Table 3. Detection of RABV in salivary gland and RABV shedding in saliva by LN34 RT-PCR in bats confirmed positive for rabies in brain tissue by the direct fluorescent antibody test.
According to a rotating group schedule, saliva samples were obtained on day of death (0) if possible, daily if clinical signs were observed, or 1–3 days before death. Symbols are: + “positive”,–“negative”, and “inc” inconclusive. Inconclusive results are those with a Ct value from 35–40 and could indicate low virus load, insufficient sample, or possible cross-contamination. A Ct value with n/d is “not detected”, n/a means sample was not available. Age groups are J = juvenile, A = adult, and p = pup. Clinical signs are categorized as furious (F) or paralytic (P), and time to death is the number of days from RABV challenge until the bat died or was euthanized.
| Bat ID | Sex | Age | Treatment | RT-PCR salivary gland |
RT-PCR saliva (days before death) |
RVNA terminal (IU/mL) | Clinical signs | Time to death (days) | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| result | Ct value | 0 | -1 | -2 | -3 | |||||||
| NON-VACCINATED | ||||||||||||
| 608 | F | J | contact | – | n/d | + | 0.06 | F | 11 | |||
| 696a | F | J | contact | + | 27.08 | n/a | 0.06 | F | 11 | |||
| 893a | M | p | none | + | 26.48 | n/a | 0.06 | F | 12 | |||
| 561e | M | A | control | + | 29.12 | – | inc | 1.53 | P | 15 | ||
| 617 | M | A | control | + | 32.76 | – | inc | 0.06 | P | 14 | ||
| 891 | p | none | + | 32.06 | – | 0.06 | F | 13 | ||||
| 894 | F | p | none | + | 32.62 | – | 0.06 | F | 35 | |||
| 692 a | F | A | none | + | 31.19 | inc | 0.06 | P | 20 | |||
| 560 | M | J | control | + | 29.32 | + | 0.06 | F | 9 | |||
| 594e | M | J | control | + | 29.60 | + | + | 0.16 | P/Fd | 14 | ||
| 636e | M | A | control | + | 33.92 | + | inc | 2.62 | F | 15 | ||
| 690e | M | J | control | + | 31.77 | + | 0.06 | F | 9 | |||
| 890 | F | p | none | + | 26.15 | + | 0.06 | n/a | 15 | |||
| 892 | M | p | none | + | 26.50 | + | 0.06 | F | 18 | |||
| 895 | F | p | none | + | 32.89 | + | + | 0.06 | F | 10 | ||
| 899 | F | p | none | + | 29.48 | + | + | 0.06 | P | 18 | ||
| 669 | F | p | none | + | 30.53 | + | 0.06 | F | 17 | |||
| VACCINATED | ||||||||||||
| 598c | M | A | topicalb | – | n/d | – | 9898.00 | Pc | 50 | |||
| 599 | M | J | topical | – | n/d | – | n/a | P | 18 | |||
| 614 | M | A | topical b | – | n/d | – | 0.06 | P/Fd | 23 | |||
| 687a | M | A | oral | – | n/d | inc | 0.40 | F | 12 | |||
| 638a,e | M | A | oral b | inc | 38.05 | – | 0.08 | P | 22 | |||
| 595a | M | A | topical | inc | 37.27 | – | 0.06 | P | 15 | |||
| 691a,e | M | A | topical b | inc | 37.14 | – | 3.42 | P | 29 | |||
| 597 | M | A | oral | + | 31.74 | – | 390.80 | P | 11 | |||
| 639e | M | A | oral b | + | 31.68 | – | 0.11 | P | 18 | |||
| 586 | M | A | topical | + | 29.99 | – | 0.06 | F | 11 | |||
a Indicates bats that were excluded from the Fisher´s exact test to compare the proportion of RABV shedding in saliva or salivary gland of bats by vaccination group
b Bats that received a booster 100 days after initial vaccination
c This bat showed progressive loss of movement and coordination, consistent with rabies but remained alive through the 50-day observation period. It was confirmed RABV positive. We tested nine of his oral swabs collected between the initial observation of clinical signs until euthanasia; the results were all negative.
d Bats 594 and 614 initially displayed signs corresponding to the paralytic presentation (incoordination, unresponsiveness) but behaved furiously before death (self-inflicted wounds, aggressive behavior, and excitability).
e Bats tested to confirm the cRABV of canine origin (coyote) using end-point RT-PCR and Sanger sequencing.