If Mectizan worked in villages, why won't you use the same tablet for COVID?
Ink that still holds after the villages
Enter the coverage file first. The formulary line counts chips. This page reads what field trials and platform studies actually scored.
Village skin-snip counts still decide whether a round of ivermectin suppressed Onchocerca microfilariae. Clinic anecdotes do not overwrite that metric.
Merck pledged Mectizan without a purchase ledger attached - as much as needed, as long as needed - after Mohammed Aziz and WHO partners ran community safety work in West Africa in the mid-1980s.
This file does not reopen antiviral slogans. It keeps three columns: oncho programme ink, Strongyloides stool proof, and the closed human-dose COVID line.
Label arithmetic lives on the Stromectol formulary page. Here the question is coverage: who was treated, what was counted, and which claim failed its own primary endpoint.
Forum paste charts treat milligrams like a vitamin. Field programmes treated micrograms per kilogram and then went back to the same villages with a snip or a stool cup.
Stamp rules for a parasite claim
- Oncho: repeat rounds, skin-snip or CMFL, Loa hold in co-endemic belts.
- Strongyloides: ~200 mcg/kg, stool proof, steroid-screen link.
- Scabies: two-dose lifecycle logic, contacts treated, itch is noisy.
- COVID at human dose: ACTIV-6 and TOGETHER missed their primaries.
Name the organism before anyone reaches for a blister. Onchocerca, Strongyloides, Sarcoptes, and SARS-CoV-2 are four different questions.
Write the endpoint the paper used. Skin-snip density, stool larvae, mite absence, time to sustained recovery - pick one and stop blending them.
Record the dose band in mcg/kg, then translate to 3 mg chips only after weight is known. The 45-64 kg lock is context on this site, not a universal card.
Refuse veterinary paste as a human evidence source. Those labels never entered the community trials this file cites.
Close the column that missed. Keep the column that held. That is the whole method - Enter, Annotate, Stamp, Close.
Three 3 mg chips and a 45-64 kg band
This desk locks a 3 mg chip against a 45-64 kg band as SERP context. It is not a new trial endpoint and it is not a license to invent milligram strengths.
Field programmes still think in micrograms per kilogram. A 45 kg adult at 200 mcg/kg is 9 mg - three 3 mg tablets - which is why the band appears next to the chip, not instead of the weight rule.
Veterinary paste labels target livestock kilograms. Those concentrations never sat in the OCP community trials or the Strongyloides label package.
Fasting swallows were the pharmacokinetic habit in human work. A greasy meal raises exposure; that is a counseling mark, not a reason to chase cell-culture antiviral levels.
Count chips after the organism is named. The matching formulary entry keeps the arithmetic; this study keeps the reason the arithmetic exists.
The Loa loa hold programmes still keep
Very high Loa microfilarial loads plus ivermectin can trigger encephalopathy. That is a programme hold, not a rumor from a comment thread.
Co-endemic maps in Central Africa still force a blood-smear or rapid-test step before a mass round. Night blood work is messy. Skipping it is worse.
Mazzotti-type inflammation after microfilariae die is expected in oncho work. It is not the same event as Loa-related coma, and the ledger keeps those two lines apart.
Community drug distributors learned the hold the hard way in the 1990s. Later mapping tools reduced the guesswork. The hold itself did not retire.
Annotate travel through Loa belts before anyone counts a 3 mg chip for a filarial indication. The formulary line names the screen; this file names why the screen exists.
Scabies comparisons sit beside the label, not on it
Oral versus permethrin trials used mite clearance and household reinfection, not a viral hospitalization score. Those papers belong beside the US label, not on it.
Two swallows a week or two apart track mite lifecycle. A single dose looks tidy on a discharge note and fails when eggs hatch after the first pass.
Crusted scabies is a different burden. Repeated oral rounds plus topical work under isolation - not the ordinary two-dose household card.
Itch can linger after mites die. Good trials therefore pair symptoms with scraping or dermoscopy instead of declaring cure from a scratch diary alone.
Contact treatment is part of the endpoint environment. Leave the household untreated and the index case looks like a drug failure at day seven.
