Hookworm
LEVELS: Highly unlikely; No human illness; Housing alone keeps it out; Laboratory-dependent; Negligible; Negligible; Some; Available, or not needed
| Register id | globocephalus_urosubulatus |
| Type | parasite |
| Scientific name | Globocephalus urosubulatus |
| NCBI taxid | 2974368 |
| Evidence | 1 document(s) |
| Assigned | 2026-09-04, against criteria version 093366e352a2 |
Overview
Globocephalus urosubulatus is the hookworm of pigs. Infective larvae develop in the soil and enter the pig either by being swallowed or by penetrating the skin, and the parasite's distribution is limited to areas that do not freeze — in North America, pigs pastured in the southern states. Young pigs are more likely to become anaemic than older, more resistant ones, but clinical disease attributed to hookworms in pigs is rare, and the reference chapter treats it as a minor parasite throughout. Diagnostically it is a nuisance out of proportion to its importance: the adults are only about 7 mm long and the eggs closely resemble those of Hyostrongylus and Oesophagostomum, so distinguishing them means culturing larvae to the third stage. It appears in no labelled anthelmintic indication for pigs; the chapter's answer is housing, since like the other pasture strongyles it transmits efficiently only where pigs are on soil. Unlike the hookworms of dogs and cats, it does not cause cutaneous larva migrans in people.
C1 Zoonotic potential
Likelihood of transmission from pigs to humans
Highly unlikely: Human infection with the agent has never been reported, or has been reported but is not attributed to pig or pork exposure
Basis. ch61 61.2.3.4: "Unlike hookworms infecting dogs and cats, Globocephalus is not associated with cutaneous larval migrans in humans."
How this level was decided
SUPPORTED rather than inferred, and unusually so for a minor parasite -- the chapter goes out of its way to rule the human risk out by name, contrasting this hookworm with the dog and cat species that do cause cutaneous larva migrans. Level 1.
C2 Zoonotic impact
Severity of human illness caused by the agent
No human illness: Agent does not cause illness in people
Basis. ch61 61.2.3.4: "Globocephalus is not associated with cutaneous larval migrans in humans." No human disease of any kind is described.
How this level was decided
C2 scores level 1 whenever the agent does not cause disease in people, and the chapter states the absence directly.
C3 Herd introduction risk
Effort required to keep the agent out of the herd
Housing alone keeps it out: Raising pigs indoors and off soil breaks the cycle, so no ongoing biosecurity program is needed and only outdoor herds stay exposed
Basis. ch61 61.2.3.4: "Infective larvae develop in the environment and infect other pigs by ingestion or skin penetration. Geographic distribution is limited to areas that do not freeze." "in North America is limited to swine pastured in southern states."
How this level was decided
MOVED L3 -> L2 on 2026-09-01. Larvae develop from pig faeces in warm ground and enter through skin as well as mouth, so exposure does not require the pig to eat -- but it does require the pig to stand on contaminated ground. Both routes close together on perforated flooring. Scored under the 2026-09-01 C3 rework: level 2 is where the farm's own housing decision closes the route permanently, and an outdoor herd's exposure is a consequence of that production choice rather than a property of the agent. Eric: "accept being an outdoor herd itself is the biosecurity failure/risk, not the agent per se, and covers things like most gut parasites." Level 3 is reserved for routes no housing system blocks. CONFIRMED AT L2 by the five-level rework later the same day. The four-level L2 had held two different amounts of work -- this case, where housing alone does it, and agents like progressive atrophic rhinitis that need a running biosecurity program and are equally excludable from an outdoor herd. Eric spotted it: the qualifier "but outdoor herds may still be exposed" is true here and false there. Those agents moved up to the new L3 and this one stayed, on a level that now says only what is true of it.
C4 Detection difficulty
Difficulty of recognizing and confirming infection
Laboratory-dependent: The presentation does not point to this disease specifically, but local or regional laboratories can confirm it with a validated assay once it is suspected
CONFIRMED by Eric. The assignment reached this level from the evidence, and he has reviewed and ratified it.
Confirmed by Eric. CONFIRMED. "l2, straightforward to diagnose"
Basis. ch61 61.2.3.4: "Adult Globocephalus are about 7 mm in length and lay strongyle-type eggs (52-56 by 25-35 um) similar to those of Hyostrongylus." "clinical disease attributed to hookworms in pigs is rare." 61.2.4.2 adds that Oesophagostomum diagnosis "is complicated by the fact that eggs of Hyostrongylus and Globocephalus resemble them. For definitive identification, larval culture to the L3 stage is needed."
How this level was decided
The third member of the indistinguishable strongyle-egg trio. Flotation finds an egg it cannot name, and separating this genus from Hyostrongylus and Oesophagostomum needs larval culture. Clinical disease is rare, so nothing prompts the test either. Level 2.
C5 Production cost
Financial impact on the infected farm's cost of production
Negligible: No measurable effect on cost of production
Basis. ch61 61.2.3.4: "Young pigs are more likely to become anemic than older, more resistant individuals. However, clinical disease attributed to hookworms in pigs is rare." "in North America is limited to swine pastured in southern states."
How this level was decided
The chapter states it directly: clinical disease is rare. It is further confined to pastured pigs in the warm-winter states, which is a small fraction of US production, and the standing note SCORING/production_cost_impact directs scoring on modern US production. No measurable effect on cost of production. Level 1.
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, uncommon disease in modern production, diagnosis has no impact on markets"
Basis. Section 61.2.3.4 records no trade measure, movement control or consumer response.
How this level was decided
INFERRED. A rare, non-zoonotic hookworm of southern pastured pigs has no route to pork supply or demand. Level 1.
C7 Treatment potential
Potential for treatment to improve outcomes
Some: Treatment exists but is inconsistent, requires extralabel use, or works only in some circumstances
INFERRED — reasoned, not stated. The evidence implies this level rather than stating it. The reasoning is below.
Corrected by Eric from L1 Little. Reason: "c7l2 based on fact there are no labelled products, but extrlabel use of some existing products is likely to be effective"
Basis. Globocephalus is not named in any of the labelled anthelmintic lists in ch61 61.7.2. It is named in 61.7.1 among the strongyles whose infection is reduced or prevented by housing: "strongyles such as Hyostrongylus, Globocephalus, and Trichostrongylus, which are transmitted much more efficiently under pasture conditions." 61.2.3.4: "clinical disease attributed to hookworms in pigs is rare."
How this level was decided
INFERRED. No product is labelled for this genus by name, which read alone might suggest level 2 for extralabel use. But the second clause of level 1 settles it more directly: clinical disease is rare, so animals do acceptably without treatment and there is little outcome for a treatment to improve. The broad-spectrum compounds that cover the other swine strongyles would in any case be expected to work. Level 1.
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 market imperative to develop a vaccine as parasite is not particularly relevant to current US production"
Basis. No hookworm vaccine is described in ch61. The chapter addresses this genus through housing alone.
How this level was decided
INFERRED. No vaccine exists and none is warranted for a parasite whose clinical disease is rare and which is confined to southern pastured pigs. Level 1 on the second clause.
Levels and evidence are generated from data/assignments/globocephalus_urosubulatus.yml; the overview is authored in data/overviews/globocephalus_urosubulatus.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.