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Let us make an in-depth study of the arthropod borne bacterial diseases and its application to nursing. The below given article will help you to learn about the following things:- 1. Genus Yersinia (Pasteurella) and 2. Genus Borrelia.
1. Genus Yersinia (Pasteurella):
The genus Pasteurella is named after Pasteur who worked extensively on this organism. Later it was realised it should be called as Yersinia in honour of Yersin, first discoverer of this agent.
The genus Pasteurella contains 3 species:
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(a) P. multocida (killer of many) causes, haemorrhagic septicaemia in animals, rarely transmitted to man by dog bite.
(b) P. tularensis(derived from Tulare area near San Francisco where it was first discovered) causing tularaemia or rabbit fever.
(c) P. pestis causes plague which is one of the major pestilence of the world. This organism is Gram-negative, short, oval with rounded ends or coccobacillary occurring singly or in pair. When stained with methylene blue, both ends are deeply stained (because of metachromatic granules) showing bipolar staining which is an important feature for identification.
It is capsulated in the tissues. It grows best at 27°C. If cultured in a flask of broth with drop of sterile oil on the surface, a characteristic growth develops consisting of “Stalactites” hanging down into the fluid from oil drops.
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It causes Oriental Plague which occurs in two forms: the severe form of illness (Pestis major) occurs either as bubonic plague or pneumonic plague. In these cases, there is sudden onset with high fever, great prostration delirium and septicaemia.
There is also ambulatory form (Pestis minor) in which the patient has mild pyrexia with vesicle or papule at the site of the rat flea (Xenopsylla cheopis) bite. Plague has, at present, almost disappeared from the world.
Tularaemia caused by P. tularensis, often occurs in persons (hunters, market men, housewives) handling wild rabbits. It may be also transmitted by ticks (arthropod). Rabbits died of tularaemia on the banks of stream, may contaminate the water which may cause an outbreak of tularaemia characterised by prolonged illness with glandular lesions and ulcers of skin. It is much less fatal than plague.
Tetracyclines can be used in the treatment of the infection.
Application to Nursing:
In plague, the nurse should adopt all measures to keep away the biting arthropods from patient and other healthy individuals. She should disinfect and dispose off all dressings soiled with blood or exudates from primary or secondary bubo (inflamed lymph node).
Plague vaccine (Haffkine’s vaccine) — prepared from heat killed bacterial suspension—can be used for prophylactic purposes. It is given subcutaneously in two doses of 1 ml and 2 ml at an interval of 7 days. Its protective value is doubtful.
During the outbreak of Tularaemia, the public should be advised to drink chlorinated or boiled water; infected rabbits should not be handled. Nurse and physicians should wear complete gowns and rubber gloves while treating bubonic plague. When handling with pneumonic plague, they should not forget to wear masks and head coverings in addition to gowns and gloves.
2. Genus Borrelia:
Borrelia was first studied by a famous French microbiologist “Borrel” It is a spirochaete that infects man and animals and is transmitted by two arthropods; Louse and tick. It is thicker and less regular curved than treponemes. It causes relapsing fever in man. B. recurrentis is transmitted by louse; but B. duttoni by tick.
(a) Louse borne relapsing fever (European relapsing fever) caused by B. recurrentis is common in America, Africa and Europe.
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(b) Tick borne relapsing fever (West African relapsing fever) caused by B. duttoni is prevalent in Africa and Western states of America and is transmitted by the bite of tick.
Relapsing fever is characterised by the frequent and regular recurrences of the fever and has got its name by this characteristic feature. Relapses of fever, chills and pain are observed for 5 to 15 days and last for several days. Usually 5 to 8 relapses of diminishing severity occur. Dark field microscopy examination will reveal the presence of spirochaetes in the fresh blood during febrile relapse. These organisms are sensitive to penicillin and tetracyclines.
Application to Nursing:
Nurse should take maximum care while collecting blood from the patient in the febrile stage, because these organisms can infect through the cuts or scratches on the hands or very rarely through the unbroken skin. She should take suitable precautions to prevent the arthropod vectors (louse, tick) from biting healthy persons or patients. Blood-engorged ticks, lice or other man-biting arthropods should be removed very carefully with forceps and incinerated immediately.
