ANNAPOLIS, Maryland — Mosquito season may be waning in Maryland, but Zika research here is in full force.
Although Maryland accounts for fewer than 3 percent of the Zika cases nationwide, there are at least five sites in Maryland researching the virus: The Johns Hopkins Hospital, U.S. Army Medical Research Institute of Infectious Diseases, the University of Maryland School of Medicine, Walter Reed Army Institute of Research in Silver Spring, and the National Institutes of Health Clinical Center in Bethesda.
“There is a lot of research going on in biomedical sciences located in the Baltimore-Washington corridor,” said Dr. Matt Laurens, a pediatrician and the director of international clinical trials for the University of Maryland School of Medicine. “It is a magnet for biomedical research.”
Being a leader in medical research is a natural fit for Maryland, said Chris Garrett, a spokesman for the Maryland Department of Health and Mental Hygiene.
“(It) is characteristic of Maryland, given our proximity to the nation’s capital, as well our stature in public health, preparedness and response,” Garrett said. “Maryland was one of the principal states leading the response to the Ebola virus in 2014 and 2015, as well.”
The hospital-based Johns Hopkins Zika Center opened in Baltimore this summer to help patients and infants with Zika. According to Johns Hopkins’ website, the center has specialists from epidemiology, infectious diseases, maternal-fetal medicine, orthopedics, pediatrics, physiotherapy, psychiatry and social work to treat patients with Zika.
Patients from around the world are welcome at the center, which is integrated into the hospital. Patients with similar symptoms are treated in rooms near each other for convenience, although there is not a separate wing of the hospital for the Zika Center.
Dr. William May, associate professor of ophthalmology at the Wilmer Eye Institute and co-director of the Johns Hopkins Zika Center, said he has seen two patients from Maryland, including one baby.
The most common symptoms of Zika in adults are fevers, rashes, joint pain and conjunctivitis, as well as muscle pain and headaches.
According to the Centers for Disease Control, Zika can also cause Guillain-Barre Syndrome, an autoimmune reaction where the immune system attacks the nerves and can cause severe paralysis. Patients usually recover, but it is fatal in 1 percent of victims.
However, the virus can have much more serious effects on babies.
Typically contracted in the womb when their mothers are bitten by a mosquito carrying the virus, babies with Zika can have severe fetal birth defects, including eye problems, hearing loss and impaired growth. According to the CDC, it can also cause microcephaly, a birth defect that causes a baby’s head to to be smaller and the brain to not fully develop or grow.
Microcephaly can lead to seizures, developmental and intellectual delays, hearing loss, and vision and feeding problems. In severe situations, it can also lead to death, according to the CDC.
There have been more than 100 cases of locally acquired Zika cases in the United States, all in Florida. Of the more than 4,000 cases of Zika confirmed in the states, about 3,900 have been travel-related, or contracted when people were travelling outside the country.
Maryland has had 105 confirmed cases of Zika as of Oct. 27, none locally contracted.
Yet with the mosquito population dwindling in the fall and winter months, the Zika focus shifts, said Garrett.
“There is a danger with people associating Zika solely with mosquito transmission,” Garrett said.
Besides being transmitted through the bite of an infected mosquito, Zika can be contracted through sex, blood transfusions, or laboratory exposure, according to the CDC.
There has been one documented case in Maryland of Zika being contracted through sexual activity. A woman contracted the virus after having sex with an asymptomatic man less than two weeks after he returned from the Dominican Republic.
About 80 percent of people who get Zika are asymptomatic, said Laurens, making it difficult to track and contain the virus.
May said he believes the virus will spread throughout the United States in a matter of years.
“It has taken about a year and a half for it to go through Central and South America into the United States,” he told the University of Maryland’s Capital News Service. “If it keeps up that rate it will take over the U.S.”
The Walter Reed Army Institute of Research has been working with Beth Israel Deaconess Medical Center in Boston on a vaccine for Zika. According to Debra Yourick, a representative for Walter Reed, researchers completed the second round of preclinical studies in August.
The researchers found a vaccine that completely protected rhesus monkeys from experimental infection with the Zika virus, according to an Aug. 4 news release.
Yourick also said clinical trials are scheduled to begin next week at Walter Reed’s Clinical Trials Center, as well as at other, unannounced locations.
The National Institute of Allergy and Infectious Diseases, a part of the National Institutes of Health Clinical Center in Bethesda, is working with the University of Maryland School of Medicine and Emory University to develop a vaccine as well.
At least 80 volunteers, ages 18-35, are enrolled in the study among the three sites. According to a report from the NIH, the study began in July and will continue until December 2018.
Unlike the flu shot or other vaccines, the immunization the NIH is developing for Zika does not contain the virus. Instead, Laurens said, it is DNA-based.
The vaccine instructs the body to make a small amount of Zika virus protein, which may build an immune response, according to the NIH.
“That is what we are evaluating in this phase 1 study,” Laurens said. “We hope that the vaccine will produce a robust immune response, capable of preventing Zika infection in persons vaccinated.”
The CDC is still researching how long Zika can stay in genital fluids, how common it is for Zika to be passed during sex and whether Zika passed to a pregnant women during sex has different risks for birth defects than Zika transmitted by a mosquito bite, according to the CDC website.
To combat Zika, the Maryland Department of Agriculture has been using prevention techniques.
“The best way to prevent (mosquitoes) from carrying anything is to not allow them to breed,” said Brian Prendergast, the program manager of mosquito control for the Maryland Department of Agriculture.
The Maryland Department of Agriculture has 15 state inspectors who go to Maryland homes, checking for still water. The inspectors generally work during mosquito season, which is May to August, said Prendergast.
But due to the unseasonably warm weather this year, the inspectors were still working into late October, he said.
After the inspectors receive permission from the homeowner, they search the front and back yards for any water vessels. The Aedes species of mosquitoes that can carry Zika breeds in objects that hold rainwater, Prendergast said.
“They do not breed in swamps or ditches or puddles,” he added.
These mosquitoes cannot travel far, often less than 50 yards. Because they are not flying long distances, finding their rafts (mosquitoes’ nests) is essential.
“If we eliminate their breeding, we eliminate the skeeters,” Prendergast said.
When examining the yard, the inspector dumps out any item that holds water. They then place it in a way that will hold no water in the future, before notifying the homeowner about what they found.
“We expend a lot of energy because people do not take the simple step of dumping anything that can hold rainwater,” Prendergast said.
The inspectors from the Maryland Department of Agriculture use three pesticides to kill mosquito larvae and a different pesticide on adult mosquitoes, Prendergast said. The inspectors can treat “any type of standing water that can’t be dumped with pesticides,” he said.
The three pesticides the inspectors use against the larvae include two chemicals and a bacterium. The tools “have no toxicity to anything other than mosquito larvae and midge larvae,” Prendergast said. “It all is environmentally friendly.”
To control adult mosquitoes, the inspectors use a pesticide called Bifenthrin, and the Department of Agriculture also uses trucks spraying Permanone 30-30 pesticide.
Prendergast stressed all the pesticides used are “biorational,” or non-toxic.
Preventing mosquitoes from reproducing is a big step for preventing Zika transmission, but, Garrett said, his focus is still on people.
“Marylanders need to make sure they follow the CDC guidance on prevention,” he said. “Particularly if they or their partners have occasion to travel to areas with ongoing Zika transmission.”
Zika is not common in Maryland, and Garrett sees the collaboration of different groups as a good way to maintain that, and potentially defeat the virus.
“We all want to see an end to the scourge of Zika and to the birth defects it has been proven to cause.”