Comments on: Good news on Toxoplasmosis Treatment

By: Joseph W Fowble

Joseph W Fowble — Wed, 15 Jul 2009 18:35:37 +0000

Look what googling your old papers comes up with Greg.
I contributed a little bit on the malaria end of things but you have done an excellent job summarizing this work. The JPC#### name is for Jacobus Pharmaceutical Company and they have made many different dihydrofolate reductase (DHFR) inhibitors over the years. When one hits the market I’m sure they’ll get a snazzier name.
The combined DHFR-TS enzyme (dihydrofolate reductase-thymidilate synthase, as found in these parasites) is different enough from human DHFR (one function enzyme) that the protein sequences don’t bear any resemblance to each other and could have evolved separately to do the same function. As these are enzymes that help make nucleotide precursors, inhibiting the right ones can lead to the inability to properly make DNA which causes parasites to die.
I’m not familiar with the actual numbers, but I think that the vast majority of cat owners have latent toxoplasmosis. A cat’s normal grooming techniques hit all the surface areas and, well, the bum. You spend a bit of time petting cats or changing infected litter boxes and then you end up with the parasite on you and then in you. Toxo persists in the environment for a long time as well so spread from cat to cat can be as easy as contacting an area another cat has been. Until the immune system beats a toxo infection into a latent stage the waves of sickness can put a good deal of stress on the body – which is one of the reasons pregnant women should be sure to avoid new toxo exposure while already established but latent infections are less deadly to the growing baby.
As for the most recent postings from users, many, many people have toxo and it’s not just people with AIDS that experience runaway toxo infections, even a temporary immune deficiency like that after a strong sickness can allow toxo infections to become activated.
Luckily, gates foundation funding has hit many tropical diseases and it currently funds investigations into toxo too. I think malaria still gets the majority of the funds but research into many other diseases are also funded through this organization.

By: Joseph W Fowble

Joseph W Fowble — Wed, 15 Jul 2009 18:00:15 +0000

By: salem ragu

salem ragu — Fri, 10 Apr 2009 06:53:05 +0000

Hi Greg, i was reading a mes here on your blog, i don’t know what xacly this toxoplasma gondi’s doing, mabe is not able to manipulate the humans, but i want to share from my experience few things. whenever i am sick with god know’s what, flu or cold or .., i do experience another recurence episode from thoxoplasmosis. SO, what hap than? i’m like under hypnosis, i have no fear, i drive mechanical, my reactions are slow,can not focus enough, light sensitivity and i do not experience fear. Also than, my liver functions become unnormal, i feel intoxicated , tired, sleepy, joint pain ( actualy i thought that i might have some sort of hepatitis, i’m clear of any of those viruses anyway).i just thought that might be good to mention those things!cheers!and all the best!!

By: salem ragu

salem ragu — Fri, 10 Apr 2009 06:36:22 +0000

i am so happy to hear good news about toxoplasmosis treatment. I am not immunocompromised, actualy i do think i have quite a strong immune system, but since i was infected with tozxoplasmosis, i have episodes whan i prefer to b ded due to the complezity of the symptoms.Now, can anyone tell me where should i write in order to benefit of this kind of treatment?i would b a happy camper again!u can drop me an e-mail at vulcanneles@yahoo.com, or udarlunar@yahoo.comoh, i will pray for those guys all tha days of my life if i get cured!!!!!

By: Horace

Horace — Sat, 15 Mar 2008 10:19:49 +0000

Would it not be difficult to make a vaccine for a protist? (compared to a bacterium?)

By: Tlazolteotl

Tlazolteotl — Fri, 14 Mar 2008 14:53:50 +0000

Toxoplasmosis is also becoming a problem for sea otters on the California coast, with as many as 40% being seropositive. (Dave Jessup has published on this). This really is a neglected disease, not only of domestic but of wild cats as well. Not only would a treatment be good, but so would a vaccine. I wonder if anyone could get the Gates Foundation interested in wildlife diseases?

By: Greg Laden

Greg Laden — Fri, 14 Mar 2008 11:59:38 +0000

Ed,Yes I read that when it came out. It makes sense. It is probably the case that more parasites manipulate their hosts than we realize as yet. Since this parasite is not really adapted to manipulating human behavior in a way, but is (if in fact it is) adapted to manipulate mice, or whatever, we would expect odd results that humans would then translate into meaningful things with labels (like “loyalty”) … because we translate everything into a form that can be described with meaningful labels.

By: Ed Yong

Ed Yong — Fri, 14 Mar 2008 11:28:47 +0000

Thanks for this Greg - a couple of commenters have asked me about Toxo-treatments and it's good to now have somewhere to point them too. Incidentally, I would be interested to see what you made of this paper that came out in Biology Letters last year and suggested that Toxo infection could have a small but significant influence on human culture.Also: "...probably the most common parasitic infection in the world," - presumably this means that it's the most common parasitic infection in humans in the world? I would have thought that overall, arthropod pathogens like Wolbachia would be more common?

By: speedwell

speedwell — Fri, 14 Mar 2008 09:14:28 +0000

While no cat is immune, and pregnant women need to be extravigilant, it’s useful to know that toxoplasmosis is mostly a disease of cats that frequent the outdoors. If Puss is a strictly indoor cat, the chances she’ll have it are very low.

By: Greg Laden

Greg Laden — Thu, 13 Mar 2008 18:08:15 +0000

The domestic cat comes from a wild species that is not Levantine specifically. In the Levant, yes, but that would be like calling Americans “people from Paramus New Jersey”There are about 15 genera of cats, about 9 are mainly tropical and 2-3 are tropical extending into temperate regions. By species, way more cats are tropical than not.On the other hand, just as the term “tropical” is a bit strange here, the idea that Toxoplasma spp are generally found in cats is being taken for granted here. I’m not sure everyone has checked all the cats.