Foodhandler-associated outbreak of hepatitis type A. An immune electron microscopic study

Area of Science:

• Hepatology
• Virology
• Immunology

Background:

• Foodhandler-associated outbreaks of hepatitis pose public health risks.
• Early detection of hepatitis A virus (HAV) is crucial for outbreak management.

Purpose of the Study:

• To investigate a foodhandler-associated hepatitis outbreak among naval recruits.
• To detect hepatitis A antigen and antibody (anti-HA) using immune electron microscopy.
• To determine the serological relationship between the MS-1 strain of HAV and naturally acquired hepatitis A.

Main Methods:

• Immune electron microscopy was employed to detect 27-nm viruslike hepatitis A antigen particles in stool specimens.
• Stool samples were collected during the acute phase of illness from 136 naval recruits.
• Serum samples were analyzed for anti-HA levels during acute and convalescent phases.

Main Results:

• Hepatitis A antigen particles were detected in stool specimens from patients with icteric hepatitis.
• Antigen detection was possible from 10 days before to the time of peak serum aminotransferase activity.
• Immunologic similarity was established between detected particles and the MS-1 strain of HAV.
• An increase in anti-HA was observed in 25 recruits between acute and convalescent serum samples.

Conclusions:

• The MS-1 strain of hepatitis A virus is serologically related to naturally acquired type A hepatitis.
• Immune electron microscopy is effective for detecting HAV antigen during the acute phase of illness.
• Early detection of HAV antigen in stool can aid in outbreak investigation and management.