Human Health and Diseases Flashcards
Secondary infection
Infection that occurs during or after the treatment of an infection (primary infection)
Disease by one pathogen + another disease by different pathogen
Reinfection
Getting infected by the same pathogen again
Nosocomial infection
Hospital-borne infection
Pathogen
Infection or disease causing microorganism
Pathogenicity
The ability of a pathogen to cause an infection/disease is called pathogenicity
Virulence
The degree of pathogenecity is called virulence
Invasiveness
Ability of the pathogen to invade the body cells and colonise
Toxigenecity
The ability of a pathogen to produce a toxin which can cause infection/disease
Incubation period
The time period between the entry of the pathogen and the development of the first visible symptom
Epidemiology
The study of occurrence and prevalence of a disease is termed as epidemiology
Sporadic disease
Restricted to a particular (small) group of people
E.g. Food poisoning
Endemic disease
Restriced to a particular area
E.g. NEPA virus in Kerala
Epidemic disease
Rapid spread of disease in a given population within a short period of time
E.g. Cholera
Pandemic disease
Spread of a particular disease across the world
E.g. AIDS, Ebola virus, Corona virus, Smallpox, Polio (eradicated in 2018)
Direct modes of transmission of pathogenic microorganisms
- Contact
- Droplet
- Soil
- Transplacental
Direct mode of transmission- Contact
STDs- Sexually transmitted diseases
E.g. AIDS
AIDS is caused:
1. through sexual contact
2. infected needles and infected blood
3. transplacental (mother to foetus)
Direct mode of transmission- Droplet
E.g. Diptheria and Tuberculosis
Direct mode of transmission- Soil
Ringworm infection (Fungal/Mycotic infection)
All soil borne infections are usually mycotic infections
Direct mode of transmission- Transplacental
Hepatitis B (inflammation of liver)
Hepatitis A and Hepatitis C are water-borne
Indirect modes of transmission of pathogenic microorganisms
- Vectors
- Vehicle borne
- Fomite borne
- Airborne
Vectors- types
- Mechanical vector
- Biological vector
What are mechanical vectors + examples
Mechanical vectors pick up pathogens on the outside of their bodies and transmit them through physical contact
E.g. Tsetse fly carries Trypanosoma which causes African sleeping sickness
E.g. Aedes mosquito carries Flavivirus which cause Dengue
What are biological vectors + examples
One part of the life cycle of the pathogen takes place in the carriers or vectors and the other part of the life cycle takes place in the host
E.g. Female anopholes mosquito carries Plasmodium (underline) causing Malaria
Vehicle borne
Water or milk
E.g. Water- Cholera
Fomite borne
Fomite- Inanimate objects which are used by the infected person are called fomite
E.g. Chickenpox