Tetanus is caused by the bacterium Clostridium tetani. This bacterium normally occurs in the intestines of horses and other herbivores without this hindering these animals to any extent. The bacterium propagates through the formation of spores that can spread through the feces of these animals in the environment. It is therefore very widespread, e.g. in the earth, feces, on objects and plants in the environment, in natural and household waste, etc. It can survive for years in this natural environment, but is killed or weakened by direct sunlight. It also can be killed by heat and disinfectants.
The bacterium can only reproduce in an environment where there is little or no oxygen. In humans, these ideal conditions occur in deep wounds or in wounds with dying and dead tissue.
Clostridium tetani itself is not dangerous to humans, but it is a toxin that it secretes. This powerful toxin blocks the action of certain nerves and thus causes uncontrolled cramps of the muscles. Even a tiny amount is deadly.
According to the WHO, in 2015, about 34 000 newborns died from neonatal tetanus,.
Symptoms of Tetanus
The incubation period is between 2 days and a few weeks. The sooner the symptoms begin, the worse the prognosis is. Often it starts with stiffness of a jaw muscle (hence the name jawclamp or trismus) which can worsen into painful muscle spasms. More and more muscles become affected as the situation worsens. Swallowing and breathing problems make the condition very serious. The muscle spasms can occur spontaneously but can also be provoked by triggers such as light and sound.
The toxin also stimulates the sympathetic nervous system and releases larger amounts of substances such as adrenaline into the blood. As a result, other symptoms such as high blood pressure, fever, sweating and cardiac arrhythmias, urinary incontinence may occur. Most of the time one remains mentally alert.
The diagnosis is usually made clinically by an analysis of the symptoms and the history. The tetanus bacterium can be detected in the wound but since tetanus is a state of high-penetration, the therapy is usually started immediately on suspicion of tetanus infection.
Treatment against Tetanus
Depending on the severity of the disease, sedation and muscle relaxing medication is given. In severe cases, ventilation must be carried out.
Wound care should be done to remove the tetanus bacterium. Although it is unclear whether antibiotics have an effect, they are still given to kill the tetanus bacteria and thus stop the production of the toxin.
Antitoxin is also given (human antibodies against the toxin).
Provided good treatment, most patients survive. But usually the disease lasts about 4-6 weeks of which on average about 3 weeks with ventilation. So it’s definitely a serious disease.
Is vaccination useful?
Some people doubt the usefulness of vaccinations in the case of tetanus and believe from a mistaken point of view that ‘nature knows best’, that the body itself must build up resistance to diseases and infections.
However, the body does not do this against in the case of tetanus. The lethal dose of the poison is so small that it is not large enough to trigger a sufficiently large immune response. So, even if a person survives an infection with the tetanus bacteria, he or she does not become immune to the toxin.
In the developing world, half a million people are thought to die from tetanus every year. Newborns are at high risk of infection. In western countries, where people have been vaccinated against tetanus fairly widely for several decades, the number of victims is much lower. According to figures, including from the United States and the Scandinavian countries, more than half of the problems caused by tetanus occur in people over the age of 60. Research shows that more than half of these people were never vaccinated against tetanus.
A similar evolution is also observed in other countries where tetanus is generally vaccinated. Most of the victims are almost invariably among the older population who have not been vaccinated or who received an incomplete vaccination.
This immense difference clearly demonstrates the importance of vaccination.
Should you get vaccinated?
Even if you are an adult and have not yet been vaccinated against tetanus, it is important to get vaccinated. To be fully vaccinated against tetanus as an adult, you need 3 vaccinations. After that, you are vaccinated enough and only need to get a vaccine every 10 to 20 years to be sufficiently protected against tetanus. This vaccination is done with a combination vaccine against tetanus, diphtheria and whooping cough.
Depending on the age, different combination vaccines are used, each time with at least one component against diphtheria and whooping cough. Separate vaccines against tetanus are no longer available.
The vaccination should be administered deep into a muscle so that there is sufficient contact with the blood to provoke a immune response. When the vaccination occurs in fatty tissue, it probably offers less, and in the worst case, no protection.
Children under the age of 12 are often poked in the glute muscle, especially to ensure they do not see anything. Moreover, the jab there is usually also less painful. The buttock is however less suitable for vaccination against tetanus because that the subcutaneous fat layer there is quite thick. This increases the chances that the jab will not get into a muscle, but in fat.
Older children and adults are therefore always prodded into the thick muscle in the upper arm on the shoulder.
Babies are never vaccinated against tetanus because they have too little muscle tissue.
Undesirable effect of tetanus vaccination
The vaccine is very safe, offers high protection and causes very few undesirable effects. Many people experience some mild local symptoms, such as a red swelling that can sometimes be painful. These complaints usually disappear spontaneously.
In some cases, a hardening or lump may be felt at the site of the injection for several weeks. Usually it also disappears without any care.
Very exceptionally, in less than 1 in 100,000 vaccinations, an abscess develops at the site of the vaccination.
People who are vaccinated against tetanus too often (e.g. every year, which would happen in some sports), are at risk of hyperimmunization syndrome. This is expressed in a clearly visible local reaction at the site of the injection with a red swelling, pain and a feeling of stiffness. In addition, there are general symptoms such as fever, flu-like sensation and muscle pain.
It is a misconception that only dirty wounds pose a risk of tetanus. Stab wounds, e.g. of a needle, nail, splinter, a thin twig, a thorn, etc. can also cause tetanus. Often they are also small wounds, but they can also offer just the ideal conditions, namely relatively deep wounds without oxygen.
Also chronic wounds, e.g. leg ulcers or bedsores, can become contaminated with tetanus bacteria. There seems to be a slightly greater risk for people with diabetes.
Because the risk wounds show such an extensive variety, it is very difficult to determine in which case there is or is no risk to tetanus. Therefore, it is all the more important that everyone has at least a full basic vaccination. This offers a high degree of protection under all circumstances.
In case of doubt about the vaccination status and in people with impaired immune system, e.g. after a transplant or anti-cancer treatment, antibodies (immunoglobulin) against tetanus should be administered directly.
In general event of doubt about the vaccination status, basic vaccination is also immediately initiated.
Mandell is currently working towards a medical degree from the University of Central Florida. His main passions include kayaking, playing soccer and tasting good food. He covers mostly science, health and environmental stories for the Scientific Origin.