Uganda/Brasil (TheTechDiscovery) — We might find the end to Zika!
- Bacterium called Wolbachia pipientis is commonly found in other insects
- Zika-causing Aedes aegypti mosquitoes were infected with the bacteria
- Scientists found mosquitoes with it were less likely to be infected by Zika
- It also stopped them from being able to transmit Zika through their saliva
A harmless bacteria found in bees and butterflies can stop mosquitoes from being able to infect people with the Zika virus, a study has found.
Scientists have discovered a benign bacterium called Wolbachia pipientis can completely block transmission of Zika in the species of mosquito responsible for passing the virus onto humans.
Trials exposing the Aedes aegypti mosquito to the bacteria are already underway in Colombia, Brazil, Australia, Vietnam and Indonesia to help control the spread of dengue virus.
It is now hoped this will be widened out to areas endemic with the Zika virus after the pilot was endorsed by the World Health Organization.
The Wolbachia pipientis bacteria can completely block transmission of Zika from mosquitoes to humans and can be introduced to the insects in laboratories
Zika has now affected 39 countries and territories in the Americas and it is expected that at least four million people will be infected by the end of the year.
Scientists believe the virus is responsible for a host of brain defects in developing foetuses, including microcephaly, which causes babies to have small heads.
It has contributed to an increase in cases of a neurological disorder called Guillain-Barre syndrome.
There are not yet any approved Zika virus vaccines or antiviral medications, and ongoing mosquito control strategies have not been adequate to contain the spread of the virus.
Researchers led by Jorge Osorio, a University of Wisconsin-Madison professor of pathobiological sciences and Professor Scott O’Neill of the the Eliminate Dengue Program (EDP), believe the bacteria could present a ‘novel biological control mechanism.’
‘In two of our initial study sites in Australia, approximately 90 per cent of the mosquitoes continue to be infected with Wolbachia after initial release more than six years ago’ said Professor O’Neill.
In the study, the team infected mice with Zika virus originally isolated from a human patient and allowed mosquitoes from Medellin, Columbia, to feed on the mice either two or three days after they were infected.
The mosquitoes were either harbouring the same strain of the Wolbachiabacteria (called wMel) used in field studies or were Wolbachia-free and the mice had levels of virus in their blood similar to humans infected with Zika virus.
Scientists believe the virus is responsible for a host of brain defects in developing foetuses, including microcephaly, which causes babies to have small heads
An additional group of mosquitoes, both wild-type and Wolbachia-infected, was allowed to feed instead from a membrane containing sheep’s blood spiked with a high concentration of Zika virus.
Four, seven, 10 and 17 days after the mosquitoes fed on Zika-virus-infected blood, the researchers tested them for Zika virus infection.
They assessed whether the virus had disseminated – or spread to other tissues in the mosquito, and examined whether the virus made its way to the mosquito saliva, where it must be present to be transmitted.
They found that mosquitoes carrying the bacteria were less likely to become infected with Zika virus after feeding on viral blood – and those that were infected were not capable of transmitting the virus in their saliva.
Wolbachia pipientis can be found in up to 60 percent of insects around the world, including butterflies and bees.
While not typically found in the Aedes aegypti mosquito – the species that also transmits dengue, chikungunya and yellow fever viruses – Professor O’Neill discovered in the early 1990s that it could be introduced to the mosquito in the lab and would prevent the transmission of the dengue virus.
The Zika virus belongs to the same family as dengue virus, leading scientists to believe the same could be true for this virus.
Once inside a mosquito, it is passed from mother to offspring, so newborn mosquitoes will contain the bacteria and incorporate it into the wild population.
EDP hopes to see greater than 80 percent of Aedes aegypti mosquitoes in study areas harbouring Wolbachia
The study is one of the first to study Zika virus transmission dynamics using a living host.
WHAT YOU NEED TO KNOW ABOUT ZIKA
WHAT IS ZIKA?
