Getting dengue fever may protect some people against Zika, study suggests
- The mosquito-carried Zika virus usually only causes mild illness in those that contract it, pregnant women can pass it to their fetuses
- Babies born with Zika often have uncommonly small heads and brain defects
- There is no cure or treatment for Zika
- Researchers from Yale University found that in a Brazilian city hard-it by the 2015 outbreak, people who had had dengue fever may be protected from Zika
- But not if they had recently had the first illness
People who had had dengue fever before the 2015 outbreak of Zika may have been protected from the disease, a study suggests.
Pau da Lima, a slum city in the Salvador region of Brazil, was hit particularly hard by Zika. Over 70 percent of the over 2.5 million people who live there contracted the mosquito born disease.
But while studying its spread, scientists from Yale University School of Public Health made an unexpected discovery.
Many of the small percentage of people who remarkably dodged the virus, shared something in common: they had had a particular strain of dengue fever before.
The more of antibodies to that virus remained in the blood, the better protected from Zika they seemed to be – but not if they’d had dengue too recently.
There is no treatment or cure for Zika, but people win Brazil who had had dengue fever in the past were less likely to catch Zika during the outbreak in 2015, a new study found
Zika is transmitted a particular species of mosquito that thrives in tropical moments and bites both day and night.
In some places, like Pau da Lima, there’s hardly any way to avoid the disease-laden bugs.
A single bite can transmit the brutal virus from the animal to a human.
For the bitten person, the infection often isn’t so bad.
Its symptoms may go entirely unnoticed for a week or more and, even when they do become noticeable, the symptoms are quite mild, including a rash, fever, headache, joint pain, red eyes and muscle pain.
But the virus can be passed to sexual partners and have devastating consequences for future generations.
The Zika virus can pass from a pregnant woman’s blood system to her fetus and infect it during development.
It’s unclear how or why, but fetuses infected in the womb often develop a condition called microcephaly, which is marked by unusually small head size and brain defects.
The virus has also been linked to a rare nervous system condition called Guillain-Barre syndrome (GBS) that causes significant muscle weakness and tingling and must be treated with blood or plasma transfusions as well as physical therapy.
And, currently, there is neither a vaccine against, nor a treatment for, Zika.
Except, perhaps, surviving dengue fever, the paradoxical Yale findings suggest.
The researchers studied 1,400 people in Pau da Lima, but never expected the protective effects of dengue fever they found.
In previous research on rats, previous dengue fever actually seemed to worse Zika’s effects.
But in humans, the people with the highest levels of one kind of dengue antibody had the lowest risk of contracting Zika.
To add confusion to an already surprising result, those who had had dengue most recently – and had higher levels of a different type of antibody to it – were actually at a higher risk of contracting Zika.
It’s a brand new discovery, and their findings ‘may represent an opportunity for vaccine trials,’ the authors wrote, but, ‘the overall high rates of immunity will present a barrier for future [Zika] incidence in this community.’