Sarcoptic Mange
LEVELS: Rarely occurs; Mild; Routine biosecurity keeps it out; Routine; Moderate; Negligible; Little; Available, or not needed
| Register id | sarcoptes_scabiei |
| Type | parasite |
| Scientific name | Sarcoptes scabiei |
| NCBI taxid | 52283 |
| Evidence | 3 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Sarcoptes scabiei var. suis is the mite that causes sarcoptic mange, historically the most important external parasite of pigs and present in 40-90% of herds in some regions. The mite burrows in the skin and the pig responds by rubbing; growing pigs develop small red papules and rub persistently, and a useful field rule is that more than one rubbing event per ten pigs in fifteen minutes suggests mange. Deaths are unlikely, but the losses are real and routinely underestimated because producers often do not recognise the problem: growth rate falls by 4.5-12%, feed efficiency drops, sows are less fertile, carcasses are trimmed and downgraded, and rubbing pigs damage the pens. Three facts make eradication feasible, and they are the reason mange is much less common than it was. Piglets are born free of mites and only acquire them by contact with infested sows or older pigs. The mite is highly host-specific and survives poorly off the pig, usually no more than three days. And modern acaricides — phosmet, amitraz and the injectable avermectins — are remarkably effective, with eradication programmes that pay for themselves. Diagnosis is by skin scraping, best from the ear, though burrowing lowers its sensitivity; ELISA is weak on individual pigs but approaches 95% sensitivity as a herd test. Human exposure to animal scabies mites causes a transient, self-limiting dermatitis rather than true scabies.
C1 Zoonotic potential
Likelihood of transmission from pigs to humans
Rarely occurs: Human infection from pigs is plausible but has only rarely been reported, and specific control points are not commonly implemented to prevent transmission to humans
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. REVIEWED ON C1_C2_RECLASSIFICATION.md, 2026-09-04, after the C1/C2 rewording that separated exposure from consequence. Eric marked up every moved cell and reversed his own earlier setting on twenty of the twenty-one: "In almost every case, I agreed with new opinion and reversed my old setting." HIS MARKUP HERE WAS "l2, I have set this to L2 because other text books reference the pig var suis strain as zoonotic. I uploaded one case study as evidence into inbox". THE ONE CELL IN THE DOCUMENT WHERE HE DID NOT ACCEPT THE RE-SCORED ANSWER, and he supplied the evidence rather than overruling on judgment: "I have set this to L2 because other text books reference the pig var suis strain as zoonotic. I uploaded one case study as evidence into inbox." That paper, grahofer_2018, was placed the same day and settles it -- a physician-confirmed scabies infestation in a 7-year-old child acquired from her family's two pet miniature pigs carrying S. scabiei var. suis. The pass had moved the cell to level 1 precisely because no pig-attributed human case was in the folder; there is one now, so the pass has moved back to level 2 and this ruling is a confirmation rather than an override.
Basis. cfsph_2012_acariasis, on the varieties and what they do in people: "Sarcoptes scabiei causes sarcoptic mange (scabies) in humans and more than 100 additional species of mammals... More than 15 varieties of this organism have been described. They include S. scabiei var hominis in people; S. SCABIEI VAR. CANIS, S. SCABIEI VAR SUIS, S. scabiei var. equi..." and "S. scabiei var hominis, which is maintained in human populations, IS THE ONLY MITE THAT CAN CAUSE PERSISTENT INFECTIONS IN PEOPLE. HOWEVER, HUMANS CAN BE INFESTED TRANSIENTLY BY THE SCABIES MITES OF A WIDE VARIETY OF DOMESTICATED AND EXOTIC ANIMALS." On rate, for the one variety anyone has measured: "THE TRANSMISSION RATE FOR S SCABIEI VAR CANIS FROM DOGS TO PEOPLE IS ESTIMATED TO BE 10-50%, AND CLOSE, PROLONGED SKIN CONTACT IS THE MOST IMPORTANT ROUTE OF TRANSMISSION." ch59 59.2.6 records the contact route in the barn from the other direction: "HUMANS WHO HANDLE INFESTED PIGS CAN ACT AS MECHANICAL VECTORS FOR THE MITES (Mock 1997), so it is important that workers with one herd must change clothes and shower before moving into another herd."
