Implementation and Evaluation of Guillain-Barré Syndrome Surveillance in Puerto Rico during the 2016 Zika Virus Epidemic.

OBJECTIVE: Guillain-Barré syndrome (GBS) is an uncommon autoimmune disorder that follows infection or vaccination, and increased incidence has been reported during Zika virus (ZIKV) transmission. During the 2016 ZIKV epidemic, the Puerto Rico Department of Health (PRDH) implemented the Enhanced GBS Surveillance System (EGBSSS). Here, we describe EGBSSS implementation and evaluate completeness, validity, and timeliness. METHODS: GBS cases were identified using passive surveillance and discharge diagnostic code for GBS. Completeness was evaluated by capture-recapture methods. Sensitivity and positive predictive value (PPV) for confirmed GBS cases were calculated for both case identification methods. Median time to completion of key time steps were compared by quarter (Q1-4) and hospital size. RESULTS: A total of 122 confirmed GBS cases with onset of neurologic illness in 2016 were identified. Capture-recapture methodology estimated that four confirmed GBS cases were missed by both identification methods. Identification of cases by diagnostic code had a higher sensitivity than passive surveillance (89% vs. 80%), but a lower PPV (60% vs. 72%). There was a significant decrease from Q1 to Q3 in median time from hospital admission to case reporting (11 days vs. 2 days, p = 0.032) and from Q2 to Q3 in median time from specimen receipt to arbovirus laboratory test reporting (35 days vs. 26 days, p = 0.004). CONCLUSION: EGBSSS provided complete, valid, and increasingly timely surveillance data, which guided public health action and supported healthcare providers during the ZIKV epidemic. This evaluation provides programmatic lessons for GBS surveillance and emergency response surveillance.

Clinical Features of Guillain-Barré Syndrome With vs Without Zika Virus Infection, Puerto Rico, 2016.

Importance: The pathophysiologic mechanisms of Guillain-Barré syndrome (GBS) associated with Zika virus (ZIKV) infection may be indicated by differences in clinical features. Objective: To identify specific clinical features of GBS associated with ZIKV infection. Design, Setting, and Participants: During the ZIKV epidemic in Puerto Rico, prospective and retrospective strategies were used to identify patients with GBS who had neurologic illness onset in 2016 and were hospitalized at all 57 nonspecialized hospitals and 2 rehabilitation centers in Puerto Rico. Guillain-Barré syndrome diagnosis was confirmed via medical record review using the Brighton Collaboration criteria. Specimens (serum, urine, cerebrospinal fluid, and saliva) from patients with GBS were tested for evidence of ZIKV infection by real-time reverse transcriptase-polymerase chain reaction; serum and cerebrospinal fluid were also tested by IgM enzyme-linked immunosorbent assay. In this analysis of public health surveillance data, a total of 123 confirmed GBS cases were identified, of which 107 had specimens submitted for testing; there were 71 patients with and 36 patients without evidence of ZIKV infection. Follow-up telephone interviews with patients were conducted 6 months after neurologic illness onset; 60 patients with and 27 patients without evidence of ZIKV infection participated. Main Outcomes and Measures: Acute and long-term clinical characteristics of GBS associated with ZIKV infection. Results: Of 123 patients with confirmed GBS, the median age was 54 years (age range, 4-88 years), and 68 patients (55.3%) were male. The following clinical features were more frequent among patients with GBS and evidence of ZIKV infection compared with patients with GBS without evidence of ZIKV infection: facial weakness (44 [62.0%] vs 10 [27.8%]; P < .001), dysphagia (38 [53.5%] vs 9 [25.0%]; P = .005), shortness of breath (33 [46.5%] vs 9 [25.0%]; P = .03), facial paresthesia (13 [18.3%] vs 1 [2.8%]; P = .03), elevated levels of protein in cerebrospinal fluid (49 [94.2%] vs 23 [71.9%]; P = .008), admission to the intensive care unit (47 [66.2%] vs 16 [44.4%]; P = .03), and required mechanical ventilation (22 [31.0%] vs 4 [11.1%]; P = .02). Six months after neurologic illness onset, patients with GBS and evidence of ZIKV infection more frequently reported having excessive or inadequate tearing (30 [53.6%] vs 6 [26.1%]; P = .03), difficulty drinking from a cup (10 [17.9%] vs 0; P = .03), and self-reported substantial pain (15 [27.3%] vs 1 [4.3%]; P = .03). Conclusions and Relevance: In this study, GBS associated with ZIKV infection was found to have higher morbidity during the acute phase and more frequent cranial neuropathy during acute neuropathy and 6 months afterward. Results indicate GBS pathophysiologic mechanisms that may be more common after ZIKV infection.

