This document discusses several infectious diseases including meningitis, typhoid, and leprosy. Meningitis is an inflammation of the membranes surrounding the brain and spinal cord that is usually caused by viral or bacterial infections. Typhoid is a bacterial infection caused by Salmonella typhi that is transmitted through contaminated food or water and causes symptoms like fever and intestinal irritation. Leprosy is a chronic infection caused by Mycobacterium leprae that affects the skin and nerves and can cause discoloration, numbness, and deformities if untreated.

1. INFECTIOUS DISEASES
BY
MS. R.GOWRI
ASSOCIATE PROFESSOR
JAYA COLLEGE OF PHARMACY
THIRUNINRAVUR

2. INFECTIOUS DISEASES-
DEFINITION
• Infectious diseases are disorders caused by
organisms — such as bacteria, viruses, fungi or
parasites. Many organisms live in and on our bodies.
• Some infectious diseases can be passed from person
to person.
• These infectious organisms are known as pathogens.
Examples: bacteria, virus, fungi

3. What is meninges?
• Meningitis is an inflammation of the membranes
(meninges) surrounding your brain and spinal
cord. The swelling from meningitis typically
triggers symptoms such as headache, fever and a
stiff neck.
• Most cases of meningitis in the are caused by a
viral infection, but bacterial and fungal infections
are other causes.

4. MENINGITIS
• A serious disease in which there is
inflammation of the meninges, caused by viral
or bacterial infection, and marked by intense
headache and fever, sensitivity to light, and
muscular rigidity.

5. MENINGITIS
• It is the inflammatory process of
leptomeninges and CSF with subarachnoid
space

6. CLASSIFICATION
• Infectious meningitis is classified in to
• Acute pyrogenic (bacterial)meningitis
• Aseptic pyrogenic (usually active viral)
meningitis
• Chronic (usually tuberculosis / fungal)
meningitis

7. CAUSATIVE AGENTS OF
MENINGITIS
• Bacterial agents
• Neonatal : E.coli
Group C streptocci
• Infants: Haemophilus
• Viral agents: entero virus, mumps virus
• Fungal agents: candida albicans, cryptococcus
neoformans
• Parasite: protozoa, nematodes

8. PATHOGENESIS
• Nasopharynx
• Nasopharangeal colonisation (epithelial cells)
• Local invasion in to intravascular space
• Bacterimia
• Reach choroid plexus adhere to cerebral
capillary endothelium
• Bacteria gain access to CSF and multiply
• Lysis of bacteria

9. PATHOGENESIS
• Subarachnoid space inflammation
• Hydrocephalus
• Decreased cerebral blood flow
• coma

10. SYMPTOMS
• Fever, chill and rigor
• Headache, nausea, vomitting
• Seizures, cranial nerve palsies
• Neck rigidity
• photophobia

11. TYPHOID
• An infectious bacterial fever with an eruption
of red spots on the chest and abdomen and
severe intestinal irritation.
• CAUSED BY: Salmonella typhi
• It is Gram negative bacilli
• The organism persist in the gall bladder and in
the biliary tract.

12. MODE OF TRANSMISSION
• Faecal oral route
• Food and water : By the faecus or urine of the
patient or carrier Ex: Shell fish
• (Taken from sewage and contaminated bed)
raw fruits,vegetables, milk

13. CLINICAL FEATURES
• Chills and high fever
• Prodromal stage: Malaise, headache,
abdominal pain and constipation
• Later stage: Splenomegaly,abdominal
tenderness and bradycardia
• Intestinal perforation and haemorrhage occurs

14. PATHOPHYSIOLOGY
• Ingestion of contaminated food
• Ingested bacilli invade small intestinal mucosa
• Taken up by macrophage and carried to lymph
node
• S.typhi multiply in intestine

15. PATHOPHYSIOLOGY
• Intact with enterocytes and M cells
• Diarrohoea
• End of incubation period- bacilli enter
bloodstream
Bacteria invade gall bladder,biliary system, and
lymphatic tissue of bowel and multiply and pass
in to intestinal tract.

16. PREVENTION
• Sanitary measures must be taken.
• Purification of drinking water supply,
improvement of basic sanitation and
promotion of food hygiene is needed.
• Health education must be imparted.

17. TREATMENT
• Fluid rich electrolyte diet should be followed
• Antibiotics, Corticosteroids, Antipyretics.
• Complete rest is essential

18. LEPROSY
• A contagious disease that affects the skin,
mucous membranes, and nerves, causing
discoloration and lumps on the skin and, in
severe cases, disfigurement and deformities.
• Also known as Hansen disease caused by
Mycobacterium leprae which involves skin
and peripheral nerves.

19. CLASSIFICATION
The clinical system of classification includes the
use of number of skin lesions and nerves
involved as the basis for categorising leprosy
patients into multibacillary (MB) and
paucibacillary (PB) leprosy.

20. MYCOBACTERIUM LEPRAE
Rod shaped bacillus
It does not grow in artificial media or even in
tissue culture
It multiplies very slowly incubation period is 5
yrs (average 3 yrs)
Leprosy transmitted via droplets from nose and
the mouth during close contact with infected
person
If untreated permanent damage to skin, nerves,
eyes.

21. MYCOBACTERIUM LEPRAE
.

22. SIGNS AND SYMPTOMS
• Pain areas: Joints
• Skin: Blister, loss of colour, rashes, ulcers, or
redness
• Sensory: Reduced sensation of touch, pins and
needles, or loss of temperature sensation
• Also common: Nerve injury or weight loss

23. PATHOPHYSIOLOGY
• Mycobacterium leprae enters the body (skin/nose
etc)
• Peripheral nerve cells
•
• Bind to schwann cells of axon
• Demyelination of nerve

24. TREATMENT
• Common drugs:The drugs used in Multi drug
therapy [MDT] are a combination of
rifampicin, clofazimine and dapsone .

25. COMPLICATIONS
Muscle weakness
Hair loss particularly in eyebrows and
eyelashes
Inability to use hands and feet
Blindness
Disfigurement

26. REFERENCE
1. Crump JA, Luby SP, Mintz ED (2004). "The global
burden of typhoid fever". Bull World Health
Organ. 82: 346–353.
2. Warrell DA, Farrar JJ, Crook DW (2003). "24.14.1
Bacterial meningitis". Oxford Textbook of Medicine
Volume 3 (Fourth ed.). Oxford University Press.
pp. 1115–29.
3. Rodrigues LC; Lockwood DNj (June 2011).
"Leprosy now: epidemiology, progress, challenges,
and research gaps". The Lancet Infectious
Diseases. 11 (6): 464–70.

27. THANK YOU