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Occupałional hijimes and Infections

Betwecn 1975 and 1981 in Scotland therc were 344 reports of orf in human bcings, most * Icsions occurring on thc hands and forearms, and most cases affecting adults, cspccially men. In 49 cases those affectcd were abattoir workers, butchers or mcat handlers. It is likely that the actual numberof cases grcatly cxceeds this figurę sińce many of the lesions, although fatractable to treatment, are of minor import-ance.

Sensible protective prccautions should be excrcised, i.e. strict hygienc and prompt and suitable treatment of cuts on hands and arms. Infected animals should be handled carefully in the lairage, and other Staff wamed of the danger.

Erysipelas

Erysipelas infection occurs through skin abra-sion or morę rareiy by ingestionT^me disease i3~7nost common in abattoir wprkers. fish handlers and those in tlufTish-meal industry (the bacilli, probably originating from sewage, have been found on the skin of many salt-water fish).

Several forms of the condition may occur: a mild, localized, cutaneous infection usually invo!ving the fingers, with or without arthritic symptoms (erysipeloid of Rosenbach); a dif-fuse or generalized skin eruption with arthritic and constitutional symptoms; and a septicaemic form with endocarditis which may or may not be accompanied by skin and arthritic lesions. Arłhritis, meningitis and brain abscesses have also been associatcd with Erysipelothrix insidiosa {rhusiopathiac) infection.

The localized skin lesion, or erysipeloid, is characterized by swclling, erythema and pain al the site of inoculation. The erythema is reddish-purple in colour and possesses a well defined raiscd zonę which extends peri-pherally as the central portion subsides. Haemorrhagic vesicles may occur on occasions at the site. Similar erythematous lesions may appear elsewhere on the hands and wrists with the disappearance of the origina! lesion. Altematively the lesions may spread by con-tiguity. The dprntion of the disease is about three weeks. The severe diffuse or generalized skin eruption has been known to last for many months and even as long as two years. The

septicaemic form, usually of.shorter_duration,

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possesses symptoms similar to those occurring in the septicaemic condition in pigs -skin eruption, arthritis and endocarditis.

Leptospirosis (haemorrhagic jaundice, canicola fever, WeiTs disease)

In certain parts of thc world leptospirosis is an important disease in the livestock industry, e g. parts of North and South America, Russia, Europę and the Near East, but not in the British Isles. Clinical cases in man do occur from time to time and are almost always associated with rats, in whose urine the lep-tospires are shed. Hcdgehogs, voles, shrews, skunks, opossums, bandicoots, certain reptiles, amphibians and.fish also act as natura! reservoirs of infection.

In addition to abattoir workers. liyestock handlers, yeterinary surgeons, poultry and fish jhandlers, sewer and canal workers,..etc.,.. are~Iiabre to infection. At least 103 different serotypes^ł leptospire have been recorded in livestock, occurring in two main complexes: Lcptospira mterrognns including most of the mammalian strains and L. biflexa including thc non-pathogenic saprophytic types.

Of the 120 cases of human leptospirosis occurring in England and Wales during 1983 most were of the ictcrohacmorrhngiae sero-group, followed by hebdomadis and canicola infections, with four deaths occurring.

Leptospirosis causing abortion in cattle was common in England in the early winter of 1984. L. interrogans servovar hardjo and i. bra-tislaoa have mainly involved with 'flu-like ill-ness occurring in farm personnel.

The reservoirof infection includes farm_ancL P?¹    (cattle, horses, sheep, pies and

dogs) and a wide rangę of wild animafe rats and other rodents acting as normal carricr hosts. The size and movement of the rat popu-lation may inerease the risk of exposure of human beings to infective materiał, thc disease in man being morę prevalent during the Iate summer and autumn months. Warm humid conditionsJend to fąvour the growth of leptospires.

Although infection usually takes place through the skin with the urine of infected animals, especially if the skin is cut or abraded, infection may also occur through inhalation or ingestion of infectivc materiał.