Microsporidial keratoconjunctivitis - first outbreak in Japan

Area of Science:

• Ophthalmology
• Infectious Diseases
• Microbiology

Background:

• Microsporidial keratoconjunctivitis is typically reported in the Southern Hemisphere.
• This study investigated the first reported outbreak in Japan among healthy soccer players.

Purpose of the Study:

• To investigate the first outbreak of microsporidial keratoconjunctivitis in Japan.
• To identify the causative agent and transmission factors in a cohort of soccer players.

Main Methods:

• Observational case series analyzing medical records of five affected individuals.
• Corneal scrapings analyzed via direct smear and Polymerase Chain Reaction (PCR) for microsporidial DNA.
• Treatment involved topical voriconazole, fluorometholone, and levofloxacin.

Main Results:

• Five immunocompetent male soccer players presented with unilateral conjunctivitis and corneal lesions.
• PCR analysis identified Vittaforma corneae in four cases, matching strains from a Singapore outbreak.
• All patients healed without residual opacities after treatment.

Conclusions:

• This case series represents the first documented outbreak of Vittaforma corneae keratoconjunctivitis in Japan.
• Contaminated water or soil exposure, potentially linked to inadequate sanitation, is a likely source of infection.
• Further research into microsporidia characteristics and transmission is recommended.