It has been estimated that presently hepatitis B kills more people every day than AIDS kills in a year world-wide. Infection with hepatitis B produces a wide range of manifestations ranging from asymptomatic carriers to persistent infections leading to chronic liver diseases and hepatocellular carcinoma. Availability of effective and safe vaccine has made all this preventable. To formulate on appropriate vaccination strategy for India the epidemiology of hepatitis B needs to be defined. This report critically reviews the available data. The burden of long term sequelae of HBV infection is probably under-diagnosed and under-reported in India. Prevalence studies of HBV markers indicate that India falls under the area of intermediate endemicity. Limited data on age-specific prevalence of HBV markers suggests that the majority of the infection seems to take place below 15 years of age, and most of it under one year. Perinatal transmission appears to contribute significantly to the carrier pool. Childhood vaccination for HB among the general population is the obvious strategy of choice. But more information is required to decide on the timing of the first dose.

Acute Disease↗

PubMedDate not supplied

Aflatoxin exposure, malaria and hepatitis B infection in rural Gambian children.

Aflatoxin-albumin adduct levels were measured in serum samples obtained from a group of Gambian children. The relationships between exposure to aflatoxin and the prevalence of malaria, between exposure and humoral and cellular responses in vitro to defined malaria antigens and, amongst children with evidence of exposure to hepatitis B infection, between aflatoxin and carriage of the hepatitis B surface antigen (HBsAg), were assessed. Aflatoxin-albumin adduct was found in nearly all serum samples collected during a survey performed at the end of the dry season and levels of adduct were generally high (up to 720 pg aflatoxin-lysine equivalent/mg albumin). Higher levels of aflatoxin-albumin adduct were detected in Wollof children than in children of other ethnic groups and marked variation in mean adduct levels between villages was observed. Aflatoxin-albumin adduct levels were higher in children who were HbsAg positive and in children with Plasmodium falciparum parasitaemia than in controls. However, levels of adduct had no consistent effect on either malaria-specific antibody responses, lymphoproliferative responses in vitro, or morbidity from malaria during the subsequent rainy season. Much lower levels of aflatoxin-albumin adduct were detected in repeat samples obtained at the end of the rainy season. There was poor correlation between dry and rainy season levels of adduct in individual children. We have shown that Gambian children are exposed to high levels of aflatoxin. The seasonal variation of aflatoxin-albumin adduct and marked fluctuation of adduct with time in individual children need to be considered in the future planning of epidemiological studies using this marker of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aflatoxins↗

PubMedDate not supplied

Cost-effectiveness of hepatitis B vaccine in The Gambia.

Hepatitis B vaccine has been progressively introduced into the Gambian programme of immunization since 1986. Other African countries are considering introduction but require evidence of cost-effectiveness to justify such a decision. The cost of the Expanded Programme on Immunization in The Gambia, which includes hepatitis B vaccine, was calculated for 1988. Estimates of the effects of this programme on the incidence of liver cancer were made, based on the national cancer registry and a case control study of primary liver cancer and hepatitis B, regarding hepatitis B vaccine costs as incremental. This gave an estimate of the cost of averting a death from liver cancer in the range US$150-200 (assuming a vaccine cost of US$1 per dose). This indicates that universal hepatitis B immunization is comparable, in terms of cost-effectiveness, to other health interventions in less developed countries.

Adolescent↗

PubMedDate not supplied

Environmental risk factors for clinical malaria: a case-control study in the Grau region of Peru.

The role of environmental risk factors in clinical malaria has been studied mainly in Africa and Asia, few investigations have been carried out in Latin America. Field observations in northern coastal Peru, where the prevalence of malaria is high during the agricultural season, suggested that the risk of disease varied according to the characteristics of the house and the house environment. Environmental determinants of the risk of clinical malaria were therefore investigated through a case-control study: 323 clinical cases of malaria, recruited through community-based active case-finding, and 969 age-, sex- and village-matched controls were recruited into the study over a period of 12 months ending June 1997. Residual spraying of houses in the previous 6 months, living more than 100 m from a canal, a level of education equal to primary school or above and working in agriculture conferred significant protection from the risk of developing clinical malaria. The presence of spaces between the wall and roof in the subject's bedroom (eaves) and a house aged > 4 years statistically significantly increased the risk of disease. Based on these results we discuss possible control measures for malaria in this area of the country.

Adolescent↗

PubMedDate not supplied

Viral hepatitis: control, seroepidemiology and surveillance.

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Hepatitis, Viral, Human↗

PubMedDate not supplied

Reduction in exposure to carcinogenic aflatoxins by postharvest intervention measures in west Africa: a community-based intervention study.

