By DR. ASHOK JAISINGANI

Typhoid fever is the result of the infection mainly by the S – typhi

The disease is mainly characterized by the typical continuous fever for three – four weeks

Relative bradycardia with involvement of the lymphoid tissues and considerable constitunal symptoms

Enteric Fever: The term enteric fever involve both the typhoid and paratyphoid fever

The Disease may occur

Sporadically

Epidemically

Endemically

Salmonella Typhi:

A gram – negative rod motile bacteria, is a major cause of the fever

Other relatively less common are

Salmonella typhi A & B

Salmonella typhi has three antigens

O, H, Vi

Man is host of the disease man may in the form of the

a) Cases

b) Carrier

Cases: In cases age group involve 5 – 19 years more prone, after the 20 years of the age the infection falls probably

Males are affected more than female

Carrier: These may

Temporary carrier

Chronic carrier

Man is the only known reservoir of the infection via cases or carrier

Cases:

The case may be mild, missed or severed a case (carrier) is infectious as long as bacilli appears in the stool or urine

Carrier:

The carrier may be temporary, incubatory, convalescent or chronic

1) Feco – oral route

2) Urine – oral route ( Rare)

Source Of The Infection:

The primary source:

Faces and urine of the cases and carriers

Secondary Sources:

Contaminated water, foods, finger and flies

There is no evidence that typhoid bacilli are excreted in sputum or milk

Enteric fever observe all through the years

The peak incidences are observed during the July and September, this period coincides with the rainy season and an increase in fly population

Outside the humane body the bacilli are found in the water, ice, milk, foods and soil for the varying period of the time

The typhoid bacilli do not multiply in the water, many of them perish within the 48 hours, but some survive for about 7 – days

The typhoid bacilli survive for over month in the ice and ice-cream

Typhoid bacilli survive for up to 70 – days in soil irrigated with the sewage under the moist winter conditions and about half of that period in drier summer conditions

Food being a bed conductor of the heat, provide the shelter to the bacilli, which may multiply and survive for the some time in food

Typhoid bacilli grow rapidly in milk without altering its test or appearance in any way

Vegetables grown in sewage form or washed in contaminated water are a positive health hazards

These factors are compounded by the such social factors as pollution of the drinking water supply

Incubation period is usually 10 – 14 days

But the incubation period may be as short as 3 – days

It may be as long as 3 – weeks thus depending on the dose of the bacilli ingested

The onset is usually insidious but in children may be abrupt with

Chills and high fever

Prodromal Stage: There is

Malaise Headache Cough and sore throat often with the abdominal pain and constipation, this fever ascend in stepladder fashion

After 7 – 10 days the fever reach a plateau and the pt looks toxic, exhausted and often prostrated

In early stages there may be marked constipation or “pea group” diarrhea Abdominal distension Lukopenia

There is blood, urine and stool cultures are positive for the salmonella typhi If there are no complications the pts conditions improve over the 7 – 10 days

Relapses may occurs for up to 2 weeks after termination of the therapy

Complication occurs in about 30% of the untreated cases and accounts for the 75% of the all deaths in typhoid fever

Intestinal hemorrhage is manifested by the sudden drop in temperature and sign of the shock followed by the dark or fresh blood in stool

Intestinal perforation is most likely to occurs during the third week

Less frequent complications are urinary retention, pneumonia, thrombophlebitis, myocarditis, psychosis, cholecystitis, nephritis and osteomyelitis

The control or elimination of the typhoid fever is well within the scope of the modern public health, this is an accomplished fact in many developed countries, there are generally three lines of the defense against the typhoid fever

a) Control of the reservoir

b) Control of sanitation

c) Immunization

The weakest link in the chain of the transmission is sanitation which is amenable to control

The usual method of the control of the reservoir are their

Identification (Identify either case or carrier)

Isolation

Treatment

Disinfections

Early Diagnosis: This of the vital importance as the early symptoms are non-specific, culture of the blood and stools are important, investigation in the diagnosis of the cases

Notification: This should be done where such notification is mandatory

Isolation: Since typhoid fever is infectious and has prolong course, the cases are better transmitted to the hospitals for the proper treatment as well as to prevent the infection

As a rule cases should be isolated till three bacteriologically negative stools and urine report are obtained on 3 separate days

Chloramphenicol remains the drug of the choice if the bacilli are sensitive to it

For the adult the dose is 500mg (approx. 50mg/kg of body weight/day), 4 – hourly while febrile and thereafter 500mg 6 – hourly for a total period of the 14 – days

Cotrimoxazole, Amoxcillin and trimethoprim are equally effective, resistance to these drugs now rise

Ciprofloxcin is now the drug of the choice

Patient seriously ill and profoundly toxic may be given an injection of the hydrocortisone 100mg daily for 3 – 4 days

Stool and urine are sole source of the infection, they should be received in closed container and disinfected within 5% cresol for at least 2 –hours

All soiled clothes and linen should be socked in the solution of the 2% chlorine and steam – sterilized

Nurses and doctor should be not forgated to disinfected their hands

Examination of the stool and urine should be done for the S- typhi 3 – 4 months after the discharge of the patient and again after the 12 – months to prevent the development of the carrier state

With the early diagnosis and appropriate treatment mortality been reduced to about 1% as compared to the about 30% of the untreated cases

Protection and purification of the drinking water supplies

Improvement of the basic sanitation and promotion of the food hygiene are essential measure to interrupt transmission of the typhoid fever

Typhoid fever never were major clinical problem when there is a clean domestic water supply

Sanitary measures are not followed by the health education may produce only temporary result

When sanitation is combined with the health education, the effect tend to be cumulative, resulting in a steady reduction of the typhoid fever morbidity

Immunization is complimentary approach to prevention

Immunization is only specific preventive measures

Immunization against the typhoid fever does not give 100% protection but definitely lower the incidences and seriousness of the infection, it can be given at any age upward of the one year

It is recommended to

Those living in endemic areas, household contact, groups at risk of the infection such as school children and hospital staff, traveler proceeding to the endemic areas

The anti-typhoid vaccine currently available as

Monovalent anti-typhoid vaccine

Bivalent anti-typhoid vaccine

TAB vaccine

The vaccine of the choice is naturally the monovalent typhoid vaccine, which is an agar grown, heat killed and phenol preserved vaccine, containing 1000 million of the S – typhi per ml

It also be prepared by the inactivation of the organisms with the acetone and the vaccine is known as AKD (Acetone killed and dried) anti-typhoid vaccine

The bivalent vaccine contain s-typhi and s-paratyphi A in the proportion of the 1000 million and 500million organisms respectively

The organisms are killed and preserved by the heating at 540C for one hour and by addition of the 0.5% phenol

The bivalent vaccine may also be prepared by the inactivation of the organisms with the acetone and dried form (AKD vaccine)

The traditional TAB vaccine contain S – typhi (1000 million), S – paratyphi A (500 – 700 million) & S – paratyphi B (500 – 750 million) organisms per liter

The paratyphoid antigens in the vaccine are not only thought to be of the doughtful effectiveness, but there presence enhanced reaction caused by the extra-protein of the paratyphoid A & B components

Therefore the traditional TAB vaccine has fallen in to disfavor

The WHO recommended that the TAB vaccine should be discontinue