Control of an outbreak of BCG complications in Gaza

Area of Science:

• Immunology
• Pediatrics
• Public Health

Background:

• Bacille Calmette Guerin (BCG) vaccination is a primary preventive measure against tuberculosis.
• BCG vaccination complications can occur, necessitating investigation into contributing factors.
• Previous vaccination practices in Gaza may have been associated with an outbreak of BCG complications.

Purpose of the Study:

• To describe the incidence and types of Bacille Calmette Guerin (BCG) complications in Gaza.
• To evaluate the impact of improved vaccination techniques and vaccine batches on BCG complication rates.
• To identify strategies for minimizing BCG-related adverse events.

Main Methods:

• Two observational studies were conducted in Gaza involving newborn infants vaccinated with BCG.
• The first study assessed complications following vaccination with a specific BCG batch (Pasteur Paris, batch 5122) during an outbreak.
• The second study, after changing the BCG vaccine (batch 101023, Denmark) and providing nurse training on intradermal injection techniques, reassessed complication rates.

Main Results:

• During the initial outbreak, BCG complications occurred in 36.61 per 1000 vaccinations, with regional lymphadenitis being the most common (61.33%).
• Following vaccine change and nurse training, the BCG complication rate significantly decreased to 6.25 per 1000 vaccinations (P < 0.001).
• One case of disseminated BCG disease resulting in death was linked to severe combined immunodeficiency.

Conclusions:

• The study highlights the importance of using less virulent BCG vaccines.
• Proper vaccination techniques, particularly strict intradermal injection, are essential for reducing complications.
• Screening infants for immunodeficiency before BCG vaccination is recommended to prevent severe adverse events.