The Zika virus is the cause of Zika fever, a mosquito-borne infection found in various tropical areas. The disease is not remarkably severe for most people and not life-threatening, but it can severely damage children in the womb.
Many governments recommend that women who are or might become pregnant should avoid travel to areas where Zika is a risk, and some (Colombia, the Dominican Republic, Ecuador, El Salvador, Jamaica and the Philippines as of early 2016) are recommending that their residents postpone pregnancy. When the government of a thoroughly Catholic country starts handing out free condoms — as Colombia has, both for locals and at the airport for visitors arriving for 2016 Carnivale — it is clear that they take the threat very seriously indeed.
The first virus of the genus Zikavirus was identified in 1947 on a Rhesus Macaque (Macaca mulatta) used as a sentinel during a study of yellow fever in the small Zika forest near Kisubi locality between Kampala and Entebbe in Uganda.. In 1948, the virus is isolated, still in Kisubi, from a female Aedes africanus and transmission by a mosquito of the genus Ædes is proved, in 1956, in a laboratory of Barcelona. Between 1954 and 1981, evidence of human infection was detected in sub- Saharan Africa, on theIndian subcontinent and Southeast Asia, however, it was not until 1964 for the first real description of a human case.
The first known outbreak occurred in April 2007 and affected the Yap Islands in western Federated States of Micronesia. The second occurred during the last quarter of 2013 in French Polynesia where it is estimated that one fifth of the population was affected. The current epidemic, although declared in May 2015 in Brazil, would be linked to the organization of the 2014 Football World Cup, during which the country received tourists from all parts of the world, including areas with intense strains of the virus. In early January 2016, this epidemic, considered as emerging, spread to all of South America (except in Chile), Mexico and the Caribbean, but also Cape Verde, Tonga and the Maldives. At the beginning of February 2016, 33 countries were affected with reported case rates per inhabitant variable from one country to another but affecting more specifically Colombia.
At the end of 2015, Brazilian doctors show a correlation between the action of the virus and the increase of cases of non-congenital microcephalia with the finding, as ofJanuary 20, 2016by the Pan American Health Organization (PAHO) of 3,893 suspected cases and 462 cases confirmed by the presence of the virus in the brain tissue of the fetus or infant. TheMarch 15, 2016, Cape Verde records its first case of microcephaly.
The number of cases of patients developing Guillain-Barré syndrome is also clearly increasing. In early February 2016, Colombia announces that three patients who contracted Zika fever followed by Guillain-Barré syndrome have died. They thus constitute the first deaths ever observed in direct relation with the presence of the virus. On February 11, Venezuela also announced the deaths of three people who had complications associated with Zikavirus.
Without evidence of transmission capacity, Brazilian researchers have discovered Zikavirus, in active form, in the saliva and urine of patients. Stranger, two travelers (an American and a Swiss) who contracted Zika fever each during a stay in a different epidemic zone transmitted the virus to their partner during sexual intercourse. This fact would be a first from a Flavivirus. If the cause of the effect were to be proven, it would mean that the virus would have the possibility of infecting other species of Ædes for whom it is unknown, such as the tiger mosquito (Aedes albopictus), themselves infecting human beings.
At the beginning of March 2016 in Colombia, the first case of microcephaly recorded and, in Guadeloupe, a new discovery with the case of a young patient with transverse myelitis in the state phase of her infection due to the presence of the virus in her cerebrovascular fluid. spinal.
If WHO declares the outbreak over1 st February 2017, it continues to issue, each month, reports of the evolution of the disease country by country.
Crisis Center – the evolution of the disease country by country Bulletins issued by the WHO
Until about 2007, this was a rare disease and geographically confined to a few parts of Africa and Asia. However, since then it has spread and by 2015 it reached epidemic levels in much of South America, Central America and the Caribbean. In February 2016, the World Health Organization (WHO) declared this an international health emergency. In the Western Hemisphere the disease has spread to Florida with several autochthonous cases in the Miami region. In August and September 2016, several hundred locally transmitted Zika infections were reported in Singapore, though as of early November there are just a few new infections every week.
Zika is also fairly common throughout Southeast Asia and occurs in parts of Africa, South Asia, and the Pacific islands, including Hawaii.
Even in Zika-infected parts of the world, Zika is much less of a risk at higher altitudes, defined as 2000 m or 6500 ft above the sea level where the aedes aegypti mosquito spreading the disease doesn’t “usually” exist.
It is very difficult to make a valid diagnosis without performing an RT-PCR test as the symptoms are similar to those of other viral diseases such as dengue fever or chikungunya, or even rubella, measles or even influenza if it does not occur. There is no rash.
The main symptoms appear after an incubation phase that lasts from 3 to 12 days. It is a continual condition of fever, headache, muscle and joint pain (mainly in the ankles and hands), general fatigue, conjunctivitis, a rash on the face before s extend to the rest of the body. These symptoms may be accompanied by gastric disorders and neurological disorders such as dizziness or lightheadedness.
The history will be followed by a test ELISA for detecting the presence of antibodies of the immunoglobulin-type M (IgM) or anti-Zika the presence of antigens viral. IgM is detectable 3 days after the start of the invasion phase. However, this test may show cross-reactions with the presence of other Flaviviruses, especially with the one that is responsible for dengue fever, especially if the patient has previously had a Flavivirus infection.
