What's Chikungunya

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV), an RNA virus in the alphavirus genus of the family Togaviridae. The name chikungunya derives from a word in the Kimakonde language of southern Tanzania, meaning “that which bends up” and describes the contorted posture of infected people with severe joint pain.

Key facts·

• Chikungunya is a disease caused by thechikungunya virus, which is transmitted tohumans by infected mosquitoes, with largeoutbreaks and sporadic cases reported mostlyin the Americas, Asia and Africa, andoccasional smaller outbreaks in Europe.
• The symptoms of chikungunya are similar tothose of dengue and Zika, makingchikungunya easy to misdiagnose and makingit more difficult for countries to accuratelydetermine the number of people infected.
• Chikungunya causes fever and severe jointpain, which is often debilitating and may beprolonged; other symptoms include jointswelling, muscle pain, headache, nausea,fatigue and rash.
• There are currently two chikungunya vaccinesthat have received regulatory approvals inseveral countries and/or have beenrecommended for use in populations at risk,but the vaccines are not yet widely availablenor in widespread use. WHO and externalexpert advisors are reviewing vaccine trial andpost-marketing data in the context of globalchikungunya epidemiology to inform possiblerecommendations for use.
• There is no specific antiviral treatment forchikungunya virus infections but antipyreticand analgesic medications (such asparacetamol) for fever and pain can be usedto alleviate these symptoms.
• Severe symptoms and deaths fromchikungunya are rare and usually occur inyoung babies or elderly people with othercoexisting health problems.

Distribution and outbreaks

CHIKV was first identified in the United Republicof Tanzania in 1952 and subsequently in othercountries Africa and Asia (1). Urban outbreakswere first recorded in Thailand in 1967 and inIndia in the 1970s (2). Since 2004, outbreaks ofCHIkV have become more frequent andwidespread, caused partly due to viraladaptations allowing the virus to be spread moreeasily by Aedes albopictus mosquitoes andbecause CHIKV has been introduced intoimmunologically naive populations. CHIKV hasnow been identified in >110 countries in Asia,Africa, Europe and the Americas. Transmissionhas been interrupted for several years on islandswhere a high proportion of the population isinfected and then immune; however,transmission often persists in countries wherelarge parts of the population have not yet beeninfected.

All regions with established populations of Aedesaegypti or Aedes albopictus mosquitoes have nowexperienced local mosquito-borne transmission.

Transmission
Chikungunya virus is transmitted by infectedfemale mosquitoes, most commonly Aedesaegypti and Aedes albopictus, which can alsotransmit dengue and Zika viruses. Thesemosquitoes bite primarily during daylight hoursand Aedes aegypti feeds both indoors andoutdoors. They lay eggs in containers withstanding water. Both species feed outdoors,
and Ae. aegypti also feeds indoors.When an uninfected mosquito feeds on a personwho has CHIKV circulating in their blood, themosquito can ingest the virus. The virus thenreplicates in the mosquito over several days,enters its salivary glands, and can be transmittedinto a new human host when the mosquito bitesthem. The virus again begins to replicate in thisnewly infected person and reaches highconcentrations in their blood, at which point theycan further infect other mosquitoes andperpetuate the transmission cycle.

Symptoms
In symptomatic patients, CHIKV disease onset is typically 4-8 days (range 2-12 days) after the bite of an infected mosquito. It is  characterized by an abrupt onset of fever, frequently accompanied by severe joint pain. The joint pain is often debilitating and usually lasts for a few days but may be prolonged, lasting for weeks, months or even years. Other common signs and symptomsinclude joint swelling, muscle pain, headache,nausea, fatigue and rash. Since these symptomsoverlap with other infections, including thosewith dengue and Zika viruses, cases can bemisdiagnosed. In the absence of significant jointpain, symptoms in infected individuals areusually mild and the infection may gounrecognized.
Most patients recover fully from the infection;however, occasional cases of eye, heart, andneurological complications have been reportedwith CHIKV infections. Patients at extremes ofthe age spectrum are at higher risk for severedisease including newborns infected duringdelivery to infected mothers or bitten by infectedmosquitoes in the weeks after birth, and olderpeople with underlying medical conditions.Patients with severe disease requirehospitalization because of the risk of organdamage and death.
Once an individual is recovered, availableevidence suggests they are likely to be immunefrom future chikungunya infections (4).

Diagnostics
Chikungunya virus may be detected directly inblood samples collected during the first week ofillness using tests such as reverse transcriptase-polymerase chain reaction (RT-PCR).

Other tests can detect a person's immuneresponse to chikungunya virus infection. Theseare typically used after the first week of infectionto test for antibodies to the virus. The antibodylevels are typically detectable by the first weekafter illness onset and can still be detected forabout 2 months.

Treatment and vaccines
The clinical management includes addressingfever and joint pain with anti-pyretics andoptimal analgesics, drinking plenty of fluids andgeneral rest. There is no specific antiviral drugtreatment for CHIKV infections.
Paracetamol or acetaminophen arerecommended for pain relief and reducing feveruntil dengue infections are ruled out, as non-steroidal anti-inflammatory drugs (NSAIDs) canincrease the risk of bleeding.
There are currently two chikungunya vaccinesthat have received regulatory approvals and/orhave been recommended for use in populationsat risk in several countries, but the vaccines arenot yet widely available nor in widespread use.WHO and external expert advisors are reviewingvaccine trial and post-marketing data in thecontext of global chikungunya epidemiology toinform possible recommendations for use.

Prevention and control
Avoidance of mosquito bites offers the bestprotection against CHIKV infection. Patientssuspected of having CHIKV infection shouldavoid getting mosquito bites during the firstweek of illness to prevent further transmission tomosquitoes, that may in turn infect other
people.The main method to reduce transmission ofCHIKV is through control of the mosquito vectorsand reduction of mosquito breeding sites. Thisrequires mobilization of communities, who arecritical in reducing mosquito breeding sitesthrough emptying and cleaning containers thatcontain water on a weekly basis, disposing ofwaste, and supporting local mosquito control
programmes.During outbreaks, insecticides may be sprayed tokill flying adult mosquitoes, applied to surfacesin and around containers where the mosquitoesland, and used to treat water in containers to killthe immature mosquito larvae. This may also beperformed by health authorities as anemergency measure to control the mosquitopopulation.
People living in or visiting areas with CHIKVtransmission are advised to wear clothing thatminimizes skin exposure to the day-bitingmosquitoes. Window and door screens should beused to prevent mosquitoes from entering homes. Repellents can be applied to exposedskin or to clothing in strict accordance withproduct label instructions. Repellents shouldcontain DEET, IR3535 or icaridin.
Insecticide-treated mosquito nets should beused against day-biting mosquitoes by personswho sleep during the daytime, for exampleyoung children, sick patients or older people.

WHo response
WHO supports countries to conduct surveillanceand control of arboviruses through theimplementation of the Global ArbovirusInitiative.
WHO responds to chikungunya in the following ways:

• supporting countries in the confirmation ofoutbreaks through its collaborating networkof laboratories;
• providing technical support and guidance tocountries for the effective management ofmosquito-borne disease outbreaks;
• reviews the development of new tools,including insecticide products and applicationtechnologies;
• formulating evidence-based strategies,policies and outbreak management plans;
• providing technical support and guidance tocountries for the effective management ofcases and outbreaks;

WHO link:
https://lnkd.in/gu8gUQAF

written by Jack Hui 

19th Asian Games Supplier | Guardian of Public Health, Food Safety and Livable Environment

Dengx Technology is a manufacturer of fly trap and mosquito killer lamp since 2016