Reuters Health Information (2004-09-15): Hepatitis A: close contacts at risk, despite immune globulin Public Health
Hepatitis A: close contacts at risk, despite immune globulin
Last Updated: 2004-09-15 12:10:38 -0400 (Reuters Health)
NEW YORK (Reuters Health) - The results of a study
conducted in the Netherlands demonstrate that immune globulin does not
always protect household contacts from hepatitis A virus (HAV)
infection.
"However, it attenuates symptoms and effectively reduces further HAV
transmission," Dr. Gerard J. B. Sonder from the Municipal Health
Services in Amsterdam and colleagues report in the September issue of
the American Journal of Public Health.
They designed the study to evaluate the current policy for
prevention of secondary transmission of HAV, the hallmarks of which are
hygienic precautions and passive immunization with immune globulin for
susceptible household contacts.
They analyzed serological outcomes of 1242 household contacts of 569
patients with confirmed HAV infection. They discovered that more than
half of the household contacts (n = 672) demonstrated HAV immunity.
Among the 570 nonimmune contacts, 161 (28.2%) were IgM positive at
their first blood test and were considered to have coprimary infections
and 86 (53%) were symptomatic.
The remaining 409 "susceptible" contacts received immune globulin
and 186 (45%) returned for a second blood test 6 weeks later. At that
time, 64 of 186 (34%) were infected with HAV, but only 12 (19%) had
symptomatic infection.
"We found a high secondary seroconversion rate (34%) among
susceptible contacts" despite timely immune globulin treatment, the
authors note.
In this study, the interval between disease onset in the index
patient and administration of immune globulin in the contact was not
associated with the seroconversion rate in contacts or the likelihood
of developing symptomatic HAV infection.
In Amsterdam, HAV infection is seen largely in two groups of people:
travelers to HAV-endemic areas and homosexual men. Current guidelines
in the Netherlands recommend HAV vaccination for both groups.
Am J Public Health 2004;94:1620-1626.
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