Table 1.

Infection, dissemination, and transmission rates of mosquitoes infected with the German USUV Africa 2 strain

Blood meal virus titer (TCID50/ml)	Mosquito species	Dpi	Infection rate (%) (95% CI)	Mean viral load bodies (viral copies/µl of total RNA)	Dissemination rate (%) (95% CI)	Mean viral load legs plus wings (viral copies/µl of total RNA)	Transmission rate (%) (95% CI)
High titer 107.4	Culex pipiens biotype molestusa	14	8/10 (80.0) (44.4–97.5)	6.9 × 105	3/8 (37.5) (8.5–75.5)	9.0 × 103	3/3 (100) (29.2–100)
		21	4/6 (66.7) (22.3–95.7)	5.6 × 105	4/4 (100) (39.7–100)	1.5 × 104	3/4 (75.0) (19.4–99.4)
	Cx. pipiens biotype molestusb	16	13/16 (81.3) (54.4–96.0)	1.9 × 106	13/13 (100) (75.3–100)	7.8 × 104	2/13 (15.4) (1.9–45.4)
		21	8/10 (80.0) (44.4–97.5)	8.1 × 105	8/8 (100) (63.1–100)	7.8 × 104	4/8 (50.0) (15.7–84.3)
	Aedes aegyptid	14	0/53 (0) (0–6.7)	NA	NA	NA	NA
		21	4/22 (18.2) (5.2–40.3)	2.3 × 105	1/4 (25.0) (0.6–80.6)	5.5 × 103	0/1 (0) (0–97.5)
Low titer 105.1	Cx. pipiens biotype molestusa	14	2/36 (5.6) (0.7–18.7)	1.2 × 102	0/2 (0) (0–84.2)	NA	NA
		21	1/19 (5.3) (0.7–18.7)	5.4 × 101	0/1 (0) (0–84.2)	NA	NA
	Cx. torrentiumc	14	1/8 (12.5) (0.3–52.7)	2.8 × 101	0/1 (0) (0–97.5)	NA	NA
		21	1/8 (12.5) (0.3–52.7)	3.9 × 106	1/1 (100) (2.5–100)	4.7 × 104	1/1 (100) (2.5–100)

Transmission rates include results from the saliva inoculation on Vero cells and from the RT-qPCRs of cell culture supernatants. All mosquitoes were incubated for 14/16 or 21 days. Absolute quantification of virus copies/µl of total RNA was performed via an RT-qPCR-based calibration curve

CI confidence interval, dpi days post infection, NA not applicable

^aCx. pipiens biotype molestus laboratory colony from “Wendland,” Lower Saxony, Germany

^bCx. pipiens biotype molestus laboratory colony from Novi Sad, the Republic of Serbia

^cCx. torrentium field-collected colony near Berlin and Bonn, North Rhine-Westphalia, Germany

^dAe. aegypti laboratory colony from Malaysia (Bayer CropScience, Langenfeld, Germany)