Spatial-temporal distribution of human brucellosis in mainland China from 2004 to 2017 and an analysis of social and environmental factors

Table 1 Temporal scan of the number of brucellosis cases between 2004 and 2017 in mainland China

Year	Time frame	Number of cases	Expected cases	Annual cases (1/100,000)	RR	LLR	P value
2004	March 2004 to July 2004	7881	4795.25	1.5	3.06	1688.52	< 0.001
2005	February 2005 to July 2005	14,116	9132.22	2.2	3.34	2838.01	< 0.001
2006	February 2006 to July 2006	14,001	9428.36	2.2	2.84	2286.67	< 0.001
2007	March 2007 to August 2007	14,124	9941.55	2.2	2.48	1836.26	< 0.001
2008	March 2008 to August 2008	20,013	13,959.37	3.0	2.55	2735.15	< 0.001
2009	February 2009 to July 2009	25,807	17,760.81	3.9	2.62	3738.03	< 0.001
2010	March 2010 to July 2010	20,745	14,156.48	3.7	2.21	2595.43	< 0.001
2011	February 2011 to July 2011	26,430	18,918.72	4.0	2.29	3032.48	< 0.001
2012	February 2012 to July 2012	27,075	19,649.54	4.0	2.20	2856.34	< 0.001
2013	February 2013 to July 2013	28,463	21,564.29	4.2	1.93	2223.25	< 0.001
2014	March 2014 to August 2014	38,903	28,846.16	5.7	2.09	3619.29	< 0.001
2015	March 2015 to July 2015	33,492	23,888.54	5.8	1.98	3265.38	< 0.001
2016	March 2016 to August 2016	31,495	23,698.30	4.5	1.99	2631.76	< 0.001
2017	February 2017 to July 2017	24,576	19,118.56	3.6	1.79	1563.96	< 0.001
2004–2017	February 2011 to August 2017	310,508	233,673.11	3.5	1.91	24,486.25	< 0.001

RR (relative risk) compares the incidence inside the cluster to that outside the cluster. LLR (log-likelihood ratio) in spatial or space-temporal scanning for disease clusters represents the significant difference between the values inside the cluster and those outside the cluster. LLR is used to evaluate the spatial concentration of cases inside the cluster. Greater RR and LLR values indicate higher risk and more concentrated brucellosis cases inside the cluster than outside the cluster

ISSN: 1347-4715