On 2016 Sep 09, Cristiane N Soares commented:

The question regarding CHIK tests mentioned by Thomas Jeanne is really relevant in this case. In fact, we were concerned about co-infections, and after the paper acceptance we performed IgM and IgG CHIK tests in serum and CSF. All samples were negatives for CHIKV.

On 2016 Sep 08, Thomas Jeanne commented:

In their case report, Soares et al. do not mention testing for chikungunya virus (CHIKV), which has considerable overlap with Zika virus (ZIKV) in both epidemiologic characteristics and clinical presentation. Brazil experienced a large increase in chikungunya cases in early 2016 (Collucci C, 2016), around the time of this patient's illness, and recent case series in Ecuador (Zambrano H, 2016) and Brazil (Sardi SI, 2016) have demonstrated coinfection with ZIKV and CHIKV. Moreover, a recently published study of Nicaraguan patients found that 27% of those who tested positive for any of ZIKV, CHIKV, or DENV (dengue virus) with multplex RT-PCR also tested positive for one or both of the other viruses (Waggoner JJ, 2016). CHIKV itself has previously been linked to encephalitis including fatal encephalitis (Gérardin P, 2016), and some have speculated that adverse interactions could result from coinfection with two or more arboviruses (Singer M, 2017). Coinfection with chikungunya as a contributing factor in this case cannot be ruled out without appropriate testing.

On 2016 Sep 08, Thomas Jeanne commented:

In their case report, Soares et al. do not mention testing for chikungunya virus (CHIKV), which has considerable overlap with Zika virus (ZIKV) in both epidemiologic characteristics and clinical presentation. Brazil experienced a large increase in chikungunya cases in early 2016 (Collucci C, 2016), around the time of this patient's illness, and recent case series in Ecuador (Zambrano H, 2016) and Brazil (Sardi SI, 2016) have demonstrated coinfection with ZIKV and CHIKV. Moreover, a recently published study of Nicaraguan patients found that 27% of those who tested positive for any of ZIKV, CHIKV, or DENV (dengue virus) with multplex RT-PCR also tested positive for one or both of the other viruses (Waggoner JJ, 2016). CHIKV itself has previously been linked to encephalitis including fatal encephalitis (Gérardin P, 2016), and some have speculated that adverse interactions could result from coinfection with two or more arboviruses (Singer M, 2017). Coinfection with chikungunya as a contributing factor in this case cannot be ruled out without appropriate testing.

On 2016 Sep 09, Cristiane N Soares commented:

The question regarding CHIK tests mentioned by Thomas Jeanne is really relevant in this case. In fact, we were concerned about co-infections, and after the paper acceptance we performed IgM and IgG CHIK tests in serum and CSF. All samples were negatives for CHIKV.