The Global Travels of Chikungunya Virus: Is it Coming to You?
By Roberta Attanasio
Chikungunya virus is spreading fast — worldwide. First described during an outbreak in southern Tanzania in 1952, it caused sporadic illness in Africa and large urban outbreaks in Thailand and India in the 1960s and 1970s. As of now, it has been identified in over 60 countries in Asia, Africa, Europe and Americas. The virus, which causes fever and severe joint pain, is transmitted to humans by the bites of infected female mosquitoes, most commonly by Aedes aegypti and Aedes albopictus — two species that can also transmit other mosquito-borne viruses, including dengue. There is no vaccine and no specific treatment for the infection.
The patient said: “”I was fine when I went to bed, but when I woke up in the morning and tried to get up my ankles hurt so much I couldn’t stand. It was very scary. After that I started getting different pains all over my body. Soon my hands were so swollen I couldn’t hold anything.”
In 2007, disease transmission was reported for the first time in a localized outbreak in north-eastern Italy. Outbreaks have since been recorded in France and Croatia. According to the Centers for Disease Control and Prevention (CDC), the first local transmission of Chikungunya virus in the Americas was identified in Caribbean countries and territories in late 2013 — local transmission means that mosquitoes in the area have been infected with the virus and are spreading it to people. Beginning in 2014, Chikungunya virus disease cases were reported among U.S. travelers returning from affected areas in the Americas and local transmission was identified in Florida, Puerto Rico, and the U.S. Virgin Islands. The current numbers of people infected with the virus within the Americas are staggering: the Pan-American Health Organization reports that, as of the end of February 2015, the initial handful of cases had exploded to 1,247,400 suspected and confirmed cases, affecting almost every country in the hemisphere.
After the first locally acquired case of Chikungunya was reported on July 17 2014 in Florida, Lyle Petersen, Director of the Division of Vector-Borne Diseases (National Center for Emerging and Zoonotic Infectious Diseases, CDC), said: “Chikungunya has been on the U.S. public health radar for some time. CDC has been working with the Pan American Health Organization since 2006, preparing for its introduction. We are working with international public health partners and with state health departments to alert health care providers and the public about this disease, equip state health laboratories to test for it and to detect cases to help prevent further spread.”
As of March 24, a total of 68 Chikungunya virus disease cases have been reported to ArboNET (a national surveillance system managed by CDC and state health departments) from 19 U.S. states for 2015. All reported cases occurred in travelers returning from affected areas. No locally-transmitted cases have been reported, yet, from U.S. states for 2015.
However, Anthony Fauci, Director of the National Institutes for Allergy and Infectious Diseases (National Institutes of Health), said in a 2014 press release: “The two species of mosquito that spread chikungunya virus are found in parts of the continental United States, so it may just be a matter of time before this illness gains a foothold here. Therefore, it is prudent to begin addressing this emerging public health threat with the development of vaccines.”
Indeed, the two species of Aedes mosquitoes that spread Chikungunya are present in the southern and eastern United States. At this time, it is difficult to predict how the disease will spread in the mainland U.S., but the CDC expects small, focal outbreaks, similar to pockets of dengue fever infections that have occurred previously in Florida and Texas. So, are Chikungunya vaccines being developed? So far, three candidate vaccines have been studied — in phase 1 trials —- with promising results. In phase 1 trials, researchers test a new vaccine in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
A new study published this month in the journal The Lancet Infectious Diseases, shows that one of these vaccines — a modified, conventional measles vaccine — has the potential to act against Chikungunya virus. It is the first promising measles virus-based candidate vaccine for use in human beings.
Bernd Jilma, one of the researchers involved in the study, said in a press release: “The modified measles virus is planted into people in Trojan horse style, and there it produces the corresponding surface particle of the Chikungunya virus. This occurs to such a low concentration that no symptoms of the disease appear. However, the Chikungunya particles are still able to stimulate the lymphatic system and to trigger the antibody production against the virus. These antibodies are then available at any time should an infection with the Chikungunya virus really occur. As a result, the disease cannot break out.”
However, the road to develop vaccines is long and winding and — despite these promising results — it will take years for an effective Chikungunya vaccine to be available for human use. What can we do, in the mean time?
