Zika Virus Outbreak

Do you know why is it called Zika Virus? It was first isolated from Rhesus monkeys in Zika forest near Lake Victoria in Uganda.

Zika Virus Outbreak

[op-ed snap] The threat of Ebola

Note4Students

From UPSC perspective, the following things are important :

Prelims level : Nothing Much

Mains level : Ebola outbreak in Congo

The health emergency declared by the WHO can counter the risk of a global spread

Background

  • After holding itself back on three occasions, the World Health Organization has declared the Ebola virus disease outbreak in the Democratic Republic of the Congo a Public Health Emergency of International Concern.
  • The outbreak in Congo, officially declared on August 1, 2018, has killed nearly 1,700 people and made more than 2,500 people ill.
  • While cases in other areas are reducing, Beni is the new hotspot.
  • The announcement of the health emergency comes amid renewed concerns that the virus could spread to other countries.
  • A single imported case of Ebola in Goma, a city in Congo with two million people and with an international airport bordering Rwanda, served as a trigger to finally declare a global emergency.
  • Surprisingly, the spread to neighbouring Uganda last month did not seem to change the way the WHO assessed the situation.
  • Even when a handful of Ebola cases were confirmed in Uganda, all the infected people had travelled from Congo and there had been no local transmission or spread within Uganda — one of the criteria used by the WHO to assess if an outbreak is a global emergency.

Previous cases

  • This is the fifth time that the WHO has declared a global emergency. The earlier occasions were in February 2016 for Zika outbreaks in the Americas, August 2014 for Ebola outbreaks in western Africa, the spread of polio in May 2014, and the H1N1 pandemic in April 2009.
  • Declaring an event as a global emergency is meant to stop the spread of the pathogen to other countries and to ensure a coordinated international response.
Availability of a candidate vaccine
  • There have been several challenges in interrupting the virus transmission cycle and containing the spread — reluctance in the community, attacks on health workers, delays in case-detection and isolation, and challenges in contact-tracing.
  • But compared with the situation during 2014-2016, the availability of a candidate vaccine has greatly helped.
  • Though the vaccine has not been licensed in any country, the ring vaccination strategy where people who come into contact with infected people, as well as the contacts of those contacts are immunised, has helped .
  • Of the nearly 94,000 people at risk who were vaccinated till March 25, 2019, only 71 got infected compared with 880 unvaccinated who got infected.
  • The vaccine had 97.5% efficacy; a majority of those who got infected despite being vaccinated were high-risk contacts.

Shortage of Vaccine

  • Owing to vaccine shortage, the WHO’s expert group on immunisation has recommended reducing the individual dose to meet the demand.
  • What is equally important is for the G7 countries to fulfil their promise to the WHO to contain the spread.
  • The agency received only less than half of the $100 million that was requested to tackle the crisis. The global emergency now declared may probably bring in the funding.A

Everything you wanted to know about Zika virus

The World Health Organization (WHO) expects that Zika virus, a mosquito-borne disease, spreading through the Americas, to affect between 3 million and 4 million people. Let’s analyse this in brief!

Where was the first Zika virus outbreak identified?

  • Zika virus is an emerging mosquito-borne virus that was first identified in Uganda in 1947 in rhesus monkeys through a monitoring network of sylvatic yellow fever.
  • It was subsequently identified in humans in 1952 in Uganda and the United Republic of Tanzania.
  • Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Asia and the Pacific.

Trivia : Do you know why is it called Zika Virus?

It was first isolated from Rhesus monkeys in Zika forest near Lake Victoria in Uganda.

Find Out why was Ebola virus named as such?


 

What makes this outbreak different?

  • The current outbreak, the first ever in the western hemisphere, is a big deal for a number of reasons
  • We now know that it’s not adults who have the most to lose but their unborn babies
  • Microcephaly is a condition where a baby is born with an abnormally small head and brain defects
  • Worldwide it affects only 1 in 30,000 to one in 250,000 newborns
  • In Brazil there are usually a few hundred cases annually at most, but since October 2015, there have been 3,500 new microcephaly cases

But, what is microcephaly?

  • Microcephaly is a rare condition where a baby has an abnormally small head.
  • This is due to abnormal brain development of the baby in the womb or during infancy.
  • Babies and children with microcephaly often have challenges with their brain development as they grow older.
  • Microcephaly can be caused by a variety of environmental and genetic factors such as Downs syndrome; exposure to drugs, alcohol or other toxins in the womb; and rubella infection during pregnancy.

How does the Zika virus spread?

  • Zika virus is transmitted to people through the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti in tropical regions
  • This is the same mosquito that transmits dengue, chikungunya and yellow fever
  • Zika virus disease outbreaks were reported for the first time from the Pacific in 2007 and 2013 (Yap and French Polynesia, respectively), and in 2015 from the Americas (Brazil and Colombia) and Africa (Cape Verde)

How bad is it now?

  • As of January 23, 2016, the Zika virus has spread to 21 countries and territories of the Americas
  • It’s speculated that the virus must have arrived in Brazil along with the throngs that swept in during the 2014 FIFA World Cup
  • Things look so grim that governments of 4 South American countries are now advising women to not get pregnant until the situation is brought under control
  • The WHO has predicted that the virus is likely to spread all over North and South America, except for Chile and Canada where the Aedes aegypti mosquito is not present
  • The reason that the WHO thinks these countries are so susceptible is that their populations have not been exposed to the virus before and hence have no immunity

Is there a cure?

  • No, there isn’t. There exists medication for symptomatic relief but these are quite useless now that we know about the microcephaly link
  • Research on the Zika virus is still quite primitive
  • Given its generic symptoms in adults, it’s very easy to miss or misdiagnose
  • Moreover, the virus doesn’t seem to show effects in common lab animals like mice and rats. Getting monkeys is extremely tough because of restrictions on primate research
  • Vaccine development and antiviral drug discovery efforts are on but this takes time, and with the Zika virus, we’ll be starting from scratch

Does Brazil have a way out?

  • Brazil needs an immediate plan of action for more than one reason
  • Rio de Janeiro is frantically spraying insecticides at the parade grounds where the annual carnival celebrations will commence soon
  • In August, the city is due to host the Olympics

What about India?

  • India is one of the Aedes aegyptis’s many homes but the Zika virus itself has not ever been detected in our country so far
  • However, in a study in the 1950s, healthy individuals from 6 Indian states showed passive immunity to the virus
  • This means that though their blood contained antibodies against the virus, this was not because they were exposed to the virus
  • Usually passive immunity is acquired through vaccines, from mother-to-child transmissions or breast milk
  • In the case of India, where the Zika virus is not known to exist, the antibodies probably arose from exposure to similar viruses
  • Nevertheless, theoretically, Zika can spread anywhere that the mosquito exists
  • That means India, too. Indians are just as susceptible if they travel to high-risk countries

 

Is there something more that you wanted to know which we did not answer yet? Drop in with your questions.

 

Published with inputs from Arun | Image - Outbreaknews
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