Typhoid Fever (Enteric Fever)

Typhoid Fever (Enteric Fever)

Typhoid fever is an acute bacterial infection characterized by fever and is primarily spread through contaminated food and water.

Causes

Typhoid fever is caused by Salmonella typhi and Salmonella paratyphi A and B.

Transmission:

• Typhoid fever is contracted by the ingestion of the bacteria in contaminated food or water.
• Patients with acute illness can contaminate the surrounding water supply through stool, which contains a high concentration of the bacteria.
• About 3-5% of patients become carriers of the bacteria after the acute illness. Some patients suffer a very mild illness that goes unrecognized, and these patients can become long-term carriers of the bacteria.
• The bacteria multiply in the gallbladder, bile ducts, or liver and pass into the bowel.
• The bacteria can survive for weeks in water or dried sewage.
• The chronic carriers may have no symptoms and can be the source of new outbreaks of typhoid fever for many years.

Signs and Symptoms of Typhoid Fever

Classically, the course of untreated typhoid fever is divided into four stages, each lasting approximately one week.

First week:

• In the first week, there is a gradual rise in temperature (step-ladder fashion) accompanied by bradycardia, malaise, headache, generalized body aching, restlessness, and cough.
• Epistaxis (nosebleeds) is observed in about a quarter of cases.
• Abdominal pain may also be present.
• Leukopenia, eosinopenia, and relative lymphocytosis are evident in blood tests.
• The classic Widal test, used to detect antibodies against Salmonella, is negative in the first week, but blood culture reveals the presence of Salmonella typhi.
• The payer patches of the distal end of the ileum are invaded by the bacillus and become inflamed, resulting in various manifestations such as slow pulse rate, severe persistent frontal headache, general malaise, anorexia, nausea, vomiting, intestinal upset (diarrhea and constipation), and depression of bone marrow.

Second week:

• The payer patches form a slough (a layer of dead skin).
• In the second week of the infection, the patient becomes severely ill with high fever, often reaching around 40°C (104°F), and bradycardia.
• Delirium is common, characterized by a state of calmness or, at times, agitation.

• Rose spots, which are pink spots, appear on the lower chest and abdomen in about one-third of patients.
• The abdomen becomes distended and painful, especially in the right lower quadrant.
• Diarrhea may occur, with stool appearing green and having a characteristic smell resembling pea soup. However, constipation can also be frequent.
• The spleen and liver enlarge (hepatosplenomegaly) and become tender.
• The Widal reaction shows strong positivity with anti-O and anti-H antibodies, while blood cultures may still be positive at this stage.
• The tongue is coated with a brownish fur, and sordes indicate severe toxemia.
• Dehydration becomes evident.

Third week:

• In the third week of typhoid fever, several complications may arise:
  • The slough separates, leaving deep ulcers in the intestines.
  • Ulcers may erode blood vessels, leading to hemorrhage, or perforate the ileum, causing leakage of intestinal contents into the peritoneal cavity.
  • The patient becomes extremely ill and toxic.
  • Temperature remains very high and intermittent.
  • Pulse becomes feeble.
  • The patient lapses into a typhoid state, experiencing delirium and confusion.
  • Twitching of limbs may occur due to loss of calcium in the diarrhea state.
  • Carforragic picking may lead to clotting issues and blood-stained clothes.
  • Tough dries and flurried lips are observed due to severe dehydration from profuse diarrhea.
  • Signs of congestive cardiac failure (CCF) due to weakened myocardium may be present.
  • The patient may experience coma every eight hours.
  • Peritonitis, inflammation of the peritoneum, may occur.
• By the end of the third week, the patient becomes emaciated, fever starts to subside, abdominal symptoms become more pronounced, and mental disturbances become prominent.

Fourth week:

• The ulcers begin to heal through granulation.
• At the beginning of the fourth week, the fever begins to decline, and the other symptoms gradually reduce as the patient\’s temperature returns to normal.
• Recovery is slow during this stage, and relapses are common.
• If left untreated, typhoid fever can prove fatal in up to 25% of all cases.

Investigations for Typhoid Fever:

1. Stool Culture: Stool culture involves collecting a sample of the patient\’s stool and incubating it under specific conditions to identify and isolate the causative bacteria, usually Salmonella typhi or Salmonella paratyphi. The presence of these bacteria in the stool confirms the diagnosis of typhoid fever. 

2. Blood Culture:  Blood sample is collected and cultured in a suitable medium to identify and isolate the bacteria causing typhoid fever. A blood culture is an effective method to confirm the diagnosis, especially in the early stages of the disease when stool cultures might be negative.

3. Widal Test: The Widal test is a serological test used to detect antibodies produced by the body in response to the infection by Salmonella typhi. The test measures the presence of specific antibodies, including anti-O and anti-H antibodies, in the patient\’s blood. A positive Widal test suggests a recent or past infection with typhoid fever. However, it is important to note that the Widal test results should be interpreted cautiously, as false-positive results can occur due to cross-reactivity with other infections or previous vaccinations.

