Author Contributions
Conceptualization, H.M., D.S.R, A.L.H., and W.B.K.; Methodology, H.M.; Software, H.M.; Validation, H.M., and D.S.R.; Formal analysis, H.M. and D.S.R.; Investigation, H.M. and D.S.R.; Resources, A.L.H., D.S.R., and W.B.K.; Data curation, H.M., J.D.L., and K.J.O.; Writing—original draft preparation, H.M.; Writing—review and editing, H.M., D.S.R., A.L.H., and W.B.K.; Visualization, H.M. and D.S.R.; Supervision, D.S.R. and A.L.H.; Project administration, A.L.H.; Funding acquisition, A.L.H., D.S.R., and W.B.K.
Figure 1.
EEEV disease in macaques. Shown are models of disease for (a) EEEV-exposed macaques with non-severe and severe courses of alphavirus disease over days post-infection (x-axis). Deep blue denotes pre-infection baseline period, vertical magenta line denotes time of infection. Green bar denotes post-infection period in animals without severe/fatal disease. For animals with severe/fatal disease, powder blue defines post-infection period before the onset of fever, and red signifies the febrile post-infection period. Skull and crossbones mark the mean time to death. Actual and forecasted temperature profiles for two macaques with severe disease requiring euthanasia: (b) M161-16, and (c) M163-16, compared to macaques without severe disease: (d) M160-16 and (e) M162-16. Red: actual temperature (°C). Blue: forecasted temperature (°C) from ARIMA modeling. Black: Residual Values (°C) (deviations from forecasted baseline). Gray Lines: upper/lower bounds for residuals. Magenta: aerosol challenge.
Figure 1.
EEEV disease in macaques. Shown are models of disease for (a) EEEV-exposed macaques with non-severe and severe courses of alphavirus disease over days post-infection (x-axis). Deep blue denotes pre-infection baseline period, vertical magenta line denotes time of infection. Green bar denotes post-infection period in animals without severe/fatal disease. For animals with severe/fatal disease, powder blue defines post-infection period before the onset of fever, and red signifies the febrile post-infection period. Skull and crossbones mark the mean time to death. Actual and forecasted temperature profiles for two macaques with severe disease requiring euthanasia: (b) M161-16, and (c) M163-16, compared to macaques without severe disease: (d) M160-16 and (e) M162-16. Red: actual temperature (°C). Blue: forecasted temperature (°C) from ARIMA modeling. Black: Residual Values (°C) (deviations from forecasted baseline). Gray Lines: upper/lower bounds for residuals. Magenta: aerosol challenge.

Figure 2.
Increase in QRS complex during the febrile period in macaques with severe EEEV. Shown are the profiles (a) of QRS complex derived from 1-min average measurements for four individual macaques infected with EEEV. Black: QRS Complex (ms), Gray: Temperature (°C), and Magenta: aerosol challenge. Blue Bars: Neurological score on corresponding day. (b) Average daily QRS complex measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 2.
Increase in QRS complex during the febrile period in macaques with severe EEEV. Shown are the profiles (a) of QRS complex derived from 1-min average measurements for four individual macaques infected with EEEV. Black: QRS Complex (ms), Gray: Temperature (°C), and Magenta: aerosol challenge. Blue Bars: Neurological score on corresponding day. (b) Average daily QRS complex measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 3.
Reduction in QT-interval during the febrile period in macaques infected with severe EEEV. Shown are the profiles (a) of QT-interval derived from 1-min average measurements for four individual macaques infected with EEEV. Black: QT-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: Neurological score on corresponding day. (b) Average daily QT-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 3.
Reduction in QT-interval during the febrile period in macaques infected with severe EEEV. Shown are the profiles (a) of QT-interval derived from 1-min average measurements for four individual macaques infected with EEEV. Black: QT-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: Neurological score on corresponding day. (b) Average daily QT-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 4.
Reduction in RR-interval during the febrile period in macaques infected with EEEV. Shown are the profiles (a) of RR-interval derived from 1-min average measurements for four individual macaques infected with EEEV. Black: RR-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: neurological score on corresponding day. (b) Average daily RR-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 4.
Reduction in RR-interval during the febrile period in macaques infected with EEEV. Shown are the profiles (a) of RR-interval derived from 1-min average measurements for four individual macaques infected with EEEV. Black: RR-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: neurological score on corresponding day. (b) Average daily RR-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M160-16, Bottom Left: M161-16, Top Right: M162-16, Bottom Right: M163-16.
Figure 5.
Heart rate variability decreases during the febrile period in macaques infected with EEEV. (a) Distributions of heart rate variability of each EEEV-infected macaque are plotted in aggregate and color-coded by disease period (Cyan: Pre-Infection, Black: Post-Infection, Red: Febrile (if applicable)). (b) Repeated measures ANOVA of HRV data for macaques with nonsevere and severe EEEV infection (p < 0.05). Central tendency of macaques with severe disease (Red) significantly diminishes after 3 dpi, compared to macaques with nonsevere disease (Blue).
