Only in counties such as India where worm parasites are very common, infecting up to half of patients, mostly undiagnosed. Parasites increase the severity of any illness, and the death rate. Treating every patient in India with ivermectin will improve their average prognosis, even though only half the patients are infected. It does not help the other half, but it doesn't hurt them either. Ivermectin is usually benign.
Jed - I want to point out that the "worm" hypothesis is highly speculative. Data to support it is contaminated (inevitably) by correlations between worms and socio-economic factors that feed into the likelihood of trials being well conducted as well as many other things. The same difficulty of analysis that makes the pro-ivermectin case bad also applies to more sophisticated examples of it - like the worm hypothesis.
I'm not saying it is not true - I have no evidence to rule that out, and it is possible. It is certainly neat! So are many things under the sun, only some of them actually pan out.
THH