Does Typhoid fever affect the brain?

Typhoid is a contagious disease commonly called enteric fever. It is spread by consumption of contaminated water and food. Common symptoms of high grade fever, loss of appetite, loose motion or constipation, abdominal pain. Sometimes in initial stages at present like flu. In some patients it may present with central nervous system symptoms. Here we will discuss, ‘Does Typhoid affect brain?’.

Typhoid fever affecting the brain is a rare complication of a Typhoid fever apart from its common symptoms. Sometimes untreated patients or if the treatment is started late or in cases of treatment failure the brain can get affected by typhoid fever. Another cause of involvement of the brain in typhoid fever is decreased immunity of the patients maybe because of some other illnesses like AIDS.

Typhoid either affects the brain directly or indirectly.

Indirect effects of typhoid fever on the brain

The health of the brain depends upon the health of your body. If your body is affected by some disease your brain health may get affected.

Some typhoid complications in the brain are because of complications in the body. In these cases the Typhoid causing bacteria salmonella typhi doesn’t invade the brain. The brain is affected by the disease process at any other place in the body. So these are direct effects of the Typhoid fever on the brain.

So indirect effects of typhoid fever on the brain are as follows:

Febrile convulsion

In cases of typhoid fever there is a high grade fever. Children of age 6 months to 5 years those who have tendency to get febrile convulsion show symptoms of seizure when fever. Is fever can be because of any cause like upper respiratory tract infection or may other illnesses like typhoid.

Typical febrile convulsion occurs within the 24 hours of the start of fever. Fabral convulsions more commonly occur when the fever is rising or decreasing. Typically they may last up to five minutes. In Indians cases there is loss of consciousness, uprolling of eyes, tightness with movement of the limbs and frothing of the mouth.

The child begins consciousness quickly after the episode with no residual loss of power.

Like other diseases this phenomenon can occur because rising body temperature is not because of salmonella directly in the brain.

Salmonella typhi directly involved in the brain for similar symptoms. But febrile convulsion is different as the patient regions consciousness quickly after the convulsion.

Electrolyte imbalance

In typhoid fever, electrolyte imbalance can occur because of loose motions and vomiting. Also electrolyte imbalance can occur because of reduced food and water intake in serious illnesses like typhoid. Electrolyte imbalance can occur in serious typhoid because of perforation of the intestine.

Changes in body level of sodium and potassium can cause convulsions, altered consciousness and loss of power in limbs.

As here in which cases the bacterium is not directly invading the brain these are complications because of the systemic illness. If the electrolyte imbalance is taken care of, the brain symptoms may recover quickly. If not treated adequately these brain symptoms may cause death in typhoid fever.

Acid base imbalance

To maintain the homeostasis in your body your pH of blood should be at 7.4. if your pH of blood is less than 7.35 it is called acidosis. If your pH of blood is more than 7.4 is called alkalosis.

This acid base imbalance can occur in typhoid fever as a complication of systemic illness. In acidosis or alkalosis there can be symptoms of brain involvement like confusion, fatigue and weakness. Other symptoms like respiratory failure and rapid breathing may follow. There can be altered consciousness.

Liver complications

If the liver is affected by Typhoid fever it may lead to hepatitis. In this case there is an altered function of the liver detected by jaundice that is an increased level of bilirubin and altered for increased levels of liver enzymes.

In severe cases of hepatitis there can be symptoms of altered sleep wake cycle, confusion, irritability. It may mimic brain illness in typhoid fever.

In severe hepatic failure there may be altered levels of serum ammonia and blood sugar levels. Along with that liver failure can also cause electrolyte imbalance and acid base imbalance. All these complications may cause brain symptoms.

Kidney complications

In typhoid fever kidneys may get affected because of dehydration and also direct effect of salmonella toxins on kidneys.

Involvement of the kidneys may cause increased urea level and electrolyte imbalance and acid base imbalance. These all complications can cause brain symptoms in typhoid fever.

Other symptoms

General systemic involvement because of typhoid fever may cause restlessness, feeling of fatigue and altered sleep cycle. These symptoms are common when fever is at its peak. In serious infections they may occur even when there is no fever. 


Sepsis is the phenomenon occurring because of the toxins of the bacterium salmonella typhi. This is the most severe complication of Typhoid fever. Sepsis can present as decreased blood pressure, increased heart rate or decreased heart rate.

These cases may also show symptoms of involvement of the brain like confusion, weakness fatigue and convulsions.


Disseminated intravascular coagulation also known as DIC is a complication of severe infection. It can occur in the last stages of Typhoid fever. 

In which cases there is increased or decrease clot formation all over the body. Disseminated intravascular coagulation can present as multiple organ failure with involvement of the brain. In this cases along with septic shock there are symptoms of convulsions and loss of power in limbs with altered consciousness.

So above all the ways Typhoid fever can affect your brain without even invading your brain. Are all indirect effects of typhoid fever on your brain. These effects can range from mild cases with no residual after effects to severe symptoms leading to death.