BACKGROUND: Aflatoxins are fungal metabolites that frequently contaminate staple foods in much of sub-Saharan Africa, and are associated with increased risk of liver cancer and impaired growth in young children. We aimed to assess whether postharvest measures to restrict aflatoxin contamination of groundnut crops could reduce exposure in west African villages. METHODS: We undertook an intervention study at subsistence farms in the lower Kindia region of Guinea. Farms from 20 villages were included, ten of which implemented a package of postharvest measures to restrict aflatoxin contamination of the groundnut crop; ten controls followed usual postharvest practices. We measured the concentrations of blood aflatoxin-albumin adducts from 600 people immediately after harvest and at 3 months and 5 months postharvest to monitor the effectiveness of the intervention. FINDINGS: In control villages mean aflatoxin-albumin concentration increased postharvest (from 5.5 pg/mg [95% CI 4.7-6.1] immediately after harvest to 18.7 pg/mg [17.0-20.6] 5 months later). By contrast, mean aflatoxin-albumin concentration in intervention villages after 5 months of groundnut storage was much the same as that immediately postharvest (7.2 pg/mg [6.2-8.4] vs 8.0 pg/mg [7.0-9.2]). At 5 months, mean adduct concentration in intervention villages was less than 50% of that in control villages (8.0 pg/mg [7.2-9.2] vs 18.7 pg/mg [17.0-20.6], p<0.0001). About a third of the number of people had non-detectable aflatoxin-albumin concentrations at harvest. At 5 months, five (2%) people in the control villages had non-detectable adduct concentrations compared with 47 (20%) of those in the intervention group (p<0.0001). Mean concentrations of aflatoxin B1 in groundnuts in household stores in intervention and control villages were consistent with measurements of aflatoxin-albumin adducts. INTERPRETATION: Use of low-technology approaches at the subsistence-farm level in sub-Saharan Africa could substantially reduce the disease burden caused by aflatoxin exposure.

Aflatoxin B1↗

PubMedDate not supplied

Liver disease in HBsAg carriers.

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Carrier State↗

PubMedDate not supplied

Central third bone-patellar tendon-bone anterior cruciate ligament reconstruction: a 5-year follow-up.

SUMMARY: Arthroscopically assisted anterior cruciate ligament (ACL) reconstruction using the central third bone-patellar tendon-bone as a free autologous graft is now a widely used procedure. However, little has been published regarding its long-term success. In this retrospective study, we report on the results of 32 patients who were followed-up over 5 years after their reconstruction. Twenty-five patients had improved on their prereconstruction Lysholm and Tegner Activity scores and the same number denied having any symptoms of instability. The mean Lysholm knee score was 88.5. All patients had within 10 degrees of full flexion and 28 had KT-1000 arthrometer readings within 3 mm of their uninjured knee. Only 3 patients had clinical evidence of failure of the graft. We conclude that this technique compares favorably with other alternatives in the long-term treatment of ACL rupture.

Adolescent↗

PubMedDate not supplied

Methods for early identification of noise-induced hearing loss.

An ideal test for identifying shifts in cochlear function would be highly repeatable and sensitive to minor damage. Three types of otoacoustic emission (OAE) test and pure-tone audiometry were evaluated for this purpose. They were compared in terms of test-retest repeatability within subjects and sensitivity to differences between subjects. The OAE measures were transiently evoked either conventionally (TEOAE) or using maximum length sequences (TEOAE-MLS), or continuously evoked as distortion products (DPOAEs). Several stimulus conditions were evaluated for each type. Thirty eight subjects with normal hearing or mild hearing losses were tested on all measures. Test-retest repeatability was rescaled according to the sensitivity of each measure to differences in hearing threshold level, thus allowing a direct comparison across methods. The most repeatable method thus defined was TEOAE-MLS which gave a rescaled standard deviation of 1.8 dB on replication. This was followed by TEOAE and DPOAE which gave rescaled standard deviations of 2.9 and 3.1 dB, respectively. All were more reliable than pure-tone audiometry which had a standard deviation of 4.9 dB. It is concluded that the various OAE measures have the potential to distinguish small changes in cochlear function from measurement uncertainty, and hence show promise for monitoring cochlear function in ears exposed to noise or other hazards.

Acoustic Stimulation↗

PubMedDate not supplied

Optical disk archiving using a personal computer: a solution to image storage problems in diagnostic imaging departments.

The paper describes an approach to solving the problem of providing a large-capacity image archive for diagnostic imaging departments at reasonable cost. Optical disk stores, when fitted retrospectively to scanners, are very expensive and may not be compatible with existing computer hardware. We describe the use of an industry standard personal computer (PC) linked to a standard 5 1/4-in. optical disk drive as a 'stand-alone' image store. Image data are transferred from the scanner using 8-in. floppy disks, and these are read into the PC using an attached 8-in. floppy disk drive and then transferred to the optical disk. The patient details (patient name, ID, date, etc.) are entered into a database program held on the PC and these are used to generate a reference pointer to the optical disk file through which the data can be retrieved. Data retrieval involves entering the patient details into the data base and inserting a blank 8-in. floppy disk into the drive attached to the PC. A sector copy is then made from the optical disk to the 8-in. floppy disk, which can then be used at the viewing station at the scanner. The system is flexible since it can accept data from a variety of sources in any format; it is also low cost and operates independently of the scanner. The hardware is industry standard, ensuring low maintenance costs.