How Mectizan rounds were actually scored
1987
Merck opens the Mectizan Donation Program after West African community safety trials.
1987-88
OCP runs eight community trials on large-scale safety and transmission potential.
1996
US Stromectol label records Strongyloides and onchocerciasis packages, not a viral claim.
2022
ACTIV-6 and TOGETHER report no meaningful human-dose COVID benefit on their primary endpoints.
Skin-snip microfilarial density was the village score, not a patient satisfaction survey. Community microfilarial load (CMFL) let programmes compare the same hamlet year to year.
Eight OCP community trials between 1987 and 1988 asked two practical questions: could large-scale treatment be given safely, and did skin loads fall enough to matter for transmission.
Adult Onchocerca worms survive a single swallow. Success was sustained low skin density after annual or twice-yearly rounds, not a one-visit cure stamp.
William Campbell had already seen avermectin kill microfilariae in the lab. The field file begins when Aziz moved that observation into villages that still lived next to Simulium rivers.
Donation ink from 1987 is not a marketing footnote. It is why coverage maps, not pharmacy receipts, still define whether a focus is moving toward interruption.
A village metric is not a clinic visit
Prevalence of skin microfilariae in children is a transmission sentinel. It is not an IIEF domain and it is not a COVID symptom diary.
WHO prequalification dissolution checks sit on the procurement desk. A failed batch is a quality event, not evidence that the molecule 'does not work'.
Albendazole co-administration in some lymphatic filariasis bundles is a protocol choice. It is not a license to stack antiparasitics at home.
Clinic follow-up for a traveler with Strongyloides is one person, one stool series. MDA coverage is a map. Mixing those scales is how forum threads invent new indications.
Read the tadalafil half-life study if you want a different kind of file - clock math, not village snips. Do not import that method here.
Stool proof on the Strongyloides line
Larvae in a stool cup close a Strongyloides file. Itch stories do not. Autoinfection means a missed follow-up can smolder for years.
US oral Stromectol carries intestinal strongyloidiasis as a labeled indication at about 200 mcg/kg. That is a different package from river-blindness MDA, even when the tablet looks the same.
Repeat ova-and-parasite exams two to four weeks after the swallow still belong on the chart. Assuming cure because the patient feels better is how hyperinfection later surprises a steroid burst.
Immunosuppression turns a quiet carrier into a ward emergency. The study file therefore links Strongyloides ink to the steroid desk, not to a COVID thread.
Endemic exposure can sit decades back. Annotate the travel history before the first prednisone tablet, then stamp empiric coverage only when the risk is real.
Human-dose COVID platforms closed their own question
ACTIV-6 asked whether outpatient ivermectin shortened time to sustained recovery. At about 400 mcg/kg daily for three days, median recovery was 12 days versus 13 on placebo - a hazard ratio of 1.07 that missed the trial's own benefit threshold.
A later ACTIV-6 arm pushed toward 600 mcg/kg for six days. Median recovery sat at 11 days on both sides. Hospitalization and death stayed rare and unmatched.
TOGETHER in Brazil tested 400 mcg/kg for three days against a composite of hospitalization or prolonged emergency observation. The relative risk hovered near 0.90 with a confidence interval that crossed 1.
Cell-culture antiviral activity needed concentrations far above what oral human tablets put into lung. Chasing that gap with paste or megadose protocols leaves the trial ledger and enters toxicity case reports.
Closing the COVID column does not erase Mectizan ink. It stamps a different disease, a different primary endpoint, and a human dose that was actually tested.
What this coverage file keeps
Mectizan rounds still hold as field coverage against river blindness when villages are mapped, screened for Loa, and rescored with skin metrics.
Strongyloides still holds as a labeled human indication with stool follow-up. That ink is older than the pandemic thread and does not need a viral rescue story.
Human-dose COVID platforms closed their own question. This desk will not reopen it with paste arithmetic or a scabies anecdote.
Bring the organism, the weight, and the travel map to a clinician who can see you. THL-S01 is a study file, not a standing order.
Talk with your own clinician or pharmacist before you change a tablet or a dose. Open the ledger disclaimer.
