Infections of the central nervous system (CNS) are a serious and potentially life-threatening condition. They can occur when bacteria or viruses enter the brain or spinal cord, causing inflammation and damage to the tissue. Symptoms of a CNS infection can include headache, fever, stiffness in the neck or back, seizures, confusion, and loss of consciousness. Early diagnosis and treatment is essential to preventing serious complications from a CNS infection.

Coronavirus HCoV-0C43

November 2016. Researchers have demonstrated a human virus (HCoV-0C43) capable of penetrating the central nervous system (brain and spinal cord). This virus would be about 20% of colds and respiratory ailments in certain vulnerable people, and could be the cause of certain neurological diseases such as multiple sclerosis encephalitis, Alzheimer’s disease or Parkinson’s disease. It caused the Severe Acute Respiratory Syndrome (SARS) in Canada.

This hypothesis comes from the fact that the researchers identified this strain in the brain of a young patient who died of encephalitis, who had a significant immune deficiency. Experiments in mice have shown that this virus can cause a form of multiple sclerosis.

In 2014, researchers hypothesized that infections could affect central nervous system by decreasing cognitive performance such as memory, reasoning and abstract thoughts.

These results of this study presented at a conference confirm the deleterious effect that bacteria and viruses (Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus and herpes virus) could have on the brain.

To reach this conclusion, American researchers (University of Miami) tested and took blood samples from 588 individuals. Half of them performed the same tests again 5 years later.

The study does not explain why these infections worsen cognitive performance. ‘It may be that the immune system’s response to infections or the infections themselves lead to brain damage,’ says Dr Wright, lead author of the study.

“However, it is impossible to predict that an antiviral or antibacterial treatment could prevent this worsening years later,” he concludes. Source: American Stroke Association’s International Stroke Conference 2014.

Hepatitis C, an infection that affects central nervous disorder

Hepatitis C could increase the risk of developing central nervous disorder such as Parkinson’s disease by 30%.

No association has been reported between hepatitis B and Parkinson’s.

It was already known that people who are chronic carriers of the hepatitis virus have an increased risk of liver disease.

The researchers analyzed the medical data of nearly 50,000 patients with hepatitis B and/or C and followed for 12 years.

Source: Tsai HH et al. Hepatitis C virus infection as a risk factor for Parkinson disease. Neurology, December 2015.

Herpes

Herpes is also in the sights of researchers who study the trail of viruses and bacteria to understand the development of Alzheimer’s disease.

Despite several hundred clinical trials, Alzheimer’s remains invincible. It is in particular this finding that prompted a group of 31 researchers from around the world to sign a column in the « Journal of Alzheimer’s Disease » to call for urgent investigation of a track that they consider so far « neglected ». Their accusing gaze is pointing straight at a probable link between Alzheimer’s and viruses and bacteria.

One virus in particular caught their attention: that of herpes. According to them, this virus, along with chlamydia bacteria and spirochetes, are the main culprits in the development of the degenerative disease.