Page 145 - LECTURE NOTES

6.6.1. Scabies

Scabies is an arthropod-associated diseases caused by the mite.

6.6.2 . Magnitude Of The Problem

An increased prevalence is seen during wars and famines. In Europe, America and
other developed countries, the rise and fall of this disease reflects the intervention of

health promotion strategies. In under developed countries like Africa, it may be

chronically endemic, particularly among the poor, overcrowded, and dirty who have
close contact with an infected individual. Epidemic scabies have been reported in South

Africa. Scabies may be transmitted sexually. Scabies can be complicated by
streptococcus pyogenes infection (pyodema) sometimes causing acute

glomerulonephritis. Scabies is often worse during the rainy season.

6.6.3. Epidemiological factors

Sarcoptes scabie var.hominis, the itch mite, is the causative agent. Mites which can not

be separated morphologically from S. scabie are found on numerous wild and
domesticated animals, including dogs and pigs, but such mites very rarely infect

humans. However, if they do the infection can persist for several weeks or even months.
Scabies mites on animals are considered to be the same species as those found on

people but physiologically adapted for life on non-human hosts.

Scabies mites are not vectors of any disease but hyperinfestation of the skin with
Norwegian itch (crusted scabies) is especially contagious. There are at least 300 million

scabies cases annually. In animals the condition caused by scabies mites is referred to
as mange.

6.6.4 Prevention and control of scabies

All cases of scabies can be cured. There are no resistant infections. Methods aimed at

killing the mites will do little to immediately alleviate the nuisance and irritation caused
by the rash, although this will eventually disappear. Preliminary antibiotic may be

necessary if secondary bacterial infections have become established. Patient requires
scrub bath before treatment but avoid vigorous scrubbing with a brush this may damage

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