The Zika Virus
When we believe that nothing can surprise us anymore in terms of diseases, a new health problem captures our attention. This is the case for Zika fever, caused by Zika virus. Even though this virus has been spreading sporadically in Africa for decades, it is worrisome the rapidity with which it is transmitted now. Most often, it can be mistaken for a common cold, but in some cases can lead to undesirable complications, as it happens in pregnant women.1
Since there is no vaccine against this virus that is spread rapidly by a mosquito, everything you can do to prevent it consists in stopping the spread of mosquitoes that transmit it, and taking safety measures when you are traveling to affected areas. Unfortunately, this virus made victims in different countries in the Americas, but not all the people who receive the virus get sick.
The World Health Organization declare Zika Virus a “public health emergency of international concern,” due to the speed with which it is transmitted, but also the consequences that it can have. Taking into consideration the proportions reported by the spread of this virus, it is important for everyone to be informed of the risks it involves.
Zika Virus belongs to the virus family Flaviviridae and the genus Flavivirus. It is primarily transmitted by Aedes mosquitoes, which are day-time active. The name of the virus comes from the Zika Forest of Uganda, where it was first discovered in monkeys in 1947. Scientists that studied yellow fever put a rhesus macaque in a cage in Zika Forest and isolated a transmissible agent from its serum. Next year the virus is isolated from the mosquito Aedes africanus and four years later, in 1952, researchers discover the first Zika virus case in Uganda.2
According to a study conducted in India in 1952, Zika virus had been wide-spreading among people for a long time. Indians that had been tested for the virus had developed an immunity response to Zika. This explains that among the 84 people of all ages infected with Zika in 1952, 50 people had immunity to the virus and all invidivuals above 40 years old were immune. In 1954, the virus was discovered in the blood of a 10-year-old Nigerian girl. She had fever and headache, but managed to recover within three days.
Although it was known that Zika virus could be transmitted to humans, the first concrete evidence in this regard appeared in 1964, when a researcher in Uganda got sick while working with Zika strains from mosquitoes. Between 1951 and 1983 were reported cases of humans infected with the Zika virus in different countries in Africa, including Egypt, Central African Republic, Sierra Leone, Tanzania, and Uganda. The virus was also spread in some areas of Asia, like Indonesia, India, Malaysia, Thailand, Pakistan, Vietnam, and the Philippines.
The exact origins of Zika virus are unknown because nobody knows for sure where it first appeared. It is known that was first identified in 1947, but it has existed in forests in Africa and Asia for a long time. Even though there were small outbreaks from its discovery, the virus remains in the parts of Africa and Asia for almost six decades.
The major Zika virus outbreak
If until 2007 the virus was spreading only in some areas of Africa and Asia, beginning with this year we see the first important virus outbreak in humans. The outbreak takes place on the Pacific island Yap in Micronesia. This is just the beginning, because between 2013-2014, Zika virus produces outbreaks in other four groups of Pacific islands, as follows: Easter Island, French Polynesia, the Cook Islands, and the New Caledonia. In 2013 had been confirmed 333 of human cases, when an outbreak takes over French Polynesia. This is the first time when the disease is connected to serious symptoms, such as neurological disorders, including Guillain-Barre syndrome.
If this virus seemed to be harmless, new discoveries have proved the opposite. People got worried when they see how rapid the virus spread through Americas and the connection of the virus with microcephaly and Guillain-Barre syndrome. Once the virus spread outside Africa and Asia, in May 2015 where detected cases of infection in Brazil, where the virus was transmitted as an Asian genotype. Until now, the virus has spread in 23 countries in Americas.
At the end of April 2016, the first American died from the complications of Zika virus. The man, who was in his 70s, had recovered from the symptoms caused by Zika Virus but developed an autoimmune disorder associated with the virus, called thrombocytopenic purpura. Every person reacts differently to the virus, and not all of those infected are lucky enough not to develop symptoms. It is best to be always informed about which areas are affected and what to do to protect yourself from getting the virus when you travel in these areas.
The mosquito that transmits Zika virus, Aedes species, is also responsible for carrying dengue fever, chikungunya virus, and yellow fever. In contrast to mosquitoes that carry malaria, this species is active during the day and can survive indoor and outdoor environments, which makes it impossible to prevent its spreading. Because the virus is mostly transmitted by a mosquito bite, this is the main risk for infection.
Zika virus needs a period of incubation of 3 to 12 days after the bite of an infected mosquito occurs. Many cases of Zika virus infections are without symptoms, but in other cases, the symptoms may be minor. Only 1 in 4 people infected with the present virus symptoms, according to Pan American Health Organization. Centers for Diseases Control and Prevents states that only 1 in 5 people infected with Zika have symptoms. The fact is that some people can be infected without knowing it, because of the lack of symptoms. If there are symptoms, they can be easily confused with those of a common cold.
The usual symptoms include fever, rash, joint pain, muscle pain, pain behind the eyes, vomiting, headache, and conjunctivitis. Because the diseases are usually mild, the symptoms last for a few days or a week, and people prefer not to go to a hospital since they don’t get very sick, and the symptoms are bearable. The virus remains in one person’s blood for a week, but in some cases can be found for a longer period. It is possible that after a person was infected, to be protected from future infections.