Direct effects of typhoid fever on brain

Typhoid fever can directly affect your brain by invasion of the salmonella typhi bacteria into your brain. These cases mein occur because of reduced immunity of the subject for delayed start or not starting the treatment aur because of treatment failure.

Following are the direct effects of the Typhoid fever on your brain.

Brain abscess

Abscess are dead tissues in an organ. These are cavities containing pus. If the salmonella typhi bacteria gets a chance to invade your brain they may create an abscess in the brain. Salmonella can invade your brain through your blood. It may be because of sepsis or bacteraemia.

Brain abscess can present as convulsion, loss of power and loss of consciousness. Hit mein mid surgical treatment with medical care with effective antibiotics.


Meninges are protective layers on the brain. Your brain is suspended in cerebrospinal fluid in the meninges. Inflammation of these meninges is called meningitis.

Meningitis can occur as salmonella typhi can infect your maninges. These cases show symptoms like stiffness of the neck, convulsions, loss of consciousness and loss of power in limbs.

Some patients with meningitis may experience loss of hearing capacity and loss of vision or photophobia.

Meningitis can cause increased intracranial pressure leading to death if not treated.

Cerebral infarction

Infection can occur because of loss of blood supply to a part of an organ. Cerebral infarct is an infection occurring in the brain because of interference of the blood supply to the part of the brain. It can occur as a complication of meningitis sepsis or DIC. Salmonella typhi bacteria invading the brain may directly cause cerebral infarction. 

These cases mainly show symptoms of brain involvement like conversion and loss of power.

Neuropsychiatric complications of the Typhoid fever

Neuropsychiatric complications of typhoid fever can occur as indirect or direct complication of the Typhoid on the brain. Neuropsychiatric complications can present like mental illness in cases of typhoid fever.

Addition to that, some antibiotics used for treatment of the Typhoid fever may induce mental illness and neuropsychiatric complications in cases of typhoid fever.

So typhoid if left untreated or there is treatment failure or if there is decreased immunity in the subject, it can affect multiple organs of the body. Typhoid ulcers can affect your brain. About all details of the Typhoid affecting the brain and its symptoms.

Investigations needed in typhoid affecting the brain

As typhoid affecting the brain is a serious complication and needs immediate attention and treatment, these cases should be immediately hospitalized preferably in the ICU.

Multiple investigations and treatment is required to save the life of the patient. These investigations detect the complications and guide the treatment.

Following are the investigations needed in these cases:

  • Neuroimaging: CT scan or MRI of the brain may be needed to detect the regions in the brain. CT scan is effective in detecting the intracranial hemorrhage and MRI is effective in detecting the brain infarcts and meningitis. CT scan and MRI can also detect brain abscess.
  • Serum electrolytes and kidney function test: as we have discussed previously that Typhoid fever can cause electrolyte imbalance and kidney failure, these tests help to detect the electrolyte imbalance and increased levels of urea and creatinine.
  • Liver function test: Typhoid fever can cause hepatitis and hepatic failure liver function tests are necessary to detect jaundice and altered liver enzymes. These tests also involve detection of the clotting mechanism. Clotting factors are all manufactured in the liver. 
  • Blood culture: It is the standard test to diagnose Typhoid fever. Salmonella typhi can be detected in blood cultures. Blood culture also suggests the resistance pattern in the bacteria. Once we identify the salmonella typhi in the blood culture and know the resistance pattern to the antibiotic we can effectively give antibiotics.
  • CSF examination: CSF examination may be needed to detect the bacteria in the brain. Cerebrospinal fluid mainly shows increased level of proteins and decreased levels of sugar in the CSF. Depending upon the stage of disease CSF mainly shows increased levels of neutrophil or lymphocytes levels. It can also detect bacteria if the CSF culture is done along with an idea of the resistance to antibiotics.

Treatment of typhoid affecting the brain

Involvement of the brain is serious complication of the Typhoid fever and its to be managed under close observation in ICU setup.

Following are the general guidelines with which the brain complications of the Typhoid are managed.

  • Patient is to be admitted in an ICU setup and kept under close observation.
  • Supportive treatment is the key along with antibiotics. Supportive treatment is life saving for patients till the antibiotics play their role and show their effect.
  • Patients should be adequately hydrated with IV fluids.
  • Electrolyte imbalance and acid-base balance should be taken care of.
  • If patients have other symptoms like convulsions anticonvulsant medicine should be started.
  • Cerebral infarct may additionally need treatment with anticoagulants.
  • Antibiotics are only the definite and effective treatment for the treatment of the Typhoid fever of any severity.
  • The broad spectrum antibiotic like ceftriaxone may be started intravenously.
  • The antibiotic therapy should later be modified depending upon the blood culture suggesting the resistance pattern.
  • Anticonvulsant may be required for the long term depending upon the brain pathology.
  • Antibiotics should be given for adequate duration initially by IV route followed by oral route.
  • If there is other organ involvement like liver, kidney or intestinal perforation it should be taken care of.

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