This is the first report to describe the frequency of chikungunya virus-related arthritis in the Americas after a 20-month follow-up. The high frequency of chronic disease highlights the need for the development of prevention and treatment methods.

IMPORTANCE The evolution of fetal brain injury by Zika virus (ZIKV) infection is not well described. OBJECTIVES To perform longitudinal neuroimaging of fetuses and infants exposed to in utero maternal ZIKV infection using concomitant magnetic resonance imaging (MRI) and ultrasonography (US), as well as to determine the duration of viremia in pregnant women with ZIKV infection and whether the duration of viremia correlated with fetal and/or infant brain abnormalities. DESIGN, SETTING, AND PARTICIPANTS A cohort of 82 pregnant women with clinical criteria for probable ZIKV infection in Barranquilla, Colombia, and Washington, DC, were enrolled from June 15, 2016, through June 27, 2017, with Colombian women identified by community recruitment and physician referral and travel-related cases of American women recruited from a Congenital Zika Program. INTERVENTIONS AND EXPOSURES Women received 1 or more MRI and US examinations during the second and/or third trimesters. Postnatally, infants underwent brain MRI and cranial US. Blood samples were tested for ZIKV. MAIN OUTCOMES AND MEASURES The neuroimaging studies were evaluated for brain injury and cerebral biometry. RESULTS Of the 82 women, 80 were from Colombia and 2 were from the United States. In 3 of 82 cases (4%), fetal MRI demonstrated abnormalities consistent with congenital ZIKV infection. Two cases had heterotopias and malformations in cortical development and 1 case had a parietal encephalocele, Chiari II malformation, and microcephaly. In 1 case, US results remained normal despite fetal abnormalities detected on MRI. Prolonged maternal polymerase chain reaction positivity was present in 1 case. Of the remaining 79 cases with normal results of prenatal imaging, postnatal brain MRI was acquired in 53 infants and demonstrated mild abnormalities in 7 (13%). Fifty-seven infants underwent postnatal cranial US, which detected changes of lenticulostriate vasculopathy, choroid plexus cysts, germinolytic/subependymal cysts, and/or calcification in 21 infants (37%). CONCLUSIONS AND RELEVANCE In a cohort of pregnant women with ZIKV infection, prenatal US examination appeared to detect all but 1 abnormal fetal case. Postnatal neuroimaging in infants who had normal prenatal imaging revealed new mild abnormalities. For most patients, prenatal and postnatal US may identify ZIKV-related brain injury.

Objective To determine the frequency of chronic joint pain and stiffness 3 years after infection with chikungunya virus (CHIKV) in a Latin American cohort. Methods A cross-sectional followup of 120 patients from an initial cohort of 500 patients who reported joint pain 2 years after infection from the Atlántico Department, Colombia. Patients were clinically diagnosed as having CHIKV during the 2014–2015 epidemic, and baseline and followup symptoms at 40 months were evaluated in serologically confirmed cases. Results Of the initial 500 patients enrolled in the study, 482 had serologically confirmed chikungunya infection. From this group, 123 patients reported joint pain 20 months after infection, and 54% of those patients reported continued joint pain 40 months after infection. Therefore, 1 out of every 8 people who tested serologically positive for CHIKV infection had persistent joint pain 3 years after infection. Participants who followed up in person were predominantly adult (mean ± SD age 51 ± 14 yrs) and female (86%). The most common type of pain reported in these patients at 40 months post-infection was pain with periods of relief and subsequent reoccurrence, and over 75% reported stiffness after immobility, with 39% experiencing morning stiffness. Conclusion To our knowledge, this is the first report to describe persistent joint pain and stiffness 40 months after viral infection. The high frequency of chronic disease highlights the need to develop prevention and treatment methods. Further studies should be conducted to understand the similarities between post-chikungunya joint pain and rheumatoid arthritis.

This is one of the largest observational studies involving analysis of the synovial fluid of chikungunya arthritis patients. Synovial fluid analysis revealed no detectable chikungunya virus. This finding suggests that chikungunya virus may cause arthritis through induction of potential host autoimmunity, suggesting a role for immunomodulating agents in the treatment of chikungunya arthritis, or that low-level viral persistence exists in synovial tissue only and is undetectable in synovial fluid.

Most alphaviruses are mosquito-borne and can cause severe disease in domesticated animals and humans. The most notable recent outbreak in the Americas was the 2014 chikungunya virus (CHIKV) outbreak affecting millions and producing disease highlighted by rash and arthralgia. Chikungunya virus is a member of the Semliki Forest (SF) serocomplex, and before its arrival in the Americas, two other member of the SF complex, Una (UNAV) and Mayaro (MAYV) viruses, were circulating in Central and South America. This study examined whether antibodies from convalescent CHIKV patients could cross-neutralize UNAV and MAYV. Considerable cross-neutralization of both viruses was observed, suggesting that exposure to CHIKV can produce antibodies that may mitigate infection with UNAV or MAYV. Understanding the impact of CHIKV exposure on population susceptibility to other emerging viruses may help predict outbreaks; moreover, identification of cross-reactive immune responses among alphaviruses may lead to the development of vaccines targeting multiple viruses.