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Biomedical subjects

J Lindberg

Publications and source records attributed to J Lindberg.

At least 73 records · Page 4Linked to original sources
PubMed1990

Age-specific prevalence of hepatitis A virus antibody in Ethiopian children.

Three groups of individuals in Ethiopia, with different socioeconomic status, were studied demographically and serologically to determine the age-specific prevalence of antibody to hepatitis A virus (anti-HAV). A total of 959 subjects, 89% of whom were children under 15 years of age, were tested for anti-HAV by radioimmunoassay. Evidence of infection started early, found in 50% of the population before 5 years of age, increased rapidly with age and became universal after 15 years of age. A comparison of anti-HAV prevalences between 2 socioeconomic groups (children of health professionals versus children of lower income group) revealed a significant difference (p less than 0.01). These data show that HAV infection in Ethiopia is widespread and that environmental and socioeconomic factors play a major role in its transmission. The widespread prevalence of anti-HAV and anti-HBs also suggest that non-A, non-B virus(es) may be a major cause of the commonly observed sporadic cases of acute viral hepatitis in adult Ethiopians.

Adolescent↗
PubMed1989

Do hospital personnel in hyperendemic areas require immunization against hepatitis B virus (HBV) infection? Is vertical transmission of HBV infection common in this group?

Medical personnel working in contact with blood and blood-contaminated body fluids are often considered to be a high-risk group for hepatitis B virus (HBV) infection and, as a result, it is recommended that they should be vaccinated against this infection. To find out if this is necessary in a country hyperendemic for HBV infection and to see if parents transmit the infection to their offspring, a total of 336 volunteer hospital employees, and 103 children of 47 of them, were tested for HBsAg, anti-HBc, anti-HBs, HBeAg and anti-HBe using the radioimmunoassay technique. Of these, 242 (72%) were found to have evidence of past or present HBV infection and only 94 (28%) had no such evidence. The infection prevalence in the 47 parents was 68% comparable to that of the total sample. Only 9 of their 103 children were positive for HBV markers. All tested parents of these positive children were either negative for all markers or positive for anti-HBs. The HBV infection prevalence among this hospital population is not different from that of the general Ethiopian population, and vertical transmission appears unlikely in this group. Therefore, mass vaccination of hospital staff in hyperendemic areas is unnecessary.

Adult↗
PubMed1988

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae type 18F.

The structure of the capsular polysaccharide elaborated by Streptococcus pneumoniae type 18F (S18F) has been investigated by using n.m.r. spectroscopy, methylation analysis, and characterisation of oligosaccharides obtained on partial hydrolysis. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure. (formula; see text) In this structure, the absolute configuration of the glycerol phosphate moiety has not been determined, but is assumed to be D-glycerol 1-phosphate (sn-glycerol 3-phosphate). The location of an O-acetyl group at O-6 of the terminal alpha-D-glucopyranosyl groups is tentative only.

Carbohydrate Conformation↗
PubMed1988

Transmission of hepatitis B virus infection in Ethiopia with emphasis on the importance of vertical transmission.

This two-year controlled study was conducted to define the mode of transmission of hepatitis B infection in Ethiopia. Twenty-five of 500 (5%) expectant mothers were identified as HbsAg positive (Group A). A control group of 29 mothers negative for HBsAg (Group B) was randomly selected. These 54 mothers and their families (husbands, infants and the infants' older siblings) were followed for two years with determinations of serological markers of ongoing or past hepatitis B virus infection at 6, 12 and 24 months. Social and clinical data as well as possible factors contributing to the spread of HBV (ie tattoos, circumcision, etc.) were compiled from questionnaires. Twenty-one of the 25 (84%) HBsAg positive mothers had anti-HBe and none had HBeAg. One case of vertical hepatitis B virus transmission was seen while horizontal transmission during the study period occurred in two infants and in two older siblings. Potential risk factors for non-perinatal transmission were highly prevalent in both groups and may represent the main route of transmitting the infection, while, as shown in the present study, the vertical transmission of HBV infection only plays a minor role in the maintenance of the high infection rate in Ethiopia. Vaccinating all babies soon after birth would, therefore, be an effective means of eradicating or reducing the hepatitis B virus infection and its sequelae.

