Today is our topic of discussion Communicable disease control
Communicable disease control
Definition:
This refers to the reduction of the incidence and prevalence of communicable disease to a level where it cannot be a major public health problem.
Methods of communicable disease control :
Elimination of the reservoir-
Man as reservoir:
When man is the reservoir, the following options are considered –
Detection and adequate treatment of cases:
Arrests the communicability of the disease (e.g. treatment of active pulmonary tuberculosis).
Isolation:
Separation of infected persons for a period of communicability of the disease. Isolation is indicated for infectious disease with the following features-
– High morbidity and mortality
– High infectivity
Quarantine:
Limitation of movement of apparently well person or animal who has been exposed to the infectious disease for duration of the maximum IP of the disease.
Animals as reservoir:
Action will be determined by the usefulness of the animals, how intimately they are associated to man and the feasibility of protecting susceptible animals. Example –
Plague:
The rat is regarded as a pest and the objective would be to destroy the rat and exclude it from human habitation.
Rabies:
Pet dogs can be protected by vaccination but stray dogs are destroyed c. Infected animals used for food are examined and destroyed.
Reservoir in non-living things:
Possible to limit man’s exposure to the affected area (e.g. soil, water, forest, etc)
Interruption of transmission:
This involves the control of the modes of transmission from the reservoir to the potential new host through-
a. Improvement of environmental sanitation and personal hygiene
b. Control of vectors
c. Disinfections and sterilization
Protection of susceptible host:
a. Immunization: Active or passive
b. Chemo-prophylaxis (e.g. malaria, meningococcal meningitis, etc)
c. Better nutrition
d. Personal protection (e.g. wearing of shoes, use of mosquito net, insect repellents, etc)
Skin rashes
Types of skin rashes:
- Macule – Small flat lesion with circumscribed change of colour .
- Papule – Small, solid & elevated lesion of <0.5 cm.
- Nodule A solid & elevated lesion of >0.5 cm.
- Crust – Dried exudates on the skin.
- Vesicle-Circumscribed fluid filled elevation.
- Pustule – A visible accumulation of pus in the skin.
Cause of different types of skin rashes:
- Macular rash: Chicken pox (followed by Papular → Vesicular→→→ Pustular→→ Crust)
- Papular rash: Scabies, chicken pox, warts & urticaria
- Vesicular rash: Chicken pox, herpes simplex virus, burn, impetigo, insect bitenoiteloel d
- Maculo-papular rash: Measles (morbilliform or measles-like), dengue & secondary syphilis
- Papulosquamous rashes: Tenia corporis, psoriasis
- Erythematous rashes: Cellulitis
- Eczematous rashes: Atopic eczema
- Pustular rashes: Acne, psoriasis
- Hypopigmented lesion: Pityriasis versicolor
- Hyperpigmented lesion: Naevi
Characteristics of different types of skin rashes:
Chicken pox:
Distribution is symmetrical. First appears on the trunk where it is abundant and then gradually spreads in the centripetal manner. The rash advances quickly through the stages of macule, papule, vesicle and scab. All stages of the rash appear simultaneously (pleomorphism).
Measles:
Dusky-red and maculo-papular rash begins behind the ear, spreads rapidly over the face and neck to extend down to the whole body within 2-3 days.
Scabies:
Small vesicular rash along with characteristic burrow in the body folds.
Dengue:
Maculo-papular rash on the body. The rash is centrifugal (begin in the dorsum of the
hands and feet and spreads centrally sparing the face)
Typhoid fever:
Rose spots which are blanching slightly raised macules usually seen on chest and abdomen in the first week.
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