Zika Virus and Hearing Loss

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Robert Traynor
June 14, 2016

 

z9Born in 1764 as the fifth of eight children, young Johann was fascinated with bugs.  Growing up in the Town of Solingen, Germany on his grandparents farm outside of town, he collected flies and other bugs and mounted them in groups that seemed to be similar.  He was formally educated to some degree in the schools of Solingen but also by tutors and his own reading.  In his twenties Johann took drawing classes and began his journey in the study of Dipterians (the study of flies).  While he primarily studied the Dipterians of Europe, his drawings of flies and other insects become world famous in the early 19th century.

Johann Wilhelm Meigen (1764-1845) was an entomologist at the time the field was just being described by William Kirby.  While Kirby, an Englishman, is considered “the father of entomology”,  Meigen is universally recognized as the “father” of Dipterology. Aside from his beautifully executed drawings Meigen’s great achievement was to employ combinations of morphological characters to work out his scientific classifications. One of his famous descriptions is that of the Aedes mosquito which he first described in 1818, and which now has 700 varieties. In categorizing this famous disease spreading culprit, Meigen used the Greek language.  The definition of the Greek word ‘aedes’ means ‘unpleasant’ or ‘odious’, a fitting description for this distinctive, destructive insect.

Life Cycle of the Aedes aegypti

Except for the application of repellant, Audiologists do not usually think much about entomology especially mosquitos, which is z3Spanish for “little fly”.  The dangerous Aedes aegypti variety is similar to mosquito species in that it will go through the usual four stages: egg, larva, pupa, and adulthood.   Tiny mosquito.com (2016) indicates that once the female lays her eggs in a suitable pool of water, they can hatch and the larvae can emerge the very same day, given the proper environmental conditions. After approximately four days, the larvae transform into pupae and remain helpless in the water for about two days, after which time the mosquitoes become full-grown adults and are able to fly, breed, and feed. The female breeds, after  World map showing countries and territories with reported active transmission of Zika virus (as of May 19, 2016). Countries are listed in the table below.she has found a blood meal, laying her eggs in water, and the cycle begins all over again. They further present that the Aedes mosquito has a lifespan of about two weeks in nature, although it is possible for it to live longer given a fitting environment.  The Aedes mosquito is typically located in tropical countries and subtropical zones such as the southern United States and Latin America. However, due to human activity, some species have been found in temperate areas and other regions of thez5 planet such as Asia and the Arctic.  In urban areas, it is possible to discover the eggs of the Aedes in various exterior objects where water collects. Garden pots, used tires, children’s pools, roof tanks and rain barrels are ideal spots for a female mosquito to lay her eggs. Therefore, it might be z10worthwhile to inspect your property and attempt to eliminate items that collect water in order to limit mosquito breeding.  In favorable climates to the Aedes, the mosquito problem can become so bad that it greatly disrupts major activities.  During the Spanish American War the United States lost more soldiers to the Aedes aegypti mosquito carrying Yellow Fever than to combat and later had significant difficulty keeping workers from this disease during the construction of the Panama Canal.

The Zika Virus?

During routine monitoring for Yellow Fever, the Zika virus was first discovered in 1947 and is named after the Zika Forest in Uganda. In 1952, the first human cases of Zika were detected and since then, outbreaks of Zika have been typically reported in tropical Africa, Southeast Asia, and the Pacific Islands. The first human cases were discovered in Uganda and Tanzania in 1952.  The Zika virus is spread to the human population through the bites of the female Aedes mosquito.  Symptoms of the virus will typically last from several days to a week after being bitten by the mosquito.  According to the US Centers for Disease Control and Prevention, the symptoms consist of fever, rash, joint pain and conjunctivitis or red eyes.  The virus is rarely fatal and the victims do not usually end up in the hospital.  Usually when the disease has passed the infected person becomes immune to further episodes of the virus.  The real victims of the Zika virus, however, are when it  infects pregnant women as it causes a serious birth defect called microcephaly leading to developmental, visual and hearing disorders.

The Current Zika Virus Outbreak

Brazil is the epicenter of the current outbreak and it is thought that it was brought to that country especially as the result of the 2014 FIFA World Cup.   Of special concern are the visitors, the athletes, and spectators at the 2016 Olympic Games slated for Rio de Janeiro, Brazil, later this year. Those of child bearing age are most at risk. Click here or on the Tree photo for a video on the  current Zika Virus Epidemic) As the epidemic progressed this spring, various health organization around the world issued statements within one week of each other about the virus and its possible effects on newborns. In  light of these recent health advisories from the US Center for Disease Control and z11Prevention, Pan-American Health Organization, the European Commission on Health Safety, and the World Health Organization, the potential risks for infants born to mothers infected with the Zika virus during pregnancy; the American Academy of Audiology and other organizations worldwide believe that it is essential for families and professionals to be aware that hearing loss  could occur at birth or even acquired later. Much like Cytomeglovirus, and other pathologies, it is crucially important to identify hearing loss through newborn and infant hearing screeningpreschool and school-aged screening programs for children at high risk for hearing loss as a consequence of Zika Virus Disease.  Special care should be taken in pediatric clinics in the assessment of infants and young children of mothers that were in the areas where the current dreaded Zika Virus threat is known to exist, especially the Caribbean, South America, New Guinea.

References:

American Academy of Audiology (2016). Zika virus disease outbreak and infant hearing loss.  Retrieved June 13, 2016.

Audiology Online (2016). Zika virus outbreak and infant hearing loss.  Retrieved June 13, 2016.

Centers for Disease Control and Prevention (2016).  Zika and Pregnancy.  Retrieved June 13, 2016.

Centers for Disease Control and Prevention (2016).  About Zika Virus.  Retrieved June 14, 2016.

Tiny Mosquito (2016). Dangers of the Aedes mosquito.  Tiny mosquito.com.  Retrieved June 13, 2016.

Images:

Center for Disease control and Prevention (2016). All countries with active Zika virus transmission.  Zika Virus.  Retrieve June 13, 2016.

European Commission on Public Health (2016).  Outbreak of Zika Virus.  Retrieved June 14, 2016.

Flyobsession (2016).  New flies in town.  Retrieved June 14, 2016.

World Health Organization (2016).  The history of the Zika virus.  The world Health Organization.  Retrieved June 14, 2016.

Videos:

SciShow (2016).  The Zika Virus:  What we know (and what we don’t know).  SciShow.  YouTube.com  Retrieved June 14, 2016.

 

 

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