The only definitive diagnosis will be based on an RT-PCR test, made possible since 2006 and the sequencing of the Zikavirus genome, which makes it possible to detect the presence of the Zikavirus- specific viral enzyme in serum and urine. This test can be done within a period of up to 15 days, for urine, after the start of the invasion phase.
RT-PCR of Zikavirus – Conduct of an RT-PCR test carried out by the Central Laboratory of Clinical Biology of the Prince Leopold Institute of Tropical Medicine.
Only about one person in five infected with the virus develops symptoms. For those that do, Zika is generally a fairly mild infection, about like a flu, often with a fever, a rash and/or inflammation of the eyes. Symptoms typically last less than a week, and the disease usually does not kill.
Zika infection in pregnant women has been linked to congenital deformities and developmental disorders, most notably microcephaly, meaning that a baby is born with a much smaller brain than normal and severely impaired intellectual ability.
There is no vaccine, no drug that prevents infection, no cure other than waiting it out, and no treatment that will eliminate the virus. All the doctors can do is advise rest and fluids, and possibly prescribe drugs for the pain and fever.
If you suspect a Zika infection, see a doctor rather than self-medicating. Zika is easily confused with Chikungunya or with dengue fever, diseases caused by related viruses carried by the same genus of mosquito, with similar symptoms and a similar geographic distribution. If what you have is dengue, then taking some common over-the-counter medicines such as aspirin and ibuprofin will increase the risk of dangerous complications.
Zika is transmitted mainly by mosquitoes, but it can also be transmitted mother-to-child in the womb and man-to-woman during sex. It is not known whether other sexual transmission is possible.
Microcephaly for the fetus appearing at the infant stage.
Guillain-Barré syndrome with cases twice as high in women than in men.
Even for pregnant women, Zika is not yet at the critical warning level. CDC use a three-point scale for their warnings:
1 take normal precautions
2 avoid travel if possible & take enhanced precautions if you do go
3 avoid all non-essential travel
As of mid-2016, Zika is only at Level 2. Enhanced precautions for Zika mean taking great care to avoid mosquito bites — screened windows, mosquito nets, clothing that covers most of your skin, permethrin treatment for clothing and gear, and insect repellents. Sexual partners to a woman who might be or later get pregnant should take the same precautions, and men who might have got the infection (whether or not they have had symptoms) should use condoms to avoid transmitting the virus, for a time of six months.
Protection against the vector
Avoiding Zika fever is first and foremost avoiding mosquito bites by taking a few precautions. Females dedes mosquitoes are active during the day with peaks of overactivity at dawn and dusk. They are at the same time exophilic, that is to say that they live outside the dwellings, and endophilous, that is to say that they live inside the houses. On the other hand, it is uncommon for them to attempt to take their blood meal on a being in motion.
Some protection tips:
wear loose, long, light colored clothing;
coat the permethrin garments or the skin of a repellent consisting of a solution containing 30% DEET for adults or 10% of the same product for children between 2 and 12 years old;
use an insecticide inside the homes;
use a fan, even if the room has an air conditioning system, since mosquitoes are sensitive to air movement;
use a mosquito net with a mesh size of less than 1.5 mm if you rest during the day and, if possible, impregnate with insecticide to protect body parts that come into contact with the net. Before each break, be sure to check that the net is in perfect condition.
Beware that if females of Ædes, propagators of Zika fever, yellow fever, chikungunya and dengue, are activated between dawn and dusk, females of other species of mosquitoes, propagators of other Viral diseases, such as Japanese encephalitis and o’nyong-nyong, or parasitic diseases such as malaria, are active during the night. The same precautions are therefore desirable during the night period.
Protection against the virus
At the beginning of 2016, there is no prophylactic or therapeutic protection against Zikavirus. Research for the creation of a vaccine began in 2015, among others in the United States and at the University of Montpellier in France, but researchers estimate that it will take between 10 and 12 years to obtain a vaccine. valid vaccine.
The only method of general prevention is to reduce the egg-laying sites of the vector by drying out the ditches, protecting the water supply with a mosquito net or cover, eliminating from nature any object that can harvest rainwater such as old pans or old tires, that is to let go in the nature of sterile males thanks to an infection caused by a bacterium of the genus Wolbachia or still let loose male mosquitoes genetically modified and incapable of reproducing. This last, now controversial, method was used in 2015 in North-East Brazil, where the 2015 epidemic started and the first cases of microcephaly were detected.
Another general prevention method is to set easily attainable egg traps. For the latter, it is sufficient to fill a container with water, to dive, obliquely, a tongue of wood that will allow the female mosquito to rest during the laying and pour into the water granules or tablets larvicide (“CULINEX Tab plus” type, etc.) to kill the larvae that hatch in the trap.
Three sources for extensive information on Zika are:
The US government Center for Disease Control (CDC)
The World Health Organization (WHO)
As of mid-June 2018, the CDC has Zika-related travel advisories for 91 countries, plus the US territories of Puerto Rico and the US Virgin Islands. The list changes often. WHO’s situation report as of March 2017 lists 84 countries where infections have been reported.