Printer Friendly

Prolonged Zika virus viremia in a patient with Guillain-Barre syndrome in Trinidad and Tobago/Viremia prolongada por el virus del Zika en un paciente con sindrome de Guillain-Barre en Trinidad y Tabago/Viremia prolongada do virus zika em paciente com sindrome de Guillain-Barre em Trinidad e Tobago.

Zika virus (ZIKV) is an arthropod-borne virus in the genus Flavivirus, family Flaviviridae (1). The genus Flavivirus encompasses many relevant human pathogens, including yellow fever, dengue, West Nile Fever, Japanese encephalitis, and tick-borne encephalitis viruses. ZIKV was first isolated in 1947 from a febrile macaque monkey in Uganda (2) and was subsequently isolated from Aedes africanus mosquitoes (3).

ZIKV disease is usually a mild and self-limiting illness associated with such symptoms as fever, maculopapular and pruritic rash, arthralgia, and nonpurulent conjunctivitis (4). Since the emergence of the disease, many reports have connected Zika virus infection with Guillain-Barre syndrome (GBS), as was demonstrated previously for other flaviviruses (5).

GBS cases temporally associated with short-term ZIKV infection (viremia less than 5 to 7 days after the onset of symptoms) have been reported in French Polynesia (6); Brazil, Colombia, the Dominican Republic, El Salvador, Honduras, Suriname, and Venezuela (7); and Haiti (8). We here report the finding of a case of GBS with prolonged ZIKV viremia, in a patient from the Caribbean island country of Trinidad and Tobago. Both molecular detection of the target viral RNA and serologic characterization of the serum were used as diagnostic approaches.


On 10 August 2016, a 29-year-old man visited his private practitioner in Tunapuna, a city that is in the north of Trinidad and Tobago, about 15 km from the capital city of Port of Spain. The initial clinical symptoms were characterized as non-quantified mild fever, headache, and malaise. No respiratory or neurological symptoms were present at that time, and the patient was sent home with symptomatic treatment. No specimens from any source were taken during this first visit.

Febrile peaks continued appearing during the days after the onset of symptoms. A generalized maculopapular rash and a tingling and weakness of lower limbs appeared on 16 August (day 7 after the onset of symptoms). However, following a medical examination by the same private practitioner, the patient was not hospitalized.

Rash completely disappeared on 20 August (day 11 after the onset of symptoms), but weakness of lower limbs (associated with walking instability) progressed to the upper limbs on 30 August (day 21), when the patient was sent by the private practitioner for neurological evaluation and hospitalization at the Port of Spain General Hospital.

After the patient was hospitalized, the clinical examination revealed a moderate to severe impairment of muscle strength. The patient was clinically diagnosed with Guillain-Barre syndrome, and therapeutic schemes based on the administration of intravenous immunoglobulin were initiated.

A blood specimen was taken that same day (August 30, day 21after the onset of symptoms) and sent to the Trinidad Public Health Laboratory for virologic/serological investigation. (This was the only blood specimen taken from the patient during the illness.) That serum sample was then sent on 5 September for laboratory investigation at the Laboratory of Virology of the Caribbean Public Health Agency (CARPHA), in the city of Port of Spain.

Enzyme-linked immunoassay (ELISA) demonstrated the absence of IgM antibodies against dengue virus (Dengue Virus IgM Capture DxSelect, Focus Diagnostics, Cypress, California, United States of America), Chikungunya virus (Anti-Chikungunya Virus ELISA IgM, EUROIMMUN AG, Lubeck, Schleswig-Holstein, Germany), and ZIKV (Anti-Zika virus ELISA IgM, EUROIMMUN AG, Lubeck, Schleswig-Holstein, Germany). Testing of viral RNA for dengue virus (DENV), Chikungunya virus (CHIKV), and ZIKV was done using Trioplex Real-time RT-PCR assay (rRTPCR) (Centers for Disease Control and Prevention (CDC), Dengue Branch, San Juan, Puerto Rico), following the CDC's instructions for its use. Viral RNA detection was found negative for DENV and CHIKV, and positive for ZIKV. The crossing threshold (Ct) value found for the sample was 34.46 (positive below 38).