Judy Stone says: “Individuals can make a big difference, as has been shown in Cuba and Southeast Asia. In both areas, there are community efforts to scour the neighborhoods for standing water, which serves as a breeding ground for both types of mosquito. Be sure to drain such sources of standing water, as drain pipes and wading pools. Even discarded tires are a major problem, and likely served to bring the mosquitoes here to the Western Hemisphere to begin with.”
In addition to reducing mosquito breeding ground such as standing water, according to the CDC, the best way to protect yourself and your family from Chikungunya is to prevent being bitten by mosquitoes by using insect repellent, wearing long sleeves and pants, using air conditioning or window/door screens to keep mosquitoes outside.
18 Comments
A.Jel
As numbers of people travel one place to another increased, it enhanced the diseases to spread faster. According to CNN, Chikungunya was identified in East African around 1950s. And it was spread to only a few countries after 10 years. But now, at least 74 countries were reported that there were people who affected by Chikungunya virus. This virus is spread to people by Aedes aegypti and Aedes Albopictus mosquito and they are active during the day unlike with most of mosquito that usually appear during the night. There is not much we can do to protect themselves from the virus but as the article mention, we can use insect repellent when you plan to stay outside and also wear long sleeve and pants.
1)As numbers of people travel one place to another increased, it enhanced the diseases to spread faster. According to CNN, Chikungunya was identified in East African around 1950s. And it was spread to only a few countries after 10 years. But now, at least 74 countries were reported that there were people who affected by Chikungunya virus. This virus is spread to people by Aedes aegypti and Aedes Albopictus mosquito and they are active during the day unlike with most of mosquito that usually appear during the night. There is not much we can do to protect themselves from the virus but as the article mention, we can use insect repellent when you plan to stay outside and also wear long sleeve and pants.
As numbers of people travel one place to another increased, it enhanced the diseases to spread faster. According to CNN, Chikungunya was identified in East African around 1950s. And it was spread to only a few countries after 10 years. But now, at least 74 countries were reported that there were people who affected by Chikungunya virus. This virus is spread to people by Aedes aegypti and Aedes Albopictus mosquito and they are active during the day unlike with most of mosquito that usually appear during the night. There is not much we can do to protect themselves from the virus but as the article mention, we can use insect repellent when you plan to stay outside and also wear long sleeve and pants.
1)http://www.cnn.com/2014/07/17/health/mosquito-disease-chikungunya-u-s-/
Chandni Jivani
Healthcare are considering the fact that to rule of dengue virus which has similar symptoms of Chickungunya. Some of the common symptoms of Chickungunya are headache, joint pains, fever, muscle pain and nausea. Chickungunya known as the disease which spread thru from a bite of mosquitos. It is classified as RNA virus. This virus is not spread person to person. It is believed that there is no cure for Chickungunya; however, all these symptoms can be treated. Individuals who are diagnosed with Chickungunya, the primary response of immune system is cytokines and interferons which plays as defense system, it works as to inhibit the virus. The release of cytokines will trigger the specific response such as attracting immune cells to cause antiviral defense. If an individuals who are does not have strong immune system will face hard time fighting this viral infection. The researchers are looking at the NK (natural killer) cells which are capable of killing directly the infected cells. The followings are diagnostic tools used to diagnose Chickungunya: antibody test such as IgM, polymerase chain reaction, and enzyme-linked immunosorbent assay and viral culture. Currently, there is no Chickungunya vaccines available to prevent and control the disease outcome.
K. Soms
While it is alarming that the CHIKV fever is becoming more frequent, it’s fortunate that the disease does not cause any serious damage/injury and most patients recover fully. Of course, a vaccine against this viral disease is important to keep the disease under control and to prevent any more painful infections or long-term complications such as arthritis. Unfortunately this virus, and other RNA viruses, is able to evade the innate immune system by masking their viral PAMPs and replicating inside vesicles. Our innate immune system’s pattern recognition receptors are unable to distinguish these foreign particles and are therefore unable to activate antigen presenting cells, and our adaptive immune response. In order to combat this virus, researchers must further study our host-pathogen interactions as well as the virus’s ability to counteract the immune system. Last year in December, there was a study on a chikungunya virus-like particle (VLP) vaccine in healthy adults. Conclusively, the VLP vaccine proved to be successful in inducing an immune response (the production of neutralizing antibodies) without having adverse effects. There was also a study about the treatment of CHIKV using high doses of intravenous Vitamin C that also proved to be highly successful in alleviating symptoms after only two days of treatment.
