Woman sneezes out maggots after fly larvae get trapped in her deviated septum

"The paranasal sinus environment does not meet temperature and humidity requirements for pupation, and host secretions, immune responses, and resident microbiota create a hostile milieu for pupal development. Still, in this poor woman's nose, the pests persisted."

"From a purely anatomic perspective, we hypothesize that the combination of high larval numbers and septum deviation impeded normal egress from the nasal passages, permitting progression to the [third larval stage] and, in 1 instance, pupation. In other words, there were so many maggots in her crooked nasal passage that they created a bottleneck on their way out."

"In animals, the third-stage larvae can't pupate when they become trapped in the sinuses. Instead, they either dry out, liquify, or calcify, which can all lead to secondary bacterial infections."

A patient underwent surgery to remove sheep bot fly larvae from her nasal passages, yielding ten larvae at various developmental stages and one pupa. Genetic testing and DNA sequencing confirmed the parasitic infection. This case is unprecedented because experts previously considered pupation in human nasal cavities biologically implausible, as the paranasal sinus environment lacks adequate temperature and humidity requirements, and host immune responses create hostile conditions. Medical entomologists hypothesize that two factors enabled this unusual infection: an exceptionally large initial larval dose and the patient's severely deviated septum. The anatomical obstruction created a bottleneck preventing normal larval egress, allowing extended residence and enabling one larva to reach pupation. Clinicians are warned to recognize potential human sheep bot fly infections globally.

Read at Ars Technica