Figure 5.
Heart rate variability decreases during the febrile period in macaques infected with EEEV. (a) Distributions of heart rate variability of each EEEV-infected macaque are plotted in aggregate and color-coded by disease period (Cyan: Pre-Infection, Black: Post-Infection, Red: Febrile (if applicable)). (b) Repeated measures ANOVA of HRV data for macaques with nonsevere and severe EEEV infection (p < 0.05). Central tendency of macaques with severe disease (Red) significantly diminishes after 3 dpi, compared to macaques with nonsevere disease (Blue).
Figure 6.
VEEV disease in macaques. Shown is the model of disease for (a) VEEV-exposed macaques over days post-infection (x-axis); all macaques developed febrile encephalitic disease. Deep blue denotes pre-infection baseline period, vertical magenta line denotes time of infection, powder blue defines post-infection period before the onset of fever, red signifies the febrile post-infection period, and yellow signifies recovery period after febrile illness subsides. Actual and forecasted temperature profiles for female macaques: (b) M164-16, (c) M165-16, and male macaques: (d) M170-16 and (e) M171-16. Red: actual temperature (°C); Blue: forecasted temperature (°C) from ARIMA modeling, Black: residual values (°C) (deviations from forecasted baseline). Gray Lines: upper/lower bounds for residuals. Magenta: aerosol challenge.
Figure 6.
VEEV disease in macaques. Shown is the model of disease for (a) VEEV-exposed macaques over days post-infection (x-axis); all macaques developed febrile encephalitic disease. Deep blue denotes pre-infection baseline period, vertical magenta line denotes time of infection, powder blue defines post-infection period before the onset of fever, red signifies the febrile post-infection period, and yellow signifies recovery period after febrile illness subsides. Actual and forecasted temperature profiles for female macaques: (b) M164-16, (c) M165-16, and male macaques: (d) M170-16 and (e) M171-16. Red: actual temperature (°C); Blue: forecasted temperature (°C) from ARIMA modeling, Black: residual values (°C) (deviations from forecasted baseline). Gray Lines: upper/lower bounds for residuals. Magenta: aerosol challenge.
Figure 7.
Reduction in QT-interval during the febrile period in macaques infected with VEEV. Shown are the profiles (a) of QT-interval derived from 1-min average measurements for four individual macaques infected with VEEV. Black: QT-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue bars: neurological score on corresponding day. (b) Average daily QT-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M164-16, Bottom Left: M165-16, Top Right: M170-16, Bottom Right: M171-16.
Figure 7.
Reduction in QT-interval during the febrile period in macaques infected with VEEV. Shown are the profiles (a) of QT-interval derived from 1-min average measurements for four individual macaques infected with VEEV. Black: QT-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue bars: neurological score on corresponding day. (b) Average daily QT-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M164-16, Bottom Left: M165-16, Top Right: M170-16, Bottom Right: M171-16.
Figure 8.
RR-interval decreases and remains decreased in macaques with VEEV encephalitis. Shown are the profiles (a) of RR-interval derived from 1-min average measurements for four individual macaques infected with VEEV. Black: RR-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: neurological score on corresponding day. (b) Average daily RR-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M164-16, Bottom Left: M165-16, Top Right: M170-16, Bottom Right: M171-16.
Figure 8.
RR-interval decreases and remains decreased in macaques with VEEV encephalitis. Shown are the profiles (a) of RR-interval derived from 1-min average measurements for four individual macaques infected with VEEV. Black: RR-interval (ms), Gray: temperature (°C), and Magenta: aerosol challenge. Blue Bars: neurological score on corresponding day. (b) Average daily RR-interval measurements, from repeated measures ANOVA, depicted in with boxes delimited by interquartile range and center line signifying median value. For (a) and (b), Top Left: M164-16, Bottom Left: M165-16, Top Right: M170-16, Bottom Right: M171-16.
Figure 9.
Heart rate variability decreases during the febrile period in macaques infected with VEEV. Distributions of heart rate variability of each VEEV-infected macaque are plotted in aggregate and color-coded by disease period (Cyan: pre-infection, Black: post-infection, Red: febrile, Yellow: recovery).
Figure 9.
Heart rate variability decreases during the febrile period in macaques infected with VEEV. Distributions of heart rate variability of each VEEV-infected macaque are plotted in aggregate and color-coded by disease period (Cyan: pre-infection, Black: post-infection, Red: febrile, Yellow: recovery).
Table 1.
EEV courses of infection in macaque cohort.
Table 1.
EEV courses of infection in macaque cohort.
