Figure: 1 Aegypti mosquitoes

Dengue fever and Chikungunya outbreaks evolve quickly, requiring emergency actions to immediately control infected mosquitoes in order to interrupt or reduce transmission and to reduce or eliminate the breeding sites of the vector mosquito, Ae. aegypti. In order to meet such emergencies, it is essential that persons at all levels, including individuals, the family, the community and the government, contribute to preventing the spread of the epidemic. The following emergency action may be taken to prevent or contain an incipient epidemic. Chikungunya virus is a heat sensitive RNA virus (family is Togaviridae and genus is alphavirus - Group IV+). There are three major groups of these viruses namely West African, central african and asian. ^[11,10,15]

Chikungunya virus requires an agent for transmission and hence direct human to human transmission is not possible. So far no such incidence is reported. Usually transmission occurs when a mosquito bites an infected person and then later bites a non infected person. Chikungunya also affects monkeys and it is also suspected that they are a major reservoir for the virus in Africa. Chikungunya (in the Makonde language "that which bends up") virus (CHIKV) is an insect-borne virus, of the genus Alphavirus, that is transmitted to humans by virus-carrying AedesHYPERLINK "http://en.wikipedia.org/wiki/Mosquitoes" \o "Mosquitoes"mosquitoes. There have been recent outbreaks of CHIKV associated with severe illness. CHIKV causes an illness with symptoms similar to dengue fever. CHIKV manifests itself with an acute febrile phase of the illness lasting only two to five days, followed by a prolonged arthralgic disease that affects the joints of the extremities. The pain associated with CHIKV infection of the joints persists for weeks or months, or in some cases years. Chikungunya is a viral disease that is very similar in symptoms and etiology to the disease, dengue fever. The virus responsible for chikungunya is alpha virus, which is transmitted through the aedesaegypti mosquito, which is active only in the daytime. The aedesaegypti mosquito is the same mosquito that is responsible for the transmission of dengue fever among humans. The condition of chikungunya is generally not fatal, and it can be remedied within five to seven days with proper treatment.^[5,6,8,24]

The word chikungunya meaning "that which bends up", which is derived from its arthritic symptoms. It is the hottest topic of discussion among public today, so is necessary to know the causes, symptoms, treatment and preventive measures of this viral fever. Usually chikungunya virus or CHIKV is spread by mosquito bites from Aedesaegypti mosquitoes, Aedesalbopictus (Tiger mosquito), Aedesluteocephalus, or A. taylori. There is no reported case of human-human transmission of CHIKV. The outbreak of infection and studies about it reveals that people living near to forest and water stores are more prone to this viral disease, since these areas provide better environment for mosquito breeding. High fever and arthritic pain, especially severe pain on extremes is characteristic of chikungunya fever. In allopathic, treatment is based on the symptoms and no preventive drugs are available. Siddha system claims some medicines for both treatment and prevention, but is not scientifically proven. By taking proper precaution against mosquito bites by using insecticides, repellents and other measures, transmission of CHIKV can be prevented to greater extent.^[9,10,12,14]

HISTORY OF CHIKUNGUNYA DISEASE

The name is derived from the Makonde word meaning "that which bends up" in reference to the stooped posture developed as a result of the arthritic symptoms of the disease. The disease was first described by Marion Robinson and W.H.R. Lumsden in 1955, following an outbreak in 1952 on the Makonde Plateau, along the border between Mozambique and Tanganyika (the mainland part of modern day Tanzania).^[12,15]

According to the initial 1955 report about the epidemiology of the disease, the term 'chikungunya' is derived from the Makonde root verb kungunyala, meaning to dry up or become contorted. In concurrent research, Robinson glossed the Makonde term more specifically as "that which bends up." Subsequent authors apparently overlooked the references to the Makonde language and assumed that the term derived from Swahili, the lingua franca of the region. The erroneous attribution of the term as a Swahili word has been repeated in numerous print sources. Many other erroneous spellings and forms of the term are in common use including "Chicken guinea", "Chicken gunaya “and” Chickengunya". ^[2,1,11] Since its discovery in Tanganyika, Africa, in 1952, chikungunya virus outbreaks have occurred occasionally in Africa, South Asia, and Southeast Asia, but recent outbreaks have spread the disease over a wider range. The first outbreak in India’s was in 1963, in Calcutta. Since then there have been sporadic outbreaks in various parts of the India. However recently reports have been show the re- emergency of the disease in India in 2005, especially in the southern states. Science the Outbreak in December 2005 there have been more than 180000, reported cases of chikungunya in India.

Beginning of 2006 between February there have been more than 2000 cases reported in Maharashtra. After the heavy rains and flooding in some parts of India, there are reports of an outbreak of chikungunya fever across the country. Hundreds have been bitten by the aedes Aegypti mosquito, which transmits the chikungunya virus. Chikungunya, a viruldeases spread through mosquitoes, has resurfaced after 32 long years, affecting lakshs of peoples across in India.

