Protothecosis is an infectious disease that affects cattle and dogs in addition to humans. The trigger of protothecosis is found in Prototheca green algae. The most common are Prototheca zopfii and Prototheca wickerhamii. In human diseases, protothecosis is most commonly based on Prototheca wickerhamii green algae.
What is protothecosis?
A first description of protothecosis was given in 1964. Basically, protothecosis is a disease that occurs relatively rarely in humans. In addition, protothecosis is generally not transmissible among people. Instead, most individuals become infected by protothecae of external origin. Occasionally, protothecae are also found in people who do not have the disease. In many people, protothecae are found primarily in the airways and gastrointestinal tract. In more than 50 percent of clinically diagnosed diseases, the patients have a weakness of the body’s own defense system. This circumstance seems to promote the occurrence of protothecosis. In the context of protothecosis, the weakened immune system often results from blood cancer, the use of corticosteroids, and organ transplantation. Regular alcohol abuse as well as diabetes mellitus also favor the infection with protothecosis. In addition, many patients with protothecosis take immunosuppressants at the same time and have already passed the third decade of life. It is also possible for protothecosis to occur in infants and patients in childhood. In addition, certain geographic concentrations of protothecosis exist. For example, protothecosis is particularly common in rural areas of Taiwan as well as the southwestern United States. Individuals who work in rice paddies or fields or who regularly come into contact with seafood are at special risk for contracting protothecosis.
Causes
The exact pathogenesis of protothecosis has not been well understood. The virulence of protothecae is generally comparatively low, so infectious processes are usually confined to a specific area. Patients often become infected by skin or respiratory contact with protothecae. In particular, injuries on the skin represent an easy entry point for protothecae. Severe manifestations of protothecosis usually present only when patients suffer from a weakened endogenous defense system.
Symptoms, complaints, and signs
Doctors distinguish in three different symptom forms of protothecosis. Thus, on the one hand, the disease manifests itself in bursitis olecrani. This involves inflammation of the bursa in the elbow area, as well as other infections. On the other hand, cutaneous protothecosis with changes and damage to the skin is possible. Finally, protothecosis also occurs in the form of infections of the urinary tract and lungs, colpitis, as well as inflammation of the meninges. The most common is cutaneous protothecosis, which is manifested, for example, in lesions of the skin or mucous membranes. The symptoms develop gradually and over a long period of time. Spontaneous healing of this form of protothecosis is comparatively rare. Typical for cutaneous protothecosis are ulcers as well as pus and crust formation on the skin. Sometimes synovitis develops as a result of this form of protothecosis. The incubation period of protothecosis is usually a few weeks. The damage to the skin is often limited to one area. Spread to other areas of the body usually occurs only in patients with a weakened immune system. The face as well as the limbs are particularly affected.
Diagnosis and course of the disease
The diagnosis of protothecosis usually occurs relatively late, because physicians rarely consider the disease in the differential diagnosis. Sometimes the suspicion of the presence of protothecosis is not substantiated until treatment attempts against other germs fail over a longer period of time. During the anamnesis, the treating physician will discuss the symptoms of protothecosis and ask about possible contact with protothecae. Histological examinations of tissue samples play an important role in the diagnosis of protothecosis. The physician takes the samples, for example, from skin areas affected by protothecosis.The use of wound secretions is also an option. At the same time, the physician usually prepares a microbiological culture to identify the pathogens causing protothecosis. Blood tests, on the other hand, contribute only marginally to a diagnosis of protothecosis.
Complications
As a rule, complications of protothecosis occur only when the disease is not treated. In this case, the affected person suffers from the symptoms of the infection, and this infection can also spread to other parts of the body. The kidneys, urinary tract or even the lungs can also be affected by the disease. Furthermore, protothecosis also causes inflammation of the hind skin. If the disease is not treated, the patient usually dies. Self-healing does not occur in most cases. The diagnosis of the disease is usually relatively late, because the disease has a long incubation period. Furthermore, the infection leads to a generally weakened immune system, making it easier for patients to contract other diseases. The treatment of the disease is carried out with the help of medication or by means of a surgical intervention. In most cases, the course of the disease is positive. Complications usually occur only when protothecosis is not treated. This may also result in a reduced life expectancy of the patient.
