HUMAN DISEASES – BACTERIAL DISEASES

Biology

HUMAN DISEASES – BACTERIAL DISEASES

  • The term disease denotes any condition or disorder that disrupts the steady state of wellbeing of the body.
  • Health is a state of physical, mental and emotional wellbeing in the internal environment of the body.
  • Some of the causes of diseases are due to entry of pathogens and parasites.
  • Pathogens include bacteria, viruses, protozoa and fungi.
  • Parasites are organisms which live on or in the body of other organisms.
  • Vectors are animals that carry the pathogen from are person to another.
  • Most are ectoparasites that transmit the disease as they feed.

Bacterial Diseases

Cholera

Causative agent a bacterium

Vibrio cholerae.

  • Transmission – It is spread through water and food contaminated by human faeces containing the bacteria.

The bacteria produce a powerful toxin, enterotoxin that causes inflammation of the wall of the intestine leading to:

  • Severe diarrhea that leads to excessive water loss from body.
  • Abdominal pain
  • Vomiting
  • Dehydration which may lead to death.
See also  DIHYBRID INHERITANCE

Prevention and Control

  • Adequate sanitation such as water purification sewage treatment and proper disposal of human faeces.
  • Public and personal hygiene e.g washing hands before meals and washing fruits and vegetables, boiling drinking water.

Vaccination

  • Carriers should be identified, isolated and treated during outbreaks. Treatment
  • Use of appropriate antibiotics.
  • Correcting fluid loss by injecting fluids or by administration of oral rehydration solutions.

Typhoid

Causative agent

  • The disease is caused by Salmonella typhi.
  • Transmission is through contaminated water and food.
  • It is also transmitted by certain ‘e.g foods, e.g. oysters, mussels and shell fish.

Symptoms

  • Fever
  • Muscle pains
  • Headache
  • Spots on the trunk of the body
  • Diarrhoea
  • In severe cases mental confusion may result and death.
See also  SUPPORT AND MOVEMENT IN ANIMALS

Prevention

  • Boil drinking water.
  • Proper sewage treatment.
  • Proper disposal of faeces, if not flushed use deep pit latrines.
  • Observe personal hygiene e.g. washing hands before meals.
  • Washing fruits and vegetables.

Treatment

  • Use of appropriate antibiotics.

Protozoa Malaria

  • Malaria is caused by the protozoan plasmodium.
  • The most common species of plasmodium are P. falciparum, P. vivax, P. rnalariae and P. ovale with varying degree of severity.

Transmission

  • Is by female anopheles mosquito as it gets a blood meal.

Symptoms

  • Headache, sweating, shivering, high temperature (40-41 0C) chills and joint pains.
  • The abdomen becomes tender due to destruction of red blood cells by the parasites .

Prevention

  • Destroy breeding grounds for mosquitoes by clearing bushes and draining stagnant water.
  • Kill mosquito larvae by spraying water surfaces with oil.
  • Use insecticides to kill adult mosquitoes
  • Sleeping under a mosquito net.
  • Take preventive drugs.
See also  SUPPORT AND MOVEMENT IN PLANTS

Treatment

  • Use appropriate anti-malarial drugs.

Amoebic dysentry (Amoebiasis)

Cause

  • This disease is caused by Entamoeba histolytica.
  • The parasites live in the intestinal tract but may occasionally spread to the liver.

Transmission

They are transmitted through contaminated water and food especially salads.

Symptoms

  • Abdominal pain, nausea and diarrhoea.
  • The parasites cause ulceration of the intestinal tract, which results in diarrhoea.

Prevention and control

  • Proper disposal of human faeces.
  • Boiling water before drinking.
  • Personal hygiene e.g. washing hands before meals.
  • Washing vegetables and steaming particularly salads and fruits before eating.

Treatment

  • Treatment of infected people with appropriate drugs.

See also

POLLUTION

HYDROPHYTES (WATER PLANTS)

POPULATION ESTIMATION METHODS

FOOD CHAINS

THE ECOSYSTEM

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