Additional Investigations (optional):

1. Polymerase Chain Reaction (PCR) Test: PCR is a molecular diagnostic test that can detect the genetic material (DNA or RNA) of the Salmonella bacteria directly from clinical samples, such as blood or stool. PCR is a highly sensitive and specific method, and it can provide rapid results, aiding in early detection and timely treatment of typhoid fever.

2. Typhoid Serology: Typhoid serology involves analyzing the patient\’s blood for specific antibodies against Salmonella typhi. This test, similar to the Widal test, helps in confirming a recent or past infection, but it may have limitations in terms of sensitivity and specificity.

3. Complete Blood Count (CBC): A CBC is a routine blood test that provides information about the number and types of blood cells. In typhoid fever, the CBC may show leucopenia (low white blood cell count), eosinopenia (low eosinophil count), and relative lymphocytosis (increased lymphocyte percentage). These abnormalities can help in supporting the diagnosis of typhoid fever.

4. Liver Function Tests (LFTs): Liver function tests assess the health of the liver and its ability to function properly. In typhoid fever, liver involvement is common, and LFTs can reveal elevated liver enzymes and other liver-related abnormalities.

5. Urinalysis: Urinalysis may be performed to check for the presence of white blood cells or other indicators of kidney involvement, which can occur in severe cases of typhoid fever.

Complications of Typhoid Fever:

I. Gastrointestinal Complications:
A. Perforation: The ulcerated areas in the intestines can lead to perforation, causing leakage of intestinal contents into the abdominal cavity. This can result in severe abdominal pain and peritonitis.
B. Hemorrhage: The erosion of blood vessels by ulcers can cause gastrointestinal bleeding, leading to blood loss and anemia.
C. Peritonitis: Perforation of the intestine can lead to peritonitis, an inflammation of the peritoneum (the lining of the abdominal cavity), causing severe abdominal pain and tenderness.

II. Gallbladder Complications:
A. Cholecystitis: The infection can spread to the gallbladder, causing inflammation known as cholecystitis, which leads to abdominal pain, fever, and tenderness in the right upper abdomen.

III. Respiratory Complications:
A. Pneumonia: In severe cases, typhoid fever can lead to pneumonia, a lung infection characterized by fever, cough, and difficulty breathing.

IV. Cardiovascular Complications:
A. Heart Failure: Severe and untreated typhoid fever can put a strain on the heart, leading to congestive heart failure, a condition where the heart fails to pump blood effectively, resulting in fluid accumulation in the body.

V. Musculoskeletal Complications:
A. Osteomyelitis: In rare cases, typhoid fever bacteria can spread to the bones, causing osteomyelitis, which is an infection of the bone and bone marrow.

VI. Neurological Complications:
A. Encephalitis: Typhoid fever can lead to encephalitis, which is inflammation of the brain. This can cause symptoms such as headache, confusion, and altered mental state.

B. Meningitis: In some instances, the infection may also spread to the meninges, the protective membranes covering the brain and spinal cord, leading to meningitis. 

C. Mental Confusion: During the advanced stages of the disease, mental confusion and delirium may occur due to the systemic effects of the infection on the central nervous system.

Management of Typhoid Fever

1. Hospital Admission:

• In severe cases of typhoid fever, hospital admission is necessary to provide close monitoring and appropriate medical care.

1. Isolation or Barrier Nursing:

• Patients with typhoid fever should be isolated or barrier nursed to prevent the spread of the infection to others.

1. Investigations:

• Blood for Culture and Sensitivity (C/S) should be performed during the first week to identify the causative bacteria and determine its sensitivity to antibiotics.
• Full Blood Sample (FBS) analysis will reveal low Hemoglobin (Hb) levels, low White Blood Cell (WBC) count, and an increased Erythrocyte Sedimentation Rate (ESR).
• The Widal test can be done around 10/7 days after the onset of symptoms to detect antibodies against typhoid bacilli.
• Blood Smear (B/S) examination should be conducted to rule out malaria.
• Stool analysis and urinalysis are important to assess gastrointestinal and urinary involvement in typhoid fever.

1. Drug Therapy:

• Antibiotic therapy is a cornerstone of typhoid fever management:
  • Ciprofloxacin at a dose of 500-750 mg twice daily for 10/7 (10 days).
  • Azithromycin at a dose of 10 mg/kg daily.
  • Cotrimoxazole at a dose of 960 mg twice daily for 3/7 (3 days) or as per a weight-based calculation for 10/7 (10 days).

1. Long-Term Carriers:

• After signs have passed, stool tests should be conducted to check if Salmonella typhi bacilli are still present. Patients may become potential long-term carriers of the bacteria, requiring a 28-day course of antibiotics to eliminate the bacteria until they are free from it.

1. Fluid and Electrolyte Management:

• Monitor intravenous (IV) fluid administration for rehydration.
• Correct fluid and electrolyte imbalances with Normal Saline (N/S), Dextrose 5% (D5%) solutions, and oral fluids.

1. Nutrition:

• Ensure adequate nutrition and provide a soft, easily digestible diet, unless the patient has abdominal complications or ileus.

1. Antipyretics:

• Administer antipyretics like Paracetamol (PCM) to manage fever.