On 12 October 2016, an aliquot of the original serum sample was sent for laboratory confirmation to the Division of Vector-Borne Diseases, which is part of the CDC's National Center for Infectious Diseases, in Fort Collins, Colorado, United States. The arboviral serology report on 17 November indicated evidence of infection with a flavivirus, according to neutralizing antibody testing, with a plaque reduction neutralization test (PRNT) titer > 1 280 for ZIKV (positive control titer > 320).

As of May 2017, the patient was still reporting a mild persistence of weakness of both lower and upper limbs (personal communication from patient, May 2017).


This study has some limitations, including the absence of early and successive (serial) samples. These samples should have been taken between days 1 to 5 after the onset of symptoms. Moreover, it also could have been useful to take some samples at different intervals (for instance, 7, 10, 15, 20, and 30 days after the onset). With all these specimens, the kinetics of the viral progression in blood could have been determined. In addition, serial sampling could have been very useful for establishing the relation between the initial symptoms and the suspected ZIKV infection. Moreover, additional samples could have also demonstrated the clearance of the virus in blood and/or other body fluids (e.g., urine). On the other hand, despite the fact that the quantification of viral load in this sample was relative instead of absolute, the Ct value reported from the rRT-PCR assay is an indication that the target RNA was present in the sample. No additional samples from this patient were obtained and, therefore, a follow-up determination of the relative amount of target RNA could not be performed.


In this study, a male was clinically diagnosed with an infection produced by ZIKV, and he later developed GBS. The patient is a resident of Tunapuna, an urban area with a large population in the northern part of the island of Trinidad. Other cases of ZIKV infection had been found in the area, and there was a relatively low incidence of other arbovirus infections, such as DENV and CHIKV, at that time.

The ZIKV case was clinically well characterized as a mild ZIKV infection with fever and maculopapular rash, with no criteria for hospitalization at the beginning of the illness. On day 7 after the onset of symptoms, neurologic symptoms were evident, which progressed from the lower limbs to the upper limbs on day 21, when the patient was hospitalized and a blood specimen was taken. According to the algorithm for detection of ZIKV infections at the CARPHA's Laboratory of Virology, such specimens are tested within 7 days after the onset of symptoms. However, in some cases, such as pregnant women or GBS patients, the laboratory staff may decide (generally for research purposes) to include the samples for diagnosis, even though the samples do not match with the algorithms for the detection of ZIKV.

Amplification of Zika virus RNA in serum samples is the most specific and sensitive diagnostic approach available, and it must be performed during the acute phase (viremic period) of the illness (up to 7 days from the onset of symptoms). In March 2016, the Pan American Health Organization (PAHO) developed case definitions and surveillance guidance for Zika virus disease and associated complications that clearly indicated a characteristic transient viremic period during ZIKV infections (9).

Abundant published evidence shows that negative amplifications have been reported for patients whose samples were tested at 6 or more days after the onset of symptoms, indicating a viremic period as brief as 5 days (10). This agrees with other observations, in which viremia was detected when symptoms were present, but not afterward (11). In contrast, prolonged Zika virus RNA has been detected in serum from symptomatic pregnant women from 35 to 53 days post-exposure (12, 13). Additionally, viremia is very often low level, making viral isolation from clinical samples difficult (10).

In a case-control study (6), acute Zika virus infection, as confirmed by a positive RT-PCR result, was observed for all patients in one of the control groups, but for none of the 41 patients tested in the GBS group. According to the authors, this corroborated some clinical observations (notably the absence of fever), suggesting that the patients in the GBS group were no longer viremic at admission. In other words, viral nucleic acid was not amplified at the time when the GBS symptoms appeared. Moreover, in a recently published preliminary report (14), the authors provided evidence that ZIKV is present in serum for a longer period than expected for other flaviviruses; the relation of this finding with GBS cases was not part of that study.