Chikungunya (pronounced as chik’-en-GUN-yah) disease was first detected in 1952 in Africa at a place called Makonde Plateau. This is a border area between Tanzania and Mozambique. The name "chikungunya" is from the Makonde language and its meaning is "that which bends up". This is a reference to the Chikungunya symptom where patients walk in a stooped posture due to joint pain. Chikungunya is also known as Chicken guinea, Chicken gunaya and Chickengunya. The similarity to the word "Chicken" has also lead to a lot of misconceptions about the disease. ^[15,16,19]

There were two medical reports published in 1955 which identified and described Chikungunya disease. "An epidemic of virus disease in Southern Province, Tanganyika Territory, in 1952-53.II. General description and epidemiology" by W.H.R. Lumsden and "An epidemic of virus disease in Southern Province, Tanganyika Territory, in 1952-53. I. Clinical features." by M. Robinson looked at the infections at Makonde Plateau. In these papers, authors note the similarity of Chikungunya to Dengue fever. Since 1952, Chikungunya showed cyclical outbreaks. Most number of Chikungunya cases were reported between 1960 and 1982 in Africa and Asia. The disease was not reported for a long time and it reappeared in 1999. From 2003 onwards frequent outbreaks were reported especially in south India. Following is a short summary of reported outbreak of Chikungunya worldwide.^[2,1,11]

CHIKUNGUNYA CASES REPORTED:

· 1952 - Outbreak of Chikungunya detected in Makonde Plateau.

· 1955 - Marion Robinson and W.H.R. Lumsden identifies and describes Chikungunya.

· 1963/64 - Chikungunya detected Indian cities mainly Calcutta, Maharashtra and vellore. The numbers of infections were in lakhs (100,000+) and over 200 deaths were reported.

· 1969 - Chikungunya detected in Srilanka.

· 1975 - Chikungunya detected in Vietnam and Myanmar.

· 1982 - Chikungunya detected in Indonesia.

· 2005/2006 - Chikungunya was reported in Reunion Islands and about 200 people died due to the disease. It was also widely reported from south Indian states namely Kerala, Karnataka, Tamil Nadu and Andhra Pradesh.

· 2007/2008 - Chikungunya infection was reported from various parts of India. It spread to other south Asian countries including Maldives and Pakistan. By 2008, infection was reported from Italy, Singapore and Australia. ^[2,1,11]

Chikungunya Virus

Chikungunya is caused by Chikungunya Virus or CHIK Virus (CHIKV) and it belongs to the alphavirus family. 27 different types of alpha viruses cause diseases in humans and other mammals. Chikungunya virus is just one of them. Under virus classification Chikungunya Virus is a Group IV virus belonging to the Togaviridae family and Alphavirus genus. There are multiple variants of Chikungunya virus and new variants may appear after genetic mutations. The photo on the right is the structure of a Togaviridae family virus and represents the photo of a Chikungunya virus. The structure has a diameter of about 50nm to 70nm. Chikungunya virus consists of a single stranded positive sense RNA^.[4]

Figure: 2 Chikungunya virus^[4]

Classification of Chikungunya Virus

Following diagram shows the classification of Chikungunya Virus. Note that the a number of alphaviruses (Ross River Virus, Chikungunya virus etc.) are usually transmitted via mosquitoes and hence is known as Arboviruses (Anthropod Borne Viruses). ^[4,21,27]

Figure: 3 Classification of Chikungunya Virus Passive immunity

Antibodies isolated from patients recovering from Chikungunya fever have been shown to protect mice from infection. ^[15]

Prognosis

Recovery from the disease varies by age. Younger patients recover within 5 to 15 days; middle-aged patients recover in 1 to 2.5 months. Recovery is longer for the elderly. The severity of the disease as well as its duration is less in younger patients and pregnant women. In pregnant women, no untoward effects are noticed after the infection.Ocular inflammation from Chikungunya may present as iridocyclitis, and have retinal lesions as well. Pedal oedema (swelling of legs) is observed in many patients, the cause of which remains obscure as it is not related to any cardiovascular, renal or hepatic abnormalities.^[17,18]

Epidemiology

Chikungunya virus is an alphavirus closely related to the O'nyong'nyong virus, the Ross River virus in Australia, and the viruses that cause eastern equine encephalitis and western equine encephalitis. The Aedesaegypti mosquito biting human flesh. Chikungunya is generally spread through bites from Aedesaegypti mosquitoes, but recent research by the Pasteur Institute in Paris has suggested that Chikungunya virus strains in the 2005-2006 Reunion Island outbreak incurred a mutation that facilitated transmission by Aedesalbopictus (Tiger mosquito). Concurrent studies by arbovirologists at the University of Texas Medical Branch in Galveston, Texas, confirmed definitively that enhanced chikungunya virus infection of Aedesalbopictus was caused by a point mutation in one of the viral envelope genes Enhanced transmission of chikungunya virus by Aedesalbopictus could mean an increased risk for chikungunya outbreaks in other areas where the Asian tiger mosquito is present. A recent epidemic in Italy was likely perpetuated by Aedesalbopictus. ^{[38,9, 11]}

In Africa, chikungunya is spread via a sylvatic cycle in which the virus largely resides in other primates in between human outbreaks. On 28 May2009 in Changwat Trang of Thailand where the virus is endemic, the provincial hospital decided to deliver by Caesarean section a male baby from his Chikungunya-infected mother—Khwanruethai Sutmueang, 28, a Trang native—in order to prevent mother-foetus virus transmission. However, after delivering the baby, the physicians discovered that the baby was infected with Chikungunya virus, and put him into intensive care because the infection had left the baby unable to breathe by himself or to drink milk. The physicians presumed that Chikungunya virus might be able to be transmitted from a mother to her foetus; however, there is no laboratory confirmation for this presumption^{.[ 26]}

Figure: 4 Transmission of virus

SIGN AND SYMPTOMS

Chikungunya symptoms begin almost immediately after the viral infection. Some of the symptoms are^[12]:-

 Fever with very high temperature.

 Acute pain all over the body.

 Sharp pain in the joints accompanied by swelling.

 Severe headache.

 Profuse rashes.

