Health and hygiene

• Health- state of complete physical, mental and social well-being and not merely the absence of disease or infirmity
• Hygiene- refers to the condition and practices that help to maintain cleanliness and hygiene.
• Disease

  • functions of organs or organ systems adversely affected characterized by various symptoms and signs
  • condition of disturbed/deranged functioning of one or more organs or organ system to infections, defective diet, heredity etc.
• Types of diseases

  • congenital- present from birth eg- genetic disease (from mother during pregnancy)
  • acquired- develops after birth
• Infection

  • entry and development/multiplication of an infective organism into the body of a host
  • infectious disease- a disease due to infection
  • non infectious disease- due to other causes eg cancer hypertension
  • contagious disease- disease that is transmitted through contact
  • incubation period- time period between infection and appearance of symptoms and signs
  • vector- organism that transmits a disease from one patient/place to another
• Diseases

  • endemic- constant presence of a disease in a region
  • epidemic- sudden increase in a frequency of a disease from the regular occurrence
  • pandemic- affecting a large population/area.
  • carrier- an infected person that harbors an infectious agent without having signs or symptoms and can spread the infection to others
  • parasite- an organism that lives in or on the body of another organism add derives nutrition from it
  • ectoparasite (ecto=out)
  • endoparasite(endo= in)
• Host

  • primary/definitive host - host in which parasite attains maturity or passes its sexual stage
  • secondary/intermediate host- host in which parasite is in larval/asexual stage
• Pathogen

  • disease causing organism
  • most parasites
  • pathogen enters our body->multiplies->interfere with our activities->damage
  • have to adapt to life with host
  • eg gut pathogen survive in low pH, resist digestive enzyme
• Infections

  • Bacteria- TB, diphtheria, pertussis(whooping cough), tetanus, cholera, typhoid, leprosy, anthrax, plague, gonorrhea, syphilis and pus forming infections.
  • Virus- HIV, common cold, viral hepatitis, polio, influenza, rabies, dengue, chikungunya, chicken pox, herpes, measles, mumps, rubella, HPV, SARS, Ebola, zika, Nipah
  • Fungi- ring worm, cryptococcus, candidiasis
  • Protozoans- malaria, amoebiasis, trypanosomiasis
  • Helminthes- filariasis, ascariasis, tape worm
• *Common diseases in humans

  a: typhoid/enteric fever

  salmonella typhi- gm -ve bacteria causes typhoid fever

  • transmission- feco- oral route food, water, dirty hands, flies, cockroaches
  • food, water-> small intestine-> blood-> organs
  • clinical features
  • i: high fever (39-40 C), pea soup diarrhea, weakness, stomach pain, constipation, headache, loss of appetite, rose colored spots on skin
  • ii: intestinal perforation(hole)/injury=death
  • iii: may affect other organs too
  • (PYQ) diagnosis- Widal test
  • treatment- antibiotics
• Pneumonia

  Inflammation of the alveoli in lungs
• Pneumonia

  1. Alveoli filled with fluid

  2. Problem in respiration
• Causes of pneumonia

  • Biological
  • Viruses (influenza(flu virus), corona, RSV etc.)
  • Bacteria (Streptococcus pneumoniae/pneumonococci, Hemophilus{blood loving bleed=continuous bleeding} influenzae etc.)
  • Fungi (aspergillus, pneumocystis etc.)
  • Rarely- physical or chemical injury
• Clinical features of pneumonia

  • Cold
  • Cough with septum{phlegm}
  • Fever
  • Dyspnea
  • Chest pain
  • Body ache
  • tachypnea (increased rate of heartbeat)
• Severe pneumonia


  • Lips, nails- grey to bluish color (cyanosis)
• Transmission of pneumonia

  1. Inhalation of droplets/aerosols

  2. Sharing of contaminated objects
• Treatment of pneumonia

  • Antibiotics
  • Supportive- oxygen etc.
• Prevention of pneumonia

  Vaccines (H.influenza, streptococcus pneumoniae, influenza)

  Other bacterial diseases:

  dysentery (loose motions + blood & mucus), plague, diphtheria, tb, tetanus etc.
• common cold

  • one of the most infectious diseases (PYQ)
  • viral infection (rhino and corona virus) of nose and nasopharynx [upper respiratory tract]
  • aka coryza/ rhino pharyngitis/ nasopharyngitis
  • infect nose + respiratory tract BUT not lungs
  • cough/sneeze -> droplets -> inhaled/through contaminated objects
  • clinical features: nasal congestion, discharge, sneezing, sore throat, fever, cough, headache, body ache, watering of eyes
  • lasts 3 - 7 days
  • prevention- social distancing/isolation, hand hygiene, covver mouth and nose
• Malaria


  Infectious disease due to protist protozoan - plasmodium
• Malaria


  • Common in tropical and subtropical regions
  • 4 species - P.vivax, P.ovale, P.malariae, P.falciparum (most lethal variant of malaria)
• Malaria transmission

  1. Transmitted by vector - infected female anopheles mosquito (also is a definitive host)

  2. Man is intermediate host
• IFAM pneumonic

  Infected Female Anopheles Mosquito
• Dr. Charles Laveran

  Discovered malarial parasite and won a Nobel prize
• Dr. Ronald Ross

  In 1897 discovered that mosquito transmits malarial parasite and won a Nobel prize
• Life cycle of plasmodium

  1. Sporos - Sporozoite

  2. Tropho - Trophozoite

  3. Schiz - Schizont

  4. Mero - Merozoite