Insight into live bird markets of Bangladesh: an overview of the dynamics of transmission of H5N1 and H9N2 avian influenza viruses

Figures & data

Table 1 Comparison of rRT-PCR influenza A positive samples by variable

Variable	Collected samples, no. (%)^a	Influenza A-positive samples, no. (%)^b	P-values^c
Sample type
Oropharyngeal	8081 (38.3%)	2689 (33.3%)	<0.001
Cloacal	4609 (21.8%)	857 (18.6%)
Environmental (fecal)	6395 (30.3%)	861 (13.5%)
Environmental (water)	2011 (9.5%)	653 (32.5%)
Species
Chickens	14 213 (67.4%)	3276 (23.0%)	<0.001
Ducks	3426 (16.2%)	844 (24.6%)
Geese	58 (0.3%)	11 (19.0%)
Pigeons	1165 (5.5%)	173 (14.8%)
Quail	2234 (10.6%)	756 (33.8%)
Bird type
Domestic	20 958 (99.3%)	5043 (24.1%)	<0.001
Pet	138 (0.7%)	17 (12.3%)
Bird health status
Dead	8 (0.0%)	0 (0.0%)	<0.001
Healthy	20 952 (99.3%)	5055 (24.1%)
Sick	10 (0.0%)	0 (0.0%)
Undetermined	126 (0.6%)	5 (4.0%)
Domestic bird location
Backyard	225 (1.1%)	5 (2.2%)	<0.001
Farm	6202 (29.4%)	597 (9.6%)
LBM	14 669 (69.5%)	4458 (30.4%)
Market type
Retail	11 137 (75.9%)	3332 (29.9%)	0.027
Wholesale	3532 (24.1%)	1126 (31.9%)

Abbreviation: live bird market, LBM.

Influenza A positive samples by rRT-PCR and the total number of samples for each variable collected from LBMs and farms in Bangladesh from 2008 to 2016. The numbers and percentages shown under the ‘collected samples’ column represent the actual number and percentage of that category out of the total number of samples for the specified variables. The numbers and percentages shown under the ‘influenza A-positive samples’ column represent the actual number and percentage of that category out of the total number of samples for the specified variables. P-values shown are based on a statistical significance of P<0.05, comparing the rates of influenza A positivity across variable categories.

^aPercentage of total samples collected.

^bOf samples within category.

^cBy χ²-test comparing positive rates across variable categories.

short-legendFigure 1

Table 2 Comparison of egg isolation positive samples by subtype and variable

Variable	Positive samples, no. (%)^a	H5	H9	Subtype^b H5/H9	Other	P-values^c
Sample type
Oropharyngeal	825 (63.4%)	48 (5.8%)	653 (79.2%)	105 (12.7%)	19 (2.3%)	<0.001
Cloacal	155 (11.9%)	18 (11.6%)	115 (74.2%)	11 (7.1%)	11 (7.1%)
Environment (fecal)	164 (12.6%)	29 (17.7%)	115 (70.1%)	6 (3.7%)	14 (8.5%)
Environment (water)	158 (12.1%)	13 (8.2%)	134 (84.8%)	11 (7.0%)	0 (0.0%)
Species
Chickens	1027 (78.9%)	42 (4.1%)	893 (87.0%)	92 (9.0%)	0 (0.0%)	<0.001
Ducks	128 (9.8%)	43 (33.6%)	12 (9.4%)	29 (22.7%)	44 (34.4%)
Geese	1 (0.1%)	1 (100.0%)	0 (0.0%)	0 (0.0%)	0 (0.0%)
Pigeons	2 (0.2%)	0 (0.0%)	2 (100.0%)	0 (0.0%)	0 (0.0%)
Quail	144 (10.2%)	22 (15.3%)	110 (76.4%)	12 (8.3%)	0 (0.0%)
Bird type
Domestic	1300 (99.8%)	108 (8.3%)	1015 (78.1%)	133 (10.2%)	44 (3.4%)	NS
Pet	2 (0.2%)	0 (0.0%)	2 (100.0%)	0 (0.0%)	0 (0.0%)
Bird health status
Healthy	1300 (99.8%)	108 (8.3%)	1015 (78.1%)	133 (10.2%)	44 (3.4%)	NS
Undetermined	2 (0.2%)	0 (0.0%)	2 (100.0%)	0 (0.0%)	0 (0.0%)
Domestic bird location
Farm	43 (3.3%)	1 (2.3%)	11 (25.6%)	0 (0.0%)	31 (72.1%)	<0.001
LBM	1259 (96.7%)	107 (8.5%)	1006 (79.9%)	133 (10.6%)	13 (1.0%)
Market type
Retail	1015 (80.6%)	80 (7.9%)	834 (82.2%)	96 (8.5%)	5 (0.5%)	<0.001
Wholesale	244 (19.4%)	27 (25.2%)	172 (70.5%)	37 (15.2%)	8 (3.3%)

Abbreviations: live bird market, LBM; not significant, NS.

Influenza A-positive samples by egg isolation and the subtypes for each variable collected from LBMs and farms in Bangladesh from 2008 to 2016. The numbers and percentages shown under the ‘positive samples’ column represent the actual number and percentage of that category out of the total number of samples for the specified variables. The numbers and percentages shown under the ‘subtype’ column represent the actual number and percentage of the specified subtypes out of the total number of samples for the specified variables. P-values shown are based on a statistical significance of P<0.05, comparing the rates of influenza A positivity across variable categories.

^aPercentage of total samples positive for influenza A.

^bPercentage of samples within category.

^cBy χ²-test comparing positive rates across variable categories.

short-legendFigure 2