Table 3. Distribution of virus infection among Sella scores, and their relationship with positive heads from Ae. aegypti collected during the ABV transmission seasons of 2016 and 2017 in Yucatán, Mexico.

Sella score	Sella score Interpretation	CHIKV	DENV	ZIKV	CHIKV/ZIKV	Total	Heads +
0	Unable to determine Sella	1 (0.6%)	0 (0.00%)	0 (0.00%)	0 (0.00%)	1 (0.60%)	1 (0.60%)
1	Empty abdomen	27 (16.3%)	2 (1.2%)	3 (1.8%)	0 (0.0%)	32 (19.3%)	5 (3.0%)
2	Engorged with intense blood	47 (28.3%)	6 (3.6%)	4 (2.4%)	0 (0.0%)	57 (34.3%)	12 (7.2%)
3	Partially engorged with dark blood	8 (4.8%)	5 (3.0%)	1 (0.6%)	0 (0.0%)	14 (8.4%)	3 (1.8%)
4	Practically half full and half empty with dark blood	10 (6.0%)	0 (0.0%)	2 (1.2%)	2 (1.2%)	14 (8.4%)	4 (2.4%)
5	Less than half with black blood	8 (4.8%)	2 (1.2%)	0 (0.0%)	0 (0.0%)	10 (6.0%)	1 (0.6%)
6	Only anterior and ventral part with black blood	14 (8.4%)	2 (1.2%)	0 (0.0%)	0 (0.0%)	16 (9.6%)	5 (3.0%)
7	Abdomen full, with eggs or no visible blood	14 (8.4%)	2 (1.2%)	5 (3.0%)	1 (0.6%)	22 (13.2%)	7 (4.2%)
Total		129 (77.7%)	19 (11.4%)	15 (9.0%)	3 (1.8%)	166 (100%)	38 (23.0%)