Diagnostic Imaging↗

PubMedDate not supplied

Molecular dosimetry of aflatoxin-N7-guanine in human urine obtained in The Gambia, West Africa.

Hepatocellular carcinoma is one of the major human cancers, causing at least 250,000 deaths each year. Two of the major risk factors for this disease are aflatoxin exposure and hepatitis B virus. This study was undertaken to explore the relationship between dietary exposure to aflatoxins and the excretion of the major aflatoxin-DNA adduct and other metabolites into the urine of chronically exposed people who were either hepatitis B virus surface antigen-positive or -negative. The diets of 20 individuals, 10 males and 10 females, with ages ranging from 15 to 56 years, were monitored for 1 week, and aflatoxin intake levels were determined for each day. Starting on the fourth day, total 24-h urines were consecutively obtained for 4 days. The subjects were generally paired for hepatitis B virus status. Preparative monoclonal antibody affinity chromatography/high-performance liquid chromatography and competitive enzyme-linked immunosorbent assays were carried out on each of the urine samples, and the relationship between aflatoxin intake values and the excretion of (a) total aflatoxin metabolites and (b) aflatoxin-N7-guanine (AFB-N7-guanine) was determined. The average intake of total aflatoxins was 12.0 micrograms for the entire study group during the 1-week collection period. However, there was considerable day-to-day variation in exposures, from a low of zero to a high of 29.6 micrograms total aflatoxins/day. Initial efforts to characterize total aflatoxin metabolites in the urine samples were made by competitive enzyme-linked immunosorbent assay. The correlation coefficient for the analysis was 0.65, with P < 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Dietary intake of aflatoxins and the level of albumin-bound aflatoxin in peripheral blood in The Gambia, West Africa.

Aflatoxin is implicated as a risk factor for hepatocellular carcinoma in areas of the world with a high incidence of this tumor. The present study was designed to validate the use of aflatoxin-albumin adducts in peripheral blood as a measure of individual exposure to this carcinogen. Dietary intake of aflatoxin was measured at the individual level in 20 residents of Keneba, West Kiang, The Gambia, over a 7-day period and correlated with the level of aflatoxin bound to peripheral blood albumin at the beginning and end of the study. Complementary enzyme-linked immunosorbent assay and high-performance liquid chromatography-fluorescence techniques were used to assay the aflatoxin adducts. All subjects were exposed to aflatoxin originating from several food types, with an average daily intake of 1.4 micrograms/day. A significant correlation (r = 0.55; P = < 0.05) was observed between the dietary intake and the level of albumin-bound aflatoxin at the end of the study. In addition, a good agreement was obtained with the two analytical techniques. A comparison of matched chronic hepatitis B surface antigen carriers with noncarriers did not reveal any difference in adduct formation for a given dietary intake of aflatoxin. These studies demonstrate the validity of aflatoxin-albumin adducts as a marker of human exposure to this carcinogen.

Adolescent↗

PubMedDate not supplied

Aflatoxin, liver enzymes, and hepatitis B virus infection in Gambian children.

The relative contribution of, and possible mechanism of interaction between, aflatoxin and hepatitis B virus (HBV) in the development of primary hepatocellular carcinoma can be better investigated now that markers of individual exposure to both factors are available. In this study, blood samples were collected over a 1-month period from 117 children aged 3 to 4 years, resident in Kuntair or Kerr Cherno in the Upper Niumi District of The Gambia. Samples were analyzed for aflatoxin-albumin (AF-alb) adducts, markers of HBV infection, liver enzymes [serum alanine aminotransferase (ALT)] as markers of liver damage, and glutathione S-transferase M1 genotype. All but two children showed detectable serum AF-alb with levels ranging from 2.2 to 250.4 pg aflatoxin B1-lysine equivalent/mg albumin. There was a significant positive correlation between AF-alb and ALT (r = 0.4; P < 0.001). HBV carriers showed moderately higher levels of AF-alb than noncarriers but the difference was not statistically significant and the association between AF-alb and ALT was unchanged when the HBV carriers were excluded from the analysis, suggesting that factors other than HBV infection contributed to the association. The null glutathione S-transferase M1 genotype was infrequent (17.7%) in this population and was not associated with any difference in AF-alb adduct levels compared to glutathione S-transferase M1-positive individuals. However, the percentage of individuals with the null genotype varied significantly between ethnic groups with 32.1% in Fula, 8.8% in Mandinka, and 13.3% in Wollof.(ABSTRACT TRUNCATED AT 250 WORDS)

Aflatoxins↗