The Centers for Disease Control and Prevention has warned of an upswing in cases of eastern equine encephalitis in New England, including—for the first time in 41 years of reporting of the disease—cases occurring in New Hampshire.
In a report discussing cases occurring during August and September of last year, in addition to the seven New Hampshire cases, there were four from Massachusetts—five times the average of 0.08 for the previous 10 years (MMWR 2006;55:697–700).
The CDC advises health care providers to be aware of the risk of Eastern equine encephalitis virus (EEEV) “even in areas that have not previously had much activity.”
EEEV is spread by mosquitoes and can affect horses, as well as humans. Mosquitoes carrying the EEEV most commonly inhabit swamps and marshes, the report said.
Notably, all of the infected patients spent time working or socializing near such wetland areas, and all lived within half a mile of a swamp or cranberry bog.
Dr. Julia McMillan, a member of the American Academy of Pediatrics' Committee on Infectious Disease and professor of pediatrics at Johns Hopkins University, Baltimore, agreed with the CDC's recommendations to use insect repellent and long-sleeved clothing to keep insects at bay.
Given that EEEV, like malaria and dengue, is caused by a virus, there is no specific treatment for this potentially fatal infection.
“I think that actually is one of the scariest things. It's the reason why protecting children and ourselves is so important,” Dr. McMillan said.
When asked if the chemicals in insect repellent are safe for children, she said that moderation is called for. “There is no way to keep a child completely safe,” she said. “But that doesn't mean [parents] should not try. It's just important to understand that everything is a balance.”
The CDC on its Web page on West Nile virus cites the Environmental Protection Agency's advice: “Do not allow children to handle the [insect repellent]. When using on children, apply to your own hands first and then put it on the child.”
Likewise, the AAP warns not to apply DEET (N, N-diethyl-m-toluamide) to the hands of young children and to avoid applying it to areas around a child's eyes and mouth.
Dengue Cases Rising in Tropics, CDC Warns
Increases in the incidence of dengue hemorrhagic fever in tropical countries also have prompted the CDC to remind health care providers to consider this disease when diagnosing febrile patients who have recently returned from areas of risk—and to remind the public of protective measures.
There were 96 confirmed cases of dengue in U.S. residents last year, the CDC reported (MMWR 2006;55:700–2). Dengue, which is not endemic to North America, is not seen commonly by physicians here—but with increasing international travel, global warming, and slackening antimosquito efforts in some countries, more suspected cases of dengue may be seen, particularly during the summer months.
Travelers need to remember that when they go to tropical areas, mosquitoes may carry diseases that are not found in the United States. Malaria chemoprophylaxis does not protect against mosquitoes—just against the malaria that they carry, Dr. McMillan noted.
The CDC advises preventing dengue transmission by using insect repellent including DEET.
Unlike EEEV, Dr. McMillan noted, dengue is not now carried by mosquitoes in this country—and EEEV is very rare where it does exist. “The CDC report [on EEEV] is significant because EEEV, unlike dengue, has high mortality rate associated with it,” she said.