Adult↗
PubMed1988

Chronic active hepatitis in Sweden. The etiologic spectrum, clinical presentation, and laboratory profile.

An epidemiologic study covering about 1/3 of the adult Swedish population showed an annual incidence of chronic active hepatitis (CAH) of 1.6 per 100,000. At least 45% had a viral cause of their CAH, the proportion being distinctly higher in large cities than in rural ones. Drugs, alcohol, and metabolic disorders were rarely identified as etiologic factors. The prevalence of ulcerative colitis and gluten enteropathy was remarkably high in idiopathic CAH. Compared with antibody-negative patients with idiopathic CAH, antibody-positive patients showed higher rates of the female sex, IgG increase, anti-HBs negativity, compliance with the Mayo criteria for treatment, and absence of previous episode of jaundice. Furthermore, in autoantibody-negative idiopathic CAH the prevalence of anti-HBs antibodies was at least three times greater than in the Swedish population, suggesting a viral cause of some forms of idiopathic CAH, a suggestion supported by the clinical pattern of the disease.

Adult↗
PubMed1988

HBsAg-positive Swedish blood donors: natural history and origin of infection.

99 HBsAg-positive blood donors (BDs) were discovered in Göteborg during 1970-84. Of the 82 patients where the outcome is known 46 had transient and 36 persistent antigenemia. Chronic hepatitis was found in 6 patients while 30 were asymptomatic carriers. Three BDs had died, 1 of them from cholangiocellular cancer. An obvious mode of transmission was demonstrated for 19 BDs, i.v. drug abuse being the most frequent one. Five BDs originated from countries with a known high prevalence of hepatitis B virus (HBV). Family contacts of the remaining carriers had serological markers for HBV in the following frequencies: mothers 46%, siblings 39%, fathers 25%, children 13%, spouses 10%. Only children of female carriers had markers for HBV infection. Intrafamiliar transmission during childhood is an important route of transmission even in a country with low HBV endemicity and amongst people without connection with endemic regions. This population may be susceptible to the consequences of a long-term carriership of HBV.

Adult↗
PubMed1987

Serological and demographic survey of Epstein-Barr virus infection in Ethiopia.

A demographic and serological survey of Epstein-Barr virus infection was carried out in 5 geographically representative regions of Ethiopia. 80% of the 500 people studied were under 15 years of age. 82% of children under 5 years of age and 94% under 10 years of age were positive for IgG anti-viral capsid antigen (VCA) antibody. 51 of 100 children under 12 months of age and from 5 different provinces were positive for anti-VCA antibody. Of these, 23 were under 6 months. The distribution of anti-VCA antibody positivity was comparable in both sexes, in each age group and in the different provinces at different altitudes. Economic status, expressed in terms of estimated income, type of water supply, mode of excreta disposal and family size, did not significantly influence the distribution of anti-VCA antibody. Thus, early exposure to Epstein-Barr virus, with asymptomatic or subclinical presentation, probably accounts for the rarity of typical infectious mononucleosis in young adult Ethiopians. The lack of a relationship between Epstein-Barr virus infection and Burkitt's lymphoma, nasopharyngeal carcinoma, malaria as well as liver diseases is briefly discussed.

Adolescent↗
PubMed1987

Chronic non-A, non-B hepatitis. A long-term follow-up study in 49 patients.

Forty-nine patients with biopsy-verified chronic non-A, non-B hepatitis (NANBH) of both percutaneously transmitted and sporadic types were followed up for up to 20 years (mean, 62 months +/- 44 months). Drug addicts were not included. Twenty-four patients had chronic persistent hepatitis (CPH), and 25 had chronic active hepatitis (CAH) or cirrhosis on the basis of the first biopsy. Patients with CPH were significantly younger than patients with CAH (mean age, 31 and 51 years, respectively; p less than 0.001). Standard laboratory data (means) correlated with histology, but great variations made liver biopsy essential for the diagnosis. Twenty-one patients were rebiopsied, and 24% had more severe lesions. In total, 16 patients (33%) had signs of cirrhosis. The disease seemed to resolve in eight patients (16%), whereas two patients died of it. Some patients with CPH might progress to CAH, and the frequent finding of cirrhosis in CAH implies the possibility of hepatic failure and fatality in chronic NANBH.