When should you see a doctor?
Protothecosis is a serious condition and should be treated promptly by a physician. When symptoms such as the typical skin lesions, systemic infections all over the body, or inflammatory reactions such as lung or meningitis occur, it is best to involve the primary care physician. People who already have protothecosis or suffer from previous diseases of the immune system belong to the risk groups. They should consult the doctor if signs of pneumonia or meningitis appear or if the overall well-being decreases rapidly. Since the disease is often diagnosed too late, treatment may need to begin immediately after diagnosis. Protothecosis is treated by the family doctor or an internist. Drug treatment using antibiotics and antifungals must be monitored by a physician. The physician must be informed about side effects and interactions so that the medication can be adjusted. In addition, a nutritionist should be involved in the treatment. The professional can suggest a supportive diet, thereby contributing to a speedy recovery.
Treatment and therapy
To date, there is no standardized treatment for protothecosis. There are also currently few statistical results on the success of possible therapeutic approaches. Mostly, physicians use a combination of a medicinal as well as a surgical treatment of protothecosis. In principle, a spontaneous healing of protothecosis occurs in the rarest cases. With regard to cutaneous protothecosis, removal of the diseased skin areas in the course of surgical interventions has proven to be successful. At the same time, patients receive local amphotericin B as well as azoles. Continuous monitoring of the therapeutic success is necessary until the protothecosis is cured. Precise statements about the prognosis of protothecosis are not possible.
Prevention
Prevention measures regarding protothecosis are not known. The developmental background of protothecosis is insufficiently understood. The known risk groups, such as rice farmers or ranchers in certain regions of the world, take special care to avoid contact with protothecae.
Aftercare
Because protothecosis can rarely be completely treated, therapy for protothecosis must always be followed by intensive aftercare. This should consist of regular blood tests for protothecosis by the primary care physician and/or treating specialist. In addition, the inflammation values in the blood should be determined in order to detect a renewed inflammation at an early stage. If peritonitis or meningitis have occurred as a result of protothecosis, additional follow-up examinations are necessary. The peritoneum should be examined regularly by imaging techniques (MRI, CT, X-ray) for new foci of inflammation. Regular lumbar punctures with cerebrospinal fluid sampling, as well as imaging procedures (MRI, CT) if necessary, should be used for early detection of a recurrence of meningitis.In addition, especially if the skin was affected by protothecosis, intensive skin hygiene should be observed. For this purpose, the entire skin should be showered daily with disinfecting soap. In addition, hands should be disinfected regularly. Hand disinfection is particularly necessary after visiting public toilets in order to avoid infection with other pathogens of chronic inflammatory skin diseases but also the spread of protothecae. Occurring skin lesions must be disinfected regularly and intensively because of the risk of renewed protothecosis. If inflammation of the skin occurs again, it must be surgically removed immediately and examined for protothecae. In addition, contact with pets must be avoided.
What you can do yourself
In the case of protothecosis, the most important self-help measure is to see the doctor immediately and to inform him as precisely as possible about the symptom picture. A diary of the illness can be used to record the individual complaints, which makes the subsequent diagnosis much easier. The actual treatment can be supported primarily by bed rest and adequate personal hygiene. Since protothecosis is an infectious disease, contact with other people must be avoided. In addition, various ointments and lotions made from natural herbs can be used to support the treatment with medical preparations. After a surgical procedure, the patient must take it easy and follow the doctor’s instructions. The medical professional will recommend a change in diet and regular intake of pain medication. At the same time, the body must be monitored so that any recurrences can be quickly detected. Accompanying this, the cause of the disease must be identified and remedied. In most cases, it is sufficient to avoid contact with the triggering protothecae. In the case of severe diseases that may have already left scars, accompanying psychological counseling is useful to avoid any psychological sequelae.
