Seniors and Mosquito Borne Viruses - Knowing the Risks

Updated: Aug 29, 2019

Connelly Law Offices, Ltd. Senior Issues
At least four confirmed cases of Eastern Equine encephalitis have occurred in Massachusetts with one confirmed death of a Fairhaven woman has health officials posting warnings in communities across the state.

As summer winds down and the days have begun to grow shorter, staying outside as dusk arrives may be proving to be a risky prospect for many here in Southern New England due to a higher than usual mosquito population. To be clear, this is not a call to arms that all mosquito bites will have deadly outcomes since such illnesses are extremely rare, but as with most diseases spread by insects, seniors are among the most vulnerable given the fact that our immune systems weaken with age. So here is what we need to know.

Even though such infections are rare, we shouldn’t take the concerns of mosquito carried viruses lightly either. In the past week, at least four cases of Eastern Equine Encephalitis Virus, one of the deadliest viruses carried by these insects, have been confirmed in Massachusetts. The first case, involving a man over the age of sixty in Plymouth County, was confirmed last week and the second case, confirmed just this past weekend, involves a man between the age of 19 and 30 from Worcester County. These were the first confirmed cases of the virus since 2013.

Then in mid-August, it was reported that a woman who was among the four people in Massachusetts who had contracted the virus had died. Laurie Sylvia passed away while receiving treatment for the infection at Tufts Medical Center, a hospital spokesperson confirmed to

Eastern equine encephalitis virus (EEEV) is a serious and often fatal infection that causes encephalitis or inflammation of the brain. It is spread by the bite of a mosquito infected with EEE virus. The virus can also infect a wide range of animals including mammals, birds, reptiles, and amphibians. The spread of EEE to mammals (including humans and horses) occurs through the bite of infected mosquitoes that feed on both birds and mammals. EEE is only spread to humans through the bite of an infected mosquito. EEE is not spread person-to-person, people to animals, or animals to people.

These cases have prompted the Commonwealth’s Public Health Commissioner, Monica Bharel, to state that the risk of EEE needs to be taken seriously by the public. In all, nine communities, including Carver, Lakeville, Marion, Middleborough, Rochester, and Wareham in Plymouth County and Acushnet, Freetown, and New Bedford in Bristol County have had their risk level raised to critical. However, Massachusetts is not the only state on the south coast with these problems.

In Rhode Island, environmental officials have stated that for the first time this year, mosquitoes have tested positive for EEE. The infected mosquitoes were collected in Central Falls earlier this month. Rhode Island also tested these insects for West Nile Virus (WNV) but none were found to carry it.

Connecticut also has found mosquitoes carrying the EEE virus in Pachaug State Forest in Voluntown in late July. About the same time, officials detected West Nile in mosquitoes that were trapped in East Haven. Dr. Theodore Andreadis, Director of the Connecticut Agricultural Experiment Station (CEAS), expressed concern about this finding. “The detection of EEE virus in July is reason for concern as conditions are suitable for further build-up of the virus in the coming weeks and months,” stated Dr. Andreadis. "We will continue to closely monitor mosquitoes for virus amplification and we encourage everyone to take simple measures such as wearing mosquito repellent and covering bare skin, especially during dusk and dawn when mosquitoes are most active."

And in Pelham, New Hampshire, officials in that state detected the EEE virus for the first time this year. The state and town are working to notify residents of the finding, and highlight the potentially serious viral infections that can occur with an infected mosquito bite. Although EEE and WNV are relatively rare infections in humans, it is important to know exactly what we are dealing with, and to understand that seniors can be especially susceptible to such illnesses.

Eastern Equine Encephalitis

Massachusetts appears to be ground zero for this infection. EEE was first found in horses in Massachusetts in 1831 and in 1938, the first confirmed human cases were found here in New England. Today, EEE is present in North, Central and South America where it is also known as called “sleeping sickness”.

A second case of EEE has been reported in Southern New England.

The mosquito that carries EEE prefers to bite animals but will also dine on humans. However other mosquitoes, who do feed on both humans and animals, can carry the disease between the species. These mosquitoes include that Aedes, which we are most familiar with.