 Conjunctivitis.

 Loss of taste in the tongue.

 Mouth.

 Ulcers

The fever of chikungunya normally comes back to normal within two to three days, but the other symptoms persist for over a week or more. The fever is quite different from normal fever since it is accompanied by chills and feelings of nausea and vomiting.

The time between the bite of a mosquito carrying chikungunya virus and the start of symptoms ranges from 1 to 12 days^.[2,12]

CHIKV infection can cause a debilitating illness, most often characterized by fever, which can reach 39°C, (102.2°F) a petechial or maculopapular rash usually involving the limbs and trunk and arthralgia or arthritis affecting multiple joints which can be debilitating. The symptoms could also include headache, conjunctival infection, and slight photophobia. In the present epidemic in the states of Andhra Pradesh and Tamil Nadu, India, high fever and crippling joint pain are the prevalent complaint. The fever typically lasts for two days and abruptly comes down. However, other symptoms like intense headache, insomnia and an extreme degree of prostration last for a variable period, usually for about1-10 days. However, arthralgia may persist for months or years. In some patients, minor hemorrhagic signs such as epistaxis or gingivorrhagia have also been described. Platelet count in the body decrease until the disease persists. A condition known as Nuetropenia occurs at times. It is a condition in which the antibodies destroy the nuetrophils which are important white blood cells that help fight infection. Children, pregnant women and person under stress will be prone for more serious form of the complications. ^[31,25]

Dermatological manifestations observed in a recent outbreak of Chikungunya fever in Southern India, Western India and Eastern India includes the following:

 Nasal blotchy erythema.

 Freckle-like pigmentation over centro-facial area.

 Flagellate pigmentation on face and extremities.

 Lichenoid eruption and hyperpigmentation in photodistributed areas.

 Multiple aphthous-like ulcers over scrotum, crural areas and axilla.

 Lympoedema in acral distribution (bilateral/ unilateral).

 Multiple ecchymotic spots (Children).

 Vesiculobullous lesions (infants).

 Subungual hemorrhage.

 Photo Urticaria.

 AcralUrticaria.

 Cephalgia.

 Lumbago.

 Coffee Colored Vomiting.

 Epistaxis.

CAUSES AND TRANSMISSION OF CHIKV

CHIKV is spread by the bite of an infected mosquito. Mosquitoes become infected when they feed from a person infected with CHIKV. Monkeys, and possibly other wild animals, may also serve as reservoirs of the virus. Infected mosquitoes can then spread the virus to other humans when they bite. In Africa, the virus is maintained through a sylvatic transmission cycle between wild primates and mosquitoes such as Aedesluteocephalus, A. furcifer, or A. taylori. In Asia, CHIKV is transmitted from human to human mainly by A. aegypti (the yellow fever mosquito), a household container breeder and aggressive daytime biter which is attracted to humans, and, to a lesser extent, by A. albopictus (the Asian tiger mosquito) through an urban transmission cycle. ^[12,32]

The time of greatest risk of chikungunya virus transmission from a mother to fetus appears to be during birth, if the mother acquired the disease, days before delivery and carries the virus, according to the Perinatal Network of Reunion. This network of physicians and researchers on the French island of La Reunion has published a wealth of data on chikungunya infection during pregnancy since the epidemic began in March 2005. Preliminary data showed that such a contamination is "rarely serious" and more than 90 percent of the infected newborns recovered quickly without sequelae.

According to Dr. Marc Gabriele and Dr. Alby Jean Dominique of the Perinatal Network, they have seen cases of mother-to-fetus infection which occurred between 3 and 4.5 months of pregnancy. Beyond this period of pregnancy, no infection was found. However, there is a 48 percentage risk of infection at birth if the virus is still present in the mother's blood^.[25,28,20]

The incubation period (time from infection to illness) can be 2-12 days, but is usually 3-7 days. “Silent” CHIKV infections (infections without illness) do occur; but how commonly this happens is not yet known. ^[20]

CHIKV infection (whether clinical or silent) is thought to confer life-long immunity. According to the Regional Department of Health and Social Affairs of La Reunion, Immunoglobulin M [IgM], an antibody, generally appears between 4 and 7 days after the onset of clinical signs. IgM, however, does not pass through the placental barrier. The body starts producing Immunoglobulin G [IgG] around Day 15 and does pass it through the placenta and confer immunity to the fetus^.
[8,19,22,]

The Health and Social Affair Department mentions that such an infection may be "at the origin of miscarriages", but that they have not seen any increases in cases of birth defects associated with the illness. Fever, in general, can trigger uterine contractions, miscarriages or fetal deaths. When the babies were infected during birth, signs of infection appeared around Day 4. More than 90 percent of the infected newborns recovered rapidly without any subsequent problems.

