First case of fatal equine meningoencephalitis caused by Halicephalobus gingivalis in Mexico.

The research article is about the first confirmed case of fatal equine meningoencephalitis caused by the nematode Halicephalobus gingivalis in a horse from Mexico.

Objective and Background

• The research focuses on an unprecedented case of fatal equine meningoencephalitis that was observed in Mexico, caused by the soil nematode Halicephalobus gingivalis.
• While cases of this nature have been reported worldwide, this was the first time an incidence had been confirmed in Mexico.

Findings and Methods

• The case involved a 10-year-old Andalusian horse that was presented with dysphagia, fever, weakness, prostration, and ataxia and succumbed during the medical attention.
• A post mortem examination was conducted, and no significant alterations were found.
• Detailed histopathology showed signs of meningoencephalitis, vasculitis, and the presence of adult nematodes, larvae, and eggs consistent with Halicephalobus spp.
• To further confirm the diagnosis, a Polymerase Chain Reaction (PCR) was conducted on formalin-fixed and paraffin wax-embedded sections of the horse’s brain.
• PCR was targeted at the nuclear large subunit ribosomal RNA gene (LSU rDNA) of nematodes.
• Subsequently, nucleotide sequence analysis of the amplified fragment solidified this diagnosis by identifying the agent as H. gingivalis.

Conclusion

• The confirmation of the pathogen as H. gingivalis marked a significant milestone because, despite H. gingivalis being recognized in other parts of the world as a causative agent of fatal equine meningoencephalitis, this instance serves as the first confirmed report of Halicephalobiasis in Mexico.