Typhoid feverPresented by Abhinay Sharma Bhugoo

What is typhoid fever?

Typhoid fever is an acute illness associated with fever that is most often caused by  Salmonella typhi bacteria. It is a general infection involving primarily the lymphoid tissues (Peyer’s Patches)

What is typhoid fever?

Typhoid fever is a bacterial infection of the intestinal tract and occasionally the bloodstream.

The disease rarely occurs in developed countries. It is most commonly seen in countries with poor sanitary conditions and contaminated water supplies.

Most of the cases are acquired during foreign travel to underdeveloped countries.

What is typhoid fever?

Outbreaks are rare.

The germ that causes typhoid is a unique human strain of Salmonella called Salmonella typhi.

Epidemiology: Incidence

World: 17 million cases per year U.S.: 400 cases per year (70% in travelers) PHILIPPINES

(Nov 2006) 478 in Agusan del Sur.

(May 2004) 292 in Bacolod City

Typhoid fevers are prevalent in many regions in the World

Who gets typhoid fever?

Anyone can get typhoid fever but the greatest risk exists to travelers visiting countries where the disease is common.

Occasionally, local cases can be traced to exposure to a person who is a chronic carrier.

Infants and persons over 60 usually have the severest cases.

Systemic bacterial infection (Enteric Fever)

1.Salmonella typhi (Typhoid fever) Most common and more severe form

2. Salmonella paratyphi A, B and C(Paratyphoid fever) Much more mild than Typhoid fever

Transmission

Ingestion of contaminated food

Typhoid germs are passed in the feces and, to some extent, the urine of infected people.

The germs are spread by eating or drinking water or foods contaminated by feces from the infected individual.

Etiology

Caused by Salmonella typhi (causative agent) which is harboured in human excreta (source of typhoid fever)

The causative agent is a gram-negative (-) motile and nonsporeforming bacillus

The organism is pathogenic only for man

Source of Infection

Since there’s NO animal hostThe source of infection are either:1. PATIENT: suffering from a disease including mild

and ambulatory cases which excretes bacilli in the feces and urine for about one month. Infected vomit and pus abscesses are also source of infection

Sources of Infection

2. Carriers : 3 types: a) Convalescent carrier – passes bacilli in the

excreta 6 months after an attack of typhoid.b) Chronic faecal carrier - passes bacilli in the

excreta 1 year after an attack of typhoidc) Chronic Urinary carrier - the renal pelvis is

infected and bacilli pass through the urine

Mode of Transmission

Shell fish contaminated with infected water Infected milk and ice cream made with infected

milk products Salads, which was contaminated with infected

water Ice Contaminated meat and poultry Flies and maggots that carries bacteria can be

considered as vectors Asymptomatic carriers

Risk factors

Travel to developing country or refugee camp

Highly dense living conditions

It is identified by biochemical reactions and serological grouping and typing of its antigens: O(somatic - a warning or signal of danger.), H(flagellar – extremity of a flagellum), and Vi(carbohydrate envelope).

O antigen

Vi antigen

H antigen

PathophysiologySalmonella Typhi

survives the acidity of the stomach

invades the Peyer’s Patches of the intestinal wall

macrophages (Peyer’s Patches)

the bacteria is within the macrophages and survives

bacteria spreads via the lymphatics while inside the macrophages

Pathophysiologyaccess to Reticuloendothelial system, liver, spleen,

gallbladder and bone marrow

First week: elevation of the body temperature

Second week: abdominal pain, spleen enlargement and rose spots

Third week: necrosis of the Peyer’s Patches

leads to perforation, bleeding

and, if left untreated, death is imminent

What are the symptoms?

The symptoms may occur rapidly, particularly in children.

However, in adults, they usually come on slowly

Relapses are common.

Fatalities are less than 1% with antibiotic treatment.

Symptoms generally appear one to three weeks after exposure.

Symptoms:

Incubation (first 7-14 days after ingestion) Usually asymptomatic Diarrhea may occur Active infection Severe Headache Generalized Abdominal Pain Anorexia Constipation more common than Diarrhea Fever [usually higher in the evening]

Intermittent Fever initially Sustained Fever to high temperatures later

Signs:

Relative bradycardia

Pulse-Temperature Dissociation (uncommon)

Rose Spots (Pathognomonic, present in 25% of cases)

Blanching pink macular spots 2-3 mm over trunk

Rashes in Typhoid

Rose spots usually occurs between the 7th and 10th days of illness. Spots last up to 3-4 days, then disappears completely. The spots may continue to appear for another 1 to 2 weeks.› Rose spots are due to

clumps of bacteria surrounded by small round cells in the skin.

› 12 in typhoid, much more numerous in paratyphoid.

