CHSE Biology Health And Disease Notes Part – 2

(Typhoid, Pneumonia & common cold / rhinitis )

Typhoid:

• Typhoid fever is commonly called as typhoid.
• It is a bacterial disease caused by pathogenic bacterium Salmonella typhi.
• The incubation period is usually 1 to 2 weeks and the duration of illness is about 4 to 6 weeks.

Symptoms:

• The patient experiences

• Headache
• Constant high fever
• Abdominal pain
• Poor appetite
• Weakness
• Diarrhea or constipation
• Lethargy
• Colored rush on chest
• Intestinal bleeding or perforation after 2 to 3 weeks of infection

Diagnosis:

• Typhoid fever is confirmed or diagnosed by WIDAL TEST.

Infection and Transmission:

• It infects humans through contaminated food and water.
• Salmonella typhi lives only in the human host.
• After the ingestion of the contaminated food or water, the Salmonella bacteria invade the small intestine and enter the blood stream temporarily.
• it generally enters the small intestine and then migrates to other organs through blood.
• Transmission takes place by eating contaminated water and beverages.
• Therefore, typhoid fever is more prevalent in areas of the world, where sanitation is poor.

Treatment:

• Typhoid fever is treated with antibiotics.
• The choice of antibiotic therapy includes fluoroquinolones for susceptible infections, ceftriaxone and azithromycin for established infections.

Prevention and control:    

• Eat food that has been thoroughly cooked and that is still hot and steaming.
• Avoid raw vegetables and fruits. These may be washed properly and then peeled.
• Avoid apparently contaminated food and drink.
• Get vaccinated against typhoid fever.
• Avoid food and beverages from street vendors.
• Typhoid fever vaccine have been successfully developed and commercialized.
• There are 2 types of vaccines:

1. Vi antigen vaccine: It is an inactivated vaccine available in injectable form.
2. Oraltype21 vaccine: This is an oral vaccine.

• The protective efficiency lasts for 2-3 years in most of the vaccines.
• For a long term protection one has to revaccinate every 3 year.

 

PNEUMONIA:

• Pneumonia is a lung disease.
• Pneumonia is a lung infection accompanied by cough, fever and difficulty in breathing.

Causes of pneumonia:

• Pathogens like bacteria and viruses usually cause pneumonia.
• Causative agents of pneumonia are Streptococcus pneumoniae and Haemophilus influenza.

• It usually starts when someone breaths the pathogens into the lungs.
• The infection is acquired by inhibiting the droplets released by an infected person or by sharing glasses and utensils with an infected person.
• Pneumonia infects alveoli of the lungs due to which the alveoli get filled with the fluid thereby, leading to problems in breathing and respiration.

Symptoms:

• Cough – one likely to secrete much mucus (sputum) from the lungs. Mucus may be rusty or green or tinged with blood.
• Fever
• Nausea and vomiting
• Headache
• Severing as though there is a chilled ambience.
• Diarrhoea
• Feeling extremely tired and weak
• Fast heart beat Chest pain that often feels worse when one coughs or breaths.
• Fast breathing and feeling breathlessness.
• In severe cases, lips, and finger nails turn gray to bluish in colour.

Diagnosis:

• Primarily a physical examination is conducted.
• If necessary, a patient undergoes chest X-ray and a blood test.
• In extreme cases, the mucus from the lungs may be pathologically examined to find out if causative pathogens are present.

Treatment:-

• If pneumonia is diagnosed to be caused by bacteria, antibiotics are prescribed.
• Plenty of rest, sleep and intake of rehydration drink are required. Smoking is totally prohibited.
• Pneumonia, caused by a virus usually is not treated with antibiotics. Sometimes antibiotics may be used to prevent complications.
• But more often rest and treating cough with conventional medicine work.

Prevention:-

• Prevention includes vaccination, environmental measures.
• People of 65 years of age or more, having smoking habit and lung problems need to have a pneumococcal vaccine.
• The vaccine does not keep pneumonia away. However, if pneumonia occurs, complications may not occur.

Common cold / Rhinitis:-

• It is one of the most infectious diseases of human.
• It is caused by some 200 types of Rhino viruses and a small bacterium, Dialister pneumosintes.
• The pathogens do not reach the lungs. They infect nose and upper respiratory passages.

Symptoms:-

• Flow of mucus
• Sneezing
• Sore throat
• Cough
• Hoarseness
• Tiredness
• Headache
• Slow fever

• Common cold spreads through oozing droplets from talking and sneezing, direct contact, hand shake and using common articles like pen, pencil, books, cups etc.
• It cures automatically after 3 to 7 days.
• Medicines are taken to reduce severity of nasal irritation and clearing the nasal tract.