Adolescent↗
PubMed1987

Prevalence of hepatitis B virus markers among Ethiopian blood donors: is HBsAg screening necessary?

Four hundred and fifty-nine Ethiopian volunteer blood donors were prospectively studied for hepatitis B virus (HBV) and Delta agent infections. The prevalence of hepatitis B surface antigen (HBsAg) was 11%, anti-HBs and only anti-HBc 66% and 2%, respectively. Thus, the total HBV infection rate was 79%. There was a single donor with antibody against Delta antigen. The rarity of HBeAg among HBsAg carriers, the lack of occurrence of factors favouring transmission and risk calculations using the available data indicate that post-transfusion hepatitis due to HBV is unlikely to be common in this highly endemic country with very limited financial resources allocated for health services. Thus, we question the validity of indiscriminate screening of all donated blood and we suggest that health policies should emphasize the need for preventive measures.

Adult↗
PubMed1986

Hepatitis A, B, and delta infection in Ethiopia: a serologic survey with demographic data.

A total of 500 individuals from five different regions of Ethiopia were studied. Demographic and clinical data were recorded and serologic tests were carried out to detect antigen and antibody markers of hepatitis B virus, hepatitis A virus, and the delta agent. Data on the economic status, number of rooms per household, number of persons per household, type of water supply, and mode of excreta disposal revealed that the majority of the population surveyed lived with economic hardship, overcrowding and poor hygiene. Only 36 persons gave a past history of jaundice. The mean carrier rate of hepatitis B surface antigen (HBsAg) was 6.2%, the mean overall hepatitis B virus marker prevalence was 42%, and in those over 14 years of age it was 76%. Among those who were positive for HBsAg, there was a tendency for hepatitis B e antigen (HBeAg) to decrease and the corresponding antibody (anti-HBe) to increase with advancing age. No woman more than 15 years of age had demonstrable hepatitis B e antigen in serum. Antibody to hepatitis A virus was detected in 84%. Three positive individuals were found to have antibody to the delta agent.

Adolescent↗
PubMed1985

Woodchuck hepatitis virus infection: serologic and histopathologic course and outcome.

Five out of seven American woodchucks inoculated with woodchuck hepatitis virus developed antigenemia after 2 to 13 weeks followed by an antibody response. One animal became a carrier, and another animal exhibited a primary antibody response. Clinical disease was not obvious and aminotransferase elevation could not be demonstrated. Liver biopsy showed mononuclear portal infiltration and little parenchymal cell necrosis.

Animals↗
PubMed1984

Immunopathologic aspects of woodchuck hepatitis.

The natural history of infection with woodchuck hepatitis virus (WHV) has been studied in a colony of 38 Marmota monax. Besides serologic assessment for WHV markers, light-microscopic findings of 61 liver biopsies were correlated with the results of immunofluorescence analysis for nucleocapsid (WHcAg) and surface (WHsAg) antigens. Twenty-four chronic WHsAg carriers all featured signs of continuous viral replication. Two major immunomorphologic patterns were observed in their livers: 1) portal hepatitis in which WHcAg accumulated in the cytoplasm and WHsAg was associated with the hepatocyte membrane and 2) periportal hepatitis in which WHcAg shifted toward nuclear localization and WHsAg became mostly intracytoplasmic. Progression from portal to periportal hepatitis, observed in 7 woodchucks, appeared to be induced by a partial recovery of specific immune reactivity to WHV, insufficient, however, to interrupt WHV replication. Deposits of WHsAg and immunoglobulins were present in the kidney and spleen of animals with severe hepatitis.

Animals↗