Zika Shown to Trigger Severe Neurological Disorder
Blood tests have proven that the mosquito-borne virus was the culprit in an outbreak in French Polynesia of Guillain-Barre syndrome.
Scientists on Tuesday said they had confirmed that the Zika virus sweeping Latin America and blamed for severe birth defects can also trigger a dangerous neurological disorder.
In a study published in the medical journal The Lancet, a team probed Zika's suspected role in a 2013-2014 outbreak in French Polynesia of Guillain-Barre syndrome (GBS) - a rare condition in which the body's immune system attacks a part of the nervous system that controls muscle strength.
Research into patients who fell ill with GBS, supported by blood tests, proved that the mosquito-borne virus was the culprit, they said.
"This is the first evidence for Zika virus causing Guillain-Barre syndrome," the study said.
The syndrome - which can also be caused by bacterial infections as well as the dengue and chikungunya viruses - provokes muscle weakness in the legs and arms.
In rich nations, GBS is lethal in about five percent of cases, and another five percent suffer lasting disabilities. More than a quarter of patients require intensive care.
With 1.5 million cases of Zika infection already recorded in Brazil, and tens of thousands in neighbouring countries, researchers warn that an outbreak of Guillain-Barre could strain healthcare facilities, especially outside of big cities.
"In areas that will be hit by the Zika epidemic, we need to think about reinforcing intensive care capacity," said Arnaud Fontanet, a co-author of the study and a professor at the Emerging Diseases Epidemiology Unit of the Institut Pasteur in Paris.
"We know that a certain number of those patients are going to develop GBS, and 30 percent of them are going to need intensive care, especially for assisted breathing," he told AFP.
By itself, Zika is no more threatening than a bad cold or a mild case of the flu. Sometimes there are no symptoms at all.
But the rapidly expanding virus - present in nearly four dozen countries, according to the World Health Organization (WHO) - is suspected to be the cause a sudden increase in cases of neonatal microcephaly, a severe deformation of the brain and skull among newborns.
Brazil reported last week 583 confirmed cases of babies with the irreversible birth defect since October 2015, four times the previous annual average.
Zika is spread among humans by the Aedes aegypti mosquito, which is found in 130 nations. But recent evidence suggests that it can also be sexually transmitted by men carrying the virus.
In the study, two dozen researchers identified 42 cases of Guillain-Barre in French Polynesia in the aftermath of a Zika epidemic that infected some 200,000 people.
For Fontanet, there was no doubt that the virus caused the upsurge in GBS cases.
"The links are as strong as they would be for saying that tobacco causes lung cancer," he told AFP.
Three kinds of evidence supported this conclusion, he said.
The first was a 20-fold increase in the number of GBS cases during the Zika epidemic.
The second was that 90 percent the patients struck with the debilitating syndrome had been infected the week before by the mosquito-borne virus.
Both epidemiological findings were supported by blood analysis.
"We found traces of the recent presence of Zika in 100 percent of the GBS patients," including antibodies built up to fight the virus, said Fontanet.
The researchers were also able to exclude previous infection with the dengue virus - also common in French Polynesia - as a cause.
They did acknowledge, however, the biological mechanism by which Zika triggers the muscle-depleting syndrome has yet to be identified. Some experts who did not participate in the research agreed that it was a breakthrough.
"This study provides the most compelling evidence to date of a causative link between Zika virus infection and the serious neurological condition Guillain-Barre syndrome," said Jeremy Farrar, director of the Wellcome Trust in Britain.
"The scale of the crisis unfolding in Latin America has taken us all by surprise, and we should be prepared for further unforeseen complications... in the coming weeks and months."
Others, though, cautioned that the findings were not conclusive, and may not apply directly to other affected regions.
"A significant amount of work has still to be undertaken before the same conclusions can be extended to the Zika outbreak in South America," said Peter Barlow, spokesman for the British Society for Immunology.
On February 1, the WHO declared a public health emergency due to rising cases of microcephaly and Guillain-Barre syndrome, even though the link to Zika remained circumstantial.
This is a transmission electron micrograph (TEM) of Zika virus.
Rarely has anyone looked at a potentially fatal infectious disease and exclaimed, "Now, that is a thing of beauty." One sculptor, however, has taken bacteria and viruses from their invisible world and placed them in ours.
Artist Luke Jerram has created a collection of glass artwork in the shape microorganisms -- bacteria and viruses no less that have the potential to infect or even kill human beings. By bringing these microscopic marauders to the light, Jerram demystifies these otherwise unknowable microorganisms. And using glass as a medium reinforces not only the fragility of the work, but also our own in the face of these diseases.
In this slide show, take a closer look at some of the highlights from Jerram's glass microbiology collection.
Turning HIV into a work of art is a seemingly impossible task. The virus is responsible for the deaths of an estimated 34 million people worldwide since the epidemic was first reported in 1981, according to UNAIDS, the joint United Nations Programme on HIV/AIDS.
The HIV virus sculpture was the first Jerram built for his collection.
If there's one disease that has plagued humankind throughout its history, it's malaria. In 2010, the World Health Organization estimated that more than 200 million people were infected with the disease, mostly in poverty-stricken regions of sub-Saharan Africa, but also parts of South America and Southeast Asia.
Malaria is transmitted through mosquito bites. Mosquito nets, insect repellant and pesticides are all effective means of prevention, but only for those with the available resources and access to afford them.
Looking at this spindly sculpture might make you the slightest bit queasy, and for good reason. E. coli is represented by this glass artwork. Although most E. coli strains are in fact harmless to humans, the strains we're most acquainted with are the ones that cause food poisoning.
This alien-looking sculpture is actually T4 Bacteriophage, a virus that targets E. coli bacteria.
Bacteriophages are small viruses that attach to the cell membrane of bacteria. The virus injects its DNA into the bacteria, which then produces replicas of the virus, filling the bacterium until it bursts.
If this model is giving you that nostalgic feeling of plagues past, you might not be surprised to find out that this work represents Severe acute respiratory syndrome, or SARS.
SARS made global headlines in 2003 when people in 37 countries and nearly reached pandemic levels. Although coverage of the illness was widely criticized for overstating the threat, nearly 9,000 were infected with the disease, with had a nearly 10 percent fatality rate.
Swine flu, shown here, was another contagious disease that drew global attention that Jerram selected for his exhibition, but this time it was personal. According to his website, Jerram came down with swine flu and constructed the sculpture "with a fever whilst swallowing my Tamiflu tablets every few hours."
Swine flu, or H1N1 strain of the influenza virus, made global headlines in 2009 as the next potential major flu epidemic. Though common among pigs, swine flu is rarely transmitted among humans. When it does infect a human, however, the symptoms associated with the virus, typical of other flu strains, are particularly acute.
Given just how common the Human Papilloma Virus (HPV) is among humans, you'd think this virus, pictured here, wouldn't be so controversial. In fact, it isn't, but the use of a vaccine to prevent the infection, which can lead to certain kinds of cancers in women.
Because the virus can be transmitted sexually, however, the idea of vaccinations, particularly compulsory ones for children -- the vaccine is in fact intended only for people 25 and younger -- generated a considerable pushback, despite the obvious benefits of the treatment.
Hand, foot and mouth disease might not get a lot of press, but these disease outbreaks are in fact fairly common, particularly among infants and children. Occasionally, they can be fatal. Symptoms are similar to the flu, with the exception of sores that can appear all over the body, but particularly the hands, feet and mouth of the carrier.
This final entry is an unrealized future mutation for a disease that doesn't exist yet. Look for it in a contaminated water main, food source or loving pet near you. (But seriously, don't.)