Maybe another possibility for prevention or treatment could be through a blood transfusion from a recovered patient. According to the CDC information page of the virus, once a person has been infected they are more likely to be protected from future infections. Perhaps more research could be done the antibodies of recovered individuals against CHIKV? Although, this may be an unconventional suggestion I think it would be an interesting approach and may provide useful insight on host-pathogen interaction.
Gabriel Beltran
I personally had no idea for the existence of the Chikungunya virus and the large outbreaks occurring across the continent in Africa and Asia. It is quite a wonder to hear about the Chikungunya virus as a potential concern especially since there is a lack of vaccination for humans. Although the quote by Bernd Jilma seems promising, “modified measles virus… produces the corresponding surface particle of the Chikungunya virus” as a means to induce clearance by the body for the virus, it is worthwhile to note how mutations can occur that might render this option useless. Therefore, it is reinforcing to hear many propositions for reducing the mosquito-human transmission by diminishing their numbers as referenced by my previous peers. Intriguing is the methodology required; it is not the males but the female mosquitos that bite individuals as a means to develop fertile eggs. To add, it is peculiar to find those individuals who seem to act as natural mosquito repellants, meaning their chances for disease transmission is diminished, such as that for the Chikungunya virus. There are different chemical and genetic parameters that these unique individuals wield that seem to act as a natural defense mechanism in addition to a natural working immune system. As an option, therefore, it would do well to continue research into such distinct alternatives, since it would decrease the causing agent population at its core. To note and consider, however, are possible confounding factors for reducing the mosquito numbers, such as the impact and effect on ecosystem web hierarchy. It seems the perpetuating itch of a mosquito bite is far from superficial, but rather one of great proportions.
Michelle Brydson
Will we have to return to the olden days where a mosquito net is our only means of protection against viral infections since no vaccines are available, scary! Emerging and re-emerging diseases are no longer concentrated at the helm of small communities, cities, and states but has become a Global concern. Chikungunya (CHIKV) has re-emerged. The mosquito-borne “alphavirus causes debilitating arthralgia in humans.” ProMED-ahead Digest Vol 32, Issue 18 issued its title, “Invasive Mosquito – USA (03): (California). It explained that the first observation of the larvae of the tropical mosquito was at a naval base in San Diego, California.
According to Shor’s text titled viruses, Chikungunya is of icosahedral shape from the family of Togaviridae and is a ++ssRNA virus. Moreover, this known characteristic makes their replication strategy very useful. The virus utilizes the cellular machinery of the host to make its early and late proteins efficiently. According to the World Health Organization, “There is no specific antiviral drug treatment for Chikungunya.” Again, this is as a result of the lack of understanding in host/pathogen interaction. In “Mechanisms of innate immune evasion in re-emerging RNA viruses,” Daphne Ma explains that the viruses that have re-emerged have a strategy for evading the immune responses. Ma stated, “Activation of the host immune response begins with recognition of the pathogen associated molecular pattern (PAMP) by pattern recognition receptors (PRRs). Ma explains that RNA viruses have the ability to inhibit the cytosolic innate immune signaling pathways. The article further states “CHIKV nucleoside triphosphatase (CHIKV nsP2) inhibits phosphorylation of signal transducers and activators of transcription (STAT) 1 and 2.”
The development of a vaccine will prove futile since the evasive mechanisms of the immune system of CHIKV RNA virus is not yet understood. In November 2014, an article was published on “Prime-Boost Immunization Strategies against Chikungunya Virus.” David Hallengard et al. explained that there are several “vaccine candidates” under development. Such includes, “attenuate or inactivated CHIKV, alphavirus chimeras, and subunit and genetic vaccines.” The researcher explained that prior clinical trials showed that vaccine candidates had the ability to evoke immunogenic responses in a mouse model. The tow vaccine candidates considered were “attenuated CHIKV” and “recombinant modified vaccinia virus Ankara (MVA) expressing CHIKV antigens. The study concluded that vaccine candidates did induce “…CHIKV specific humoral and cellular immune responses together with identified protective efficacy.” Further evaluations of the vaccine candidates are underway for trials in nonhuman primates.