Chikungunya disease is a viral disease transmitted in humans by the bite of infected mosquitoes. Aedesaegypti mosquito (also called yellow fever mosquito) is the primary transmission agent for Chikungunya Virus (CHIKV). This is usually found in tropics and hence the reason why Chikungunya is predominantly seen in asian countries. In recent cases, another mosquito species named Aedesalbopictus is found to be a carrier. Aedesaegypti bites during day time and hence day time mosquito bite is the main reason for transmission. Over years Aedes mosquito has evolved and has adapted itself for effective biting of humans! They even reduce humming of wings while approaching humans. They attack from below so there is minimal detection. This mosquito was usually seen in urban areas, but recently it has spread to many rural areas also. Aedes mosquito needs only 2ml of water for breeding and their eggs can lay dormant upto 1 year! Carrier mosquitos can even pass the infection to its next generation.^[8,19,22,]

DETECTION OF CHIKUNGUNYA VIRUS (CHIKV)

Chikungunya is a viral disease spread by mosquitoes which causes fever and severe joint pain – the name derives from a verb meaning ‘to become contorted’ and describes the appearance of sufferers bent with pain. Chikungunya is an alphavirus of the family Togaviridae and is usually spread by Aedesaegypti mosquitoes. In 2005-2006, however, a point mutation in one of the viral envelope genes facilitated transmission by Aedesalbopictus (tiger mosquito), increasing the risk of outbreaks in areas where the Asian tiger mosquito is present. In the coming years, expansion of the ranges of mosquitoes and changes in insect vectors could increase the spread of Chikungunya virus and other arboviruses^.[3,35,36]

There is no cure for Chikungunya and treatment is focussed on relieving symptoms. There is also no commercially available vaccine but researchers in the US have now developed an experimental vaccine using non-infectious virus-like particles (VLPs). Selective expression of viral structural proteins produced VLPs that resemble replication-competent alphaviruses and immunization with these VLPs led to neutralizing antibodies against envelope proteins from alternative Chikungunya strains. Rhesus macaques produced high-titre neutralizing antibodies that protected against viremia after high-dose challenge. When the monkey antibodies were transferred into immunodeficient mice, they protected against subsequent lethal viral challenge, indicating a humoral mechanism of protection. VLPs could potentially be developed to offer protection from other alphaviruses such as O’nyong’nyong virus, Ross River virus and Barmah Forest virus. Virus-like particle based-vaccines against human papillomavirus and hepatitis B virus have already been approved by the Food and Drug Administration. Blood test is the way to detect chikungunya virus. Conventional RT-PCR with a detection limit of 0.1PFU/ml., immunofluorescence analysis and one-step SYBR Green I-based real-time RT-PCR assay with detection limit of 10(7)-0.1PFU/ml is available.

Chikungunya disease is a viral disease transmitted in humans by the bite of infected mosquitoes. Aedesaegypti mosquito (also called yellow fever mosquito) is the primary transmission agent for Chikungunya Virus (CHIKV). This is usually found in tropics and hence the reason why Chikungunya is predominantly seen in asian countries. In recent cases, another mosquito species named Aedesalbopictus is found to be a carrier. Aedesaegypti bites during day time and hence day time mosquito bite is the main reason for transmission. Over years Aedes mosquito has evolved and has adapted itself for effective biting of humans! They even reduce humming of wings while approaching humans. They attack from below so there is minimal detection. This mosquito was usually seen in urban areas, but recently it has spread to many rural areas also. Aedes mosquito needs only 2ml of water for breeding and their eggs can lay dormant up to 1 year! Carrier mosquitoes can even pass the infection to its next generation. Chikungunya virus is indigenous to tropical Africa and Asia, where it is transmitted to humans by the bite of infected mosquitoes, usually of the genus Aedes. Chikungunya virus belongs to alpha-virus under Togaviridae family. ^[17,18]

PATHOPHYSIOLOGY

Pathophysiology is the study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome. More formally, it is the branch of medicine which deals with any disturbances of body functions, caused by disease or prodromal symptoms. An alternate definition is "the study of the biological and physical manifestations of disease as they correlate with the underlying abnormalities and physiological disturbances. Chikungunya virus (CHIKV) is an arbovirus responsible for acute febrile arthralgia. It re-emerged abruptly in 2005 and caused a massive outbreak in the Indian Ocean region, and then extended to Asia. Here we review the pathophysiology of CHIKV infection, based on human and mouse studies, and also present prospects for prevention and therapy of this infection^.[1,22,].

Chikungunya is a self limiting infection and most patient recover fully most patient recover from chikungunya virus infection. They get better after a few days however sometimes joint pain can persist for a longer period after the other symtoms have disappeared. Science that have been reportted in few countries but this may have been due to the in appropriate use of antibiotics and anti inflammatory drugs. As this virus can cause decrease platelets and result in bleeding one have to be careful that the drugs that are used not causing further drop the platelets or cause bleeding due to gastric inflammation and erosions or ulcer. Chikungunya virus (CHIKV) is a re-emerging arbors virus responsible for a massive outbreak currently afflicting the Indian Ocean region and India. Infection from CHIKV typically induces a mild disease in humans, characterized by fever, myalgia, arthralgia, and rash. Cases of severe CHIKV infection involving the central nervous system (CNS) have recently been described in neonates as well as in adults with underlying conditions. The pathophysiology of CHIKV infection and the basis for disease severity are unknown. To address these critical issues, we have developed an animal model of CHIKV infection. We show here that whereas wild type (WT) adult mice are resistant to CHIKV infection, WT mouse neonates are susceptible and neonatal disease severity is age-dependent. Adult mice with a partially (IFN-α/βR^+/−) or totally (IFN-α/βR^−/−) abrogated type-I IFN pathway develop a mild or severe infection, respectively.^[11]In mice with a mild infection, after a burst of viral replication in the liver, CHIKV primarily targets muscle, joint, and skin fibroblasts, a cell and tissue tropism similar to that observed in biopsy samples of CHIKV-infected humans. In case of severe infections, CHIKV also disseminates to other tissues including the CNS, where it specifically targets the choroid plexuses and the leptomeninges. Together, these data indicate that CHIKV-associated symptoms match viral tissue and cell tropisms, and demonstrate that the fibroblast is a predominant target cell of CHIKV. These data also identify the neonatal phase and inefficient type-I IFN signaling as risk factors for severe CHIKV-associated disease. The development of a permissive small animal model will expedite the testing of future vaccines and therapeutic candidates. Chikungunya virus (CHIKV) is transmitted by mosquito bites. CHIKV has recently re-emerged and is responsible for a massive outbreak in the Indian Ocean region and India. It has also reached Italy, indicating that CHIKV has a great potential to spread globally. Infection from CHIKV typically induces a mild disease in humans, characterized by a flu-like syndrome associated with muscle and joint pain and rash. Cases of severe infection involving the central nervous system (CNS) have recently been described, notably in neonates.^[2,6,3]We have developed the first animal model for CHIKV infection and studied the pathophysiology of the resulting disease. We show here that mouse neonates are susceptible to CHIKV and neonatal disease severity is age-dependent. Adult mice with a partial or complete defect in type-I interferon pathway develop a mild or severe infection, respectively. In mice with a mild infection, CHIKV primarily targets muscle, joint and skin fibroblasts, a cell and tissue tropism similar to that observed in biopsy samples of CHIKV-infected humans. In case of severe infections, CHIKV also disseminates to the CNS. Our work indicates that CHIKV-associated symptoms perfectly match viral tissue and cell tropisms, and demonstrate that the fibroblast is a prominent target cell of CHIKV. It also identifies the neonatal phase and inefficient type-I interferon signaling as risk factors for severe CHIKV-associated disease. The development of a permissive small animal model will expedite the testing of future vaccines and therapeutic candidates.^{[21,27,34,35]}

