I usually link blog posts to Tweets, rather than re-hash my Twitter musings (weese_scott) on the blog, but two things I posted on Twitter today may be of interest here.

COVID-19 in captive gorillas

Not surprisingly, COVID-19 has been identified in captive gorillas, in this case at the San Diego zoo.  It’s suspected that the gorillas were infected by an asymptomatically infected keeper, despite the intense precautions that have been taken to try to protect the animals since the pandemic began. It’s not at all surprising, since we assumed gorillas (and other non-human primates) that are relatively closely related to humans would be very susceptible to the SARS-CoV-2 virus, just like we are. With COVID-19 running rampant in California, it’s also completely unsurprising to have had an asymptomatically infected keeper at the zoo.

The more interesting aspect might be how the virus was actually transmitted from person to gorilla. Zoos tend to have very strict control measures in place to prevent this from happening (even when there isn’t a global pandemic), and the San Diego Zoo is an excellent facility. Figuring out how this occurred (e.g. inadequate practices, inadequate compliance) will be important to guide control measures at other facilities.

Toxoplasma gondii associated with brain cancer

Toxoplasma gondii is a protozoal parasite that has been linked to lots of issues in people, often with somewhat questionable evidence. Cats are the definitive host of this parasite, for which they get a very bad rap, but most human exposure is from the environment or food.

A recent paper has made some interesting but tenuous links between Toxoplasma infection and glioma, a type of brain cancer. It was interesting research, involving a large prospective study in which they collected blood samples from cancer-free people, and then followed them over time. After 13 years, they looked at the risk of gliomas in those who did or did not have antibodies against T. gondii prior to diagnosis (probably no real reason for picking 13 years… long enough for cancer to develop and it happened to be when they were ready to look at that).

There were some weak associations between one type of Toxoplasma antibody and development of glioma and glioblastoma. The data aren’t too convincing, but there are some similar results from elsewhere, which shows the subject needs more study.

What does this mean for cat owners?

  • Very little. Gliomas are a rare cancer, and while Toxoplasma exposure is quite common, it’s not usually from someone’s pet cat. Toxoplasmosis is a “don’t eat poop” disease, so there are lots of simple, routine things we can do to reduce the risk from pet cats (like not touching cat feces and washing your hands after cleaning the litter box).

More of my comments are posted on Twitter here: https://twitter.com/weese_scott/status/1348707854430167040

We have more information about Toxoplamsa on the Worms & Germs Resources – Pets page.