Complications of Zika virus
Although it seems like a harmless virus, knowing there is a link between infection with Zika and certain neurological disorders is quite worrisome. Researchers analyze a possible connection between infection with Zika virus in pregnant women and infant microcephaly. This concern arose after what happened in Brazil, where had been reported an increase in the number of infants born with microcephaly, since October 2015. In other regions, like French Polynesia, it was reported an increase in spine and brain defects in fetal and newborn babies.
Microcephaly is a neurological disorder, in which infants are born with a head that has a smaller circumference than normal size for babies of the same age. Unfortunately, microcephaly could lead to different complications, including mental retardation, hyperactivity, seizures, facial distortion and dwarfism or short stature. It is not known the exact stage of pregnancy in which an infected mother presents a risk for the fetus or if are other factors that may contribute to the fetus infection. However, the higher number of cases of microcephaly recorded after the widespread of Zika virus worries researchers.
Along with microcephaly, another source of concern is the connection between Zika virus and Guillain-Barre syndrome. In this condition, the immune system destroys the peripheral nervous system, which leads to muscle weakness and, even paralysis. In some countries with Zika outbreaks, there is an increase in the number of the cases with Guillain-Barre syndrome.
If some people infected with the virus can suffer from serious complications, others are able to recover completely in about a week, without facing any complication. It is important to visit a doctor when your situation worsens and the symptoms don’t improve, even if you followed a treatment to reduce them.
In 2007, Zika virus is detected for the first time outside Africa and Asia, when the first important outbreak occurs in Yap Island in the southwestern Pacific Ocean. The virus’ outbreaks continue between 2013 and 2015 in different region of Pacific. At the beginning of 2015 human cases of Zika virus were reported in Columbia and Brazil. The virus spreading makes many victims, and in six countries are recorded cases of microcephaly and malformations of the central nervous system that can be associated with Zika infection.
On the middle of June, 2016 a number of 52 countries in different regions all over the world reported autochthones cases of Zika virus in the last nine months. It is possible that the virus persists in the Americas, Africa, Asia and the South and Western Pacific. In South America, the virus is spread in Venezuela, Suriname, Peru, Paraguay, Guyana, Ecuador, French Guiana, Colombia, Brazils, Bolivia, and Argentina. The territories affected from Oceania include American Samoa, Fiji, Marshall Islands, Micronesia, New Caledonia, Papua New Guinea, Samoa, and Tonga.3
The Caribbean is also affected by Zika virus. In areas like Virgin Islands, Trinidad and Tobago, Saint Maarten, St Lucia, Saint-Barthelemy, Saint Martin, Puerto Rico, Martinique, Jamaica, Haiti, Guadeloupe, Dominican Republic, Dominica, Curacao, Cuba, Bonaire Barbados and Belize were reported cases of Zika virus infection. In Africa, from where the virus begins to spread, Cabo Verde islands are affected. It is recommended to follow safety measures in the following Asian countries, to avoid Zika virus infection: Vietnam, Laos, Maldives, and Philippines.
Human cases of Zika virus infection are registered in different countries from Central America, including Panama, Nicaragua, Honduras, Guatemala, El Salvador, and Costa Rica. In North America people who go to Mexico should be careful, because here there is also a risk of contaminating the virus. From isolated cases of infections with Zika virus in Africa and Asia we are facing now a widespread, which is not without serious complications that can endanger the lives of the people affected.
In ten countries are reported cases of virus transmission from person to person. The reports on virus complication are not at all encouraging. Twelve countries had reported cases of microcephaly and other central nervous system malformation that are associated with Zika virus. Reports of congenital malformation connected to Zika virus were made in Europe as well, in Spain and Slovenia, by persons who traveled in the affected areas. In thirteen countries was reported a growth in cases of Guillain-Barre syndrome and some of these cases have a laboratory confirmation of Zika virus infection.
Only in Brazil were reported 7936 cases of microcephaly and other nervous system disorders between October 2015 and 11 June 2016. From 1581 confirmed cased of microcephaly, 226 are laboratory confirmed of having Zika virus infection. It is vital to take all the necessary cautions before going to an affected area. Keep in mind that the virus is transmitted by mosquitoes, as well as by sexual intercourse. Because the complications that can be produced by Zika infections could be so serious, it is crucial to prevent mosquitoes’ bites when you live or travel in the affected areas.4
Zika virus is transmitted by infected mosquitoes that also transmit other diseases, including chikungunya and dengue. So, the main risk of contracting the disease is travelling or living in areas where infected mosquitoes exist and precautions to prevent mosquitos’ bites are missing. Because people from Central, North, and South America haven’t been exposed to virus, they have no immunity, which explains the rapidity with which the virus was spreading.