L. Benson
The fact that the Chikungunya virus has seen a rapid global expansion over the last 30 years is alarming. The virus is carried by the Aedes Albopictus and Aedes Aegypti mosquitoes, which are both known to be invasive species. While research is being conducted toward creating a vaccine for the Chikungunya virus, controlling the ever-expanding territory of the mosquito could be addressed. Research conducted in Panama1 indicates that the mosquito is transported to new locals by humans. There is strong evidence that the larvae may be transported in cargo items that have standing water and adults transported as passive passengers on ships, airplanes, and vehicles. It may be prudent when a transportation vessel is traveling from a country of known viral load to a country that has no confirmed cases of the virus to be fumigated before entry. Fumigation would help to control both the population and the spread of the disease causing vectors.
1. “PLOS Neglected Tropical Diseases: Geographic Expansion of the …” Insert Name of Site in Italics. N.p., n.d. Web. 30 Mar. 2015 .
twynn
I was reading the list of Caribbean countries that have reported infections as of March 6, 2015, and I was shocked to see the Bahamas on the list. Only because I have never heard of this virus and because I just came from the Bahamas two weeks ago. I agree with A.Jones that it would be a smart idea for airports and cruise lines to inform their passengers, so that they know the risks. I agree that it is a good idea to start addressing this issue now while we have minor cases in the United States. As I was reading the other comments, I noticed that someone said we should introduce chemicals (pesticides) in our natural lakes and ponds. I do not think this would be a smart idea because if you’re killing the mosquito population, what else are you killing in the water. We should think rationally and start small by protecting ourselves with repellants and by keeping clear of standing waters as previously stated. I was reading on the American Mosquito Control Association that “Traditional mosquito methods of truck-mounted and aerial sprays are ineffective in controlling these mosquitoes. Removal of water-bearing containers and sanitation are key preventive strategies”.
S.Mashayekh
I agree that using pesticides is a bad idea to try to protect us, humans, from the Aedes mosquito population, and that the more effective way to form a way of protection is to keep our environment clean. Pesticides not only harm the environment, but they actually also harm humans. In an article, about the potential risks of using pesticides, one of the topics was human health. A study done, in Harvard University, showed that residue from pesticides on fruits and vegetables actually causes a higher chance of children getting ADHD. Also, who knows if the fish in that water are not to get poisoned or carry some of the pesticide in their system, which would cause us to get harmed by it when we eat the fish eventually? So, not only would the environment around the mosquitoes be harmed, but the humans living in that environment would be harmed as well, causing problems such as systemic poisoning, nerve, skin, and eye irritation, headaches, and the list goes on.
A. Jones
It was briefly mentioned that Chikungunya virus is locally transmitted in some Caribbean countries. However, there needs to be a greater emphasis on the fact that there is a great amount of local transmission in popular vacation destinations. According to a Health and Wellness article in the Boston Globe, countries such as El Salvador, Barbados, Curacao, and Jamaica are all experiencing local transmission. But at least the travel authorities are taking proper precautions, right? Not at all. Being from Jamaica I was made aware of this outbreak by many family members and friends. Thus, when I travelled to Jamaica for vacation last year I was prepared with mosquito repellant and sheer long sleeve clothing. So what about the majority of the people who were flying with me? I’m sure most of them had never even heard of Chikungunya virus, much like most of you reading this have never heard of it either. Travel authorities have a responsibility to protect it customers and passengers. The airport, the airlines, the cruiselines, and the cruise docks all hold the responsibility of protecting those whom pay a hefty penny to travel with them. These companies are multimillion-dollar industries, the least they can do is make a pamphlet for the passengers or sell necessary protective equipment at a discounted rate. S.Mashayekh made an earlier comment about “people keep coming back” with the virus. Well, anyone could easily get infected if they didn’t even know there was a virus going around at their vacation destination and once one falls ill on vacation the first thing they want to do is return home. I place that responsibility in the hands of the travel companies to let people be aware of the virus before they travel to these countries so they will be able to take the proper precautions.
