Can Mosquitoes Spread Coronavirus?

FOX NEWS | by Alexandria Hein | April 9, 2020

Dr. Peter Hotez discusses if it’s possible for mosquitoes to transfer coronavirus and if seasonality has anything to do with virus spread.

Mosquitoes are a common summer-time foe that are known vectors of the West Nile Virus, Zika, Chikungunya and several other diseases that sicken humans, but what about the novel coronavirus?

As the weather warms and many move their stay-at-home orders to their backyard, the question of whether you can contract COVID-19 through a mosquito bite continues to surface.

There are several types of human coronaviruses, including MERS and SARS, which each caused deadly outbreaks of their own. COVID-19, however, has never been seen before, and is caused by SARS-CoV-2. As a whole, coronaviruses are a large family of viruses that are common in people and can affect different species of animals, but rarely can an animal coronavirus infect a human and then spread between people. However, such instances were seen with MERS-CoV and SARS-CoV, and has also now been documented with COVID-19, which is caused by SARS-CoV-2.

And recently, researchers confirmed that humans spread the virus to tigers at the Bronx Zoo. There have also been reports outside of the U.S. involving pets – particularly cats – becoming infected after close contact with contagious people.

Typically, the virus that causes COVID-19 is thought to spread mainly person-to-person through respiratory droplets produced when an infected person coughs or sneezes. However, it’s also possible to be spread when an infected person’s droplets are transferred to a surface, and an uninfected person then touches the contaminated surface and then transfers it to their face.

This raises the question then, of if a mosquito bites an infected person, and then lands on an uninfected person, can the disease be transferred?

“There are no reports of any spread of coronavirus to humans by mosquitoes,” Dr. Mary Schmidt, infectious disease and internal medicine specialist, told Fox News. “If this was a route of transmission, we would have seen it in the Middle East, where the Middle East Respiratory Syndrome (MERS) caused by the coronavirus has been present for 6 years.”

Schmidt referenced a study that revealed that if mosquitoes were fed a blood meal of the coronavirus MERS, it was detected for up to one day in the insect. However, for this to become a threat to humans, a series of particular events would need to occur.

“In order for this to happen in real life, the mosquitoes would have to acquire the virus during feeding, the virus then undergoes replication in the gut tissue, disseminates to the secondary sites of replication, including the salivary glands, and is ultimately released into the arthropod’s salivary secretions, where it may be inoculated into the skin and cutaneous vasculature of the host (human) during subsequent feeding,” Schmidt said.

Given those findings, Schmidt said that mosquitoes should continue to be monitored. The American Mosquito Control Association (AMCA) has also said that it will continue to monitor the situation in conjunction with public health officials.

In early March, the World Health Organization (WHO)  said there has been no information nor evidence to suggest that COVID-19 can be transmitted by mosquitoes.

One-third of children in Zika virus study show developmental problems

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“Children who were exposed to Zika during their mothers’ pregnancy need to have developmental assessments over time, and eye and hearing exams should be performed,” said lead study author Dr. Karin Nielsen-Saines.

July 10, 2019 | HealthDay New

Researchers say that children exposed to Zika virus in the womb should be screened for effects of the virus. File Photo by mycteria/Shutterstock

New research shows that neurological damage for babies who were exposed to the Zika virus while in the womb continues to unfold years after birth.

Developmental problems were found in one-third of the 216 children studied, some of whom were 3 years old. The problems affected language, thinking and motor skills development. Some also had eye and hearing issues.

Surprisingly, the researchers also discovered that fewer than 4 percent of the children had microcephaly — a smaller-than-normal head that is one of the hallmarks of Zika exposure in the womb. And in two of those cases, the head actually grew to normal size over time.

“Children who were exposed to Zika during their mothers’ pregnancy need to have developmental assessments over time, and eye and hearing exams should be performed,” said lead study author Dr. Karin Nielsen-Saines. She is a professor of clinical pediatrics at the University of California, Los Angeles.

“If there is risk of developmental delay, or developmental delay is identified, there are cognitive, language and behavior interventions that can be put in place to improve outcomes for these children,” she added in a university news release.

The finding that some children born with microcephaly went on to develop normal head circumference by age 1 means that “microcephaly is not necessarily static,” Nielsen-Saines said.

The study was published July 8 in the journal Nature Medicine.

The researchers noted that they didn’t have a comparison group of non-exposed children who were born at the same time and raised in the same settings as those known to have been exposed to Zika in the womb.

“Zika exposure can be a very difficult condition to diagnose in retrospect, so we can’t rule out undiagnosed Zika infection in a control group of children enrolled at the same time,” Nielsen-Saines said.

“Neurodevelopmental tests should be done simultaneously in similar populations with the same background,” she suggested.

“These children require close attention and ongoing surveillance, so that prompt interventions to improve their development can be provided if needed,” Nielsen-Saines said.

More information

The U.S. Centers for Disease Control and Prevention has more on Zika.

‘Chagas Considered Emerging Global Disease’ – CSUF Researchers study spread of Plague to Parasites. Note, Kissing Bugs are cousins to Bed Bugs.