From August-October 2014, 11 AFM cases were identified in CO during a national outbreak of EV-D68 respiratory disease. The significance of EV-D68 detection in the nasopharynx (NP) and development of AFM is unclear.
A case-control study design compared EV-D68 detection in NP specimens from AFM cases in Colorado to controls from the same location and time period. Cases were 1-18 years old with acute focal limb weakness and MRI findings of spinal cord lesions largely restricted to gray matter with no known etiology. Controls were children of the same age with NP specimens collected at outpatient visits at CHCO for (1) respiratory viruses (RV) or (2) Bordetella pertussis (BP) testing. Cases and controls were classified as ‘EV-D68' if EV-D68 detected by real-time RT PCR; or ‘other enterovirus' if pan EV PCR positive and EV-D68 rRT-PCR negative in NP specimens. Multivariable logistic regression controlled for significant covariates.
Ten of 11 (91%) cases had respiratory symptoms, compared to 96/123 (80%, p=0.69) of RV and 264/275 (98%, p=0.25) of BP tested controls. Cases were older than RV controls (8 vs 5 median y, p=0.04) and had specimens collected later (10 vs 5 median d, p<0.01). Cases had fever more often than BP tested controls (91% vs 34%, p<0.01). EV-D68 was detected in NP specimens of 4/11 (36%) AFM cases compared to 5/123 (4%) of RV tested controls (p<0.01) and 21/275 (8%) of BP tested controls (p<0.01). AFM cases had 12 times higher odds of EV-D68 compared to RV tested controls, and 9 times higher odds compared to BP tested controls in adjusted multivariable models (Table). Non-EVD68 enterovirus was not associated with AFM.
Odds of EV-D68 detection in AFM cases significantly exceeded those in outpatient controls with respiratory illness during the outbreak period in CO, supporting an epidemiologic association between EV-D68 and AFM.
Adjusted multivariable models testing the association of enterovirus with AFM
RV tested controls
BP tested controls
12.4 (2.1, 81.2)¹
9.3 (1.8, 50.5)¹
4.6 (0.6, 38.6)
2.2 (0.4, 12.0)
¹ p<0.05; 2Adjusted for age, days between symptoms and specimen collection and specimen collection week;
3adjusted for fever, specimen type and collection week
D. M. Pastula, None
E. Leshem, None
C. C. Robinson, Biofire: Scientific Advisor , Consulting fee
W. A. Nix, None
M. S. Oberste, None
J. Sejvar, None
D. Feikin, None
S. Dominguez, None