How this level was decided
MOVED BACK L1 -> L2 ON NEW EVIDENCE, 2026-09-04. Eric supplied the paper that settles this cell -- "l2, I have set this to L2 because other text books reference the pig var suis strain as zoonotic. I uploaded one case study as evidence into inbox." THE PASS HAD MOVED IT TO LEVEL 1 for a reason that is now answered: the folder held no pig-attributed human case, and the reworded level 2 requires one. grahofer_2018 IS ONE. Two pet miniature pig littermates carried S. scabiei var. suis, one with crusted scabies, and the owner's 7-year-old daughter, in frequent contact with them, developed pruritic papular lesions on the legs that A PHYSICIAN CONFIRMED AS SCABIES; both pigs and the child resolved after treatment. The authors call it the first reported zoonotic transfer from pet pigs and cite Chakrabarti 1990, "Pig handler's itch", as the prior occupational report. They also note that DNA studies found "only limited genetic diversity, and one clade included both human and pig genotypes". So human infection from pigs is reported, and rarely -- the level 2 label exactly. IT IS NOT LEVEL 3, because level 3 needs a known risk following the failure of a named control point, and there is no control point directed at mite transfer. NOTE THE HUSBANDRY QUALIFIER the authors themselves put on it: these were pet pigs living in a house, in a country where mange is eradicated from commercial farms, and their conclusion is that miniature pigs are a niche reservoir and a hazard TO SPF farms.
PREVIOUS ANSWER: MOVED L2 -> L1, re-read 2026-09-04 AGAINST THE REWORDED LABELS. cfsph_2012: "S. scabiei var hominis... IS THE ONLY MITE THAT CAN CAUSE PERSISTENT INFECTIONS IN PEOPLE", and no report of a person catching mange from a pig is quoted anywhere in the folder -- the only transmission rate given is 10-50% for the DOG variety. This is one of the four entries Eric named on 2026-09-03 as the pattern the rewording was written for: "if you try hard enough, or look hard enough you find exposure in humans but the link to pigs as the attributable cause is weak".
PREVIOUS ANSWER, kept because the evidence behind it has not changed, only the level boundary: Level 3, INFERRED AND FLAGGED, and the flag is about the level rather than the fact. THE FACTS ARE FIRM: var. suis is named as one of the zoonotic varieties, human infestation by animal scabies mites is reported, the route is close prolonged skin contact, and swine workers have exactly that contact with hyperkeratotic sows. WHAT IS MISSING is any pig-specific number or case series -- the only transmission rate in the folder is 10-50% for the DOG variety, and no report of a person catching mange from a pig is quoted anywhere. LEVEL 3 IS SCORED because this reads as an occupational risk controlled by a control point that can fail: the control point is a mange-free herd, and where the herd is mange-free nobody is exposed. THE ARGUMENT FOR LEVEL 2 is that transmission from PIGS specifically is nowhere documented in this folder, only inferred from the genus and from dogs, which is the level 2 label -- plausible but rarely reported. You will know from practice whether swineherds get this; I do not, from the folder.
C2 Zoonotic impact
Severity of human illness caused by the agent
Mild: Human illness is usually mild and self-limiting, and serious disease occurs only rarely
Basis. cfsph_2012_acariasis: "Within S. scabiei, the degree of host specificity seems to vary with the variety of mite and the specific host. SOME MITES DO NOT APPEAR TO REPRODUCE ON THE ABERRANT HOST, AND THE INFESTATION IS SELF-LIMITING (E.G., INFESTATION OF HUMANS BY ZOONOTIC VARIETIES OF S. SCABIEI)." And: "S. scabiei var hominis... is the only mite that can cause PERSISTENT infections in people. However, humans can be infested TRANSIENTLY by the scabies mites of a wide variety of domesticated and exotic animals." Earlier: "Humans occasionally become infested with zoonotic mites, which can cause DISCOMFORT AND DERMATITIS... most zoonotic infestations are SELF-LIMITING."
How this level was decided
Re-read 2026-09-04 against grahofer_2018 and UNCHANGED AT LEVEL 2, now with a described human case behind it rather than the dog-variety transmission rate. The child had pruritic papules treated with an antipruritic ointment and resolved; the review the paper cites says infestations "are typically self-limiting but cases of persistent infection requiring several months to resolve have been described". Usually mild and self-limiting with serious disease rare -- the level 2 label.
