Table 4.
Vector competence of New Zealand (NZ) mosquitoes for select alphaviruses (Togaviridae)
| Mosq species and virus† | Blood meal‡ (log10 pfu/mL) | EIP§ (days) | % Infect¶ (no. tested) | % Dissem‖ (no. infect) | % Transm** (no. infect) |
|---|---|---|---|---|---|
| New Zealand mosquitoes | |||||
| Culex pervigilans | |||||
| BFV | 6.4 | 20 | 0 (35) | – | – |
| 31 | 0 (10) | – | – | ||
| CHIKV | 8.4 | 20 | 0 (40) | – | – |
| RRV | 7.7 | 17 | 22 (23) | 100 (5) | 20 (5) |
| Opifex fuscus | |||||
| BFV | 9.7 | 7 | 88 (8) | 100 (7) | 13 (7) |
| CHIKV | 6.2 | 11 | 98 (47) | 100 (46) | 46 (46) |
| RRV | 7.7 | 11 | 100 (19) | 100 (19) | 46 (19) |
| SINV | 5.9 | 8 | 94 (31) | 48 (29) | 11 (29) |
| 6.0* | 11 | 29 (35) | 30 (10) | 4 (10) | |
| Aedes antipodeus | |||||
| BFV | 10.0 | 21 | 92 (25) | 100 (23) | 43 (23) |
| CHIKV | 7.8 | 21 | 100 (15) | 73 (15) | 0 (15) |
| RRV | 8.4 | 21 | 82 (22) | 89 (18) | 61 (18) |
| 28 | 69 (16) | 100 (11) | 55 (11) | ||
| Aedes australis | |||||
| BFV | 9.8 | 7 | 96 (25) | 84 (24) | 0 (24) |
| 14 | 100 (25) | 92 (25) | 44 (25) | ||
| RRV | 8.7 | 7 | 96 (25) | 75 (24) | 4 (24) |
| 14 | 96 (25) | 92 (24) | 46 (24) | ||
| SINV | 8.6 | 14 | 14 (35) | 80 (5) | 0 (5) |
| Aedes notoscriptus | |||||
| BFV | 10.1 | 14 | 91 (11) | 80 (10) | 10 (10) |
| CHIKV | 10.5 | 14 | 36 (22) | 75 (8) | 0 (8) |
| Culex quinquefasciatus (NZ) | |||||
| BFV | 8.2 | 14 | 22 (50) | 27 (11) | 18 (11) |
| 30 | 12 (50) | 33 (2) | 17 (1) | ||
| RRV | 8.6 | 14 | 3 (36) | 100 (1) | 100 (1) |
| SINV | 6.7 | 7 | 0 (25) | – | – |
| 14 | 12 (25) | – | – | ||
| 21 | 24 (25) | 50(3) | 17(1) | ||
| Control mosquitoes | |||||
| Aedes aegypti (Panama) | |||||
| CHIKV | 8.4 | 20 | 19 (47) | 67 (9) | 0 (9) |
| Culex pipiens (USA) | |||||
| BFV | 6.4 | 8 | 2 (50) | 0 (1) | – |
| RRV | 7.7 | 16 | 15 (27) | 0 (4) | – |
| SINV | 6.0 | 11 | 8 (48) | 50 (4) | 25 (4) |
| Culex quinquefasciatus (USA) | |||||
| BFV | 8.2 | 14 | 6 (49) | 100 (3) | 33 (3) |
| 30 | 6 (36) | 100 (2) | 0 (2) | ||
| RRV | 8.6 | 14 | 6 (50) | 100 (3) | 0 (3) |
†
BFV = Barmah Forest virus; CHIKV = Chikungunya virus; RRV = Ross River virus; SINV = Sindbis virus.
‡
All blood meals were freshly harvested cell culture virus unless noted with an asterisk (*) indicating frozen stock.
§
Extrinsic incubation period at 24°C except Ae. antipodeus, which were held at 16°C
¶
Percentage (number) of blooded mosquitoes with virus-positive bodies.
‖
Percentage (number) of infected mosquitoes with virus-positive legs.
**
Percentage (number) of infected mosquitoes with virus-positive expectorates.