The risk of contracting the EEE virus is highest during the summer months and those who live and work near wetland and swamp areas are at higher risk of infection. And as we stated earlier, EEE is only spread to humans via mosquito bite and not through infected animals.

Of those who contract the EEE virus, the elderly (ages 50 and older) and the young (ages 15 and younger) are at the greatest risk of developing encephalitis. Latest numbers indicate that Massachusetts leads the country in EEE infections followed by Florida, North Carolina and New York. Although the numbers are low, with an average of just seven infections reported annually, if it is your loved one with EEE, the low incidence of infection offers little solace.

EEE can lead to a fever, headaches, vomiting, diarrhea, irritability, drowsiness, lack of appetite, seizures, falling into a coma, and potentially death. So dangerous is this disease that one in three people who contract it do not survive. According to the CDC, death can be rapid, just 2 to 10 days after symptoms appear. Those who do survive are usually left with lingering mental and physical impairments, such as difficulty thinking, personality disorders, seizures, paralysis, and various types of nervous system dysfunction.

WPRI-TV12 showed a graphic of the areas most at risk for EEE. Among the towns in the affected areas are Pawtucket, Central Falls, New Bedford and Fall River.

West Nile Virus

This year marks the twentieth anniversary of the detection of the West Nile virus in this country. Last year, there were over 2500 cases of West Nile virus in the United States, a slight uptick from the case counts reported in the previous five summers. The last time the US saw more cases was in 2012 when there were 5674 cases reported. According to the CDC, West Nile virus is now the leading cause of mosquito-borne disease in the continental United States. As of June of this year, there have been 8 human cases documented.

This virus was first isolated in Africa in 1937 and quickly spread throughout the region. Then in 1999, a strain of the virus that was active in Israel and Tunisia was imported into New York and resulted in a huge outbreak that spread throughout the continental United States. Today, the virus has firmly established itself in this country.

The virus is transmitted by the Culex mosquito, who acquire the virus by feeding on infected birds. The strain that is active in the United States is extremely deadly for crows, so the sight of dead birds may indicate the presence of this virus in the area.

About 80 percent of those who are bitten by infected mosquitoes do not develop any symptoms, but in the 20 percent who do, they develop fevers, aches and nausea -- and about 1 in 150 of this group will develop encephalitis, a much more serious disease, that could result in death.

Unfortunately, people older than 50 and especially those over 65, have the highest risk of developing encephalitis. There is no vaccine for West Nile and treatment consists of addressing the symptoms such as fever and dehydration. In severe cases, hospitalization may become necessary.

CDC West Nile Virus activity so far in 2019.

We Live In A Smaller World

We discussed the two viruses we are most concerned with here in Southern New England, but the reality is that today’s seniors are much more mobile and are on the move around our country and the world, putting them at risk for other infections carried by these insects. Still others, who may have immigrated to this country, return home to visit family members and come in contact with various diseases and viruses not seen here. This includes those traveling to the Caribbean, Asia and parts of Africa.

Cheaper flights and larger planes allow people to travel between countries now more than ever.

“It’s great that our seniors are traveling and visiting other countries," said Attorney Connelly. “But with this travel come concerns that seniors must be aware of. This includes the infections carried by mosquitoes in parts of the world that don’t have the same standards of hygiene as we do here or have the immunity that those living there may have. Traveling does come with risks. And knowing these risks and the precautions to take may keep them safe.”

Among these risks include some of the major infections carried by mosquitoes not commonly seen in Southern New England like Zika, Chikungunya, Yellow Fever, Rift Valley Fever, Malaria and Dengue. Let's briefly look at them.


Just a few years ago, the Zika virus made headlines about its rapid spread across the globe. Although the Zika hysteria has subsided, it doesn’t mean it has disappeared. in fact, one could argue that Zika may pose more of a risk to people than EEE and WNV because of the ways it can be transmitted.

