O’nyong-nyong fever is a viral disease caused by the virus of the same name. The disease is common in sub-Saharan Africa and is transmitted primarily by mosquitoes. Fatal courses have not been reported, so the prognosis for patients is relatively favorable.
What is O’nyong-nyong fever?
In infectious diseases, microorganisms such as viruses, bacteria, or fungi enter an organism to settle and multiply. Mosquitoes are known to transmit various viral infections. One of these infections is O’nyong-nyong virus, which is most common in sub-Saharan Africa. In Kenya and Malawi as well as Mozambique, Tanzania and Uganda, the disease has been reported so far. The same is true in black African areas such as Senegal and the Central African Republic. Infected persons suffer from the so-called O’nyong-nyong fever after being bitten. This fever is relatively common in sub-Saharan Africa. Around 80 percent of the population is estimated to be infected with the viral disease. The fever was first described in the context of a momentous epidemic that made headlines in Uganda in the early 1960s. Around two million people were affected by the disease at the time. Literally translated, “O`Nyong-nyong” means “breaking of joints“. Presumably, there is an extrahuman reservoir for the virus.
Causes
The cause of O`nyong-nyong fever is the O`nyong-nyong virus. This viral infection is a form of RNA virus that belongs to the togavirus group. Human cells are used as host cells by RNA viruses. The infected cells do not possess a mechanism for repairing ribonucleic acid. For this reason, synthesis errors occur in RNA viruses, which are associated with high mutation rates. As RNA viruses replicate, they thus change every ten thousandth base. Viral mutants are created that help the viruses play hide-and-seek with the human immune system. RNA viruses such as the O’nyong-nyong virus are transmitted to humans primarily through the bite of certain mosquitoes. These mosquito species include Anopheles funestus and Anopheles gambiae. Both species are crepuscular mosquitoes found exclusively near standing water. The O’nyong-nyong virus appears to be closely related to the equally fever-causing chikungunya virus.
Symptoms, complaints, and signs
Patients with O’nyong-nyong virus suffer from a febrile illness after a certain incubation period, which is accompanied by various accompanying symptoms. Usually, the incubation period after being bitten by a mosquito is a little more than a week. During this week, those affected show no symptoms. Only then does chills set in, which are associated with signs of infection such as headache. The fever is accompanied by swelling of the lymph nodes, which indicates the activity of the immune system. Fever and virus got their name because of the joint pain that characteristically occurs. In addition, in the course of fever there are myalgias and a sharp decrease in leukocytes. Inflammation of the oral mucosa is a common symptom of the virus. Lymphocytes proliferate greatly until lymphocytosis is present. Joint pain in the context of the viral disease is usually symmetrically expressed and persists for several weeks. Symptoms such as mucosal inflammation and rashes recede after about two weeks. In individual cases, the disease can be ‘silent’ and in this case does not result in any feeling of illness.
Diagnosis and course of the disease
With appropriate symptoms, the physician makes the diagnosis of O’nyong-nyong fever by means of a typical travel history. The tentative diagnosis is confirmed by antibody detection in the blood. This detection is necessary because the clinical symptoms may resemble other viral diseases. With the antibody detection, the physician thus carries out a differential diagnostic differentiation from similar viruses. Patients with O’nyong-nyong fever have a relatively favorable prognosis. Fatal courses are not known. Usually, the disease resolves completely within weeks and results in long-lasting immunity.
When should you see a doctor?
O’nyong-nyong fever occurs only in people who live in South Africa or stay there for some time.If health irregularities occur in the region after the bite of a mosquito, they should be observed. In most cases, a doctor is not needed, as the consequences of the insect bite completely recede within a short time and no complications occur. Cooling the affected area and using an appropriate ointment to heal an insect bite can help the recovery process. If the patient is free of symptoms, it is not necessary to see a doctor. If the health condition deteriorates a few days after the insect bite, it should be clarified by a doctor. In case of persistent fever, chills as well as pain, a doctor is needed. Priority must be given to ruling out serious illnesses, as O’nyong-nyong fever often does not require further treatment. Swelling, pain of the joints as well as restrictions of the movement possibilities are to be presented to a physician. A feeling of illness, anxiety or inner restlessness may occur. If the complaints increase in intensity, a visit to the doctor should be made. Inflammations or irregularities of the mucous membranes indicate a disease that needs treatment and medical care. Changes in skin appearance, dizziness or a general feeling of malaise should be discussed with a physician.