Our target sample was taken on day 21 from the onset of fever and day 15 from the onset of rash. By that time, according to our crossing threshold result (Ct = 34.46) in the rRT-PCR assay, the sample contained moderate amounts of target nucleic acid (Zika virus RNA) (considering a value of < 29 as a strong positive, between 30 and 37 as a moderate positive, and 38 to 40 as a weak or negative reaction). Given the high sensitivity and specificity of the rRT-PCR assay and the clinical and epidemiological characterization of this case, it appears that this infection with ZIKV was strongly associated with GBS in the patient. It also indicates that the viremia persisted beyond the time reported previously for Zika and other flaviviruses.

Isolation of ZIKV to demonstrate infectivity could not be performed at the CARPHA laboratory. Nevertheless, the resultant amplification of the target viral RNA is strong evidence that the nucleic acid was extracted from intact (and therefore, infective) viral particles. Free viral RNA in serum is unlikely due to ribonucleases, and remnant virus or non -infective particles are not described for most flaviviruses, at least in the context of persistent infections.

In serology testing (ELISA IgM), the sample was negative for DENV, CHIKV, and ZIKV. Many of the commercial kits for detection of IgM antibodies against ZIKV have low sensitivity, according to one study (15) and a recently circulated CARPHA internal report. This may explain a possible false-negative result, although a failure of IgM response cannot be completely ruled out.

An interesting question at this point is why ZIKV clearance in this patient was delayed and how the immune response could have been implied. One possible explanation is the existence of an unknown or poorly defined immune response mechanism in the course of a flavivirus infection. In fact, a 2014 study demonstrated that West Nile Virus-specific immune responses are severely impaired and delayed in diabetic mice (16), suppressing key antiviral defense responses such as those elicited by IFN-[alpha], IgM, and IgG antibodies. In the same study, suppressed clearance of virus was observed in serum, peripheral tissues, and the brain, thus explaining the persistence of West Nile Virus. In our study there is no evidence that a known or unknown factor might have been responsible for the negative ELISA results and the prolonged viremia in the patient. However, other underlying and still not-defined mechanisms might be implicit. An impaired IgM response is one hypothesis.

The plaque reduction neutralization test (PRNT), an assay used to quantify the titer of neutralizing antibodies, showed neutralization of ZIKV at > 1 280 serum dilution. The neutralization observed is a consequence of the presence of neutralizing antibodies (mostly IgG) against ZIKV. Due to the limited amount of sample available, the lack of sensitivity, and the intense cross-reactivity among flaviviruses, demonstration of IgG antibodies against ZIKV and other flaviviruses was not included in this study. Nevertheless, it is logical that other anti-flavivirus IgG antibodies were present in the patient's serum. That is especially true given that these viruses (such as DENV) have been endemic in the tropics for many years ago and that yellow fever vaccine is regularly applied in Trinidad and Tobago.

A mechanism known as antibody-dependent enhancement might be involved, in which IgG antibodies against viral envelope proteins resulting from a prior infection bind to virus particles of a subsequent infection. This leads to enhanced replication, and potentially more severe illness (17). Thus, persistent viremia that produces GBS could be related with that antibody-dependent enhancement mechanism. Evidence from in vitro experiments suggests cross-reactivity between DENV and ZIKV antibody responses and antibody-dependent enhancement of ZIKV by DENV antibodies (17-19). More research is needed on ZIKV persistent viremia and its relationship with immune response. Additionally, causes of further development of GBS must be investigated.

Many aspects of the ZIKV infection and pathogenesis in humans remain unclear. One remarkable example is whether amplification of viral RNA is related with effective infectious particles. Another striking case is the mechanisms responsible for the appearance of neurologic complications during the ZIKV exposure. With regards to the neurologic damage, one explanation indicates a possible antibody-response mechanism against specific antigens on the ZIKV particles. Another proposed explanation is direct damage of peripheral nerves produced by the virus itself (4, 13). Persistent ZIKV viremia, demonstrated as RNA presence in serum or blood, could be involved in those proposed mechanisms. Long-term ZIKV nucleic acid amplification has recently been related with congenital central nervous system problems, mostly microcephaly and brain development alterations (20). It should be established whether nervous tissue damage is a direct consequence of ZIKV infection. The molecular mechanisms implicated in this damage should also be assessed.

