Serological antibodies comparison of a hepatitis E outbreak / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To compare the serological characters of an outbreak of hepatitis E and evaluate sensitivity and specificity of anti-HEV E2-IgM.</p><p><b>METHODS</b>The sera collected from the employees of an outbreak unit were detected for anti-HEV E2-IgM and IgG, and the serum samples from a neighboring department were used as control. The results detected with anti-HEV E2-IgM, IgG and Genelab anti-HEV IgM, IgG in some samples were compared.</p><p><b>RESULTS</b>The positive rate of anti-HEV E2-IgM in the control group was 0.11%. The results between the positive and the negative samples can be distinguished easily. The specificity of anti-HEV E2-IgM is about 99.89%. The positive rate of anti-HEV E2-IgM in outbreak stricken population was 8.66%, significantly higher than that in the control group (P < 0.001). The results from HEV patients' serial samples in the outbreak unit showed that the anti-HEV E2-IgM titer was high 30-60 days after the infected and then declined clearly. The positivity seemed unrelated to neither sex nor age. Among the 115 positive to anti-HEV E2-IgM, 27 were negative to Genelab anti-HEV IgG, the fact indicated a rather high risk of misdiagnosis of about 23.48%. In the 179 randomized samples of the control group, the positive rate of Genelabs anti-HEV IgG was about 11.17%. In 110 samples for the positive anti-HEV E2-IgM, the positive ratio of Genelabs anti-HEV IgG was about 76.36%, and that of Genelabs anti-HEV IgM only 69.09%. There were 16 samples negative for both Genelabs anti-HEV IgG and IgM. The ratio of the difference between the Genelabs anti-HEV IgG and IgM was about 25.45%.</p><p><b>CONCLUSION</b>The specificity of anti-HEV E2-IgM was about 99%, and false positive rate was low. The sensitivity of anti-HEV E2-IgM in acute hepatitis E infection was 25%-30% higher than that of Genelabs anti-HEV IgM,IgG. The infected persons in the outbreak unit can be preferably distinguished from the non-infected persons by anti-HEV E2-IgM. Anti-HEV E2-IgM can image the characters of the outbreak of HEV and played a great role in the control of outbreak and in the early diagnosis for hepatitis E.</p>

Serological characteristics of a hepatitis E outbreak / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To look into the serological characteristics of a hepatitis E outbreak.</p><p><b>METHODS</b>Sera from the first five patients with acute icteric hepatitis who developed the disease successively within ten days and the 1,675 employees routinely having their lunch in a dining hall of a department (outbreak population) were examined for anti.HEV IgM and IgG at 26th days after the outbreak, and the 883 employees of a neighboring department not having their lunch in the hall were selected as control (control population).</p><p><b>RESULTS</b>The five patients were all positive for anti-HEV IgM and IgG. The positive rates of anti-HEV IgM and IgG in outbreak population were 8.7% and 38.4% respectively, both significantly higher than those in control population which were only 0.1% and 28.6%. The numbers with abnormal ALT in the 145 individuals with anti-HEV IgM(+) of outbreak population were significantly higher than those in the IgM(-) individuals of the same group as well as in control, while the abnormal ALT ratio in the IgM(-) individuals of the outbreak was not higher than that in control. The results from the four patients' serial sera showed that the anti-HEV IgM titers declined gradually and were undetectable at about 4th month after infection, and the IgG titers increased to peak in about 2-3 months after infection, then declined very slowly. The mean IgG titer of the anti-HEV IgM(+) individuals was significantly higher than that of the IgM(-) but IgG(+) individuals in outbreak population, and the latter was significantly higher than the IgG(+) individuals in control, which suggested that the post-infection individuals' immunities to HEV were boosted during the outbreak. There was no difference between sex or age groups for the anti-HEV IgM(+) ratio, but the abnormal ALT was much more frequent in the anti-HEV IgM(+) male than in the female, and no difference was observed between age groups.</p><p><b>CONCLUSION</b>The pathogen of the outbreak of acute icteric hepatitis was hepatitis E virus and associated with food intake. Anti-HEV IgM and IgG were used not only for diagnosis of hepatitis E but also for surveilance in mass population. The attack risk was not associated with age or sex, but the abnormal ALT was much more frequent fresh infectors in male.</p>