The most publicized effect of Zika are babies born with microcephaly

Those who contract this virus usually experience no symptoms or only a mild disease that may involve fever, rash, and joint pain in most people who become infected. However, the disease can cause severe neurological defects in the developing fetuses of pregnant women who are infected with Zika virus. A significant number of the babies of these women are born with microcephaly, a rare disorder in which a baby’s head is much smaller than normal. This defect can lead to developmental problems ranging from mild to severe and is sometimes fatal.

Zika was an obscure virus that was not associated with serious disease until it emerged explosively in Brazil in 2015 and spread rapidly throughout Latin America. With the Olympic games being held there in 2016, visitors and athletes were cautioned about the bites of the mosquitoes. Because Zika virus had not been found in the Americas previously, there was no immunity to the virus in the population meaning that nearly everyone was susceptible.

But the one thing that makes Zika much different than EEE and WNV is that it can be spread from human to human through sexual intercourse, a sexually transmitted infection of sorts. The type of sex that can spread Zika includes vaginal, anal, and oral sex and even the sharing of sex toys. Zika can even be passed through sex even in a committed relationships. The time frames that men and women can pass Zika through sex are different because the Zika virus can stay in semen longer than in other body fluids. Zika can also be spread through blood transfusions.

In a recent study, Zika has be shown to live outside the body, on non-biological surfaces, for up to eight hours. And according to researchers, in environments where blood or blood spatters are present, it can survive much longer.

Although Zika has been primarily discussed around the dangers for pregnant women, there are some very specific risks for senior citizens which include the following:

Guillain-Barre Syndrome is a rare autoimmune condition in which the immune system attacks peripheral nerves and damages the myelin insulation. Symptoms rapidly progress from pain to muscle weakness and even paralysis.
  • Guillain-Barré syndrome (GBS) is associated both with older age and Zika virus. GBS is a rare disorder that causes a person’s immune system—how the body fights off disease—to damage its own nerve cells. It can cause muscle weakness and paralysis, sometimes affecting the muscles that control a person’s breathing. In severe cases, GBS can result in death. Risk for GBS increases with age, and people age 50 and older are most affected.

  • And remember, age does not protect you from sexually transmitted diseases. Zika can be passed from a person who has the virus to his or her sex partners. No matter how old you are, you should practice safe sex and use condoms if you or your partner show symptoms or have recently traveled to an area where Zika is found.

As with the previous viruses we discussed, there is no vaccine and treatment consists of addressing the symptoms.

The 2019 image of where the Zika virus has been reported and/or contracted.


Although rarely fatal, chikungunya is a virus that causes debilitating joint pain accompanied by fever and rash. First found in the tropics of Africa, it rapidly spread east into Europe and then into the America’s. By 2017, there were more than 1.7 million infections in North and South America. Although not currently spreading in the United States, there have been nearly 1000 cases identified in 44 states as a result of travel where this virus is active in mosquitoes.

Chikungunya infection as it manifests on the skin

In countries where chikungunya is most active, health experts say there are more chances of elderly patients succumbing to the disease due to their low immunity levels, combined with chronic health problems like heart or kidney ailments.

"The problem can be severe among those who already have kidney problems, chest infections and heart diseases. The virus can stop the functioning of the organs. This is mostly common among elderly patients with low immunity power. The whole story is about immunity," said Dr. Sumit Ray, who heads the critical care unit at Sir Ganga Ram Hospital in India, where this virus has a stronghold.

There is no vaccine for chikungunya and the symptoms are treated. However during the first week of the virus, a mosquito can spread it from the infected person to another.

Chikungunya, a virus spreading north in the United States.

Yellow Fever

Yellow fever, you might ask? Why is this being discussed in the United States. Well, the United States has quite a history of Yellow Fever outbreaks.

The Yellow Fever outbreak in Philadelphia killed more than 5000 people. In fact, during the Civil War, more soldiers died from the fever than by battle related causes.

One of the first Yellow Fever outbreaks here occurred during the late 1600s followed by another during the summer of 1793 when refugees from a yellow fever epidemic fled the Caribbean and ended up in Philadelphia. Within weeks, the city was loaded with citizens reporting symptoms. By early fall, over 100 people were dying daily. By the time it was over, over 5000 people died in Philadelphia alone.