PREVENTION

The best way to avoid CHIKV infection is to prevent mosquito bites. There is no vaccine or preventive drug in allopathic. Prevention tips are similar to those for dengue or West Nile virus and these are as follows.^[18]

1. Use insect repellent containing a DEET (N, N-diethyl-3-methylbenzamide, N, N-diethyl-m-toluamide) or another EPA-registered active ingredient on exposed skin. Always follow the directions on the package of repellent. Length of protection from mosquito bites varies with the amount of active ingredient, ambient temperature, and amount of physical activity/perspiration, any water exposure, abrasive removal, and other factors. For long duration protection use a long lasting (micro-encapsulated) formula and re-apply as necessary, according to label instructions.

EPA recommends the following precautions when using insect repellents:

 Apply repellents only to exposed skin and/or clothing.

 Do not use repellents under clothing.

 Never use repellents over cuts, wounds or irritated skin.

 Do not apply to eyes or mouth, and apply sparingly around ears. When using sprays, do not spray directly on face. Spray on hands first and then apply to face.

 Do not allow children to handle the product. When using on children, apply to your own hands first and then put it on the child. You may not want to apply to children’s hands.



Use just enough repellent to cover exposed skin and/or clothing. Heavy application and saturation are generally unnecessary for effectiveness. If biting insects do not respond to a thin film of repellent, then apply a bit more.

 After returning indoors, wash treated skin with soap and water or bathe. This is particularly important when repellents are used repeatedly in a day or on consecutive days. Also, wash treated clothing before wearing it again. (This precaution may vary with different repellents).



If anybody gets a rash or other bad reaction from an insect repellent, stop using the repellent, wash the repellent off with mild soap and water, and call a local poison control center for further guidance.

2. Certain products which contain permethrin are recommended for use on clothing, shoes, bed nets, and camping gear, and are registered with EPA for this use. Permethrin is highly effective as an insecticide and as a repellent. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other arthropods and retains this effect after repeated laundering. The permethrin insecticide should be reapplied by following the label instructions. Some commercial products pretreated with permethrin are available.

3. Wear long sleeves and pants (ideally treat clothes with permethrin or another repellent).

4. Have secure screens on windows and doors to keep mosquitoes out.

5. Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths weekly. Drill holes in tire swings so water drains out. Keep children's wading pools empty and on their sides when they aren't being used.

6. Additionally, a person with chikungunya fever should limit their exposure to mosquito bites in order to avoid further spreading of infection.Insiddha,Balasanjeevi Tablet is given in the water boiled with cumin seeds (jeeragam) and thulasi regularly, to act as a best preventive medicine against Chikungunya.

7.Currently there is no vaccine for Chikungunya. There is only way to prevent Chikungunya fever - don't get bit by a mosquito! This is easier said than done in a tropical area such as India. Some of the following precautions can help reduce the risk of mosquito bites.

The following guidelines must be followed in case chikungunya: -

1. All stagnant water must be treated and removed. Stagnant water is where the infecting mosquito aedesaegypti breeds. Use insect repellants such as DEET or promythrin in the vicinity.

2. The water cannot be removed but used for cattle or other purposes, emephos can be used once a week at a dose of 1 ppm (parts per million). Pyrethrum extract (0.1% ready-to-use emulsion) can be sprayed in rooms (not utside) to kill the adult mosquitoes hiding in the house. In case there is an outspread of chikungunya, wear long pants and long sleeves hirts. The doors and windows of the houses must be kept closed, especially in the dawn and dusk periods. Chikungunya becomes an epidemic through people who travel from an affected area to an unaffected area. For this reason, it is very necessary to regulate travelers, from a place that has several cases of chikungunya.

Persons infected with chikungunya fever should be isolated from further mosquitoes bites to reduce the risk of further transmission of the virus.^[12,22,27]

Reducing the risk of mosquito bite

 Use mosquito net when sleeping during daytime.

 Wear dress which covers most of the body. Also there are repellents available which can be applied on dress materials.

