Communicable diseases are illnesses that can be transmitted from one person to another. Some of the examples include;
Gonorrhea
Tuberculosis
Malaria
Meningitis
Transmission is the passing of communicable diseases from an infected host individual or a con- specific (belonging to the same species) individual or group, regardless of whether the other individual was previously infected. MODES OF INFECTION
The main modes of infection are categorized into three;
Direct
Indirect
Airborne
1.DIRECT MODE OF INFECTION
DIRECT TRANSMISSION
By direct or immediate transfer of the agent to an appropriate portal of entry by personal contact, e.g. touching, biting, kissing, sexual intercourse By the direct projection of droplets onto the new host (through sneezing,coughing), but this must occur over a very short distance (1 meter or less) to be considered direct It is the spread of diseases from one infected host to a susceptible host. Two categories:
i.Person to person transmission
ii.Animals transmission
PERSON TO PERSON TRANSMISSION
A.VENEREAL
1.SEXUAL CONTACT
Examples include;
Gonorrhoea
Genital warts
Chlamydia
Hepatitis B
Herpes
Trichomoniasis
2.THROUGH AIR
They are transmitted through aerosols.
These are airborne particles with organisms in droplet form. Can also be spread by ventilation system. Examples include;
Tuberculosis
Measles
Chicken pox
Influenza
Mumps
Bacterial meningitis
3. FAECAL ORAL
This is the mode of transmission in which microorganisms are transmitted through contaminated water, food and objects Examples include;
a.Hepatitis A
b.Polio
c.Cholera
d.Rotavirus
e.Amoebiasis
f.Shigelosis
g.Giardiasis
4. FORMITES
Inanimate or substance capable of carrying infectious organisms such as germs or parasites hence transferring them from one individual to another. They are transmitted through skin cells, beddings, clothing, hair. Examples include ;
Fungal infections:-
Tinea verscolour,
Ring worms
B. ZOONOTIC
This is a mode of transmission where diseases spread from animals to
humans. Examples of zoonotic transmission include;
Animal bites
Example include;
Rabies
2. INDIRECT TRANSMISSION
Indirect transmission requires less intimate contact with the source. Two major types of indirect transmission are:
Vehicle-borne
Vector-borne
VEHICLE BORNE
For vehicle borne transmission, contaminated inanimate materials transfer the agent. These include fomites.
Fomites are objects such as clothes, bedding, eating utensils needles, surgical instruments, water. Examples of vehicle borne diseases:
TB,
cholera
Samonellosis
Tetanus
VECTOR BORNE
Vector borne transmission involves a living organism (besides a human). Vector borne transmission usually involves an arthropod. There are two general types of vector borne modes:
Mechanical
Biological
a)MECHANICAL VECTOR
For mechanical vector borne transmission, the organism is transmitted when it is carried on the vector’s body or passed through the vector’s gastrointestinal tract. The agent does not multiply or develop in the mechanical host. Examples of mechanical vector-borne diseases:
Diarrheal diseases
TB
Polio
b)BIOLOGICAL VECTOR
With a biological vector, multiplication and/or some part of the agent’s development must occur in the vector before the agent can be transferred to humans. Examples of biological vector borne diseases:
Malaria,
Scabies,
Trypanosomiasis(sleeping sickness)
3. AIRBORNE TRANSMISSION
Transfer of an infectious agent via air over longer distances (greater than 1 meter). Results when the agent can remain suspended in the air for longer periods of time and/or over larger areas. Occurs when agents are suspended in either droplet nuclei (fluid) or attached to dust particles. Examples of airborne transmission:
Influenza
TB.