we analyzed passive surveillance data on hca cases reported to the national center for disease control and public health ( tbilisi , georgia ) during 20102012 .
self - reported source of infection was ascertained from categorical responses that included butchering / slaughtering cattle , handling / preparing meat , performing field work / harvesting crops , processing hair / wool , receiving an insect bite , unknown , or other .
we also obtained information about regional - level anthrax cases in livestock ( www.oie.int/wahis_2/public/wahid.php/diseaseinformation/statusdetail ) .
hca cases and incidence per million persons were plotted over time with livestock cases . to estimate changes in hca risk over time , we compared data for the study period with data for 20072009 by using a cumulative incidence ratio ( total cases / median year population ) .
we calculated incidence risk ratios for demographic characteristics by using a negative binomial regression ( technical appendix ) .
data were anonymized and aggregated to each case - patient s community of residence and mapped in a geographic information system .
we extrapolated current population from the 2002 census using the united nations medium variant population growth projections ( http://data.un.org/ ) .
cumulative incidences per 10,000 population were calculated for each community ( total cases / median year population ) .
we adjusted for community population heterogeneity using empirical bayes smoothing estimates of the cumulative incidence ( technical appendix ) .
kernel density estimation was used to map the cumulative incidence risk / km ( technical appendix ) . to identify community - level hca spatial clustering
, we used the poisson model in satscan ( 7 ) with a maximum cluster size of 25% of the population at risk .
we compared the proportion of urban and rural communities inside and outside clusters using a  analysis ( proc freq , sas institute , cary , nc , usa ) . during 20102012 ,
a total of 251 hca cases and 74 livestock cases ( 38 cattle , 1 pig , 4 sheep / goats , 1 horse ) were reported ( figure 1 ) .
hca cases peaked in 2012 ( 142 cases ) , corresponding to a national incidence of 31.7 per million population ( 95% ci 28.436.1 ) . compared with 20072009 ( 133 cases ) ,
the period studied had a higher risk for hca ( cumulative incidence ratio 1.89 [ 95% ci 1.642.33 ] , p<0.01 ) .
total number of human cutaneous anthrax cases ( light gray ) and livestock cases ( dark gray ) , georgia , 20102012 .
incidence rates ( irs ) ( 95% cis ) of human cutaneous anthrax per million population are displayed above the bars .
cases occurred predominantly in males ( 209 [ 84% ] ) ( table 1 ) .
butchering / slaughtering cattle as a source of infection was more common among male patients ( 143 [ 68% ] ) ; processing / handling meat was more common among female patients ( 28 [ 68% ] ) .
the adjusted incidence risk ratios from the negative binomial model showed a stronger association of risk in males ( 4.95 [ 95% ci 2.918.42 ] ) than in females ( table 2 ) .
persons 5064 years of age were at greater risk than were persons in all other age groups .
risk did not differ between case - patients who processed / handled meat and those who slaughtered / butchered cattle .
* population estimates were obtained from the georgian state statistical office ( geostat , http://geostat.ge ) and are based on median year population totals for the study period .
*  goodness - of - fit test indicated the model fit the data ( df  =  31 ,   =  40.71 , p = 0.11 ) .
empirical bayes smoothed incidence per 10,000 population ranged from 0.11 ( 95% ci 0.030.37 ) to 213.8 ( 95% ci 72.8552.6 ) ( figure 2 , panel a ) .
the kernel density analysis identified a higher risk per squared kilometer in the southeast and west ( figure 2 , panel b ) .
we identified 3 spatial clusters of high risk ; the clusters comprised 58 communities with 197 cases ( figure 2 , panel c ) .
cumulative incidence inside the clusters was 12.8/10,000 population compared with 0.96/10,000 population outside the clusters .
the proportion (   =  0.65 , p = 0.4 ) of urban and rural communities ( 22 and 36 , respectively ) within clusters did not differ from the proportion outside clusters ( urban : 14 ; rural : 24 ) .
clusters 1 and 2 in the southeast bordered the densely populated urban area of the capital ( tbilisi ) and were associated with grazing lands , whereas cluster 3 bordered the urban area of poti in the west and was associated with a higher percentage of croplands .
a ) empirical bayes smoothing cumulative incidence ( per 10,000 population ) of human cutaneous anthrax at the community level , georgia , 20102012 .
green star indicates the location of the capital , tbilisi ; gray star indicates the fourth most populous city , rustavi .
c ) spatial clustering of human cutaneous anthrax cases as determined by using satscan ( 7 ) . rr , risk ratio .
despite an apparent decline in hca cases worldwide ( 8) , incidence in georgia has increased and is now comparable with that in turkey , where the disease is hyperendemic ( 1,9,10 ) . our analysis identified clusters of communities that were of historical importance for hca risk and new communities that represent areas of ( re)emergence ( 6 ) .
our findings indicate that hca cases were concentrated within specific areas associated with agriculture and in close proximity to urban centers ( figure 2 ) , consistent with research linking urban livestock trading centers and markets to outbreaks and higher rates of hca ( 5,911 ) .
sick and dying animals are often slaughtered and brought to market quickly to mitigate economic losses , thereby exacerbating exposure risk while limiting livestock reporting ( 10,11 ) .
hca is primarily associated with rural , agrarian areas ( 2,3,12 ) , but we found no difference in the proportion of urban and rural communities in high - risk clusters .
this association with urban zones suggests reliance on these areas for commerce , coupled with increased agricultural employment from 25% of the population in 1990 to 55% in 2010 ( 5,13 ) .
one hypothesis is that contaminated meat is brought into urban areas and sold at informal meat markets that because of fiscal constraints have little to no regulation .
cases were predominantly linked to contact with infected livestock or meat , as observed elsewhere ( 2,3,9,11 ) .
field work was a self - reported source of infection in 27 ( 10.7% ) cases . this risk factor is not well documented and might reflect recall bias or unwillingness to admit to slaughtering infected animals .
our findings that males were at higher risk than females for hca , as reported elsewhere ( 2,14 ) might reflect occupational exposures or gender roles , with males slaughtering / butchering livestock and females more involved in preparing meat ( 14 ) .
in contrast , no gender differences were reported in turkey or kazakhstan ( 3,9 ) . although age was not a risk factor in other regions ( 2,3 ) , persons 5064 years of age in this study were at higher risk for infection ( table 2 ) , reflecting changing sociocultural practices related to an agrarian lifestyle .
although the true cause of the increase in hca cases is unknown , it is probably due to a combination of factors related to decreased public health funding and agricultural reform resulting in a shift from collectivization to private ownership ( 1,5,13 ) .
these factors , coupled with limited veterinary control and the cessation of compulsory livestock vaccination , have played plausible roles in the increased incidence of hca .
livestock cases were out of sync temporally and spatially with human cases , indicating anthropocentric reporting or high incidence from relatively few animals , although differences in the aggregation of livestock cases limit the inference of spatial synchrony
. controlling hca requires controlling the disease in livestock ( 1,2,9 ) and highlights the need for a one health approach .
our findings can be used to formulate public health interventions aimed at controlling anthrax in livestock and increasing awareness of the disease , particularly in urban areas . given the limited resources available , future efforts should focus on high - risk areas for livestock surveillance and control , such as targeted vaccination campaigns ( 15 ) .
 we assessed the occurrence of human cutaneous anthrax in georgia during 2010-2012 by examining demographic and spatial characteristics of reported cases . 
 reporting increased substantially , as did clustering of cases near urban centers . 
 control efforts , including education about anthrax and livestock vaccination , can be directed at areas of high risk . 
The Study
Conclusions
None