What is Coxsackie B3?

The Coxsackie B3 virus is one of the worldwide spread viruses that belong to the picornavirus family . They are the cause of diseases such as aseptic meningitis, type 1 diabetes and pancreatitis. The Coxsackie B3 viruses are the main cause of myocarditis in people under 40 years of age. In not exactly rare cases, these can lead to sudden cardiac death.

What is the morphology of Coxsackie B3 viruses?

The viruses are approx. 20 -40 mm in size and consist of a single-stranded RNA. The genome is surrounded by a so-called cubic capsid. Coxsackie B3 viruses do not have a viral envelope. They are very survivable in acidic environments and are only sensitive to disinfectants that contain chlorine. Standard disinfectants with alcohol or detergents have no effect on the viruses. They can easily survive for days at room temperature.

How are Coxsackie B3 viruses transmitted?

The Coxsackie B3 viruses are transmitted from person to person by droplet infection or also by contact with faeces. The viruses are isolated from the body mainly through faeces.

What are the symptoms of Coxsackie B3 viruses?

An infection with the Coxsackie B3 virus usually runs its course without any symptoms or only a few and minor symptoms. The most common symptom is fever. Since Coxsackie B3 viruses are transmitted predominantly in the summer months and early autumn, the first symptoms are mistaken for signs of illness of a summer flu . However, after the corresponding incubation period of about 3-6 days, those affected develop high fever, headache as well as feeling unwell. It is not uncommon for infection with Coxsackie B3 viruses to be accompanied by symptoms such as rhinitis, pharyngitis, nausea and vomiting. Mild gastroenteritis may also occur. The symptoms usually last about 4 days, but no longer than one week.

Coxsackie B3 viruses are mainly responsible for the following illnesses:

• aseptic meningitis,
• Encephalitis,
• Paralysis,
• Exanthema
• Generalised disease in the newborn,
• Hand-foot-and-mouth disease,
• Herpangina,
• Pericarditis, myocarditis,
• Pneumonia,
• Pleurodynia.

Myocarditis

The most common disease caused by Coxsackie B3 viruses is myocarditis. The disease occurs most frequently in newborns and adolescents and young adults. More than 60 % of patients are male. Those affected often present with upper respiratory symptoms such as dyspnoea, cardiac arrhythmias, fever and chest pain. In some cases, heart failure may develop. An ECG will show ST-segment elevations or other changes. Auscultation reveals pericardial rubbing in about half of the cases. Blood tests often show elevated cardiac enzymes. For newborns, infection with Coxsackie B3 viruses often develops into a disease with severe course. In older children or adults, usually heals completely. In about 10 % of all those affected, dilated cardiomyopathy develops and persists over the long term. More rarely , chronic constructive pericarditis develops.

How are Coxsackie B3 viruses diagnosed?

Depending on how the clinical picture presents itself, the appropriate diagnostic measures are taken. In the acute phase of the infection , a diagnosis can be made with the help of molecular biological evidence in cerebrospinal fluid, stool or throat lavage water. Serological tests are not reliable for making the diagnosis, but they can be helpful to check the rise of the titre in the blood .

How are Coxsackie B3 viruses treated?

In most patients, an infection with the Coxsackie B3 viruses runs its course completely without symptoms. Nevertheless, symptomatic treatment with antipyretics and analgesics is often carried out in order to enable the patient to remain as symptom-free as possible during the course of the disease. If the course of the disease is severe, gamma globulin preparations are often used. If secondary infections with bacteria develop, antibiotics become the treatment of choice. So far antiviral drugs are still in the trial and testing phase. However, the drug interferon, which is used especially for cardiomyopathies, has proven to be very effective.How long is the Coxsackie B3 virus contagious?

Those affected are highly contagious, especially in the first few weeks after infection. But even after the symptoms have subsided, the virus is still excreted in the stool for another few weeks. That is why those affected are considered contagious for a very long time. Even after the complaints and symptoms have subsided, the important hygiene rules must continue to be observed so that transmission of the virus can be avoided.

What is the prognosis for the Coxsackie B3 virus?

For the most part the disease is mild and is only treated symptomatically. Should the disease develop severely, gamma-blobulin preparations can be used. For the most part, those affected recover well from the infection. Nevertheless, complications such as meningoencephalitis, meningitis, myocarditis or pericarditis must be expected .

How can the Coxsackie B3 virus be prevented?

To prevent infection, the following measures should be taken:

• In particular efficient hospital hygiene on the neonatal ward is to be observed, this means that only antivirally effective agents are used for disinfection, nappy hygiene and gown change are to be followed and observed according to hygiene regulations. In some cases, it is necessary for infected newborns to be isolated.
• Exposure prophylaxis: adequate hand hygiene, wash hands thoroughly and disinfect afterwards.
• Post-exposure prophylaxis, which means that if the risk is particularly high, gamma globulins must be given within 3 days.

 
Isolated cases with the coxsackie B3 virus are not reportable, but if outbreaks increase, the responsible laboratory director must issue a report to the respective health authority. Patients after surviving an infection with the virus have lifelong immunity to it. A vaccination against the Coxsackie B3 viruses does not yet exist today.