Typhoid Fever

Introduction

• Typhoid means “like typhus” which means smoke in Greek.
• The smoke refers to the mental clouding that characterizes advanced cases of both typhoid and paratyphoid fevers.
• Vigorous public health measures alone have controlled the disease before the introduction of antibiotics.
• Typhoid is distributed throughout the world and is transmitted by the faeco-oral route. The source in most cases is an asymptomatic or recently symptomatic individual who carries the organism. Salmonella typhi thrives in milk products and cold meat.
• Immune Response: After an attack of typhoid fever, there is a cell-mediated response lasting for 16 weeks. There is a specific humoral immune response lasting up to 48 weeks. Circulating Anti “O” and “H” agglutinins persist up to 2 years. The serum antibody titers observed in typhoid have no correlation with the clinical outcome or relapse rates. But there is a strong association between persistently elevated titers of antibody and chronic carriage.

Clinical Presentation

• Fever: Step ladder pattern is not usually observed nowadays. The fever rarely shows an abrupt onset and rigors are uncommon. When fully developed, fever may go up to 39o to 40oC which shows strikingly little diurnal variation. This pattern may vary in complicated typhoid.
• Headache is very common, can be the first symptom in many patients
• Nonspecific symptoms: Malaise, lassitude, myalgia, arthralgia, anorexia
• Bowel symptoms:

a. Constipation is a frequently early symptom

b. Loose motion in majority of patients, at some time during the course of the disease

• Acute gastroenteritis resembling zoonotic salmonellosis, can be seen in some patients
• AIDS patients present with fulminant diarrhoea and colitis
• Pea soup stools are not uncommon; bloody diarrhoea is rare
• Nausea and vomiting are relatively infrequent, but can be seen in severe cases with abdominal distension
• Cough and sore throat can occur. Dry cough is very common

In the late stage:

• Weight loss
• Mental changes
• Intestinal haemorrhage
• Perforation peritonitis
• Refractory hypotension

Physical Examination

• Vital signs:
• Pulse: Tachycardia is commoner than relative bradycardia
• BP: To be recorded regularly to detect hypotension
• Temp: Elevated body temperature
• Coated tongue with clear periphery is commonly seen
• Oral herpetic lesion is rare (unlike in malaria and pneumonia)
• Reticular rose spots on the anterior abdominal wall after end of 1st week. It blanches on pressure and can extend on to the trunk and arms (rarely made out in dark skinned individuals). Purpuric macules may also occur
• Respiratory system: Scattered rhonchi over the chest may be heard in some patients
• Abdomen: Typhoid rash, abdominal distension, right iliac fossa tenderness, urinary retention leading to distended bladder, hepatosplenomegaly. Be careful not to miss the minor degree of splenomegaly which is soft
• In third week of illness: Typhoid facies (thin flushed face with bright eyes and dull heavy staring, apathetic expression, tremor of hands, and tongue.) If the condition deteriorates further,

The following can occur:

• Muttering delirium
• Twitchings of the fingers and wrists (subsultus tendinum)
• Agitated plucking at the bed clothes (carphology)
• Staring unarousable stupor (coma vigil).

Diagnosis

Most cases can be diagnosed on clinical features alone in an endemic area. But isolation of the organism is required for diagnosis in difficult cases and for epidemiological purposes. Isolation from blood is possible in the first week only.

1. The yield of positive blood culture can reach 90% (blood to broth 1:10) in the first week, 75%, in the second week, 60%, in the third week and 25% till the fever subsides.
2. Bone marrow culture by needle aspiration. This technique has the advantage of getting a positive culture in second or third week also even after the starting of the antibiotic therapy for a few days.
3. Urine and faeces cultures will only exceptionally provide a positive culture.
4. Isolation of organisms from the faeces increases during the course of the illness.
5. Rose spot aspirate and culture can yield positive results in 70% of patients.
6. Duodenal string capsule to collect intestinal fluid for culture of Salmonella in bile is useful in children and in chronic carriers

Treatment

For some years, most of the organisms were chloramphenicol resistant and there are even multidrug-resistant strains. Because of decreased use of chloramphenicol for the last many years, the present isolates are often sensitive.

• If organisms are still sensitive to chloramphenicol: Chloramphenicol 50-75 mg/kg PO/IV in 4 divided doses × 14 days
• If organism is resistant to chloramphenicol: — Ciprofloxacin 0.5 to 0.75 gm PO BD or 200 mg IV BD × 10-14 days — Ofloxacin 200 mg PO/IV BD × 10 days — Pefloxacin 400 mg PO BD × 14 days
• Furazolidone 7.5 mg/kg PO QID × 14 days
• Ceftriaxone 1 gm IV BID for 7 days, if there is history of poor response to other drugs or contraindications for their use. Nowadays, an increasing number of Salmonella including Salmonella typhi are resistant to ciprofloxacin while sensitivity to chloramphenicol is slowly increasing.