Virus | Macaque | Sex | Dose * | TTD δ | Neuro £ | ΔMax γ | Onset γ | Duration γ | Fever-Hours γ |
---|
EEEV | M161-16 | M | 8.2 | 6 | Y | 4.2 | 3 | 70.8 | 144.2 |
M163-16 | M | 7.5 | 6 | Y | 4.4 | 3 | 65.0 | 154.9 |
Mean | | 8.0 | | | 4.3 | 3 | 67.9 | 149.6 |
M160-16 | M | 7.0 | S | N | 0.7 | | 14.3 | 6.5 |
M162-16 | M | 5.7 | S | N | 1.8 | | 41.5 | 30.5 |
Mean | | 6.8 | | | 1.3 | | 27.9 | 18.5 |
VEEV | M164-16 | F | 7.1 | S | Y | 2.8 | 1 | 187.8 | 171.6 |
M165-16 | F | 6.9 | S | Y | 3.1 | 1 | 260.5 | 282.5 |
M170-16 | M | 6.3 | S | Y | 2.9 | 1 | 180.5 | 153.8 |
M171-16 | M | 6.0 | S | Y | 3.3 | 1 | 238.0 | 305.9 |
Mean | | 6.8 | | | 3.0 | 1 | 216.7 | 228.4 |
Table 2.
Repeated measures ANOVA statistics for QRS complexes.
Table 2.
Repeated measures ANOVA statistics for QRS complexes.
Virus | Macaque | Sex | Dose £ | TTD δ | F-Statistic | p-Value |
---|
EEEV | M161-16 | M | 8.2 | 6 | 4.780 | 0.0346 * |
M163-16 | M | 7.5 | 6 | 4.034 | 0.0490 * |
M160-16 | M | 7.0 | S | 3.833 | 0.058 |
M162-16 | M | 5.7 | S | 3.046 | 0.331 |
VEEV | M164-16 | F | 7.1 | S | 29.55 | <0.00001 * |
M165-16 | F | 6.9 | S | 164.7 | <0.00001 * |
M170-16 | M | 6.3 | S | 48.40 | <0.00001 * |
M171-16 | M | 6.0 | S | 84.17 | <0.00001 * |
Table 3.
Repeated measures ANOVA statistics for QT-interval.
Table 3.
Repeated measures ANOVA statistics for QT-interval.
Virus | Macaque | Sex | Dose * | TTD δ | F-Statistic | p-Value |
---|
EEEV | M161-16 | M | 8.2 | 6 | 6.472 | 0.016 * |
M163-16 | M | 7.5 | 6 | 24.95 | 0.00005 * |
M160-16 | M | 7.0 | S | 3.884 | 0.055 |
M162-16 | M | 5.7 | S | 2.962 | 0.335 |
VEEV | M164-16 | F | 7.1 | S | 36.30 | <0.00001 * |
M165-16 | F | 6.9 | S | 62.56 | <0.00001 * |
M170-16 | M | 6.3 | S | 25.46 | <0.00001 * |
M171-16 | M | 6.0 | S | 82.35 | <0.00001 * |
Table 4.
Repeated measures ANOVA statistics for RR-interval.
Table 4.
Repeated measures ANOVA statistics for RR-interval.
Virus | Macaque | Sex | Dose * | TTD δ | F-Statistic | p-Value |
---|
EEEV | M161-16 | M | 8.2 | 6 | 6.626 | 0.014 * |
M163-16 | M | 7.5 | 6 | 13.92 | 0.0004 * |
M160-16 | M | 7.0 | S | 3.420 | 0.073 |
M162-16 | M | 5.7 | S | 2.227 | 0.376 |
VEEV | M164-16 | F | 7.1 | S | 49.07 | <0.00001 * |
M165-16 | F | 6.9 | S | 175.9 | <0.00001 * |
M170-16 | M | 6.3 | S | 15.65 | <0.00001 * |
M171-16 | M | 6.0 | S | 183.0 | <0.00001 * |
Table 5.
Fundamental frequencies of EEEV and VEEV courses of infection.
Table 5.
Fundamental frequencies of EEEV and VEEV courses of infection.
Virus | Macaque | Sex | Pre-Infection Frequency | Post-Infection Frequency | Febrile Period Frequency | Recovery Period Frequency |
---|
EEEV | 161-16 | M | 0.395 | 0.879 | 0.571 | |
163-16 | M | 0.242 | 0.769 | 0.549 | |
160-16 | M | 0.351 | 0.242 | | |
162-16 | M | 0.307 | 0.351 | | |
VEEV | 164-16 | F | 5.974 (0.373) | 11.070 (0.275) | 4.393 (0.275) | 3.514 (0.220) |
165-16 | F | 5.974 (0.373) | 11.070 (0.286) | 4.568 (0.286) | 3.514 (0.220) |
170-16 | M | 11.245 (0.351) | 13.881 (0.434) | 4.217 (0.132) | 3.163 (0.099) |
171-16 | M | 11.245 (0.351) | 13.705 (0.428) | 5.271 (0.165) | 3.163 (0.099) |