The Zika (ZEE’-ka) virus was first discovered in monkey in Uganda in 1947 – its name comes from the Zika forest where it was first discovered.
It is native mainly to tropical Africa, with outbreaks in Southeast Asia and the Pacific Islands.
It appeared in Brazil in 2014 and has since been reported in many Latin American countries and Caribbean islands.
HOW IS IT SPREAD?
It is typically transmitted through bites from the same kind of mosquitoes – Aedes aegypti – that can spread other tropical diseases, like dengue fever, chikungunya and yellow fever.
It is not known to spread from person to person.
Scientists have found Zika can be transmitted sexually. The World Health Organisation recently warned the mode of transmission is ‘more common than previously assumed’.
And, the Centers for Disease Control and Prevention recently issued first-time guidance, saying couples trying to conceive should abstain or wear condoms for six months if the male has confirmed or suspected Zika.
Zika is typically transmitted through bites from the same kind of mosquitoes – Aedes aegypti – that can spread other tropical diseases, like dengue fever, chikungunya and yellow fever
Additionally, the CDC said couples should abstain or wear condoms for eight weeks if the female has confirmed or suspected Zika, or if the male traveled to a country with a Zika outbreak but has no symptoms.
During the current outbreak, the first case of sexually transmitted Zika was reported in Texas, at the beginning of February.
The patient became infected after sexual contact with a partner diagnosed with the virus after travelling to an affected region.
Now, health officials in the US are investigating more than a dozen possible cases of Zika in people thought to be infected during sex.
There are also reported cases in France and Canada.
Prior to this outbreak, scientists reported examples of sexual transmission of Zika in 2008.
A researcher from Colorado, who caught the virus overseas, is thought to have infected his wife, on returning home.
And records show the virus was found in the semen of a man in Tahiti.
So far, each case of sexual transmission of Zika involves transmission from an infected man to his partner. There is no current evidence that women can pass on the virus through sexual contact.
The World Health Organization says Zika is rapidly spreading in the Americas because it is new to the region, people aren’t immune to it, and the Aedes aegypti mosquito that carries it is just about everywhere – including along the southern United States.
Canada and Chile are the only places without this mosquito.
Scientists revealed a molecular map of the Zika virus, which could help scientists develop new treatments for the disease
ARE THERE SYMPTOMS?
The majority of people infected with Zika virus will not experience symptoms.
Those that do, usually develop mild symptoms – fever, rash, joint pain, and red eyes – which usually last no more than a week.
There is no specific treatment for the virus and there is currently no vaccine to protect against infection, though several are in the developmental stages.
WHY IS IT A CONCERN NOW?
In Brazil, there has been mounting evidence linking Zika infection in pregnant women to a rare birth defect called microcephaly, in which a newborn’s head is smaller than normal and the brain may not have developed properly.
Brazilian health officials last October noticed a spike in cases of microcephaly in tandem with the Zika outbreak.
The country said it has confirmed more than 860 cases of microcephaly – and that it considers them to be related to Zika infections in the mother.
Brazil is also investigating more than 4,200 additional suspected cases of microcephaly.
However, Brazilian health officials said they had ruled out 1,471 suspected cases in the week ending March 19.
Now Zika has been conclusively proven to cause microcephaly.
The WHO also stated that researchers are now convinced that Zika is responsible for increased reports of a nerve condition called Guillain-Barre that can cause paralysis.
A team of Purdue University scientists recently revealed a molecular map of the Zika virus, which shows important structural features that may help scientists craft the first treatments to tackle the disease.
The map details vital differences on a key protein that may explain why Zika attacks nerve cells – while other viruses in the same family, such as dengue, Yellow Fever and West Nile, do not.
CAN THE SPREAD BE STOPPED?
Individuals can protect themselves from mosquito bites by using insect repellents, and wearing long sleeves and long pants – especially during daylight, when the mosquitoes tend to be most active, health officials say.
Eliminating breeding spots and controlling mosquito populations can help prevent the spread of the virus.
Original Post By: Dailymail