Common human diseases

Bacterial diseases • Dysentery • Plague • Diphtheria • Cholera • Typhoid • Pneumonia Viral diseases • Common cold • Mumps • Measles • Viral hepatitis • Dengue fever • Chikungunya • Chicken pox • Poliomyelitis Fungal diseases • Candidiasis • Athlete’s foot Protozoan diseases • Malaria • Amoebiasis • African sleeping sickness • Kala-azar Helminthic diseases • Ascariasis • Filariasis Bacterial resistance If an antibiotic is used too often to fight a specific bacterial infection, the bacteria may become resistant to the specific antibiotic. Hence the specific antibiotic can no longer be used to treat the bacterial infection. Some bacteria have developed resistance to many antibiotics. Therefore, infections caused by these bacteria are difficult to be cured.

Risk of bacterial resistance can be reduced by observing the following steps • Avoid using antibiotics to treat minor infections that can be taken care by our immune system. • Do not use an antibiotic to treat viral infections such as common cold or flu. • Always follow the prescription. Skipping doses or failing to complete the prescription may allow antibiotic resistance to develop.

living cells. Outside the living cells they cannot carry out the characteristics of a living organism. Viruses invade living cells, forcing the cells to create new viruses. The new viruses break out of the cell, killing it and invade other cells in the body, causing Human Health and Diseases S.

No Diseases Causative agent Site of infection Mode of transmission Symptoms Shigellosis (Bacillary dysentery) Shigella sp. Intestine Food and water contaminated by faeces / faecal oral route Abdominal pain, dehydration, blood and mucus in the stools Bubonic plague ( Black death) Yersinia pestis Lymph nodes Rat flea vector- Xenopsylla cheopis Fever, headache, and swollen lymph nodes Diphtheria Corynebacterium diphtheriae Larynx, skin, nasal and genital passage Droplet infection Fever, sore throat, hoarseness and difficulty in breathing Cholera Vibrio cholerae Intestine Contaminated food and water/ faecal oral route Severe diarrhoea and dehydration Tetanus ( Lock jaw) Clostridium tetani Spasm of muscles Through wound infection Rigidity of jaw muscle, increased heart beat rate and spasm of the muscles of the jaw and face Typhoid ( Enteric fever) Salmonella typhi Intestine Through contaminated food and water Headache, abdominal discomfort, fever and diarrhoea Pneumonia Streptococcus pneumoniae Lungs Droplet infection Fever, cough, painful breathing and brown sputum Tuberculosis Mycobacterium tuberculosis Lungs Droplet infection Thick mucopurulant nasal discharge Table . . Bacterial diseases in human beings diseases in human beings.

Rhino viruses cause one of the most infectious human ailment called the “ Common cold ”. Viral diseases are generally grouped into four types on the basis of the symptoms produced in the body organs. Common cold is caused by more than different strains of Rhino viruses. More over their RNA genome keeps changing due to mutation.

Hence it is very difficult to prepare a common vaccine for the disease. Human Health and Diseases S. No Diseases Causative agent Site of infection Mode of transmission Symptoms Common cold Rhino viruses Respiratory tract Droplet infection Nasal congestion and discharge, sore throat, cough and headache Mumps Mumps virus (RNA virus), Paramyxo virus Salivary glands Saliva and droplet infection Enlargement of the parotid glands Measles Rubeola virus (RNA virus), Paramyxo virus Skin and respiratory tract Droplet infection Sore throat, running nose, cough and fever, reddish rashes on the skin, neck and ears Viral hepatitis Hepatitis - B virus Liver Parenteral route, blood transfusion Liver damage, jaundice, nausea, yellowish eyes, fever and pain in the abdomen Chicken pox Varicella -Zoster virus (DNA Virus ) Respiratory tract, skin and nervous system Droplet infection and direct contact Mild fever with itchy skin, rash and blisters Poliomyelitis Polio virus (RNA virus) Intestine, brain, spinal cord Droplet infection through faecal oral route Fever, muscular stiffness and weakness, paralysis and respiratory failure Dengue fever (Break bone fever) Dengue virus or Flavi virus