Analysis highlights strong Zika-GBS association

[Guest Nicole]

A new analysis based on data from seven countries hit hard by Zika virus found a strong link between Zika infection and Guillain-Barre syndrome (GBS), a complication marked by numbness, weakness, and sometimes paralysis of the limbs.

In other Zika research developments, scientists published new reports on co-infections with other mosquito-borne viruses and fatal encephalitis.

GBS elevated up to 10-fold

For months now, global health officials have said there's a scientific consensus about a link between Zika virus and GBS. The syndrome is a rare complication of other virus infections, including other members of the flavivirus family.

Today's letter to the New England Journal of Medicine reviews Zika and GBS patterns in seven countries: Brazil, Colombia, the Dominican Republic, El Salvador, Honduras, Suriname, and Venezuela. Authors include health ministry officials and experts from the World Health Organization (WHO) and its Pan American Health Organization (PAHO).

According to data submitted by the countries for Zika and GBS, changes in Zika incidence in 2015 and 2016 were closely associated with the rise and fall of GBS. Differences from GBS baselines for some countries, however, were much higher than others, with the greatest percentage rises reported in Suriname and Venezuela.

The team explored a possible link between dengue infection and GBS incidence but didn't find one.

Women had a 75% higher incidence rate of Zika than men, especially those in the 20- to 49-year-old age-group, which could reflect differences in exposure, more severe symptoms, or differences in healthcare-seeking behavior, the report said. The GBS incidence, though, was 28% higher in men and increased with age, consistent with findings for other similar diseases.

The investigators concluded that the levels they found—2.0 to 9.8 times as high as baseline—shows that GBS poses a substantial burden on health systems in the region. They added that more studies are needed to show that Zika infection is a cause of GBS.

Zika, chikungunya, dengue co-infections

Multiplex testing for Zika, chikungunya, and dengue viruses in Nicaragua found that coinfections are common, a research group from the United States and Nicaragua reported yesterday in Clinical Infectious Diseases.

They based their findings on 346 serum samples submitted by healthcare providers and tested from Sep 1, 2015, to Apr 3, 2016. Of 263 that were positive for one or more viruses, 192 tested positive for one of the three mosquito-borne viruses and 71 had evidence of co-infection involving two or all three viruses.

The researchers concluded that co-infections are common and that because the diseases have similar clinical presentations, multiplex tests are needed to help with patient care and surveillance.

Fatal encephalitis in an adult

Brazilian researchers, meanwhile, reported the first known case of fatal encephalitis in an adult infected with Zika virus.

According to their report in the Journal of Clinical Virology, the patient was a previously healthy 47-year-old woman who wasn't pregnant. She sought care for an itchy rash in joint pain in early January. Four days later she experienced lower limb weakness, dysarthria, and confusion.

The next day she was admitted to the hospital, where her condition deteriorated rapidly, requiring mechanical ventilation. Cerebrospinal fluid was positive for Zika antibodies and her urine tested positive for Zika virus. Her doctors saw massive brain swelling on computed tomography. Despite aggressive treatment, the woman died 11 days after she was admitted.

The authors said the case is a reminder for clinicians to consider Zika virus as a cause of encephalitis and to be aware of how severe the infections can be.

http://www.cidrap.umn.edu/news-perspective/2016/08/analysis-highlights-strong-zika-gbs-association

[The Librarian]

This news makes Zika much more a serious threat than we previously thought. 

[Arauna]

I recently read another study which showed that the effects of Zika are worse in socio-economically deprived locations...... it seems it could be a combination of bad nutrition and mosquito infections which makes the outcome worse... ...