Guillain-Barré Syndrome During Ongoing Zika Virus Transmission - Puerto Rico, January 1-July 31, 2016.

Guillain-Barré syndrome (GBS) is a postinfectious autoimmune disorder characterized by bilateral flaccid limb weakness attributable to peripheral nerve damage (1). Increased GBS incidence has been reported in countries with local transmission of Zika virus, a flavivirus transmitted primarily by certain Aedes species mosquitoes (2). In Puerto Rico, three arthropod-borne viruses (arboviruses) are currently circulating: Zika, dengue, and chikungunya. The first locally acquired Zika virus infection in Puerto Rico was reported in December 2015 (3). In February 2016, the Puerto Rico Department of Health (PRDH), with assistance from CDC, implemented the GBS Passive Surveillance System (GBPSS) to identify new cases of suspected GBS (4). Fifty-six suspected cases of GBS with onset of neurologic signs during January 1-July 31, 2016, were identified. Thirty-four (61%) patients had evidence of Zika virus or flavivirus infection; the median age of these patients was 55 years (range = 21-88 years), and 20 (59%) patients were female. These 34 patients were residents of seven of eight PRDH public health regions. All 34 patients were hospitalized and treated with intravenous immunoglobulin G (IVIg), the standard treatment for GBS; 21 (62%) required intensive care unit admission, including 12 (35%) who required endotracheal intubation and mechanical ventilation. One patient died of septic shock after treatment for GBS. Additionally, 26 cases of neurologic conditions other than GBS were reported through GBPSS, including seven (27%) in patients with evidence of Zika virus or flavivirus infection. Residents of and travelers to Puerto Rico and countries with active Zika virus transmission should follow recommendations for prevention of Zika virus infections.* Persons with signs or symptoms consistent with GBS should promptly seek medical attention. Health care providers in areas with ongoing local transmission seeing patients with neurologic illnesses should consider GBS and report suspected cases to public health authorities.

Update: Ongoing Zika Virus Transmission - Puerto Rico, November 1, 2015-April 14, 2016.

Zika virus is a flavivirus transmitted primarily by Aedes species mosquitoes, and symptoms of infection can include rash, fever, arthralgia, and conjunctivitis (1).* Zika virus infection during pregnancy is a cause of microcephaly and other severe brain defects (2). Infection has also been associated with Guillain-Barré syndrome (3). In December 2015, Puerto Rico became the first U.S. jurisdiction to report local transmission of Zika virus, with the index patient reporting symptom onset on November 23, 2015 (4). This report provides an update to the epidemiology of and public health response to ongoing Zika virus transmission in Puerto Rico. During November 1, 2015-April 14, 2016, a total of 6,157 specimens from suspected Zika virus-infected patients were evaluated by the Puerto Rico Department of Health (PRDH) and CDC Dengue Branch (which is located in San Juan, Puerto Rico), and 683 (11%) had laboratory evidence of current or recent Zika virus infection by one or more tests: reverse transcription-polymerase chain reaction (RT-PCR) or immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA). Zika virus-infected patients resided in 50 (64%) of 78 municipalities in Puerto Rico. Median age was 34 years (range = 35 days-89 years). The most frequently reported signs and symptoms were rash (74%), myalgia (68%), headache (63%), fever (63%), and arthralgia (63%). There were 65 (10%) symptomatic pregnant women who tested positive by RT-PCR or IgM ELISA. A total of 17 (2%) patients required hospitalization, including 5 (1%) patients with suspected Guillain-Barré syndrome. One (<1%) patient died after developing severe thrombocytopenia. The public health response to the outbreak has included increased laboratory capacity to test for Zika virus infection (including blood donor screening), implementation of enhanced surveillance systems, and prevention activities focused on pregnant women. Vector control activities include indoor and outdoor residual spraying and reduction of mosquito breeding environments focused around pregnant women's homes. Residents of and travelers to Puerto Rico should continue to employ mosquito bite avoidance behaviors, take precautions to reduce the risk for sexual transmission (5), and seek medical care for any acute illness with rash or fever.

