Detecting Guillain-Barré syndrome caused by Zika virus using systems developed for polio surveillance.

Abstract

Zika virus disease is caused by a ribonucleic acid (RNA) virus, which is transmitted to humans by mosquitoes of the Aedes aegypti species. Around 80% of infections are asymptomatic. (1) Symptomatic infections are characterized by mild fever lasting from four to seven days, associated with maculopapular rash, arthralgia, conjunctivitis, muscle pain and headache. Until recently, Zika virus disease has never been associated with deaths, intrauterine infections, or congenital anomalies. In 2013 and 2014, during an outbreak in French Polynesia, the disease was linked with GuillainBarre syndrome. (2) Zika infection can be established by detection of Zika virus RNA or specific viral antigens in human clinical samples. It is suspected that over 40 countries had autochthonous Zika virus transmission in 2015 and early 2016. (3,4) In some countries, there is a temporal association of Zika virus infections with severe clinical manifestations, particularly Guillain-Barre syndrome and congenital neurological malformations. (3,4) In December 2015, officials from the Brazilian Ministry of Health reported 76 patients diagnosed with neurological syndromes, of whom 42 (55%) were confirmed as having Guillain-Barre syndrome. (4) Similarly, between December 2015 and January 2016, Salvadorian health officials reported 46 patients with Guillain-Barre syndrome, more than 50% of whom had febrile illness lasting between seven to 15 days before onset of the syndrome. (4) A case-control study conducted in 2013 and 2014 in French Polynesia has shown evidence of Zika virus infections causing Guillain-Barre syndrome. (2) The French Polynesia study found, in most of the patients, neurological symptoms following Zika virus infections lasted a median of six days. (2) With increasing evidence of linkages between Guillain-Barre syndrome and Zika virus infection, (2-4) it is imperative to enhance Guillain-Barre syndrome surveillance. This can be done using existing surveillance systems like the one for acute flaccid paralysis (AFP) used by polio eradication programmes. (5) Scientists warn that in view of outbreaks that occurred in Africa, south-east Asia, the Pacific Islands, and the Americas, the disease now has pandemic potential. (6) In February 2016, the World Health Organization (WHO) declared that the reported clusters of microcephaly and other neurological disorders from the WHO Region of the Americas constituted a Public Health Emergency of International Concern and recommended to enhance surveillance for Zika virus infection. (7) The Aedes species of mosquitoes that transmits the Zika virus and other infections like dengue, chikungunya and yellow fever exists worldwide, posing a high risk for global transmission. (6) A 2016 modelling study looking at the potential for Zika virus spread predicted substantial international spread by travellers from Brazil to the rest of the world. (8) Many cases of microcephaly and Guillain-Barre syndrome are now being reported from countries affected by Zika. (2,4) Surveillance for timely detection and monitoring of Zika infection and screening for microcephaly and Guillain-Barre syndrome will be essential to guide the public health response. Governments and other stakeholders use existing AFP surveillance systems in countries to monitor progress towards a global polio eradication goal. (9) Currently, 91% (177 out of 194) of WHO Member States conduct AFP surveillance. Reporting of AFP in children younger than 15 years is followed by laboratory diagnosis of stool specimens to either confirm polio or identify nonpolio AFP cases. Guillain-Barre syndrome cases are classified as non-polio AFP cases. Guillain-Barre syndrome is the most common non-polio cause for AFP. Most countries achieve or surpass the global standard of an annual rate of at least one case of non-polio AFP per 100000 population of children younger than 15 years. In 2015, globally, 99 582 AFP cases among children younger than 15 years, including 72 laboratory-confirmed wild poliovirus cases, were reported. …