PREVIOUS ANSWER: Level 2, and the folder states the level rather than implying it. Human infestation with an animal-variety scabies mite is discomfort and dermatitis that resolves on its own, because the mite cannot reproduce on human skin -- mild and self-limiting is the level 2 label in terms. IT DOES NOT MOVE IF C1 MOVES, which is worth saying since the two are flagged together: whether the itch happens is C1, and how bad it is when it happens is this cell, and the answer to the second is on the page.
C3 Herd introduction risk
Effort required to keep the agent out of the herd
Routine biosecurity keeps it out: Quarantine of incoming stock, transport and fomite control, cleaning and disinfection, and the usual monitoring reliably exclude it
Basis. ch59 59.2.1: "The mite of swine scabies is HOST-SPECIFIC; HENCE, THE SOURCE OF MITES IS OTHER SWINE." 59.2.2: "ENVIRONMENTAL CONTAMINATION IS NOT IMPORTANT IN THE TRANSMISSION of scabies mites; however, pigs may become infested when placed in pens immediately after infested pigs have been removed. Although mites have been kept alive for 3 weeks under optimum laboratory conditions, UNDER FIELD CONDITIONS, SURVIVAL OFF OF THE HOST IS POOR, USUALLY NO MORE THAN 3 DAYS." 59.2.7, and it is the criterion stated almost as a level label: "The establishment and maintenance of mange-free herds and populations is facilitated by three important facts. FIRST, PIGLETS ARE BORN FREE OF MITES and become infested through contact with infested sows or older growing pigs. SECOND, THE MITES ARE HIGHLY HOST-SPECIFIC AND SURVIVE POORLY AWAY FROM THE PIG HOST. Third, modern acaricides are remarkably effective... BIOSECURITY MEASURES THAT FOCUS ON CAREFUL SCRUTINY OF A MINIMAL NUMBER OF SOURCES OF INCOMING STOCK ARE USUALLY ADEQUATE TO PREVENT THE INTRODUCTION OF THE PARASITE. In a number of countries, major breeding-stock suppliers maintain mange-free herds, and LARGE POPULATIONS OF PIGS IN INTEGRATED PRODUCTION SYSTEMS HAVE BEEN KEPT FREE OF THE PARASITE FOR MANY YEARS." 59.2.6: "All animals introduced into the herd must be treated before coming into the herd", and workers moving between herds must change clothes and shower.
How this level was decided
Level 3. The route is other pigs, so housing does nothing and this is not level 2; and the chapter says in terms that scrutiny of incoming stock is usually adequate to exclude it, with treatment of introductions, C&D of pens and worker hygiene between herds -- which is the level 3 list item for item. NOT LEVEL 1, and this is the judgment in the cell: scabies "historically has a high prevalence in swine herds (40-90% in some locales)", which reads like an already-in-the-herd agent. But the chapter's point is that the history has been reversed -- "many modern production systems and seed-stock suppliers have been successful in eliminating scabies", integrated systems have stayed free of it for years, and "this should be the goal of most farms". An agent that a routine programme keeps out, and demonstrably does keep out at scale, is level 3 however common it used to be.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
Routine: The disease would be suspected from clinical signs, history and epidemiology in normal practice, and confirmed by tests that local or regional laboratories run routinely
Basis. ch59 59.2.4: "SCABIES SHOULD BE SUSPECTED WHEN GROWING PIGS WITH SMALL RED PAPULES ON THE BODY ARE RUBBING. Rubbing can be evaluated by observing a group of pigs for 15 minutes. It has been suggested that IF MORE THAN 1 RUBBING EVENT PER 10 PIGS OCCURS within this time frame, scabies may be present. FINDING THE MITES BY MEANS OF SKIN SCRAPINGS CONFIRMS THE DIAGNOSIS, but burrowing of mites reduces the sensitivity of this diagnostic method." The ear is the best sampling site, crusts are broken onto black paper or macerated in 10% hydroxide and read under low magnification. "SEVERAL ENZYME-LINKED IMMUNOSORBENT ASSAYS (ELISAS) HAVE BEEN USED to detect antibodies to Sarcoptes scabiei in serum... INDIVIDUAL SENSITIVITY VARIES FROM 29 TO 64%, BUT AS A HERD TEST, SENSITIVITY APPROACHES 95%."
