HELLO

EVERY

ONE

Nervous system disease

Meningococcal meningitisLeprosyRabies

Encephalitis

Neisseria meningitisMeningococcal Meningitis

Neisseria Meningitidis• N. meningitidis is gram negative, Diplococci, capsulated.• Aerobic- breaths oxygen• Lives in mucous membranes in the nose a throat.• spread through the exchange of respiratory and throat secretions (i.e.,

coughing, kissing). • --not spread by casual contact or by simply breathing the air where a

person with meningitis has been.

• Bacteria can grow in the cerebrospinal fluid in the subarachnoid space of the CNS.

• The blood brain barrier (capillaries) prevents passage of some materials (such as antimicrobial drugs) into the CNS.

• Meningitis: Inflammation of meninges.

Common symptoms include :-Regular fever, vomitting Lethargy, un-active, Drowsy Rashes on skin Irritability, muscle painHeadache and a stiff neck is sometimes seen.

The bacteria and leukocytes metabolize the glucose normally found in cerebrospinal fluid potentially depriving the brain of nutrients.

In addition, N. meningitis circulates in blood and produces an endotoxin that causes a drop in blood pressure leading to shock

• Highest incidence in children younger than 5 years and particularly those younger than 1 year of age as passive maternal antibody declines and as infants immune system matures.

• Commonly colonize nasopharynx of healthy individuals; highest oral and nasopharyngeal carriage rates in school-age children, young adults and lower socio-economic groups

Epidemiology of Meningococcal Disease

Epidemiology of Meningococcal Disease

• Humans only natural hosts

• Person-to-person transmission by aerosolization of respiratory tract secretions in crowded conditions

• Close contact with infectious person (e.g., family members, day care centers, military barracks, prisons, and other institutional settings)

Laboratory Characterization of Neisseria meningitidis

• Large numbers of encapsulated, small, gram-negative diplococci.

• Transparent, non-pigmented non-hemolytic colonies on chocolate blood agar with enhanced growth in moist atmosphere with 5% CO2

• Oxidase-positive

• Acid production from glucose and maltose.

Prevention and Treatment of Meningococcal Disease

• Penicillin is drug of choice for treatment in adjunct with supportive therapy for meningeal symptoms.

• Chloramphenicol or cephalosporins as alternatives

• Chemoprophylaxis of close contacts with rifampin or sulfadiazine (if susceptible)

• Polyvalent vaccine is effective in people older than 2 years of age adjunct to chemoprophylaxis

Leprosy• Mycobacterium leprae

• causes leprosy, or Hansen’s disease.

• Acid-fast rod that grows best at 30°C.

• Grows in peripheral nerves and skin cells.

• Transmission requires prolonged contact with an infected person.

Carrier• Armadillo

Humans and Armadillos are only known natural hosts

Zoological name- Cingulata

Resistance• Viable for 9 -16 days, and in

moist soil for 46 days• Direct sunlight for two hours.• Ultraviolet light for 30

minutes..

Leprosy

• Leprosy is not highly contagious and is spread by prolonged contact with exudates.

• Untreated individuals often die of secondary bacterial complications, such as tuberculosis.

• Patients with leprosy are made noncontagious within 4 to 5 days with sulfone drugs and then treated as outpatients.

LeprosyTuberculoid (neural) form

Lepromatous (progressive) form

•Loss of sensation in skin areas•positive lepromin test

•Disfiguring nodules over body•negative lepromin test

Leprosy

Figure 22.9

Symptoms

nodules on skinloss of sensation

white patchesItching,some times scaly skin

At extream:- deformation of body parts starts:- nose,eyes,hands

fingures,foot ,legs

Diagnosis of Leprosy• Diagnosis must therefore be made by

doing a biopsy, in which a small piece of skin is taken to analyse for the leprosy bacterium. Early diagnosis is very important because it can prevent permanent deformities and disability.

Leprosy

• Laboratory diagnosis is based on observations of acid-fast rods in lesions or fluids and the lepromin test.

Treatment of Leprosy• Multidrug regime Rifampicin 600 mg / once month Dapsone 100/day Clofazimine 50 mg/daily. Continue for 6 monthsOther Drugs for Leprosy 1.Ethionamide 2.Prothionamide.

Family: Rhabdoviridae

Neurotropic virus

Single stranded RNA genome

enveloped These are 2–10 µm in

diameter

Cause acute infection of the central nervous

system.

How Is Rabies Transmitted?

How Is Rabies Transmitted?

