Zika virus infection, known since 1947, is a viral disease transmitted by mosquitoes. It has occurred predominantly in Africa, Southeast Asia, and the Pacific Islands. Since 2015, a very rapid and extensive spread of Zika virus has also been detected in South American countries.
What is the Zika virus?
The virus was first discovered in a monkey in Uganda in 1947 and was named after a forest near the Ugandan capital of Kampala. Like the dengue fever and yellow fever viruses, Zika virus belongs to the Flaviviridae family. In 1968, the first human case was reported, according to the World Health Organization (WHO). The virus is transmitted by infected mosquitoes, such as the Asian tiger mosquito (Aedes albopictus) and the yellow fever mosquito Aedes aegypti. It is also possible that the disease can be transmitted from person to person through sexual intercourse. Zika infections are usually harmless in adults. Often the infection goes unnoticed. The disease otherwise causes mild fever, rash and itching, as well as headache, joint and muscle pain. However, in rare exceptional cases, more dangerous developments may occur. The danger to newborns should be taken seriously. Experts believe it is likely that the Zika virus causes deformities to develop during pregnancies, especially in the head area of the fetus. A vaccination or a cure for the disease is not yet available. Only the symptoms that occur can be treated.
Occurrence, distribution, and characteristics
The virus, which originated in Uganda, occurs mainly in tropical areas. Worldwide, many people have already fallen ill from insect bites. At the same time, numerous cases have not been recorded. The insects pick up the virus by biting people who are already infected. The eggs of the yellow fever mosquito are considered to be highly survivable. When they cover long distances in shipping containers, airplanes or trucks, small puddles of water are sufficient for them to survive. Since the viral diseases occur in areas where mosquitoes are also widespread, they can be regarded with a high degree of probability as the main cause of virus transmission. After the diseases have been detected in Africa, Asia and the Pacific region, the virus is spreading mainly in South America. The virus may have been transmitted there during the 2014 World Cup in Brazil. In North, South and Central America, 21 countries have already been affected, including Brazil, Colombia, Bolivia, Mexico, Barbados, Haiti and Guadeloupe. In 2013, the virus infected approximately ten percent of the French Polynesian population. Cases have been reported in this context that have also been diagnosed with the so-called Guillain-Barré syndrome. This is a nerve disease that can cause paralysis, among other things. No evidence of the simultaneous occurrence of Guillain-Barré syndrome has yet been reported from other countries affected by the Zika virus. Since May 2015, reports of Zika virus infections have been accumulating from Brazil. There, in addition to numerous viral infections, 3893 newborns with microcephaly (malformation of the head due to an insufficient cranial circumference) have been recorded. A total of 49 of these children have already died as a result of the malformation. Some women suffered miscarriages, and some of the babies lived only a few days. Some of the newborns were diagnosed with severe mental disabilities due to the malformations of the brain. In contrast, only 147 cases of microcephaly were registered in the entire previous year. In Colombia, many people have also been sickened by the pathogen so far. Initial cases have also occurred in the United States and Great Britain, among other countries. In the state of Florida, three people have been diagnosed with Zika illness, which is believed to have been contracted during travel in Colombia and Venezuela. In the entire USA, 10 cases have been registered so far, in which the virus transmission probably also occurred during stays abroad. According to the Robert Koch Institute, laboratory-confirmed findings of Zika illnesses have also already been recorded in a few individual cases by German vacationers abroad.
Diseases and ailments
To reduce the risk of contracting Zika virus disease, comprehensive mosquito protection that is as effective as possible should be practiced in affected areas. This includes wearing long, light-colored clothing all over the body, as well as appropriate defense with insect sprays. From experience, the helpful technical support of mosquito nets should also be resorted to. A huntertprozentiger protection is not possible thereby however. The yellow fever mosquito is not only attracted to bodies of water, but also to sweet foods and drinks of any kind. Those who are infected despite precautionary measures can usually hope for a quick and harmless course of the disease. Often there are hardly any symptoms and the disease passes almost unnoticed. The situation is much more worrying for pregnant women and their fetus. There is some evidence that the virus can reach the fetus and as a result the cranial sutures close prematurely. As a result, the circumference of the skull can hardly grow further and a developmental disorder of the brain is caused. In women in whom the ultrasound images before birth already showed the insufficient head circumference, amniotic fluid was taken and analyzed. It turned out that the virus had multiplied in it. The Guillain-Barré syndrome, which has so far only occurred in Polynesia in addition to the Zika virus disease, can present itself as a great danger. However, there is still no scientific evidence of a causal relationship. Guillain-Barré syndrome is a disease of the nerve tracts in which the most common consequences are paralysis and sensory disturbances. Muscle weakness ascending from the legs can lead to complete paralysis of the arms and legs, and in bad cases also of breathing. The disease is sometimes painful and can often also trigger cardiac arrhythmias. Immediate medical attention is required if breathing and heart are affected.
