Chronic Pain and Zika Virus: What You Need to Know
Infectious disease experts explain what the recent outbreak of Zika may mean for patients with chronic pain.
Interviews with Alexander Garza, MD, MPH, Matthew B. Laurens, MD, MPH, Thomas Voss, PhD.
If you have been following the news, you probably have heard about the recent outbreak of the Zika virus. The headlines have raised awareness and concern about the virus because of its potential to cause the birth defect known as microcephaly.
But the virus presents a different set of issues for people with chronic pain, experts say. While there is still much that is not known about Zika and its long-term effects, several infectious disease experts told Practical Pain Management that people with chronic pain conditions should exercise great caution when traveling to areas where Zika and other similar viruses are endemic.
The majority of people who get infected with Zika never have symptoms at all. Those who do get sick usually have very mild symptoms—fever, rash, joint pain, and red eyes or conjunctivitis. Other common symptoms include muscle pain and headache. Symptoms usually last several days, up to a week.
The incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week, noted the Centers for Disease Control and Prevention. Zika is generally diagnosed through a blood test.
To date, there have not been any documented reports of long-term joint pain or the development of arthritis in people infected with the Zika virus, according to Thomas Voss, PhD, Vice President of SRI Biosciences and Director, SRI Center for Infectious Diseases in Menlo Park, California.
“With joint pain being such a predominant symptom of Zika, it would make sense that it might exacerbate existing joint pain in people with conditions like arthritis, but we can’t say definitively,” said Alexander Garza, MD, MPH, associated dean for public health practice at Saint Louis University's College for Public Health and Social Justice.
First Zika Outbreak
During the first outbreak of Zika from 2013-2014 in French Polynesia, national health authorities reported an unusual increase in Guillain-Barré syndrome (GBS), a condition in which the body’s immune system attacks part of the nervous system. It can be caused by a number of viruses, and may lead to muscle weakness and tingling in the arms and legs. In severe cases the respiratory muscles are affected. Most people recover. The GBS outbreak also coincided with an ongoing dengue outbreak.
In late February 2016, researchers who analyzed blood samples from 42 patients diagnosed with Guillain-Barré during the Zika virus outbreak in French Polynesia said they have found the first evidence that Zika might cause GBS. In a study in The Lancet, the researchers concluded that if 100,000 people were infected with Zika, 24 would develop GBS.
Most of the patients with GBS reported they had experienced symptoms of Zika virus infection on average 6 days before any neurological symptoms, and all carried Zika virus antibodies. The researchers wrote, “The results of our study support that Zika virus should be added to the list of infectious pathogens susceptible to cause Guillain-Barré syndrome.”
Zika virus occurs in tropical areas with large mosquito populations, and is currently circulating in many countries in Central and South America, as well as part of the Caribbean. The CDC have reported cases cropping up in the United States, as well. It can be difficult to distinguish the effect of Zika disease with those of other infections, such as dengue or chikungunya infection, Dr. Voss said. All three are spread through mosquitos, and all of the infections can cause fever and rash.
According to the CDC, within the United States:
- No local mosquito-borne Zika virus disease cases have been reported in US states, but there have been travel-associated cases.
- There is evidence that the Zika virus can be sexually transmitted by a man to his sex partners. In the two cases of likely sexual transmission, both men had symptoms. The virus is present in semen longer than in blood.
- With the recent outbreaks, the number of Zika cases among travelers visiting or returning to the United States will likely increase.
- 80% of cases will not be diagnosed.
- These imported cases could result in local spread of the virus in some areas of the United States.
- On December 31, 2015, the Puerto Rico Department of Health reported the first locally acquired case of Zika virus disease.
- On February 17, 2016, the FDA issued a new guidance recommending the deferral of individuals from donating blood if they have been to areas with active Zika virus transmission, potentially have been exposed to the virus, or have had a confirmed Zika virus infection.
No Treatment or Vaccine To Date
There are currently no antiviral medications available to treat Zika, noted Matthew B. Laurens, MD, MPH, a pediatric infectious disease specialist at the University of Maryland School of Medicine's Institute for Global Health.
“We know more about what not to do than what to do,” he said. “A person infected with Zika should stay well hydrated, rest and can take acetaminophen for the pain. Don’t take aspirin or ibuprofen, because these can potentially worsen bleeding, which is a problem if a person with Zika-like symptoms actually has dengue or a similar infection.”
He explained that the infecting organism in dengue affects the platelets responsible for clotting and may increase the tendency of a person to bleed. Aspirin and ibuprofen also have similar action. A person with dengue who takes aspirin or ibuprofen could bleed excessively, he added.
Dr. Laurens says that until more is known about Zika, it may be wise for people with chronic conditions to avoid traveling to areas where the virus is widespread. “If you do travel to these areas, take the necessary precautions to protect against mosquitos that might carry Zika, malaria, or other organisms,” he said.
According to the CDC, if you think you have been exposed to the virus, you should:
- Get plenty of rest.
- Drink fluids to prevent dehydration.
- Take medicine such as acetaminophen (Tylenol) to relieve fever and pain.
- Do not take aspirin and other non-steroidal anti-inflammatory drugs.
- If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.
Precautions to Take
The World Health Organization recommends people traveling to high-risk areas protect themselves from mosquito bites by using insect repellents, wearing light colored, long sleeved shirts and pants, and ensuring rooms are fitted with screens to prevent mosquitoes from entering.
Anyone with chronic pain who is on steroids or other medication that can suppress the immune system should be particularly cautious in traveling to endemic areas, Dr. Laurens said. “If a person taking these medications becomes infected with Zika, they can potentially have more serious manifestations of the disease, and may be more likely to develop complications,” he said.
Photo credit: James Gathany/CDC