Active surveillance for acute viral hepatitis in rural villages in the Nile Delta.
BACKGROUND
Acute viral hepatitis is less frequent in Egypt than serum antibody levels suggest. Because acute viral hepatitis has a wide clinical spectrum, we tested the hypothesis that many cases are undetected because of mild illness caused by initial, early-childhood exposure to hepatitis viruses.


METHODS
During active case detection among 20,000 inhabitants of rural villages in Egypt, we screened 1715 symptomatic patients for serum alanine aminotransferase (ALT) levels. Viral hepatitis markers were tested in 47 subjects who had ALT levels that were least twice the normal level.


RESULTS
Of the 47 individuals tested, 4 children aged 3-5 years had immunoglobulin M (IgM) antibodies to hepatitis A virus (anti-HAV IgM). One also had a possible false-positive result to a test for IgM antibodies to hepatitis E virus. None had serological evidence of acute hepatitis B virus (HBV) infection or hepatitis C virus (HCV) infection. However, 33 of the remaining 43 had active HCV infection, having both antibodies to HCV (anti-HCV) and HCV RNA. Four others anti-HCV without HCV RNA, and 2 others had seroconversion to anti-HCV during follow-up. Two patients who were positive for hepatitis B surface antigen had chronic HBV infection. Only 3 with elevated ALT levels had no evidence of acute or chronic infections with known hepatitis viruses. Immunoglobulin G antibodies to hepatitis E virus was detected in 40 patients.


CONCLUSIONS
Active surveillance covering approximately 50,000 person-years detected only 4 cases of acute HAV infection. Almost all persons with mild symptoms and elevated ALT levels had serological evidence of chronic viral hepatitis, most often associated with HCV. Many of these cases were probably "flare-ups" of HCV infection or incidental illness in patients with chronic HCV infection, but some could have been caused by difficult-to-confirm initial HCV infections. Although serological evidence for exposures was highly prevalent, hepatitis viruses seldom caused acute viral hepatitis in these communities.
Meky
Fatma A
FA
Department of Community, Environmental and Occupational Medicine, Ain Shams University, Cairo, Egypt.
Stoszek
Sonia K
SK
Abdel-Hamid
Mohamed
M
Selim
Sahar
S
Abdel-Wahab
Ayman
A
Mikhail
Nabiel
N
El-Kafrawy
Sherif
S
El-Daly
Mai
M
Abdel-Aziz
Fatma
F
Sharaf
Soraya
S
Mohamed
Mostafa K
MK
Engle
Ronald E
RE
Emerson
Suzanne U
SU
Purcell
Robert H
RH
Fix
Alan D
AD
Strickland
G Thomas
GT
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006506:Hepatitis A / Q000175:diagnosis / Q000453:epidemiology*; D035922:Hepatitis A Antibodies / Q000097:blood; D006526:Hepatitis C / Q000175:diagnosis / Q000453:epidemiology*; D018937:Hepatitis C Antibodies / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012424:Rural Population
D035922:Hepatitis A Antibodies; D018937:Hepatitis C Antibodies