Communicable Infectious Diseases.

Chickenpox (Varicella)-জলবসন্ত
Caused by: Varicella zoster virus

Spreads by droplets or by contamination from the discharge from ruptured lesions of the skin Chiefly affects children under 10 years of age. The incubation period is 14-21 days.

Appearance of the rash may be the first sign. Palate may be the first site before the-rash appears on the trunk.

• The distribution is centripetal; trunk--> face--> limbs in that order.

• Macules appear first--> within a few hours the lesions become papular--> then vesicular and in next 24 hours pustular.

• Itching may be troublesome. Whether or not the pastules rupture, they dry up in a few days to form scabs. The spots appear in crops.

Complications:

1. Direct viral affects- Pneumonia, myocarditis.
2. Post viral affects- Glomerulonephritis, encephalitis.
3. Secondary bacterial infection- skin infection, septicemia, osteomyelitis etc.

Diphtheria-কণ্ঠনালীর রোগবিশেষ

Caused By: Corynebacterium diphtherie (in the form of membrane)

Usually in the upper respiratory tract with a wide spread systemic affect by a powerful exotoxin which mainly involve the heart and nervous system.

It usually occurs in infants and children (preschool).

The incubation period is 2-4 days

Clinical features:

1. Sore throat. Mild to moderate rise of temperature (99-10 1°F). Pulse rate is raised.
2. Characteristic feature is the membrane formation. on the tonsils with a well defined edge and surrounded by a zone of inflammation. The membrane is firm and adherent, bleeds on removal.
3. The cervical glands are often enlarged and tender due to secondary infection. There may be swelling of the neck (bull neck).
4.  In anterior nasal diphtheria there is nasal discharge often tinged  with blood.
5. In laryngeal diphtheria, there is husky voice, high pitched cough and a danger of respiratory obstruction. 
6. Complexion 'pale, pulse rapid and poor in volume. B.P low even pt. died from acute circulatory failure.
7. Involvement of nervous system cause, palatal palsy, nasal voice, nasal regurgitation. paralysis of accommodation.
8. In tonsilar diphtheria usually causes sore throat, patient
9. becomes ill and apathetic.

Investigations:

• Identification of organism by Albert's stain.
• Culture of swab to isolate bacilli.
• Blood- leukocytosis
• Urine- may show albumin ECG- may show evidence of myocarditis

Complications of Diphtheria:

Respiratory system-

• Respiratory obstruction. 
• Husky voice

C.VS-

1. Myocarditis.
2. Arrhythmia.
3. Acute circulatory failure.

C.N.S

1. Palatal palsy.
2. Loss of accommodation.
3. Poly neuritis.
4. Paralysis of respiratory muscles

Measles-হাম

Causative Agent: Paramyxovirus.

Spreads by droplet infection. Most people suffer from measles in childhood. Incubation period is about 10 days.

Clinical features:

Catarrhal stage-

• Day 1-2: onset like common cold with fever, running nose, red, watery eyes. 
• Day 2+: cough, photophobia, appearance of Koplik's spots. In children there may be convulsion during the appearance of rashes.

Exanthematous stage-

• Day 3-4: Koplik's spots disappear & red macular or maculo-papular rashes develop.
• Day 6-7: fever settles and rashes begin to fade into brown staining spots and finally disappear by a fine desquamation of skin epithelium after several days.

Comphcations:

Effects of measles virus.

1. Stomatitis
2. Gastroenteritis
3. Pnenmonia
4. Keratitis

Secondary bacterial infection-

• Otitis media
• Bronchopneumonia

Conjunctivitis Neurological complications-

• Post-viral encephalitis
• Subacute sclerosing pan encephalitis 

Nutritional-

• Severe weight loss
• Kwashiorkor (tropics)
• Corneal ulceration (tropics- Vit. A deficiency) 

Investigations:

1. Blood examination shows leucopenia. Leucocytosis suggests bacterial superinfection.
2. Serological confirmation may be made by complement fixation and hemagglutination inhibition test. 

Poliomyelitis-শিশুর পক্ষাঘাত, রোগ বিশেষ

Caused by Poliovirus and usually occur through the nasopharynx.

The virus affects the grey matter of the spinal cord, brain stem and cortex and has a particular propensity to damage anterior horn cells specially those within the lumber segment. The incubation period is 7-14 days. 

Diagnosis:

1.CSF shows-

• lymphocytosis
• Rise in protein 50-100 gm% with
• Normal sugar level. .
• Increased cells, initially polymorphs followed by lymphocytes 50- 400/cmm

2. Virus may be isolated from throat washing in the early stages and from stool in late stage as well as in early stage.

3. CFT may be positive during the second week.

Clinical features:

Abortive poliomyelitis: Some cases of poliomyelitis may have recovery after initial symptoms of fever, headache, sore-throat, vomiting, diarrhoea and constipation.

Non-paralytic poliomyelitis: Apart from symptoms mentioned above, muscle spasm of the neck and back. There may be tenderness of the muscles. Straight leg rising is positive. No paralysis occurs in this variety.

Paralytic poliomyelitis: Paralysis is almost always symmetrical and scattered. Lower limbs are more frequently affected than the upper and trunk. Reflexes are lost. Sensory loss is, rare. Bulbar paralysis may develop and paralysis of respiratory muscles is the most dangerous complication.

Asymptomatic poliomyelitis: This refers to alimentery invasion without viremia. The virus can be demonstrated in the stools.

WHOOPING COUGH-হুপিং কাশি

This is due to respiratory infection caused by Bordetella pertussis. The disease most commonly affects infants. Incubation period is 7-14 days.

Clinical features:

Classically there are three stages-

Catarrhal stage-- lasting for about one week during which conjunctivitis, rhinitis and an unproductive cough are present.

Paroxysmal stage-- follows and is characterized by severe bouts of coughing. Initially the cough is short, later gathering in speed and duration and ending in a deep inspiration & produces a characteristic sound 'whoop' The last paroxysm frequently ends with vomiting.

Convalescent stage-- during which' the cough becomes less frequent and the sputum less tenaceous. 

Complications:

Bronchopneumonia, segmental or lobar collapse, bronchiectasis, subconjunctival hemorrhage, prolapse of the rectum etc.

Diagnosis:

• Bordetella pertussis may be isolated by culture of per nasal swabs or cough plates.
• Blood examination shows lymphocytosis. W.B.C. count is increased.