 Use mosquito coils or repellents (which contain Picaridin, oil of lemon eucalyptus or DEET). But you should be aware that prolonged uses of these are not recommended. Also ensure adequate ventilation when these are used.

 Use curtains or window nets which prevent entry of mosquitos to the house.

 Use of cream or spray that can be applied on skin. This masks body odour and effectively you are invisible from mosquito. Very handy if you are visiting an area where Chikungunya is reported.

Another way to reduce the mosquite bite is to take steps to reduce its breeding. This needs to be a community effort since only one individual alone cannot achieve much. Some of the following steps can be taken to reduce mosquito breeding in your area,

Reducing mosquito breeding

The circled areas on the image displayed on the right side shows possible mosquito breeding sites.

 Drain all the water collected around your house (for example in a pot or water cooler).

 Ensure that drainages etc. are either closed or chemicals are applied which kill mosquito larvae (larvicides).

 Another technique is to collect water in a container and once mosquitos lay eggs in it destroy them. This technique can be quite effective if multiple people apply it at their area.

 If there is a pond which contains stagnant water, biological method is best. Fish varieties such as guppy can be introduced in the pond which will eat all the mosquito larvae.

That most infection happens occur outside the house and hence mosquito control is the most effective way to prevent Chikungunya outbreak. It is also important that patients with infection don't get bitten by mosquito. The most effective means of prevention are protection against contact with the disease-carrying mosquitoes and mosquito control. These include using insect repellents with substances like DEET (N,N-Diethyl-meta-toluamide; also known as N,N'-Diethyl-3-methylbenzamide or NNDB), icaridin (also known as picaridin and KBR3023), PMD (p-menthane-3,8-diol, a substance derived from the lemon eucalyptus tree), or IR3535. Wearing bite-proof long sleeves and trousers (pants) also offers protection. In addition, garments can be treated with pyrethroids, a class of insecticides that often has repellent properties. Vaporized pyrethroids (for example in mosquito coils) are also insect repellents.

DNA VACCINE

Chikungunya virus (CHIKV) is an emerging arbovirus and is an important human pathogen. Infection of humans by CHIKV can cause a syndrome characterized by fever, headache, rash, nausea, vomiting, myalgia, arthralgia and occasionally neurological manifestations such as acute limb weakness. It is also associated with a fatal haemorrhagic condition. CHIKV is geographically distributed from Africa through Southeast Asia and South America, and its transmission to humans is mainly through the Aedesaegypti species mosquitoes. The frequency of recent epidemics in the Indian Ocean and La Reunion islands suggests that a new vector perhaps is carrying the virus, as A. aegypti are not found there. In fact, a relative the Asian tiger mosquito, Aedesalbopictus, may be the culprit which has raised concerns in the world health community regarding the potential for a CHIK virus pandemic. Accordingly steps should be taken to develop methods for the control of CHIKV. Unfortunately, currently there is no specific treatment for Chikungunya virus and there is no vaccine currently available. Here we present data of a novel consensus-based approach to vaccine design for CHIKV, employing a DNA vaccine strategy. The vaccine cassette was designed based on CHIKV capsid- and envelope-specific consensus sequences with several modifications, including codon optimization, RNA optimization, the addition of a Kozak sequence, and a substituted immunoglobulin E leader sequence. The expression of capsid, envelope E1 and E1 was evaluated using T7-coupled transcription/translation and immunoblot analysis. A recently developed, adaptive constant-current electroporation technique was used to immunize C57BL/6 mice with an intramuscular injection of plasmid coding for the CHIK-Capsid, E1 and E2. Analysis of cellular immune responses, including epitope mapping, demonstrates that electroporation of these constructs induces both potent and broad cellular immunity. In addition, antibody ELISAs demonstrate that these synthetic immunogens are capable of inducing high titer antibodies capable of recognizing native antigen. Taken together, these data support further study of the use of consensus CHIK antigens in a potential vaccine cocktail. DNA vaccination is a technique for protecting an organism against disease by injecting it with genetically engineered DNA to produce an immunological response. Nucleic acid vaccines are still experimental, and have been applied to a number of viral, bacterial and parasitic models of disease, as well as to several tumour models. DNA vaccines have a number of advantages over conventional vaccines, including the ability to induce a wider range of immune response types. A recent study supports a novel consensus-based approach to vaccine design for Chikungunya virus employing a DNA vaccine strategy. The vaccine cassette was designed based on CHIKV Capsid and Envelope specific consensus sequences with several modifications, including codon optimization, RNA optimization, the addition of a Kozak sequence, and a substituted immunoglobulin E leader sequence. Analysis of cellular immune responses, including epitope mapping, demonstrates that these constructs induces both potent and broad cellular immunity in mice. In addition, antibody ELISAs demonstrates that these synthetic immunogens are capable of inducing high titer antibodies capable of recognizing native antigen. Taken together, these results support further study of the use of consensus CHIKV antigens in a potential vaccine cocktail.There are no commercialized vaccines or therapeutics against CHIKV. In fact, very little is known about the basis for CHIKV-based disease, including the mechanism of immune-based viral clearance and the causes of clinical symptoms. Considering the potential for global spread of CHIKV, understanding the virus's pathogenic mechanism.
Inovio scientists used its proprietary SynCon approach to develop a universal CHIKV DNA vaccine. The candidate vaccine is delivered as a single DNA plasmid construct containing consensus sequences of key surface antigens. The universal CHIKV vaccine was designed by aligning numerous primary sequences of key surface antigens and choosing the most common amino acid or base pair at each site.^[20,34]