Rabies Virus (Rhabdovirus)• Transmitted by animal bite.• Virus multiplies in skeletal muscles, then brain cells causing encephalitis.• Initial symptoms may include muscle spasms of the mouth and pharynx and

hydrophobia.• The virus multiplies in skeletal muscle and connective tissue.• Encephalitis occurs when the virus moves along peripheral nerves to the

CNS.• Symptoms of rabies include

– spasms of mouth and throat muscles followed by extensive brain and spinal cord damage.

Rabies Virus (Rhabdovirus)

Clinical Findings• Bizarre behavior.• Agitation• Seizures.• Difficulty in drinking.• Patients will be able to eat solids• Afraid of water - Hydrophobia.• Spasms of Pharynx produces choking.• Death in 1 -6 days.• Respiratory arrest / Death / Some may survive.

WOUND MANAGEMENT

Cleansing-with soap and water (minimum 10min) punctured wound irrigated with catheters

Chemical treatment-virucidal agents- 70%alcohol, povidine iodine, tincture iodine, etc

Local adminisration of rabies antiserumSuturing -done after 24-48hrs with antiserum locallyAntibioticsImmunization against tetanusWound not to be dressed or bandaged

IMMUNIZATION OF DOGS

• Most important weapon in rabies control• 80-90% dog popoulation-accesible for vaccination• Mass vaccination-effective tool• Primary immunization-age-3 to 4 months• Booster dose-regular interval based on type of

vaccine

ENCEPHALITIS

Encephalitis Basics

• Encephalitis is irritation and swelling (inflammation) of the brain, most often due to infections.

• Encephalitis is a rare condition. It occurs more often in the first year of life and decreases with age. The very young and the elderly are more likely to have a severe case.

• Parenchymal damage varying from mild to profound.

Causes of EncephalitisEncephalitis is most often caused by a viral infection. Many types of viruses may cause it. Exposure to viruses can occur through:

• Breathing in respiratory droplets from an infected person

• Contaminated food or drink• Mosquito, tick, and other insect bites• Skin contact

Symptoms of Encephalitis

• Some patients may have symptoms of a cold or stomach infection before encephalitis symptoms begin.

• When a case of encephalitis is not very severe, the symptoms may be similar to those of other illnesses, including:

• Fever that is not very high• Mild headache• Low energy and a poor appetite• Clumsiness, unsteady gait• Confusion, disorientation• Drowsiness• Irritability or poor temper control• Light sensitivity• Stiff neck and back (occasionally)• Vomiting

PROBLEMS

Complications with Encephalitis

• Permanent brain damage may occur in severe cases of encephalitis. It can affect:

• Hearing• Memory• Muscle control• Sensation• Speech• Vision

•Antiviral medications, such as acyclovir (Zovirax) and foscarnet (Foscavir) -- to treat herpes encephalitis or other severe viral infections (however, no specific antiviral drugs are available to fight encephalitis)

•Antibiotics -- if the infection is caused by certain bacteria

•Anti-seizure medications (such as phenytoin) -- to prevent seizures

•Steroids (such as dexamethasone) -- to reduce brain swelling (in rare cases)

•Sedatives -- to treat irritability or restlessness

•Acetaminophen -- for fever and headache

If brain function is severely affected, interventions like physical therapy and speech therapy may be needed after the illness is controlled.

Prophylaxis

Prophylaxis • The goals of treatment are to provide

supportive care (rest, nutrition, fluids) to help the body fight the infection, and to relieve symptoms. Reorientation and emotional support for confused or delirious people may be helpful.

Fundamental Principles of Bacteriology,6TH Edition, bY:- A.J SALLE, TATA McGraw-HILL PUBLISHING COMPANY LTD.

Prescott,Harley,and Klein’s Microbiology,7TH Edition, by:- Joanne M. Willey, Linda M. Sherwood, Christopher J. Woolverton , McGraw-HILL INTERNATIONAL EDITION

IMAGES:- Google images

http://wwwnc.cdc.gov/travel/diseases/meningococcal-disease

http://www.who.int/mediacentre/factsheets/fs141/en/

http://www.webmd.com/skin-problems-and-treatments/guide/leprosy-symptoms-treatments-history

http://www.nlm.nih.gov/medlineplus/ency/article/001347.htm

http://www.who.int/mediacentre/factsheets/fs099/en/

http://www.nlm.nih.gov/medlineplus/ency/article/001334.htm

http://kidshealth.org/parent/infections/bacterial_viral/encephalitis.html

http://www.encephalitis.info/

REFERENCE