1. Hygiene and Infection Control:

• Pay close attention to handwashing and limit close contact with individuals during the acute phase of the infection to prevent its spread.
• Encourage proper waste disposal, covering of food, and proper food preparation to reduce contamination risks.
• Encourage early screening and management to prevent the worsening of the disease.

1. Proper Water Treatment and Storage:

• Educate patients on the proper treatment and storage of water to avoid waterborne transmission of the bacteria.

1. Regular Follow-Up and Monitoring:

• Ensure regular follow-up and monitor for complications and clinical relapses.

1. Management of Delirium:

• Encourage the use of Phenobarbital at a dose of 30-60 mg in case of delirium.

Prevention:

• Maintain cleanliness in the premises and ensure proper disposal of rubbish.
• Keep hands clean and maintain trimmed fingernails.
• Wash hands thoroughly with soap and water before eating or handling food and after using the toilet or changing diapers.
• Drinking water should be free from microorganisms; it is preferable to boil water before consumption.
• Avoid high-risk foods, such as raw or semi-cooked food.
• During food preparation, wear clean, washable aprons, and caps.
• Clean and wash food thoroughly, including scrubbing and rinsing fruits in clean water.
• Store perishable food in the refrigerator, covering it properly.
• Cook food thoroughly before consumption.
• Consume food as soon as it is prepared.
• If necessary, refrigerate cooked leftover food and consume it promptly. Reheat it thoroughly before consumption.
• Exclude infected individuals and asymptomatic carriers from handling food and providing care to children.
• Consider immunization, especially for those traveling to high-risk areas, where vaccines are available in oral and injectable forms.

Test MCQ Questions

Question 1:
What is the primary mode of transmission for typhoid fever?
A) Mosquito bites
B) Contaminated food and water
C) Airborne droplets
D) Direct physical contact

Question 2:
Which bacterium is responsible for causing typhoid fever?
A) Escherichia coli
B) Salmonella typhi
C) Streptococcus pneumoniae
D) Staphylococcus aureus

Question 3:
Which of the following complications can occur in severe cases of typhoid fever?
A) Fractures
B) Renal failure
C) Dental caries
D) Cholecystitis

Question 4:
Which diagnostic test is used to identify the presence of Salmonella typhi in the blood?
A) Blood smear examination
B) Stool culture
C) Urinalysis
D) Blood culture

Question 5:
What is the recommended antibiotic therapy for treating typhoid fever?
A) Penicillin
B) Amoxicillin
C) Ciprofloxacin
D) Erythromycin

Question 6:
Why is hospital admission often recommended in severe cases of typhoid fever?
A) To provide psychological support to the patient
B) To administer vaccines for long-term immunity
C) To ensure isolation and prevent disease transmission
D) To allow close monitoring and provide appropriate medical care

Question 7:
What is the primary preventive measure to avoid typhoid fever transmission in the community?
A) Proper handwashing with soap and water
B) Mosquito net usage
C) Wearing masks in public places
D) Vaccination against other bacterial infections

Question 8:
Which gastrointestinal complication can occur due to typhoid fever?
A) Pneumonia
B) Peritonitis
C) Otitis media
D) Conjunctivitis

Question 9:
Which of the following is NOT a recommended step to prevent typhoid fever?
A) Drinking untreated water from natural sources
B) Cooking food thoroughly
C) Washing hands properly before eating
D) Proper waste disposal

Question 10:
Who should be excluded from handling food and providing care to children during a typhoid fever outbreak?
A) Asymptomatic carriers and infected individuals
B) Healthcare professionals only
C) Pregnant women
D) Children under 5 years of age

Answers:

1. B – Contaminated food and water
2. B – Salmonella typhi
3. D – Cholecystitis
4. D – Blood culture
5. C – Ciprofloxacin
6. D – To allow close monitoring and provide appropriate medical care
7. A – Proper handwashing with soap and water
8. B – Peritonitis
9. A – Drinking untreated water from natural sources
10. A – Asymptomatic carriers and infected individuals

Explanation:

1. Typhoid fever is primarily spread through contaminated food and water, making option B the correct answer.
2. Salmonella typhi is the bacterium responsible for causing typhoid fever, making option B the correct answer.
3. Cholecystitis is one of the gastrointestinal complications associated with typhoid fever, making option D the correct answer.
4. Blood culture is used to identify the presence of Salmonella typhi in the blood, making option D the correct answer.
5. Ciprofloxacin is one of the recommended antibiotics for treating typhoid fever, making option C the correct answer.
6. Hospital admission is recommended in severe cases of typhoid fever for close monitoring and appropriate medical care, making option D the correct answer.
7. Proper handwashing with soap and water is the primary preventive measure to avoid typhoid fever transmission, making option A the correct answer.
8. Peritonitis is a gastrointestinal complication that can occur due to typhoid fever, making option B the correct answer.
9. Drinking untreated water from natural sources is NOT a recommended step to prevent typhoid fever, making option A the correct answer.
10. Asymptomatic carriers and infected individuals should be excluded from handling food and providing care to children during a typhoid fever outbreak, making option A the correct answer.