The data presented in this study provide evidence to support changing how we distinguish between an acute ZIKV infection and a nonacute one. Epidemiological surveillance systems, especially those for neurological disorders (for instance, acute flaccid paralysis surveillance for discarding polio virus infection), could be direct beneficiaries of a change in the parameters for laboratory detection (algorithms) of agents implicated in neurological illnesses (as with ZIKV and GBS).

There is growing evidence on the differences among flaviviruses in terms of the early stages of the illnesses, the clinical and epidemiological findings, and the duration of the viremia. The data presented in this article indicate that it is possible to determine an etiological diagnosis of a particular neurological disorder by modifying some laboratory algorithms, thus extending the proposed time for detection of some viral agents, including ZIKV.

To our knowledge, this is the first report that directly links long-term persistence of ZIKV infection with a non-congenital neurologic syndrome. We here demonstrated the concurrence of Zika virus viremia with the development of a case of Guillain-Barre syndrome. Further investigations are needed on the epidemiological relevance of our findings, the duration of the viremia, and the syndromes associated with ZIKV infection.

Acknowledgments. The authors would like to thank the staff of the Caribbean Public Health Agency (CARPHA), the Ministry of Health of the Republic of Trinidad and Tobago, the patient, and the physician for their input and contributions to this paper.

Conflicts of interest. The authors declare no conflicts of interest of any kind.

Disclaimer. The authors hold sole responsibility for the views expressed in the manuscript, which may not necessarily reflect the opinion or policy of the Caribbean Public Health Agency (Port of Spain, Trinidad and Tobago), the Ministry of Health of the Republic of Trinidad and Tobago (Port of Spain), the RPSP/ PAJPH, or PAHO.


(1.) Gubler DJ, Kuno G, Markoff L. Flaviviruses. In: Knipe DM, Howley PM, eds. Fields virology, 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2007:1155-227.

(2.) Dick GW, Kitchen SF, Haddow AJ. Zika virus. I. Isolations and serological specificity. Trans R Soc Trop Med Hyg. 1952 Sep; 46(5):509-20.

(3.) Haddow AJ, Williams MC, Woodal JP, Simpson DI, Goma LK. Twelve isolations of Zika virus from Aedes (Stegomyia) africanus (Theobald) taken in and above a Uganda forest. Bull World Health Organ. 1964;31:57-69.

(4.) Duffy MR, Chen T-H, Hancock WT, Hancock T, Powers AM, Kool JL, et al. Zika virus outbreak on Yap island, Federated States of Micronesia. N Engl J Med. 2009 Jun 11;360(24):2536-43.

(5.) Sejvar JJ, Bode AV, Marfin AA, Campbell gL, Ewing D, Mazowiecki M, et al. West Nile virus-associated flaccid paralysis. Emerg Infect Dis. 2005;11:2021-7.

(6.) Cao-Lormeau VM, Blake A, Mons S, Lastere S, Roche C, Vanhomwegen J, et al. Guillain-Barre syndrome outbreak associated with Zika virus infection in French Polynesia: a case-control study. Lancet. 2016;387:1531-9.

(7.) Dos Santos T, Rodriguez A, Almiron M, Sanhueza A, Ramon P, De Oliveira W, et al. Zika virus and the Guillain-Barre syndrome--case series from seven countries. N Engl J Med. 2016 Oct 20;375(16): 1598-1601.

(8.) Kassavetis P, Bajo J-M, Perloff MD, Roosevelt F, Berkowitz AL. Zika virus-associated Guillain-Barre syndrome variant in Haiti. Am Acad Neurol. 2016;87:336-7.

(9.) Pan American Health Organization. Guidelines for Zika virus disease and its complications 2016. Washington, D.C.: PAHO, 2016. Available from: http://iris. eng.pdf?sequ-ence = 1&isAllowed=y Accessed 10 May 2017.

(10.) Lanciotti RS, Kosoy OL, Laven JJ, Velez JO, Lambert AJ, Johnson AJ, et al. Genetic and serologic properties of Zika virus associated with an epidemic, Yap State, Micronesia, 2007. Emerg Infect Dis. 2008;14:1232-9.

