摘要:

In an endemic area of Costa Rica nonparenteral type B hepatitis occurs at a yearly rate of 160/100,000, in an endemoepidemic pattern with periodic localized outbreaks. In a recent episode in the village of San Rafael, 23 clinical and 67 subclinical cases, all subtype adw, originated from two carriers living in opposite ends of the village. Contact transmission was identified as the mode of spread.In a coincidental outbreak in another village, San Juan, 17 clinical and 40 subclinical cases were observed. Thirty-seven cases of HBSAg/ayw positive hepatitis occurred in the Western sector of the village, apparently originating from contact with three HBSAg/ayw carriers found in that area. There were also 20 cases of HBSAg/adw positive hepatitis, but these occurred almost exclusively in the Eastern sector, where subtype adw disease has been prevalent in previous years. The geographic distribution of antibody subtypes found in the two separated sectors of the village coincided fully with that of the antigen subtypes. These observations show that personal contact is definitely a mode of transmission of hepatitis B.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

“Nonparenteral” transmission of acute viral hepatitis was implicated in 50.5 per cent of 346 patients included in this study and in 67.5 per cent of 1,235 cases reviewed for the period 1969–1973. Hepatitis B surface antigen (HBSAg) was detected in 48.3 per cent of these patients. Of 476 family contacts of HBSAg carriers 71 per cent had HBSAg or anti-HBS, this being true for 88.8 per cent of siblings and for 67.7 per cent of offspring. Anti-HBSwas detected in 10.4 per cent to 49.3 per cent of the populations tested, its frequency correlating with that of HBSAg and increasing with age. Significant differences in the patterns of exposure to the hepatitis B virus (HBV) were seen between offspring and siblings of HBSAg carriers mainly determined by the observed HBSAg prevalence in relation to their age. It was calculated that as many as 25 per cent of all Greeks may come into familial contact with HBSAg carriers and acquire the infection mainly by nonparenteral mechanisms. It is concluded that in Greece there is already a wide exposure to HBV before adulthood and that this should be borne in mind when considering possible future vaccination programs.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The exclusion of commercial and hepatitis B surface antigen (HBSAg)-positive donors, as measured by counterelectrophoresis, has markedly reduced the frequency of posttransfusion hepatitis (PTH). A further, significant reduction in type-B PTH can be achieved by prescreening donors for HBSAg by solid-phase radioimmunoassay (RIA). When a voluntary donor population, pretested by RIA, is used, approximately 90 per cent of residual hepatitis is serologically unrelated to either the type-A or type-B hepatitis viruses. Similarly, cytomegalovirus and the Epstein-Barr virus are not serologically implicated in “non-A, non-8” hepatitis. Additional human hepatitis virus(es) may exist.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Elimination of commercial blood, mandatory HBS Ag testing by third generation techniques, and detection and interdiction of incriminated blood donors have all contributed to a dramatic 63 per cent reduction in the estimated number of cases of transfusion-associated hepatitis from 424 in 1970 to 158 in 1973 and an even more dramatic drop in fatalities from 55 in 1970 to 10 in 1973.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

Hepatitis B core antigen, antibody to core antigen, and DNA polymerase activity were measured in sera from a select group of post-transfusion hepatitis B patients who had been followed prospectively following blood transfusion. Preliminary results of this study have revealed (1) that RIA testing of blood would not eliminate but would reduce posttransfusion hepatitis B infections by about 50 per cent; (2) that infection with HB virus is modified or aborted in the presence of preexisting antibody to HB surface antigen; and (3) that transfusion of blood containing anti-HBSdoes not increase the risk of post-transfusion hepatitis B. HBCAg and/or DNA polymerase activity were observed in the sera of all recipients tested who developed liver enzyme abnormalities along with HBSAg and anti-HBC. DNA polymerase activity usually occurred in the early stages of incubation before the transaminase became abnormal, whereas HBCAg was more often associated with increasing enzymatic evidence of liver damage, suggesting release of core structures from the hepatocytes. The presence of DNA polymerase without detectable HBCAg may be due to the presence of intact Dane particles in the sera, preventing recognition of the core antigen. No serological evidence of hepatitis B was observed in the sera of 24 other recipients who developed abnormal transaminases. Immunoelectron microscopy of these same sera revealed evidence of exposure to hepatitis A antigen following transfusion in at least two recipients.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

In several countries where there is a high prevalence of HBV the risk of PTH has been investigated. One study demonstrated that HBV immunity provided protection against infection following transfusion of HBS Ag-positive blood in that a higher proportion of immune recipients failed to develop, or developed only transitory, HBS antigenemia. Forty (61 per cent) of 66 recipients who received HBS Ag positive (IAHA) units developed hepatitis, which was subclinical in 37 (93 per cent) of the 40. Six recipients of HBS Ag-containing units had HBS Ag in the pre-transfusion serum. In four, HBS Ag disappeared in the early post-transfusion period, and anti-HBs was detected within days, persisting for the duration of the study. The mechanism of this change in HBV immune status is unknown but it may be related to the existence of HBS Ag immune complexemia detectable by radioelectro-complexing in approximately 80 per cent of HBS Agpositive blood donors. The phenomenon of apparent “cure” of the HBS antigenemic state warrants further attention.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The Veterans Administration has been conducting a cooperative randomized, double-blind, controlled trial to evaluate the efficacy of conventional and hepatitis B immune serum globulin for the prevention of post-transfusion hepatitis. Data collected between 1969 and 1974 provide the opportunity to describe the annual incidence and characteristics of the hepatitis that has developed, and the risk factors which have been identified. Anicteric hepatitis has developed four times more frequently than icteric hepatitis, the total incidence for all six years being 11.3 per cent. The incidence of HBSAgassociated hepatitis declined dramatically after 1973 with the institution of routine screening of donor blood by radioimmunoassay techniques, although no change in the incidence of antigen-negative hepatitis has occurred. There is indirect evidence to suggest that an undefined agent is responsible for the majority of instances of post-transfusion hepatitis occurring presently. The most important risk factor responsible for the development of hepatitis is the use of commercial blood, and it is strongly urged that this form of blood be removed from general use.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID

摘要:

The value of conventional gamma globulin in prophylaxis of hepatitis A has not been confirmed in recent years but there is no evidence that ineffectiveness has been encountered as a result of declining immune experience among antibody donors in open populations. Fortunately, specific tests for hepatitis A antibody are becoming available as a means of estimating effectiveness of currently manufactured gamma globulin. Hepatitis B prophylaxis by conventional gamma globulin is much more uncertain but the negative evidence must be considered in light of rising anti-HBstiters of globulin manufactured more recently. The latter have appeared to be effective in pre-exposure prophylaxis when non-parenteral transmission was implicated. Post-exposure prophylaxis against massive inocula of hepatitis B, as in transfusions, would appear to require large amounts of HBsantibody. Protection against hepatitis from small inocula accompanying accidental punctures with contaminated needles is under controlled study to determine whether the anti-HBstiter of special globulin preparations is a predictive index of protection. Results are expected by midyear, 1975.

ISSN:0002-9629    

出版商:OVID    

年代:1975

数据来源: OVID