L. Benson
I do not believe that it is the airlines, cruise lines or travel authorities who need to be responsible for informing passengers of the health risks associated with traveling to foreign destinations. They are responsible for keeping you safe while onboard there vessel. Most travel agents or travel books will suggest that the traveler check with their doctor or the CDC for any health concerns they may encounter while traveling to the destination country.
When people travel for either business or pleasure it is their responsibility to determine the health risks that they may be exposed. The information is easily accessible through the CDC. It took a matter of minutes for me to find the information for travel to Jamaica and it clearly states that the Chikungunya virus is present in that country. (1) They also include a link telling all about the virus and how to keep from contracting it.
1. http://wwwnc.cdc.gov/travel/destinations/traveler/none/jamaica?s_cid=ncezid-dgmq-travel-single-001
LKennel
We all know that Chikungunya is spread through specific species of mosquitos and that the way to prevent infection, if the mosquitoes are present in your area, is through using repellent or making sure you have no standing water in your area for them to breed, however the government could take an additional step to reduce the mosquito population around tropical areas by treating the water. If they treated the water with chemicals that would stop mosquito larvae from developing or kill mosquitoes before they can lay eggs we would prevent the possibility that they would be able to acquire the virus if they haven’t already and prevent the ones that do have it from spreading it. I agree with S.Mashayekh that there is a possibility of infected people introducing the virus to uninfected mosquitoes, which would in turn lead to a local outbreak. The article said drain-standing water but mosquitoes breed in the shallow parts of ponds and lakes too so treating bigger bodies of water with pesticides would reduce the likelihood of spreading the virus.
deb kaplan
Do you think pesticides are safe for us, for plants, and for wildlife? Why do you like the idea of having pesticides all around us? Are you aware of the dangers posed by the toxicity of pesticides?
Ayanha Lubin
Even if these pesticides and repellents were not toxic to human life; Chikungunya is most prevalent in third world countries with tropical climates where there’s often no access to repellents and large standing bodies of water due to rainfall on unpaved roads.
mbilderback1
As a Georgia resident the possibility of the Chikungunya virus spreading to our area is a real threat. Our extended warm season allows mosquitoes to be present beginning in early spring, thriving throughout the summer, and dying down in the fall until cold climates arrive. Additionally, although we have had droughts in recent years Georgia still tends to have enough rainfall to provide pockets of still water in which allows mosquitoes to lay their eggs. The threat of mosquitoes transmitting disease in our area has been recently demonstrated in a study at Emory that discovered large amount of mosquitoes positive for West Nile virus in parks around Atlanta, such as Grant Park. While taking a class at the Atlanta Zoo last semester we learned that they must monitor their bird population closely due to this threat, as they can also be infected with West Nile and can lead to encephalitis. As an Atlanta resident, I certainly hope we are able to quickly manufacture an effective vaccine and thus far the results look promising. In the phase I trials of an attenuated measles vaccine, named the Schwarz strain, groups of patients were administered low, medium, and high doses of the vaccine. The most effective group based on the results was the medium-dose group in which 92% of patients produced neutralizing antibodies after one dose compared to the low-dose and high-dose groups whose participants produced 44% and 90% neutralizing antibodies, respectively. The research also indicated that preexisting measles antibodies did not impact the immune response’s abilities to react to the vaccine, but needs to be confirmed in larger studies. Additional research, such as this, needs to be completed in order for a vaccine to be approved and distributed. Until that time comes where we can vaccinate ourselves against Chikungunya we must prevent the spread of the disease by combating mosquitoes and we can do this by wearing insect repellent containing DEET and removing still water to prevent larvae and a breeding ground for mosquitoes.
Lisa Benson
According to the NRDC, 28 states are home to the two types of mosquitoes that are vectors for dengue fever. The CDC reports that the Florida Keys have seen locally transmitted cases of Dengue fever between 2009 and 2010. With global warning and climate change it will only be a matter of time before Dengue fever makes its presence in Georgia. Similar to the Chikungunya virus, dengue fever has symptoms of high fever, headache, rash, joint and bone pain and in severe cases hemorrhagic bleeding. Individuals with compromised immune systems, children and senior citizens are the most vulnerable. The virus has four known strains of dengue and initially a person infected once will have immunity to all four strains. This immunity is not long term though, about 8-12 weeks, and if the individual acquires an infection of a different strain the possibility of more severe reaction is probable the second time around. This increased virulence is due to a phenomenon known as antibody-dependent enhancement of infection. The antibodies that were produced from the initial infection actually help the new infection spread the virus more rapidly. The antibodies attach to the virus but cannot effectively neutralize it. The antibody-viral complex then binds to monocytes and the virus is then able to penetrate the cell membrane more efficiently. The increased viral load leads to a more severe immune response with stronger symptoms. While it is important to develop a vaccine for the Chikungunya virus, it is equally important to try to find a viable vaccine for the dengue virus also.
