Mass sociogenic illness initially reported as carbon monoxide poisoning

Area of Science:

• Medical Outbreaks
• Psychosomatic Medicine
• Environmental Health

Background:

• Mass sociogenic illness (MSI) is a rare phenomenon where physical symptoms manifest in a group without an organic cause.
• This case describes an outbreak initially suspected to be carbon monoxide (CO) poisoning.

Purpose of the Study:

• To detail an outbreak of MSI that was misdiagnosed as CO poisoning.
• To highlight diagnostic challenges in mass illness events.

Main Methods:

• 22 individuals presented with neurological, gastrointestinal, and respiratory symptoms after a church event.
• Initial field tests suggested elevated carboxyhemoglobin (COHb) levels, leading to hospitalizations.
• Subsequent laboratory analyses, including venous blood gas and pulse oximetry, revealed normal COHb and methemoglobin levels.

Main Results:

• All affected individuals recovered rapidly, with symptoms resolving within 15 minutes of transport.
• Physical examinations and laboratory results were normal, contradicting the initial CO poisoning hypothesis.
• Hazardous materials team investigation found no evidence of toxic gas exposure.

Conclusions:

• The rapid onset, resolution, and normal diagnostic findings strongly suggest Mass Sociogenic Illness (MSI).
• Field oximeter readings were likely inaccurate, possibly due to operator error or false positives.
• Clinicians should consider MSI in mass illness outbreaks after excluding toxicological causes.