The Zika virus causes a disease that gives fever, rashes, joint pain, malaise, voimiting and red inflamed eyes. Usually the disease does not last more than a week and most often the symptoms are mild.
In rare cases, however, the disease is complicated by a reaction called Guillan-Barre syndrome. This syndrome give muscle weakness, that can progress to paralysis, that even can affect the breathing function. The syndrome can last several weeks or months, and sometimes some of its effects get permanent. In severe cases this syndrome makes it necessary with artificial ventilation and other type of life support for a longer time.
The syndrome is caused by an autoimmune reaction against the nervous system, because the immune defense in some cases mistakes elements of own body for elements of the virus.
If a pregnant woman gets the disease, also the foster can get infected through the placenta, which may cause birth defects. One suspects the virus for causing microcephaly, where the child has an abnormally small head and brain, mental handicaps and risk for early death, but the connection is not surely proven.
One suspects the connection because Brazil had only 147 reported cases of this defect in 2014, while 2400 in 2015, after the spread of the virus, and because many of the mothers reported symptoms of the disease in the early part of the pregnancy. But the Zika virus has been found in only very few of the children.
The virus belongs to the same family as those causing dengue, West Nile disease and chikungunya. It is spread by stings from the mosquito Aedes egypti, and possibly related mosquitoes. It does probably not spread directly between humans, but one cannot exclude totally a spread by blood and semen contact. The incubation time between the mosquito sting and the first symptoms vary from 3 to 12 days, but most infected persons do not get any symptoms.
Since the symptoms of the virus are fairly unspecific, a sure diagnose must be done by probing blood samples for the presence of Zika DNA by a polymerase chain reaction (PCR) test.
The virus was detected in Africa several decades ago. As by early 2016 the virus and the associated disease has spread over most of Latin America, and it has begun invading the USA, and there has been sporadic cases in Europa and Asian countries. The epidemic in Asia and America seems to be caused by another subtype of the virus than that endemic in Africa. This epidemic has made the World Health organization declare international emergency. But based on the usually mild nature of the disease, this move, however, is likely to be an overreaction produced by some degree of mass hysteria.
There are reports in media about the disease steadily getting more serious as it is spreading, but this impression can also be the result of the mass publicity the most serious cases are subjected to.
There is no real treatment against the disease, except medications for relief of pain and fever, and life support when serious complications occur. Patients affected by the disease are advised to rest a lot and drink enough water. By 2016 there is still not any vaccine, but efforts to make a vaccine is under way.
The best prevention for the disease, is to hinder stings from mosquitos. This can be done by mosquito traps in the house, bednets to hold mosquitoes away, and grating at windows to hinder mosquitoes from entering. When one goes outside in areas where the mosquitoes are frequent one can cover the body by clothes and use fragrances of a kind that repulse the insects. If there are dams in the environment where the mosquitoes are breeding, those can be drained. If one has a garden dam or swimming pool one can hinder mosquitoes from breeding by frequent change of water or by sterilizing it with an appropriate measures. If it is possible one can avoid traveling in areas with a high frequency of cases.
To apply any measure possible in order to hinder mosquito stings and thereby infection from this or other diseases that are contagious by mosquito stings can however be both impractical and uncomfortable, and they can make the environment very boring for people living at a place. Also measures to poison larvae can possibly cause irritation, allergic reactions or cancers in humans and animals. One must therefore calculate how far it is wise to go with such measures, and not let a mass hysteria lead to a battery of countermeasures that do more harm than good. It seems to be most important for pregnant women to avoid being infected.