Introduction

Anthrax is a disease caused by the spores of Bacillus anthracis and can have a high fatality rate. It is a zoonosis and mostly affecting animals. In this study I want to find out risk factors on population scale for anthrax cases and deaths in humans and animals, and look at the relation of anthrax with weather patterns.

Methods

I searched for anthrax outbreaks in different countries, mainly yearly reports. I looked at human cases, human deaths, livestock deaths and wildlife deaths. Different risk factors were considered: country size, population characteristics, Human Development Index (HDI), total cattle number, cattle per human ratio, mean annual temperature, mean temperature of the warmest 1 and 3 months, annual precipitation and minimum and maximum precipitation in 1 month and 3 months. Linear regression was used. Statistics were repeated without China because it was often the single outlier in the figures. Statistics were also repeated with the countries aggregated in continents because of the modifiable area unit problem.

Results

Data was found for 28 countries resulting in 36 data points. There was a significant relation between human cases and cattle number, human deaths, country size and population size. There were also significant relations between wildlife deaths and population size, country size and mean temperature of the warmest month. Without China relations between human cases and maximum precipitation in 1 and 3 months, and between livestock deaths and country size were significant. For continents a significant relation between human cases and cattle ratio, cattle deaths and HDI.

Conclusion

This study mainly shows that high cattle numbers and cattle deaths due to anthrax are risk factors for human cases. Also seasonal precipitation is a risk factor. Bigger country size and population size may be indirect risk factors as these usually accompany higher cattle numbers.

Geographically, Pakistan is in the western part of south Asia at about 24-37 °N latitudes and62-75 °E longitudes. Livestock and agriculture are two major sectors in Pakistan and play animportant role in the country economy.The tick infestation in livestock is not only devastating for animals and their products but alsobecome the cause of transmission of pathogens into humans. Crimean Congo fever (CCHF) isa viral tick-borne fatal disease. The dissemination of ticks and amplification of Crimean Congofever (CCHF) pathogen throughout the tick-animals-tick cycle, increases risk of transmissionto humans many times. In Pakistan, cases are reported in all areas, particularly those areaswhich lie on the border to CCHF endemic countries. There is a high prevalence of CCHF inboth Baluchistan and Khyber Pakhtunkhwa regions. Baluchistan is bordering with Afghanistanand Iran and Khyber Pakhtunkhwa with Afghanistan. Linear regression analysis revealed apositive significant association of high level of CCHF cases in livestock, with camels, goatsand sheep. The literacy rate is negatively significantly corelated with the numbers of cases.Statistical analysis of border effect revealed a high positive significant correlation of CCHFprevalence in areas near to borders. Both Baluchistan and Khyber Pakhtunkhwa (KPK) haslow literacy rate than other regions of Pakistan. Islamabad (capital city) has a higher literacyrate than all other regions but there is still a high CCHF prevalence. This is not only becauseof high population density but people from other regions, particularly from Baluchistan andKPK come here for animals selling or to seeking medical facilities in the large city hospitals.The study gives a proof that illiteracy and borders are the major respondent factors in theCCHF incidences and prevalence in an area. There is a need to raise awareness about ticksand tick-borne disease in the public and establishment of monitoring system across the bordersto prevent the spread of CCHF virus.