How this level was decided
Re-read 2026-09-04 against grahofer_2018, which bears on this cell and does not move it. The paper states the difficulty plainly -- "a conclusive diagnosis of swine scabies is difficult, because a single, reliable and sensitive diagnostic tool is not available", early infestations give negative skin scrapings, and mange mimics atopic dermatitis and insect bites -- but it also names the routine answer: skin scrapings are easy in crusted cases where thousands of mites are present, and several ELISAs detect antibodies 5-6 weeks post infection.
PREVIOUS ANSWER: Level 1, and it is the worked example at this level in criteria_levels.yml. Both halves of the label hold: rubbing pigs with papules raise it in ordinary practice -- there is even a pen-side rule of thumb, one rubbing event per ten pigs in fifteen minutes -- and confirmation is a skin scraping read under a hand lens or a serum ELISA at a regional laboratory. NOTE THE LIMITATION THAT DOES NOT LIFT THE LEVEL: every test here is poor on the individual pig and good on the herd, because the mites burrow and most infested pigs carry few of them. Individual ELISA sensitivity is 29-64% and herd sensitivity approaches 95%. This is a herd diagnosis made with routine tools, which is still level 1; it is not a case where the assay is missing or confined to a reference laboratory.
C5 Production cost
Financial impact on the infected farm's cost of production
Moderate: Losses measurably increase cost of production but remain manageable within normal farm operations, whether acute, chronic, or associated with endemic disease
Basis. ch59 59.2.8: "Deaths are unlikely unless concurrent disease is present. THE MOST SIGNIFICANT EFFECT OF SARCOPTIC MANGE IS REDUCED GROWTH RATE (4.5-12%) AND FEED EFFICIENCY IN GROWING PIGS. Other economic effects include DOWNGRADING AND TRIMMING OF CARCASSES AT SLAUGHTER, as well as DAMAGE TO PENS AND FIXTURES caused by rubbing pigs. Field studies indicate that good control of scabies may INCREASE LACTATION, REDUCE PIG MORTALITY DUE TO OVERLYING, AND INCREASE WEANING WEIGHTS." 59.2: "Herds infested with scabies suffer REDUCED GROWTH RATES, REDUCED FEED EFFICIENCY, AND DECREASED FERTILITY IN BREEDING SOWS... THE REAL ECONOMIC IMPORTANCE TENDS TO BE UNDERESTIMATED because pork producers may not recognize the presence of scabies in their herds."
How this level was decided
Level 3. A 4.5-12% reduction in growth rate with matching feed efficiency loss is a measured, quantified, continuous cost, and the level 3 label covers exactly this shape -- losses that measurably increase cost of production but remain manageable within normal farm operations, "whether acute, chronic, or associated with endemic disease". NOTE HOW THE STANDING NOTE SCORING/production_cost_impact APPLIES HERE AND WHY IT DOES NOT PULL THE LEVEL DOWN. The note says score on modern US production, and most modern US herds are mange-free -- but C5 asks about THE INFECTED FARM'S cost of production, so the cell is conditional on infestation and the prevalence is C3's business, not this criterion's. On an infested farm the number is 4.5-12% of growth, every day, in every growing pig. That is not the Listeria or anthrax case where confinement has engineered the clinical disease out; it is a disease confinement rearing can make worse, since the chapter says close association allows ectoparasite populations to build.
C6 Market impact
Duration of material disruption to pork and pig markets
Negligible: Little or no material disruption to supply or demand when disease occurs on one or more farms
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c6l1, no market impact, ancient disease"
Basis. Sarcoptic mange is endemic worldwide and historically present in 40-90% of herds in some locales (ch59 59.2), and no trade measure, movement restriction or consumer response to a scabies diagnosis is recorded anywhere in chapter 59 or in the CFSPH factsheet. The only slaughterhouse consequence described is carcass trimming and downgrading on the affected animals themselves.
How this level was decided
INFERRED. Level 1 under the standing note SCORING/market_impact: an agent long endemic and routinely diagnosed in US pigs, with no market move ever observed. NOTE THE DISTINCTION THAT MATTERS FOR THE REPORT: carcass trimming and condemnation for skin blemishes is a real cost, but it lands on the infested farm and is scored in C5. C6 asks about disruption to pork and pig MARKETS, and a trimmed carcass is not one.
