Typhoid Fever

Typhoid Fever:

Typhoid fever is very common in developing countries like Pakistan and India. In common words, it is called Intestinal Fever. Typhoid Fever occurs in all parts of the world where water supply and sanitation are substandard. The disease is now common in developing countries. In the UK, Typhoid Fever has been brought very close to eradication. In the USA, there were only 206 cases of typhoid fever in 2006.

Nearly 6 Million people are affected by Typhoid Fever every year and Annual deaths due to Typhoid Fever are about 600,000. Due to the Presence of All the factors responsible for typhoid fever and the spread of disease, typhoid fever is very much common in Pakistan. It is hyperendemic in Pakistan

It is an acute infectious communicable disease characterized by continuous fever with relative bradycardia with the involvement of Lymphoid Tissue.

Relative bradycardia as a characteristic feature of specific disease was found for typhoid fever (P = 0.003).

Causing Factors:

It is caused by bacteria named Salmonella Typhi and Salmonella Paratyphi Type A and B.

salmonella typhi is the major cause of typhoid fever and has three antigens.

O Antigen: Somatic Antigen
H Antigen: Flagella Antigen
Vi Antigen: Virulence Antigen

Some other factor predispose the disease condtion.

These are.

Poor Sanitation
Poor Housing
Overcrowding
Large Family
Rainy Season
Poor personal hygiene

Age: can affect any age but the peak incidence is from 9 to 15 years.
Sex: Males are at greater risk.
Immunity: All ages are susceptible to infection. Gastric acidity and intestinal immunity provide some degree of immunity.

Source of Infection:

Feces and Urine of People already suffering from typhoid fever
Contaminated food, water, milk, Flies, Fingers,

It is Transmitted by Feco-Oral Route and Urnin Oral Route. The incubation period is 14 days which means human will get typhoid fever after 14 days of infestation with Salmonella Typhi.

Signs:

In the First Week of disease, there is a headache, body ache, malaise, sore throat and anorexia ( loss of appetite )
Tongue Coated with raw tips and edges
Fever is low in the morning and gradually increases in the night . This is called Step Ladder Fever
A cough
In Second Week temperature becomes high and sleep becomes palpable at the end of the first week
Rose Spots appear on the body usually on the upper part of the abdomen.
Fever deceases in Third Week and Toxemia increases. Intestinal Haemorrhage and perforation may occur.
In the case of perforation, the patient becomes very serious. Heroic measures are needed to save the patient life.

Diagnosis:

Typhoid fever can be diagnosed by following Tests.

WBC Count which shows Relative Leukoplakia( increased number leukocytes)
Blood Culture
Stool Culture ( Efficient Test to diagnose Typhoid fever once for all )
Typhidot Test
Widal Test

Widal Test ( It is a common test to diagnose but it has less accuracy nowadays).It can be interpreted as

Higher Titers of Antibodies to O Antigen (1:160) indicates active infection.
Higher Titers of Antibodies to H Antigen ( 1:160) indicates past Infection or Past Immunization
Higher Titers to Vi Antigen indicates Carriers

Prevention:

It can be prevented by

Control of Reservoir ( Early diagnosis and Treatment of affected person by antibiotics like chloramphenicol, cotrimoxazole, amoxicillin, disinfection and follow up)
Control of Sanitation ( Do good sanitation measures. Eat and drink Pure and Healthy )
Immunization

Immunization can be given at any age older than 1 year. A vaccine is recommended to endemic areas.

Anti-Typhoid Vaccine:

Monovalent: Provides immunity against S.typhi . Vaccine contains 1000million typhi/ml
Bivalent: Contains S.typhi and S.Paratyphi A in proportion to 1000million and 500 million.
TAB VACCINE: Contains S.typhi( 1000million) S.paratyphi A (500million) and S.paratyphi B( 500million) organism/ml.

Dose: