The Pan American Health Organization as the regional office for the World Health Organization in the Americas issued a briefing note on July 10, 2023, regarding the unusual outbreak of Guillain Barré Syndrome (GBS) in different parts of Peru.
GBS is a rare but serious heterogenous autoimmune disease characterized by rapidly progressive, symetrical limb weakness, areflexia, sensory abnormalities, and cytoalbuminologic dissociation in the cerebrospinal fluid. Molecular mimicry, antiganglioside antibodies and, likely, complement activation are involved in the pathogenesis of GBS. An upper respiratory or gastrointestinal illness typically precedes GBS. The most frequently identified precipitant of GBS is Campylobacter jejuni infection, which is usually associated with the acute motor axonal neuropathy form of GBS.
On June 26, 2023, the National Center for Epidemiology, Prevention, and Disease Control of Peru issued an epidemiological alert due to an increase in cases of GBS in different regions of the country. Between epidemiological week 1 and 27 (until 8 July 2023), 191 cases of GBS, which met the established case definition, have been reported. 77 of these cases were confirmed, including four deaths. The reported deaths were registered in January (1), March (1), and May (2).
In 2023, 58.6% of reported cases were males, with an average age of 41 years (ages ranged 2–86 years). 77 cases (40.3%) were adults between 30 and 59 years old, 51 cases (26.7%) were older adults (> 60 years), and 38 cases were children under 17 years of age.
Based on the clinical manifestations, 44 cases (23%) had gastrointestinal infection, 46 cases (24.1%) had respiratory infection, and 31 cases (16.2%) had fever. In terms of neurological manifestation, 131 cases (71.9%) had ascending muscle weakness, and 21.9% had some type of sequelae.
For epidemiological surveillance and laboratory diagnosis of GBS in Peru, the samples were collected from the cases. Campylobacter jejuni has been found in eleven cases.
Outbreaks of GBS are uncommon. National surveillance in Peru detected an unusual outbreak of Guillain Barré Syndrome in 2019, with the large number of cases. The incidence rate was nearly 25 times higher than expected and higher than previously reported GBS outbreaks. The outbreak of GBS affected several regions of the country, with over 900 cases. Based on the clinical and epidemiological characteristics, it was concluded that this outbreak was associated with the presence of Campylobacter jejuni genotype sequence type 2993, which has been associated with GBS outbreaks in China.
In the year 2020, a total of 448 cases were reported, with a weekly average of 11 cases. In 2021, there were 210 cases with an average of 4 cases per week, and in 2022, there were 225 cases with an average of 4 cases per week. According to these data (excluding the 2019 outbreak), the average monthly number of registered GBS cases was below 20 cases. However, between epidemiological week 23 and 27 of 2023, 96 cases per month were reported.
On July 8, 2023, The Presidency of the Republic of Peru issued a Decree, declaring a health emergency at the national level due to the unusual increase in cases of GBS.
Pan American Health Organization / World Health Organization. Briefing Note: Increase in case Guillain-Barré Syndrome Peru. 10 of July 2023, Washington, D.C.: PAHO/WHO; 2023 https://www.paho.org/en/documents/briefing-note-increase-cases-guillain-barre-syndrome-peru