Treatment and therapy
No causal therapy is available for patients with O’nyong-nyong fever. Unlike other viral diseases, travelers also cannot get vaccinated against the virus before going to black African areas. Since no causal therapy is available, the disease is treated exclusively symptomatically. For example, patients can be given painkillers to combat severe joint pain. However, painkillers should not be administered for too long, as there is a risk of dependence. Antipyretic drugs are not mandatory and are only given if the fever reaches threatening levels. Basically, patients can support their body in its fight against the virus. Supportive measures include, above all, sufficient fluid intake. Hot tea, in particular, can alleviate symptoms in the long term. Although no vaccination against O’Nyong-nyong fever is available, some preventive measures exist. Ideally, those who follow these preventive steps before and during stays in sub-Saharan Africa will not contract the fever.
Outlook and prognosis
Those who contract O’nyong-nyong fever in the tropics can expect a good prognosis for the outcome of the infection. The fever, which is prevalent primarily in sub-Saharan Africa, is never fatal, according to current knowledge. Many people in black African countries have already been infected with O’nyong-nyong fever by a mosquito. The virus of the same name is classified as a togavirus. Sometimes an infection with the O’nyong-nyong virus passes quietly and unnoticed. In other cases, it leads to aching limbs, rash, inflamed mucous membranes, and chills. These symptoms disappear after a few weeks. To prevent O’nyong-nyong fever from being confused with other diseases of similar symptomatology, differentiation by differential diagnosis is useful. The outlook is also good because after recovering from the symptoms of O’nyong-nyong fever, affected individuals are immunized for life. Symptoms are usually mild enough that sufferers do not need to see a doctor. However, if fever episodes persist with pain and chills, a visit to the doctor is advisable. It could also be a disease requiring treatment, such as malaria or another tropical fever. There is currently no preventive vaccination available against O’nyong-nyong fever. The disease can only be treated symptomatically. As a preventive measure against mosquito bites that transmit O’nyong-nyong fever, clothing that covers the body is the most sensible measure.
Prevention
In the context of O’nyong-nyong fever, preventive measures are limited to steps to prevent the infection-transmitting mosquito bite. These steps include dressing in long clothing. Short pants and T-shirts virtually invite the transmitting mosquitoes to bite. Protection from mosquito bites is also provided by mosquito nets. In addition, sprays are available to protect against insect bites in general.Since the infected mosquito species are usually only active at dusk and in the vicinity of stagnant water, stays near water should be avoided at dusk. These preventive measures do not promise one hundred percent prevention, but at least they reduce the risk of infection with the virus.
Follow-up
In O’nyong-nyong fever, measures of direct follow-up are severely limited in most cases. For this reason, the affected person should ideally see a doctor at an early stage to prevent the occurrence of other complaints or complications. The earlier a doctor is consulted, the better the further course of the disease usually is. Since O’nyong-nyong fever is a highly contagious disease, the affected person should avoid contact with other people as far as possible in order not to infect them as well. It is also not possible to cure the disease on one’s own, so the main priority with this disease is to diagnose it at an early stage. Most patients are dependent on taking various medications. It is always important to ensure that the correct dosage is taken and that the medication is taken regularly in order to alleviate the symptoms. In the event of severe side effects or if there is any uncertainty about how to take the medication, a doctor should always be consulted first. Patients should also remain on bed rest, and it is not uncommon for them to be dependent on the help and care of their own family in their daily lives. If O’nyong-nyong fever is recognized and treated in time, there is usually no reduction in the life expectancy of the affected person.
This is what you can do yourself
O’nyong-nyong fever is an infectious disease caused by viruses. They are transmitted by mosquitoes, which are mainly native to sub-Saharan Africa. Like most diseases caused by viruses, there is only a way to treat the individual symptoms of O’nyong-nyong fever. For example, cold calf wraps are recommended for chills with a high fever. Swelling should also be cooled. If joint pain is severe, anti-inflammatory painkillers are helpful and are available over-the-counter at pharmacies. If the illness is severe, a doctor who is familiar with tropical diseases should be consulted. During the illness, patients are advised to take it easy or even to remain on bed rest. Generally, O’nyong-nyong fever is cured in a few weeks. But until that time comes, patients should strengthen their body’s immune defenses to help it fight the viruses. Toxins such as alcohol or nicotine should be avoided. The patient should also pay attention to a healthy diet that contains plenty of fresh fruits and vegetables, but at the same time sufficient calories. It is also important to drink plenty of fluids, mainly water, hot teas or even thin soups. Depending on the outside temperature, two to three liters of fluid should be consumed per day.