DIAGNOSIS OF CHIKUNGUNYA:

Chikungunya is diagnosed by ELISA blood test. Blood test is the only reliable way to identify Chikungunya since the symptoms are similar to much more deadly dengue fever. Also co-occurance of these diseases is seen in many places. Detection of virus nucleic acid in serum by RT-PCR. This needs to be conducted within 5 days of infection. The clinical manifestations of chikungunya fever resemble those of dengue fever. Laboratory diagnosis is critical to establish the cause of diagnosis and initiate specific public health response.[^16,17]

Types of Laboratory tests

Detection of virus nucleic acid in serum by RT-PCR. This needs to be conducted within 5 days of infection. The clinical manifestations of chikungunya fever resemble those of dengue fever. Laboratory diagnosis is critical to establish the cause of diagnosis and initiate specific public health response.Three main laboratory tests are used for diagnosing Chikungunya fevers: virus isolation, serological tests and molecular technique of Polymerase Chain Reaction (PCR). ^[18]

Virus isolation

Virus isolation is the most definitive tests. Between 2-5 ml of whole blood is collected during the first week of illness in commercial heparinzed tube and transported on ice to the laboratory. The CHIK virus produces cytopathic effects in a variety of cell lines including BHK-21, HeLa and Vero cells^.
[7] The cytopathic effects must be confirmed by CHIK specific antiserum and the results can take between 1-2 weeks. Virus isolation must only be carried in BSL-3 laboratories to reduce the risk of viral transmission.

RT-PCR

Recently, a reverse transcriptase, RT- PCR technique for diagnosing CHIK virus has been developed using nested primer pairs amplifying specific components of three structural gene regions, Capsid (C ), Envelope E-2 and part of Envelope E1. PCR results can be available from within 1-2 days. Specimens for PCR is same as the virus isolation i Chikungunya (CHIK) virus is enzootic in many countries in Asia and throughout tropical Africa. In Asia the virus is transmitted from primates to humans almost exclusively by Aedesaegypti, while various aedine mosquito species are responsible for human infections in Africa. The clinical picture is characterized by a sudden onset of fever, rash and severe pain in the joints which may persist in a small proportion of cases. Although not listed as a haemorrhagic fever virus, illness caused by CHIK virus can be confused with diseases such as dengue or yellow fever, based on the similarity of the symptoms. Thus, laboratory confirmation of suspected cases is required to launch control measures during an epidemic. CHIK virus diagnosis based on virus isolation is very sensitive, yet requires at least a week in conjunction with virus identification using monovalent sera.^[7,3]We developed a reverse transcription–polymerase chain reaction (RT-PCR) assay which amplifies a 427-bp fragment of the E2 gene. Specificity was confirmed by testing representative strains of all known alphavirus species. To verify further the viral origin of the amplicon and to enhance sensitivity, a nested PCR was performed subsequently. This RT-PCR/nested PCR combination was able to amplify a CHIK virus-specific 172-bp amplicon from a sample containing as few as 10 genome equivalents. This assay was successfully applied to four CHIK virus isolates from Asia and Africa as well as to a vaccine strain developed by USAMRIID. Our method can be completed in less than two working days and may serve as a sensitive alternative in CHIK virus diagnosis.^[17]

Serological diagnosis

For serological diagnosis between 10-15 ml of whole blood sera are required; an acute phase serum must be collected immediately after clinical onset and a convalescent phase serum10-14 after the disease onset. The blood specimen is transported at 4 degrees and not frozen to the laboratory immediately. If testing cannot be done immediately, the blood specimen is separated into sera that should be stored and shipped frozen. Serologic diagnosis can be made by demonstration of fourfold increase in antibody in acute and convalescent sera or demonstrating IgM antibodies specific for CHIK virus. A commonly used test is the Immunoglobulin M Antibody (IgM) capture enzyme-linked immunosorbent assay (MAC-ELISA). Results of MAC-ELISA can be available within 2-3 days. Cross-reaction with other flavirus antibodies such as o’nyong-nyong and SemlikiForest occur in the MAC-ELISA; however, the latter viruses are relatively rare in South East Asia but if further confirmation is required it can be done by neutralization tests and Hemagglutination Inhibition Assay (HIA). ^[17,18,19]

 Interpretation of the results

Sero-diagnosis rests on demonstrating a fourfold increase in CHIK IgG titer between the acute and convalescent phase sera. However, getting paired sera is usually not practical. Alternatively, the demonstration of IgM antibodies specific for Chikungunya virus in acute-phase sera is used in instances where paired sera cannot be collected. A positive virus culture supplemented with neutralization is taken as definitive proof for the presence of Chikungunya virus. PCR results for E1 and C genome either singly or together constitute a positive result for Chikungunya virus.

Laboratory Diagnosis in the world:

The virology laboratory network in South East Asia, from India, Indonesia, Myanmar,

Sri Lanka and Thailand can perform many of the laboratory tests for CHIK virus.^[27,28]

Table:1 Laboratory Diagnosing of Chikungunya

Country	Serological Test	PCR
India	National Institute of Virology, Pune	National Institute of Virology, Pune
Indonesia	NIHRD, NAMRU-2,	NIHRD ,NAMRU-2
Myanmar	Department of Medical Research	NA
Sri Lanka	Medical Research Institute	Medical Research Institute
Thailand	NIH, Bangkok, AFRIMS	NIH, Bangkok, AFRIMS

Molecular diagnosis for chikV:

