Epidemiological survey and follow-up of transfusion-transmitted virus after an outbreak of enterically transmitted infection.
An outbreak of enterically transmitted hepatitis occurred during 1996 among students at a vocational school. Viral fragments homologous to transfusion-transmitted virus (TTV) were detected in faeces. To elucidate the endemic status, an epidemiological survey and case follow-up after the outbreak were carried out. During and after the outbreak, virus carriers among staff were, respectively, 32.1% and 31.3% in serum, and 24.6% and 18.2% in faeces. After the last outbreak, attacks were still occurring among new students with an incidence of 2.4% in 1997 and 2.3% in 1998. There was also a small-scale outbreak in 1998 with a prevalence of 17.9%. On follow-up at 6 and 18 months after onset, alanine aminotransferase (ALT) elevation was found in 29.7% and 13.9% of patients. At 6 months, viral fragments were detected in serum in 78.1% and 46.7% of patients, with and without ALT elevation, respectively. At 18 months the corresponding figures were 55.6% and 19.2%, respectively. At the 18-month follow-up, viral fragments were detected in faeces in 29.6% and 19.3% of patients with and without ALT elevation. In conclusion, this disease might be transmitted from asymptomatic virus carriers. According to the laboratory data, both parenteral and non-parenteral transmissions are involved, and the faecal-oral route might be more important.
Kangxian
L
L
Department of Infectious Disease, Nanfang Hospital, Guangzhou, China.
Weifang
L
L
Lian
Z
Z
Zhiying
C
C
D000410:Alanine Transaminase / Q000097:blood; D001483:Base Sequence; D002353:Carrier State / Q000453:epidemiology / Q000821:virology; D002681:China / Q000453:epidemiology; D017931:DNA Primers / Q000235:genetics; D004196:Disease Outbreaks; D004812:Epidemiologic Methods; D005243:Feces / Q000821:virology; D005500:Follow-Up Studies; D006518:Hepatitis Viruses / Q000235:genetics / Q000302:isolation & purification; D006525:Hepatitis, Viral, Human / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D006801:Humans; D013334:Students; D014766:Viremia / Q000453:epidemiology / Q000821:virology
D017931:DNA Primers; D000410:Alanine Transaminase