Question

Research and describe the infection chain for Strep throat, which is caused by a different Streptococcus found in the upper respiratory tract (1p each). 1. Causative agent: 2. Reservoir: 3. Portals of entry AND exit: 4. Mode(s) of transmission: 5. Ways to BREAK the chain

Answer 1

STREP THROAT

1. Causative agente

Streptococcal pharyngitis also known as strep throat is an infection of back of throat including tonsil is caused by Group A Streptococcus (GAS) or Streptococcus pyogenes .

GAS is a species of gram positive, aerotolerant bacterium. These bacteria are extra cellular and made up of non motive and non sporing cocci. It is the pre dominent species harbouring the lancefield Group A antigen, thus called Group A Streptococcus. Both Streptococcus dysgalactiae and Streptococcus anginosus Group can posses Group A Antigen.

2. Reservoir

Human Nose throat and skin are the primary reservoir for GAS and can survive seven days in human epithelial cell in respiratory tract. And the bacteria is often carry without symptoms, this huma carriers are less contagious than symptomatic carrier of bacteria. Infected childern are an important reservoir for infection in adult. The incubation period is usually one to three days.

Cattle can also act as reservoir,

The bacterium can survive on a dry surface for three days to 6.5 months. It has been found to survive in ice cream (18 days), raw and pasteurized milk at 15 to 37 degree celsius (96 Hrs).

3. Portals of entry and exit

Portal of entry and exit via respiratory droplets, hand contact with nasal discharge and skin contact with impetigo lessions. The pathogen can be found in its carrier state in anus, vagina, skin and phryns, and contact with these surface cn spread the infection. The bacterium can be spread to cattle and back to human through milk as well as contaminated food source.

4. Five ways to break the chain

(A) There is no vaccine available to prevent strepthroat. Hand washing is one of the best way to prevent the spread of common infection.

(B) Don't share drinks or food with someone who has strepthroat.

(C) If someone in your home has strepthroat do not share their towel, sheet or pillow case.

(D) Wash dishes and laundary in hot water with soap.

(E) If you have strepthroat, Sneeze or cough in to the crook of your elbowor a tissue, rather than into your hand.