During the Civil War, more soldiers died from disease than from actual battle related injuries. Yellow Fever, called "Yellow Jack" by the soldiers, could wipe out a platoon in a matter of weeks. But with better sanitation, knowledge of mosquito control methods and education on protection against the bites of this insect, diseases like Yellow Fever have all but disappeared from the United States. But it is still widespread in areas where Americans travel and visit relatives.

This does not mean that we will never experience another Yellow Fever outbreak here. In April of 2018, the World Health Organization identified Miami, Florida as one of the global cities that is susceptible to the spread of this disease because travel here does not require an immunization. Infected travelers arriving in South Florida could be bitten by mosquitoes here, which could then spread the disease through bites to other people.

In mild cases, yellow fever causes a fever, headache, nausea and vomiting. But yellow fever can become more serious, causing heart, liver and kidney problems along with bleeding (hemorrhaging). Up to 50 percent of people with the more-severe form of yellow fever die of the disease.

The good thing is, there does exist a vaccine for Yellow Fever. But it comes with caution – it does contain the live virus. Yellow fever vaccine should be given cautiously to people older than 60 years, and it should not be given at all to people with certain immune-suppressing conditions. Seniors should discuss their detailed travel plans with their doctors and, if necessary, alternatives to vaccination.

Once yellow fever is contracted, the symptoms are treated and not the disease. Because Yellow Fever can cause bleeding, certain medications that interfere with clotting need to be avoided.

Traveling to these areas? The CDC recommends the Yellow Fever vaccine but it can be harmful to some seniors.


Dengue has emerged as a worldwide problem only since the 1950s. Although dengue rarely occurs in the continental United States, it is endemic in Puerto Rico and in many popular tourist destinations in Latin America, Southeast Asia and the Pacific islands.

The Manila Standard headlines tell the story of the Dengue epidemic that is gripping that nation

The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.

Dengue is a neglected tropical disease that is increasingly affecting elderly patients. However, with aging population there has been an increase in dengue incidence rates in older adults. In Taiwan older adults have the highest reported dengue incidence rate and risk of fatality. Likewise in Singapore elderly patients accounted disproportionately for the majority of dengue deaths highlighting the urgent need for enhanced understanding of dengue in the elderly to improve clinical management and outcome.

However, just last week in the Philippines, the government declared a "national dengue epidemic" according to a release from Manila's Department of Health (DOH). Dengue has been so serious this year in that country that there have been more than 146,000 recorded cases of dengue fever from Jan. 1 through July 20, 2019, with a total of 622 deaths. The rate of recorded cases in the Philippines has increased 98% from reported cases in 2018. There are many families of Filipino descent here in Southern New England who travel annually to their homeland and they need to take the necessary precautions given the seriousness of the current problem.

Once dengue is contracted, it is only the symptoms that can be treated. The Dengue fever risk is very close to the continental United States and very active in vacation spots frequented by seniors, including Caribbean, Mexico and South American "hot spots".

Dengue fever cases on the increase with the Philippines currently being ravaged by the virus.

Rift Valley Fever

Rift Valley fever (RVF) is an acute, fever-causing viral disease most commonly observed in domesticated animals (such as cattle, buffalo, sheep, goats, and camels), with the ability to infect and cause illness in humans. It was first reported in livestock by veterinary officers in Kenya’s Rift Valley in the early 1910s. RVF is generally found in regions of eastern and southern Africa where sheep and cattle are raised, but the virus exists in most of sub-Saharan Africa, including west Africa and Madagascar.

Government officials in some African countries are working to control the spread of Rift Valley Fever and inform citizens of the dangers of this virus that can spread from animals to humans.

In September 2000, a RVF outbreak was reported in Saudi Arabia and subsequently, Yemen. This outbreak represents the first cases of Rift Valley fever identified outside Africa. People are infected with RVF virus (RVFV) through contact with blood, body fluids, or tissues of RVFV-infected animals, mainly livestock.