Events in a Typical typhoid Fever

The typical ‘FACE OF TYPHOID’. This diagnosis is often be made at the bedside before the patient is being examined

Cheeks are usually flushed and the eyes bright during the first week of illness. In the second and third weeks the expression becomes dull, the pupils dilated, and the skin and lips are dryA patient shows a rather indefinite state on admission that can best be described as ‘toxic”.

Pathological Changes

Peyer’s Patches of the ileum changes and vary from hyperplasia and ulceration to frank ulceration and typhoid perforation

Liver may be enlarged with fatty changes The skin may show changes with the collection

of bacilli, which causes the ‘Rose Spots’

Pathological Changes

Cholecystitis may lead to formation of infected gall stones in the gall bladder› These may be asymptomatic and may be potent source

of infection in the typhoid carrier, sometimes many years after the initial infection

The spleen is enlarged and soft The mesenteric gland is enlarged

› peritoneum responsible for connecting the jejunum and ileum (parts of the small intestine) to the back wall of the abdomen. 

Pathological Changes

The kidneys shows cloudy swelling and this may result to albuminuria

Bronchitis is common in typhoid fever, and diffuse rales are usual findings on clinical auscultation of the lungs in typhoid fever

In severe case of typhoid fever, the heart may be enlarged and affected by the fatty degeneration

Finally, thrombosis of the deep vein may occur, particularly in the lower limb, and lead to a fatal pulmonary embolus

Pathological Changes

Pathological Changes

Complications:

(occurs in 10-15% of cases)

Gastrointestinal Bleeding (2-10% of cases)

Bowel perforation

Typhoid encephalopathy

For how long can an infected person carry the typhoid germ?

The carrier stage varies from a number of days to years.

Only about 3% of cases go on to become lifelong carriers of the germ and

This tends to occur more often in adults than in children.

Diagnosis

Good history taking Clinical picture : Clinical Signs Culture of:

› Bone marrow› Blood (1st week)› Duodenal Bile› Stool and Urine (3rd week)

Serology : Widal agglutination reaction. (2nd week)

Laboratory study Detection of bacterial DNA

Immune Response in Typhoid

Typhidot test

Typhidot test (if illness is 4 days or longer)

Interpretation:

Ig M Ig G

(+) (- ) Acute infection

(+) (+) Recent infection

(- ) (+) Equivocal: Past

infection or acute

infection

Should infected people be isolated?

Because the germ is passed in the feces of infected people, only people with active diarrhea who are unable to control their bowel habits (infants, certain handicapped individuals) should be isolated.

Most infected people may return to work or school when they have recovered, provided that they carefully wash hands after toilet visits.

Children in daycare, health care workers, and persons in other sensitive settings must obtain the approval of the local or state health department before returning to their routine activities.

Food handlers may not return to work until three consecutive negative stool cultures are confirmed.

Is there a vaccine for typhoid?

A vaccine is available

but is generally reserved for people traveling to underdeveloped countries where significant exposure may occur. Strict attention to food and water precautions while traveling to such countries is the most effective preventive method.

Treatment

BED REST: Hospitalization for low classes of people because of bad

hygienic measures

FULL NUTRITION Soft diet is recommended

ANTIBIOTICS

VITAMINS Especially water soluble (B&C)

Management: Antibiotics

Specific antibiotics are often used to treat cases of typhoid.

Antibiotic Resistance is increasing

First-Line: Fluoroquinolones

Alternative antibiotics (resistance is common)

Chloramphenicol

Amoxicillin

Trimethoprim-Sulfamethoxazole (Septra)

Prevention

Choose foods processed for safety Prepare food carefully Foods prepared by others (avoid if possible) Keep food contact surfaces clean (3 wash cycle) Eat cooked food as soon as possible Maintain clean hands Steam or boil shellfish at least 10 minutes All milk and dairy products should be pasteurized Control fly populations

Mary Mallon (September 23, 1869 – November 11, 1938)

Mary Mallon (September 23, 1869 – November 11, 1938)

Also known as Typhoid Mary

was the first person in the United States to be identified as a healthy carrier of typhoid fever.

She seemed a healthy woman when a health inspector knocked on her door in 1907, yet she was the cause of several typhoid outbreaks.

Mary Mallon (September 23, 1869 – November 11, 1938)

Since Mary was the first "healthy carrier" of typhoid fever in the United States, she did not understand how someone not sick could spread disease -- so she tried to fight back.

She was forcibly quarantined twice by public health authorities and died in quarantine.

Over the course of her career as a cook, she infected 47 people, three of whom died from the disease.

It was also possible that she was born with the disease, as her mother had typhoid fever during her pregnancy.

Mary Mallon (September 23, 1869 – November 11, 1938)

Mary Mallon died on November 11, 1938 at the age of 69

due to pneumonia (not typhoid), six years after a stroke had left her paralyzed.

However, an autopsy found evidence of live typhoid bacteria in her gallbladder.

Her body was cremated with burial in Saint Raymond's Cemetery in the Bronx.

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