Reemergence of Dengue in Southern Texas, 2013.

During a dengue epidemic in northern Mexico, enhanced surveillance identified 53 laboratory-positive cases in southern Texas; 26 (49%) patients acquired the infection locally, and 29 (55%) were hospitalized. Of 83 patient specimens that were initially IgM negative according to ELISA performed at a commercial laboratory, 14 (17%) were dengue virus positive by real-time reverse transcription PCR performed at the Centers for Disease Control and Prevention. Dengue virus types 1 and 3 were identified, and molecular phylogenetic analysis demonstrated close identity with viruses that had recently circulated in Mexico and Central America. Of 51 household members of 22 dengue case-patients who participated in household investigations, 6 (12%) had been recently infected with a dengue virus and reported no recent travel, suggesting intrahousehold transmission. One household member reported having a recent illness consistent with dengue. This outbreak reinforces emergence of dengue in southern Texas, particularly when incidence is high in northern Mexico.

Local Transmission of Zika Virus--Puerto Rico, November 23, 2015-January 28, 2016.

Zika virus, a mosquito-borne flavivirus, spread to the Region of the Americas (Americas) in mid-2015, and appears to be related to congenital microcephaly and Guillain-Barré syndrome (1,2). On February 1, 2016, the World Health Organization (WHO) declared the occurrence of microcephaly cases in association with Zika virus infection to be a Public Health Emergency of International Concern.* On December 31, 2015, Puerto Rico Department of Health (PRDH) reported the first locally acquired (index) case of Zika virus disease in a jurisdiction of the United States in a patient from southeastern Puerto Rico. During November 23, 2015-January 28, 2016, passive and enhanced surveillance for Zika virus disease identified 30 laboratory-confirmed cases. Most (93%) patients resided in eastern Puerto Rico or the San Juan metropolitan area. The most frequently reported signs and symptoms were rash (77%), myalgia (77%), arthralgia (73%), and fever (73%). Three (10%) patients were hospitalized. One case occurred in a patient hospitalized for Guillain-Barré syndrome, and one occurred in a pregnant woman. Because the most common mosquito vector of Zika virus, Aedes aegypti, is present throughout Puerto Rico, Zika virus is expected to continue to spread across the island. The public health response in Puerto Rico is being coordinated by PRDH with assistance from CDC. Clinicians in Puerto Rico should report all cases of microcephaly, Guillain-Barré syndrome, and suspected Zika virus disease to PRDH. Other adverse reproductive outcomes, including fetal demise associated with Zika virus infection, should be reported to PRDH. To avoid infection with Zika virus, residents of and visitors to Puerto Rico, particularly pregnant women, should strictly follow steps to avoid mosquito bites, including wearing pants and long-sleeved shirts, using permethrin-treated clothing and gear, using an Environmental Protection Agency (EPA)-registered insect repellent, and ensuring that windows and doors have intact screens.