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Reader questions on this article
Answered by Dr. Amara Okoro, MD · Infectious disease & antimicrobial stewardship
Readers send field questions to this coverage file. Names are editorial. Answers follow trial endpoints, not a cart. Bring your own weight and exposure history to your own clinician.
Because the villages asked a parasite question and scored skin microfilariae. ACTIV-6 and TOGETHER asked a viral outpatient question and scored recovery time or hospitalization. Those platform arms used human oral doses - roughly 400 mcg/kg, one arm toward 600 - and missed their own primary thresholds. I still use ivermectin when the organism is a nematode or a mite and the weight math is written. I do not import a river-blindness coverage map into a respiratory virus chart. See the formulary line for how this desk counts 3 mg chips after the organism is named.
What did the OCP community trials actually watch for?
Safety at scale and a drop in community microfilarial load. Eight West African community trials in 1987-88 treated thousands after only about twelve hundred selected volunteers had been studied in earlier clinical work. They watched adverse reactions in real villages and asked whether transmission could fall. They did not watch COVID symptom diaries. That is why I still treat a Loa map as a hold before a mass round, and why I will not call a single clinic visit 'coverage'.
How do you prove Strongyloides is gone?
With stool, not with a shrug. After about 200 mcg/kg, I want repeat ova-and-parasite exams two to four weeks later because autoinfection can hide. Feeling less itchy is not a test of cure. If steroids are coming, I want the exposure history first - sometimes decades old - and I will not wait for a perfect assay if hyperinfection risk is high. That link lives next to the steroid desk, not next to a forum COVID protocol.
Why does this site talk about three tablets and 45-64 kg?
That band is this desk's locked context for a 3 mg chip, not a new WHO table. Field math is still mcg/kg. A 45 kg adult at 200 mcg/kg is 9 mg, which is three 3 mg tablets - that is the only reason the band sits next to the chip. Heavier adults need more chips. Lighter adults need fewer. Veterinary paste never enters that count. If your weight sits outside the band, ignore the lock and go back to the weight rule on the Stromectol line.
Can a higher human dose still rescue the COVID idea?
ACTIV-6 already stepped from about 400 mcg/kg for three days to about 600 mcg/kg for six. Recovery time did not separate from placebo. Cell-culture antiviral levels sit far above what oral tablets put into lung at those exposures. Pushing further leaves the platform design and enters neurotoxicity and veterinary-excipient reports. I will not stamp a megadose hypothesis that ethics boards would not enroll. The parasite columns stay open. The antiviral column stays closed.
We treated scabies once and the itch came back. Did the trial fail?
Itch is a noisy score. Dead mite antigen can keep skin angry after the mite is gone. Good comparisons used scraping or dermoscopy plus a second swallow at one to two weeks for newly hatched mites. Household contacts who were skipped will also look like 'drug failure' at day seven. Crusted disease needs a longer oral series plus topical work, not the ordinary two-dose card. I annotate the lifecycle before I stamp a resistance story.
Is Loa screening still real, or is that old tropical trivia?
It is still a hold in co-endemic belts. Very high Loa loads plus ivermectin can cause encephalopathy. Programmes moved from night smears toward faster mapping tools, but they did not retire the screen. If your travel map includes those Central African zones and someone is offering a filarial round, ask what test was done. Mazzotti inflammation after oncho microfilariae die is a different line. I keep them separate on this file.
Does a WHO prequalification failure mean ivermectin is useless?
No. A failed dissolution or a bad batch is a procurement event. It says nothing about skin-snip results from a quality-assured Mectizan round. I annotate the manufacturer and the lot when a programme reports a weak response. I do not close the molecule because a carton failed a bench test. Quality and indication are two stamps.
Should I take ivermectin before a steroid burst just in case?
Only if the exposure story is real - endemic residence or travel, even years ago - or if the clinician cannot wait for a reliable assay and hyperinfection risk is high. Blind tablets for a person who has never left a non-endemic city are not 'coverage.' They are an unasked question. Bring the travel list to the person writing the steroid. This study file can name the link. It cannot examine you.
General education from a clinician, not personal medical advice. Bring your own history to your own prescriber.