We urgently established the molecular and serological methods for the diagnosis of Chikungunya virus (CHIKV) from various types of samples. METHODS: CHIKV RNA was detected using a highly sensitive real-time RT PCR assay. A co-extracted and co-amplified internal control RNA was used to identify RT PCR inhibitors. Depending on their nature samples were pretreated before nucleic acid extraction. Viral loads were measured using a synthetic RNA calibrator. CHIKV immunoglobulin (Ig) G and M antibodies were detected by ELISA either from sera or from blood absorbed on filter paper. RESULTS: CHIKV RNA was found in various types of samples such as plasma, cerebrospinal fluid, and placenta, but was not found in some samples including maternal milk and synovial samples. Detection of IgG from filter paper absorbed blood is specific and sensitive. Routine data showed that maternally transferred IgG and naturally acquired IgMpersist at least 12 and 18 months, respectively. The techniques enabled the diagnosis of chikungunya in known and newly described forms of the disease. They are used for routine diagnosis and large scale surveys.^[25,26,27]

TREATMENT OF CHIKUNGUNYA

Allopathic treatment

There is no antiviral drug or medicine specifically for Chikungunya. But since chikungunya is cured by immune system in almost all cases there is no need to worry. Treatment usually is for the symptoms and include taking sufficient rest, taking more fluid food and medicines to relieve pain (paracetamol for example). Aspirin should be avoided. Honey and lime mix is found to have soothing effect on the disease. Avoiding specific medicines is actually recommended for quick recovery. Also very mild exercise to joints can help ease the pain.Currently there is no vaccination against Chikungunya. Research is on going on the development of DNA vaccination against Chikungunya.

Usually the disease starts to decrease in intensity after 3 days and it may take up to 2 weeks for recovery. But in elderly the recovery is very slow and may take upto 3 months. In some cases the joint pain can last even upto a year. There is no specific vaccine or specific antiviral treatment for Chikungunya. Vaccine trials were carried out in 2000, but funding for the project was discontinued and there is no vaccine currently available. Chloroquine is gaining ground as a possible treatment for the symptoms associated with Chikungunya and as an antiviral agent to combat the Chikungunya virus. According to the University of Malaya, in unresolved arthritis refractory to aspirinand nonsteroidal anti-inflammatory drugs, chloroquine phosphate (250 mg/day) has given promising results. Research by Italian scientist, Andrea Savarino, and his colleagues, in addition a French government press release in March 2006 have added more credence to the claim that chloroquine may be effective in treating Chikungunya. The researches on treatment of CHIKV infection advises against usage of Aspirin. Ibuprofen, Naproxen and other non-steroidal anti-inflammatory drugs are recommended for arthritic pain and fever. ^[30.31,32]

In siddha, for the treatment of chikungunya, antipyretic is given to reduce the temperature. Nilavembu Kudineer (Kudineer-Decoction) is one of the best antipyretic drug. Along with this decoction, VathajuraKudineer can be given; it helps to reduce the joint pain and swelling. ^[33,34,35]

Ayurvedic treatment

Since there is no medicine for Chikungunya in allopathy, people increasingly turning to traditional indian medicines (ayurveda). Ayurveda treatment of Chikungunya uses herbal drugs. Some of the kashayams (concoctions) prescribed are Amrutharista, Dhanvantaram Gutika and Amruthotharam Kashayam. Ancient ayurveda describes a similar condition called Sandhijwara which is similar to Chikungunya in its symptoms (joint pain). Hence some of the medicines can sooth joint pain. At the same time there are reports of fake medicines in which steroids are added. These can cause severe side effects in long term. Hence the best advice is to take rest and drink plenty of fluid food.^[34,35]

Homeopathic treatment

According to homeopathic experts effective drugs are available to prevent as well as to speed up recovery from Chikungunya. In some of the south Indian cities this type of treatment is tried out. It is claimed that the medicine Eupatorium perf can prevent Chikungunya infection. Other medicines prescribed for the disease include Pyroginum, Rhus-tox, Cedron, Influenzinum, China and Arnica.^[36,37]

CONCLUSION:

Chikungunya, the disease spreads by Chikungunya virus (CHIKV) is a member of the genus Alphavirus, in the family Togaviridae. Its cause, mode of transmission, detection of virus, symptoms, treatment and prevention is discussed. Vaccine trials have been going on but not yet found any. Mutation of virus causing additional problems for the treatment. NSAIDS are good to reduce fever and pain but aspirin should be avoided in acute stage. Infected patient should be cautious to avoid further mosquito exposure to avoid transmission of disease. All must take protective measures to prevent mosquito breeding and bite by keeping surround clean, periodically emptying the water storages, using proper insecticides and repellents. Each government must take the responsibility to make aware the public about chikungunya fever; so that this ″killing″ sick may keep away from public. The RT-PCR assays have potential utility for detection and quantification of CHIKV. These assay systems have been demonstrated to be rapid, easy to handle, highly sensitive, quantitative and specific. These features make it an excellent tool for laboratory detection of CHIKV in tissue-cultured supernatant as well as acute-phase patient serum samples. The RT-LAMP assay is an emerging gene amplification tool, having all the characteristics of rapidity and high sensitivity of real-time assays as well as the added features of adaptability under field conditions owing to its simple operation, rapid reaction, and easy detection. The rapidity and sensitivity of these real-time assays will assist in precise diagnosis, which will be extremely useful to facilitate suitable control measures and patient management at the earliest stages of outbreak.

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Received on 10.11.2011

Modified on 05.12.2011

Accepted on 15.12.2011

Research J. Pharmacology and Pharmacodynamics. 4(1):Jan. - Feb., 2012, 62-73