C7 Treatment potential
Potential for treatment to improve outcomes
Little: Effective pathogen-directed treatment is available and works, or animals recover acceptably without it
Basis. ch59 59.2.5: "Successful treatment of scabies is dependent upon the correct use of acaricides. THE LARGE MAJORITY OF REGISTERED PRODUCTS WILL KEEP SCABIES UNDER CONTROL AND SOME EVEN ERADICATE IT, provided the correct dosage and treatment schedules are used... MORE MODERN ACARICIDES (see Table 59.1) ARE SAFER, HAVE HIGHER EFFICACIES, AND ARE EASIER TO ADMINISTER... Effective modern acaricides include PHOSMET, used as a pour-on; AMITRAZ, used as a spray; and THE AVERMECTINS (IVERMECTIN, DORAMECTIN, AND MOXIDECTIN), which are given as injections. THE AVERMECTINS ARE BROAD-SPECTRUM ANTIPARASITICIDES EFFECTIVE AGAINST MOST INTERNAL PARASITES AS WELL AS LICE AND SARCOPTIC MANGE MITES." 59.2.7: "MODERN ACARICIDES ARE REMARKABLY EFFECTIVE", and 59.2.6 records a controlled result -- "a single dose of ivermectin (300 ug/kg body weight) given to sows 8 days before farrowing was HIGHLY EFFECTIVE IN PREVENTING TRANSMISSION of the mites to the piglets."
How this level was decided
Re-read 2026-09-04 against grahofer_2018 and unchanged: "Sarcoptic mange in pigs is successfully managed by two subcutaneous injections of ivermectin or a single intramuscular injection of doramectin", which is the level 1 label -- effective pathogen-directed treatment is available and works. Both pigs in the case cleared on that regimen.
PREVIOUS ANSWER: Level 1, and it is one of the least equivocal C7 cells in the register. Effective treatment exists, is registered, and works well enough that the disease is not merely controlled but ERADICATED from herds and whole integrated systems with it. THE LABEL TEST IS SATISFIED WITHOUT AMBIGUITY, which is worth noting because the label question has been the hard part of C7 in the last two batches: US ivermectin swine labels name sarcoptic mange mites explicitly, and the chapter refers throughout to "registered products" with manufacturers' dilutions and withholding periods. This is level 1 for the reason level 1 exists.
C8 Vaccine availability
Availability of effective vaccines or bacterins
Available, or not needed: Effective vaccines are widely available in the US or secured for national outbreak response, or the disease does not clinically or economically justify vaccinating
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "c8l1, no clinical or market imperative for vaccine, disease completely eradicable and excludable without vaccine"
Basis. No vaccine against Sarcoptes scabiei is mentioned anywhere in chapter 59 or in the CFSPH factsheet, and no vaccine research is referred to. What the chapter offers instead is 59.2.7: "MODERN ACARICIDES ARE REMARKABLY EFFECTIVE... ERADICATION OF SARCOPTIC MANGE IS POSSIBLE WITH A VARIETY OF PROGRAMS developed around the use of effective acaricides, provided the processes and procedures are properly executed... ALL OF THESE APPROACHES CAN BE EFFECTIVE AND ARE JUSTIFIED ECONOMICALLY."
How this level was decided
INFERRED. Level 1 on the "not needed" clause, and the claim is made affirmatively rather than by default -- which is the test your PCV4 ruling of 2026-09-03 imposed. Saying a vaccine is not needed is a claim about the disease, and here the folder supports the claim directly: a single injection eradicates the parasite from a herd, whole integrated production systems have stayed free of it for years on that basis, and the chapter states the economics work. A vaccine would be an expensive replacement for something that already succeeds. CONTRAST WITH THE CASE THE CLAUSE MUST NOT COVER: this is not an agent of unknown disease-causing potential where "not needed" would be a guess. Mange is well characterised, its cost is quantified at 4.5-12% of growth, and the reason not to vaccinate is that the existing answer works, not that nobody has looked.
Levels and evidence are generated from data/assignments/sarcoptes_scabiei.yml; the overview is authored in data/overviews/sarcoptes_scabiei.md. Do not hand-edit this page — corrections go in data/assignments/CORRECTIONS.yml.
Quoted material marked Basis is from Zimmerman JJ, Karriker LA, Ramirez A, Schwartz KJ, Stevenson GW, Zhang J, eds. Diseases of Swine, 12th edition. Hoboken: Wiley Blackwell, 2025 — except where another source is named in the quotation itself.