MVesela
Mosquitoes transmit a variety of viruses, from The West Nile Virus and Malaria to the Dengue Fever. These flying, disease transmitting vectors are very difficult to control, making the spread of these viruses especially effortless. The Chikungunya virus, a virus that infects the joints, is one of the most recently discovered diseases that infect humans through the bites of infected mosquitoes. Dr. Attanasio mentioned in the article that there are two species of mosquitoes that are susceptible to carrying this virus—Aedes albopictus and Aedes aegypti. One of these, however, was a carrier much longer than the other, and not until several years ago, did both of them become primary sources of transmission. In a report dated back to 2008, the Aedes albopictus, or the Asian Tiger Mosquito, was discovered to be a second vector to this unfortunate disease. The article argues that the Chikungunya virus is accommodating itself in this species of mosquitoes in order to adapt to different regions of the world through evolutionary convergence. Originally, the virus was concentrated in Africa and Asia, being spread by the Aedes aegypti mosquito, but with the introduction of Aedes albopictus species, this virus has spread into Europe and parts of the Americas. Evolutionary convergence is usually applied to viruses, for instance, the Influenza virus, which modifies itself annually. In this case, the main concern lies in the possibility of other mosquitoes becoming vectors for the Chikungunya virus in the near future. If this occurs, the Chikungunya virus will be a challenging virus to manage and treat because of the different mutations that may develop due to the virus adjusting to a different species of mosquitoes in an alternate environment. With this concern in mind, the best solution to minimize the spread of the disease is to use repellents and pesticides against mosquitoes, and minimize the formation of standing water where mosquitoes prefer to breed. Preventing the spread of mosquitoes will aid in the control of the virus, localizing it to certain regions and helping accelerate the production of vaccinations without having to worry about the virus eventually mutating.
S.Mashayekh
Insect transmitted viruses are very tricky. Insects are all around us all the time and are so small, that they go unnoticed until they have done their deed and bitten you. Even though, as Dr. Attanasio stated above, the two Aedes mosquito species are here in the U.S. now, they have not been found to be carriers of the virus until now. Yet, if people keep coming back to the U.S. from areas that are endemic to this virus and have it in their system, who is to say that if they were to get bitten here by one of these Aedes mosquito vectors upon coming home, that a new strain of this virus will not start in these non-exposed species of mosquito? As stated by WHO, these species of mosquito are day time biters, so it is more easily to get bitten doing your daily activities, out in the open, than sleeping at night. It is important to always stay protected in areas endemic to certain species of insects that have the ability to spread a virus, infection, or disease. With time, hopefully some form of vaccine or protection will be formed to protect our immune system from giving in to this virus. The faster we find a vaccine for this, the better it will be, so our bodies can start forming antibodies to fight it off.
P. Gopal
The chikungunya virus is caused by mosquitos, in which it causes a high fever for up to two weeks. There is swelling in the wrists, arms, legs, hands, fingers, joints, and knees. There have been studies on individuals with the onset of the disease to have symptoms like nausea, vomiting, fatigue, conjunctivitis, and cervical lymphadenopathy will also occur with the illness. There is a possibility that one can have other complications such as excess bleeding, myocarditis, meningioencephalitis, and Guillian-Barre Syndrome. Although these complications may be rare, those that do undergo these complications have a greater chance of death. There was another study that showed individuals with severe joint pain from the virus, were symptoms of tissue haplotype HLA-B27.
The infections caused by the chikungunya virus and the dengue virus is often confused because the first symptom seen is fever, and both infections are caused by a mosquito bite. In order to confirm the diagnosis of CHIKV infection, a serological test must be performed; a reverse transcriptase PCR is done to detect viral RNA. Also antibodies are detected by the immunofluorescence assay.