(11.) Bearcroft WG. Zika virus infection experimentally induced in a human volunteer. Trans R Soc Trop Med Hyg. 1956;50:442-8.

(12.) Meaney-Delman D, Oduyebo T, Polen KN, White JLWhite JL, Bingham AM, Slavinski SA, et al. Prolonged detection of Zika virus RNA in pregnant women. Obstet Gynecol. 2016;128(4):724-30.

(13.) Driggers RW, Ho CY, Korhonen EM, Kuivanen S, Jaaskelainen AJ, Smura T, et al. Zika virus infection with prolonged maternal viremia and fetal brain abnormalities. N Engl J Med. 2016;374:2142-51.

(14.) Paz-Bailey G, Rosenberg ES, Doyle K, Munoz-Jordan J, Santiago GA, Klein L, et al. Persistence of Zika virus in body fluids-preliminary report. N Engl J Med. 2017 Feb 14. doi: 10.1056/NEJMoa1613108. [Epub ahead of print].

(15.) Steinhagen K, Probst C, Radzimski C, Schmidt-Chanasit J, Emmerich P, van Esbroeck M, et al. Serodiagnosis of Zika virus (ZIKV) infections by a novel NS1-based ELISA devoid of cross-reactivity with dengue virus antibodies: a multicohort study of assay performance, 2015 to 2016. Euro Surveill. 2016 Dec 15;21(50):30426.

(16.) Kumar M, Roe K, Nerurkar PV, Namekar M, Orillo B, Verma S, et al. Impaired virus clearance, compromised immune response and increased mortality in type 2 diabetic mice infected with West Nile virus. PLoS One. 2012;7(8):e44682. doi: 10.1371/journal.pone.0044682.

(17.) Dejnirattisai W, Supasa P, Wongwiwat W, Rouvinski A, Barba-Spaeth G, Duangchinda T, et al. Dengue virus sero-cross-reactivity drives antibody-dependent enhancement of infection with zika virus. Nat Immunol. 2016 Sep;17(9):1102-8. doi: 10.1038/ni.3515.

(18.) Priyamvada L, Quicke KM, Hudson WH, Onlamoon N, Sewatanon J, Edupuganti S, et al. Human antibody responses after dengue virus infection are highly cross-reactive to Zika virus. Proc Nat Acad Sci. 2016;113(28):7852-7.

(19.) Paul LM, Carlin ER, Jenkins MM, Tan AL, Barcellona CM, Nicholson CO, et al. Dengue virus antibodies enhance Zika virus infection. Available from: http:// 050112 Accessed 10 May 2017.

(20.) Oliveira DBL, Almeida FJ, Durigon EL, Mendes EA, Braconi CT, Marchetti I, et al. Prolonged shedding of Zika virus associated with congenital infection. N Engl J Med. 2016;375:12-14.

Manuscript received on 22 November 2016. Revised version accepted for publication on 23 May 2017.

Gabriel Gonzalez-Escobar, [1] Anne Marie Valadere, [1] Rosmond Adams, [1] Karen Polson-Edwards, [1] Avery Q.J. Hinds, [1] Akenath Misir, [2] and C. James Hospedales [1]

[1] Caribbean Public Health Agency (CARPHA), Port of Spain, Trinidad and Tobago. Send correspondence to Gabriel Gonzalez-Escobar at

[2] Ministry of Health, Port of Spain, Trinidad and Tobago.
COPYRIGHT 2017 Pan American Health Organization
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Short communication
Author:Gonzalez-Escobar, Gabriel; Valadere, Anne Marie; Adams, Rosmond; Polson-Edwards, Karen; Hinds, Avery
Publication:Revista Panamericana de Salud Publica
Date:Sep 1, 2017
Previous Article:Response regarding Colombian regulation of biotherapeutic products / Respuesta sobre la regulacion colombiana de los productos bioterapeuticos.
Next Article:La ruta abreviada de comparabilidad colombiana para medicamentos biotecnologicos: ?tendencia global o caso unico?

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters