A recent experimental study showed that viable
OVMC could not be identified in pla-ra fermented for 3 days or more
(Prasongwatana et al., 2013). Typically, pla-ra is fermented for many months before eating, while pla-som is usually fermented and eaten
within one week. At day 3 of fermentation, viable OVMC were found
in pla-som but not in pla-ra (Prasongwatana et al., 2013), implying
that pla-som presents a higher risk of infection with OVMC as opposed
to pla-ra.