Mosquito

Zika declared public health emergency by WHO

The World Health Organisation that the Zika virus, predominantly affecting Latin America is a public health emergency of international concern. Officials have described Zika as moving “from a mild threat to one of alarming proportions”.

The virus is transmitted by the Aedes Aegypti mosquito, which also carries dengue fever, yellow fever and chikungunya. The virus grows in human blood and any other mosquito can then pick it up while biting and transmit it further.

The symptoms include fever, headache, conjunctivitis, rash, myalgia, and arthralgia. Zika, which often resembles a light case of the flu, is often so mild that people don’t realize that they have it.  Not all infected people develop symptoms either, roughly only one in five people develop the aforementioned symptoms. A short illness may last from several days to a week, but in some rare cases, Zika virus sufferers may have abdominal pain, diarrhoea or constipation and dizziness and it can ultimately result in death.

The “high rate” of patients with Zika have no symptoms at all is concerning to virologists, who believe that Zika could easily establish a foothold in the southern United States and other areas with tropical climates because people may not know they are infected.

Painkillers and drugs to alleviate the fever are normally prescribed and Brazil’s health ministry has also spent R$6 million (£1 million) on 500,000 zika testing kits to help improve detection but there is no vaccine and whilst the government claim to be funding one, experts have warned that developing a vaccine could take over five years.

“The main thing we can do is combat the vectors,” said Dr Kleber Luz, an infectologist at the Federal University of Rio Grande do Norte in one of the worst-affected cities, Natal.

“A new vaccine would be very difficult to do quickly. It will take at least five years or more.”

The Zika virus is a tropical disease which takes its name from the Zika forest in Uganda, where it originated in 1947 and was outside of Africa until 2014 after being identified on Easter Island early in the year. Researchers believe the virus may have arrived in Brazil during the 2014 Football World Cup, carried by visitors from French Polynesia, where an outbreak had just occurred.

It is now spreading locally in some 20 Latin American and Caribbean countries, as far north as Mexico but Brazil has been the hardest hit.

Health experts blame the chaotic growth of urban centers as well as the proliferation of plastic, which provides the mosquito with breeding grounds. However the rise in cases of the virus has also been linked to unusually wet weather, poor sanitation and a public health service weakened by economic crisis.

Virologists studying the spread of subtropical diseases say it’s unclear why the virus spread around the world so fast. Most believe increased international travel is at least partly responsible, but others theorize that increasingly warm global temperatures resulting from climate change could play a role.

The virus is a serious threat to unborn babies. The Zika virus has been linked to of microcephaly, a birth defect in which babies are born with unusually small heads which can potentially lead to death or severe disabilities amongst those who survive, by The World Health Organisation. Although microcephaly has not been scientifically proven with Zika, experts believe that there is a link, as the virus has been found in brain tissue and amniotic fluid from babies who were born with microcephaly.

Christian Lindmeier, the organisation’s spokesman said there were 3,893 suspected microcephaly cases in Brazil, which included 49 deaths. Before last year there were about 160 cases of microcephaly in Brazil on average leading to Brazil declaring a public health emergency in November.

“The link between the Zika and the microcephaly … is still being investigated,” Mr Lindmeier added, but acknowledged that Zika “seems the strongest candidate.”

The reported cases of microcephaly remain concentrated in Brazil’s deprived north-eastern region. However, the developed southeast, where Rio de Janeiro and São Paulo are located, is the second hardest-hit region.

The US Center for Disease Control and Prevention has advised pregnant women to avoid traveling to Brazil and several other countries in the Americas where Zika outbreaks have occurred. The warning comes months before the Olympic Games, which will be held in Rio de Janeiro, and some are concerned that it could scare visitors away. However the local organizing committee stressed that because the games are during the southern hemisphere winter, Brazil’s dry season, the mosquito population will be smaller. Brazilian authorities also say that inspections for mosquito presence will begin four months before the Olympics and sweeps will be performed during the games. Fumigation will also be used in extreme cases, to avoid health issues for athletes and audiences.

Meanwhile health experts have warned that this February’s Carnival celebrations could aggravate the spread of the Zika virus as millions of tourists will descend on Brazil’s coastal cities, including Rio de Janeiro and Salvador, in the middle of the southern hemisphere summer, the peak breeding season for mosquitoes. Few visitors are likely to wear protective clothing on the beach or to Carnival street parties, making them vulnerable to insect bites.

“I am worried about this large group of susceptible people going to Carnival,” said Dr Eurico Arruda, a professor of virology at the University of São Paulo.

“They will be exposed. It is likely the cases [of Zika] will increase.”

In Colombia, deputy health minister Fernando Ruiz said his country has recorded 13,531 suspected cases of Zika and that could hit a half-million this year. In Lima,  Peruvian authorities disinfected a large cemetery in the fear that Zika-bearing mosquitos were breeding in the flower pots.

Authorities in Brazil, Colombia, Ecuador, El Salvador and Jamaica have also advised couples to avoid pregnancy for the time being. Public Health England also advised woman who are pregnant or planning to become pregnant to consider avoiding areas affected by the virus. Women in El Salvador should wait until 2018 before getting pregnant, the deputy health minister Eduardo Espinoza said, while Jamaica has asked women to avoid pregnancy for 6 to 12 months. This has been a controversial issue for some human rights groups and there are concerns that pregnancy is not often a choice for women across the region where 50% of pregnancies are unplanned and sexual violence is rife.

Marcelo Castro said that nearly 220,000 members of Brazil’s armed forces would go door-to-door to help in mosquito eradication efforts by clearing possible mosquito breeding sites, according to Rio de Janeiro’s O Globo newspaper. It also quoted Castro as saying the government would distribute mosquito repellent to some 400,000 pregnant women who receive cash-transfer benefits.

Repellent has disappeared from many Brazilian pharmacies and prices have skyrocketed when available after the government announced the suspected link between Zika virus and microcephaly. Elsewhere, Brazilians are being offered cash incentives or being threatened with fines if they fail to ensure their properties are free of mosquitoes.

The simplest advice against contracting the Zika virus is to avoid mosquito bites by wearing long-sleeved clothes and using mosquito repellent.

The World Health Organisation’s actions are under intense scrutiny after its handling of the Ebola virus which killed over 11,000 people. Its efforts to prevent the spread of the disease were widely criticised and it was deemed to have been too slow to declare an emergency.

Image credit: flickr.com/joao_trindade

The following two tabs change content below.
Naina Bhardwaj

Naina Bhardwaj

Naina Bhardwaj

Latest posts by Naina Bhardwaj (see all)

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.