (age 2 to 14 years) prospectively studied when they were admitted to Embaba Fever Hospital in Cairo, Egypt, between January and April 1983. The diagnoses were: hepatitis A (4%), hepatitis B (33%), acute hepatitis in HBsAg carriers (10%), dual infections with A and B (2%), and hepatitis non-A, non-B (NANB) (50%). Past hepatitis A was diagnosed in 96%. Among acute hepatitis B infections, 17% (5 of 29 tested) had anti-delta antibody; of HBsAg positive persons, 15% (6 of 40) were HBeAg positive. Two patients had simultaneous presence of HBsAg and antiHBs. For differential diagnosis, clinical, epidemiological, and biochemical findings were evaluated but did not distinguish hepatitis B from NANB hepatitis. Males predominated for HBV infections. No risk factors were found for 58% of HBV and 70% of NANB infections; of the remaining patients, 42% percent of HBV and 30% of NANB infections were associated with injections or surgery but none with transfusion or known contact with hepatitis cases.

Hepatitis A antibodies in two socioeconomically distinct populations of São Paulo, Brazil

To evaluate the prevalence of antibody against hepatitis A in two socioeconomically distinct populations of a developing country, 540 serum specimens from children and adults living in São Paulo, Brazil, were tested for IgG anti HAV by a commercial radioimunoassay (Havab, Abbott Laboratories). The prevalence of anti-HAV in low socioeconomic level subjects was 75.0% in children 2-11 years old and 100.0% in adults, whereas in middle socioeconomic level significantly lower prevalences were observed (40.3% in chidren 2-11 years old and 91.9% in adults). Voluntary blood donors of middle socioeconomic level showed a prevalence of 90.4%. These data suggest that hepatitis A infection remains a highly endemic disease in São Paulo, Brazil.

A 7 year survey of acute hepatitis type B

Epidemiological and clinical features of acute symptomatic hepatitis type B were evaluated in 51 otherwise healthy children and in 13 children receiving immunosuppressive treatment for leukaemia and malignancy, who were admitted to hospital with acute hepatitis B surface antigen (HBsAg) positive hepatitis during a period of 7 years. Blood transfusions, or intimate contacts with asymptomatic HBsAg carriers or with contaminated material during repeated admission to hospital were the possible sources of infection in the immunosuppressed patients, whereas percutaneous exposure was identified as the source in a minority of non-immunosuppressed patients. Features of the acute phase of the illness differed little between the two groups of patients (acute liver failure developed in one patient with leukaemia and in two untreated children). Conversely, chronic evolution was observed in 69% of immunosuppressed patients but in only 9% of untreated children and affected only patients born to HBsAg positive mothers (two of four patients) or patients presenting with papular acrodermatitis (both patients).