The virus cannot be transmitted from person to person, but there have been cases of sexual, transmission. According to the CDC, the virus may be present in semen for up to ten weeks after the it was installed. Until now, it isn’t known if the virus can remain in the semen for more than ten weeks or if an infected man, who hasn’t shown symptoms, can transmit the virus to their sex partner. It is advised for partners of pregnant women who lives or returns from areas with Zika virus outbreaks, to practice safer sex or to abstain for the duration of the pregnancy.
Women who plan to remain pregnant should wait for at least eight weeks if they live or return from areas with Zika virus. Both men and women who return from an area with Zika should use condoms or abstain from sex for at least eight weeks. If men experience symptoms associated with Zika virus, they should practice safer sex or abstain from sex for at least six months.
Another risk for Zika transmission is blood transfusion, according to the health officials from Brazil. They confirmed two cases of virus transmission through blood transfusions from infected donors. Unfortunately, it is impossible for a donor to know he is carrying Zika virus, if the virus is free of symptoms. Testing for Zika virus is necessary before blood transfusion for people that may be infected.
As it has been proven, Zika virus can be transmitted from an infected mother to her fetus during pregnancy, as well as at childbirth. It is recommended for pregnant women, especially if they experienced symptoms of Zika disease, to monitor closely their pregnancy. Regarding breastfeeding, the virus had been detected in breast milk, but it hasn’t been proved if the virus can be transmitted to babies through breastfeeding.
Unfortunately, there is no vaccine that makes possible the prevention of Zika virus disease. Since the virus is spread mainly through the bites of infected mosquitoes, it is important to protect yourself. When you are in areas where the virus is transmitted, it is good to wear shirts with long-slleved and long pants and keep mosquitoes outside the places you live. Use windows and doors with screens, as well as air condition to prevent mosquitoes from entering inside. It is also important to use insects repellent that are effective and protects you from insects.
The most affected by mosquito bites are children and babies. In order to protect them, it is important to dress them with clothes that completely cover their arms and legs, as well as to use mosquito nets to cover their strollers, carriers, and cribs. Repellents can help prevent mosquito bites in children, but the CDC recommends using product that contain DEET, picaridin and IR335. They also recommend products with oil of lemon eucalyptus para-methane-diol, if you want to get a longer protection.
People who have been infected with Zika virus should avoid future mosquitoes bites during the first week of infection, because the virus will be transmitted by humans to mosquitoes through blood, which will make it riskier to be spread to a higher number of people. If you have been infected to Zika virus, make sure others won’t get sick. To do so, practice safe sex and even abstinence, the latter being the only way you can be sure the virus is not transmitted through sex.
Zika virus can be transmitted through blood transfusion. Therefore, the American Red Cross, which is the biggest blood collection organization in the world, made public steps to be followed by donors, to prevent virus transmission. The donors who had traveled to the affected countries should wait four weeks before donating blood. Each measure of prevention if important, not only for people who have the most increased risks of developing complications, as for all those living or traveling to the affected areas.
Today we don’t have approved medications or vaccines against Zika virus. Scientists from the National Institutes of Health work on a vaccine that was first developed for the West Nile virus. A safety trial for this vaccine will be launched in September. The treatment that can be taken for Zika disease has only one purpose – to reduce symptoms and help the infected person feel better. Therefore, people with Zika can take a treatment to reduce headache, fever and other symptoms similar to those of a common cold. Therefore, it is recommended to drink a lot of water and fluids, to get enough rest and to take acetaminophen for reducing body aches, fever, and headache.
Keep in mind that a person with Zika shouldn’t take aspirin or any other type of non-steroidal anti-inflammatory pill, such as ibuprofen or naproxen, because these can produce bleeding problems. In addition, it is not recommended taking antibiotics to treat Zika infection, because they have no effect against a viral infection. As you know, using antibiotics may have side effects, so they should be taken only when they are really necessary.
It is extremely important to seek urgent medical help when the symptoms do not improve. Normally, symptoms should pass in a few days, but there may be exceptional circumstances when can lead to complications. It is best to prevent infection with the virus Zika. If you are traveling in areas affected by the virus, make sure to avoid being bitten by mosquitoes responsible for spreading the virus and give your best to protect yourself. Therefore, prevention is the best treatment possible for Zika virus.
Even if symptoms are not too worrisome for some of you, especially because not all the infected people develop them, it doesn’t mean that we don’t have to do everything it is in our power to protect ourselves from this virus, which spreads so easily. Regardless of age, but especially for children and pregnant women, it is best to stay away from affected areas, and to protect yourselves to prevent infection with Zika. There are high hopes that we will be able to use a virus to prevent Zika infection, but until then we must do everything we can to protect ourselves and prevent it.
1. [Text of footnote 1]https://www.cdc.gov/zika/
2. [Text of footnote 2]http://www.medicinenet.com/zika_virus/article.html
3. [Text of footnote 3]http://healthycanadians.gc.ca/diseases-conditions-maladies-affections/disease-maladie/zika-virus/surveillance-eng.php
4. [Text of footnote 4]http://ecdc.europa.eu/en/healthtopics/zika_virus_infection/zika-outbreak/Pages/epidemiological-situation.aspx