Recognising and responding to outbreaks of hepatitis A associated with child day-care centres

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Vaccinology

Background:

• Hepatitis A outbreaks pose a significant risk in child day-care settings.
• Effective protocols for outbreak recognition and response are crucial for public health.
• Immunoglobulin administration and subsequent vaccination timing require careful consideration.

Purpose of the Study:

• To evaluate the effectiveness of a protocol for identifying and managing hepatitis A outbreaks in child day-care centres.
• To determine if measles-mumps-rubella (MMR) vaccine was administered prematurely after normal human immunoglobulin (NIGH) in young children during outbreak control efforts.

Main Methods:

• Prospective surveillance was employed to identify hepatitis A cases and outbreaks in day-care centres.
• Key outcome measures included the proportion of sentinel hepatitis A cases that were also index cases of outbreaks.
• The timing of MMR vaccination following NIGH administration in children aged 9-13 months was assessed.

Main Results:

• Only 16% of sentinel hepatitis A cases were identified as index cases, indicating a low predictive value for outbreaks.
• Hepatitis A outbreaks involved 105 cases across 18 centres, with high NIGH administration rates among children and staff.
• Three out of five children (9-13 months) received MMR vaccine less than three months after NIGH.

Conclusions:

• A single hepatitis A case in a day-care centre is an unreliable indicator of a larger outbreak.
• Protocols for hepatitis A outbreak management in day-care centres require refinement.
• Strict adherence to recommended intervals between normal human immunoglobulin and live virus vaccines, such as MMR, is essential to prevent potential interference.