Typhoid fever is the result of systemic infection mainly by the organism salmonella typhi, which is acquired after ingestion of contaminated food or water. The term 'Enteric fever' includes both typhoid and Paratyphoid fever.

Paratyphoid fevers are caused by Salmonella Typhi A & Salmonella Typhi B

SOURCE OF INFECTION

Primary - Faeces and urine of cases or carriers
Secondary - Contaminated water, contaminated food, fingers & flies

RESERVOIR OF INFECTIONS

Infected Cases and Carriers eg the famous case of " Typhoid Mary "

INCIDENCE

Typhoid may occur at any age. Highest incidence occurs in the 5-19 age group. It is observed throughout the year. The peak incidence is reported during July - September. This period coincides with the ra rainy seasons and an increase in the fly population.

INCUBATION PERIOD

Usually 10-14 days
May be as short as 3 days

WHAT ARE THE SYMPTOMS?

The disease is charecterized by - a typical continuous prolonged fever for 3-4 weeks

* Malaise & considerable constitutional symptoms - fatigue, anorexia, headeache
* Abdominal pain and tenderness
* Gastro Intestinal Symptoms like diarrhoea
* Rose spot rash
* Mental status changes like delirium and stupor
* There may be inverse relationship between temparature and pulse rate
* The child may appear to be acutely ill, disoriented and lethargic

COMPLICATIONS

* Intestinal perforation and haemorrhage
* Encephalopathy
* Cholecystits
* Secondary infections

HOW TO DETECT TYPHOID FEVER

Diagnosis is by history and combining resporatory tests

(i) Serological tests (Widal test)
(ii) Blood cultures are frequently positive
(iii) Urine & stool cultures are positive after the stage of secondary septicemia sets in.

HOW TO PREVENT TYPHOID FEVER

(A) Control of Resevoir
(i) CASES
* Early diagnosis of cases
* Isolation of the patients to prevent the spread & contamination
* Proper treatment with antibiotics
* Disinfection of stools & urine, soiled clothes & linen

(ii) CARRIERS
* Identification by culture & serological tests (Widel tests)
* Treatment of the carriers
* Preventing carriers from handling food, milk or water
* Health education - proper hand washing with soap and water before preparing and eating food & after defeacation and urination

(B) Control of Sanitation

* Protection & purification of drinking water by boiling etc.
* Improvement of basic sanitation , washing hands with soap & water, proper disposal of excreta
* Promotion of food hygiene :-
Washing raw food
Proper cooking of food
Pasteurization of milk
Avoiding "bazaar" food
Protecting food from flies & dirt
Keeping utensils clean

The individuals handling food should be aware of their potential contagiousness and importance of handwashing and personal hygiene

(C) Immunization - May reduce this disease

This is recomended for
* groups at risk of infection like the school children
* Household contacts of cases
* For everyone above the 2 years of age

There are two types of vaccinations
(1) Oral (2) Parenthetical

Oral :- The live oral Ty 21a vacccine is to be swallowed whole on Day 1, 3 & 5

Injection :- The Vi antigen vaccine is the most popular
The vaccine is boosted every 3 years

TREATMENT

* The maintanance of appropriate fluid & electrolyte balance is essential
Home management requires the patient to be given plenty of oral fluids, semisolid diet
* Drug Therapy
Presently with the problem of MDRST, (Multidrug Resistant Salmonella Typhi) it is best not to choose an antibiotic oneself. It is better to visit the doctor for appropriate antimicrobial
* Prolonged Septicemia & Toxaemia may require hospitalization