Factors Associated with Repeated Outbreak of Anthrax in Bangladesh: Qualitative and Quantitative Study

J. Adv. Vet. Anim. Res., 2(2): 158-164. Available at- http://bdvets.org/JAVAR OPEN ACCESS ORIGINAL ARTICLE Volume 2 Issue 2 (June 2015) DOI: 10.5455/javar.2015.b72 Factors associated with repeated outbreak of anthrax in Bangladesh: qualitative and quantitative study Jayedul Hassan1, Md. Murshidul Ahsan2, Md. Bahanur Rahman1, Shah Md. Ziqrul Haq Chowdhury3, Md. Shafiullah Parvej1 and KHM Nazmul Hussain Nazir1,* 1Department of Microbiology and Hygiene, Faculty of Veterinary Science, Bangladesh Agricultural University (BAU), Mymensingh-2202, Bangladesh; 2School of Biotechnology, Yeungnam University, Gyeongsan 712-749, Republic of Korea; 3Bangladesh Agricultural Research Council (BARC), Dhaka, Bangladesh. *Corresponding author’s email: [email protected] ABSTRACT Keywords Anthrax, caused by Bacillus anthracis is an acute, Anthrax prone season, Knowledge, Managerial factor, febrile disease of warm blooded animals including Rainfall, Repeated outbreak, Soil, Temperature humans. Social norms and poverty in addition to climatic factors such as soil conditions, seasons of ARTICLE HISTORY year, ambient temperature and rainfall influence the Received : 12 November 2014, Revised: 3 January 2015, persistence of the B. anthracis and anthrax outbreaks. Accepted : 5 January 2015, Published online: 3 February 2015. The present study was designed to reveal the factors influencing the repeated outbreak of anthrax in Bangladesh. Considering the previous outbreaks of anthrax, Sirajganj, Bogra, Kushtia, Tangail and INTRODUCTION Mymensingh districts of Bangladesh were selected for this study. To elucidate the factors, qualitative Anthrax (popularly known as “Torka” in Bangladesh) is data relating to the animal management, knowledge an acute infectious zoonotic disease caused by Bacillus and behavior of the people; and quantitative data anthracis, a soil-borne, spore forming bacterium (OIE, relating to soil conditions, ambient temperature and 2008). The anthrax spore (i.e., dormant stage) is rainfall were acquired, and analyzed critically. Based resistant to heat and chemical disinfectants, and this on the outbreak histories, a year was divided into two dormant stage may persist and remain viable for seasons, anthrax prone season (May-November) and several decades in soil (Hirsh and Zee, 1999; Dragon et anthrax dry season (December-April). Anthrax spores al., 2001; OIE, 2004). The bacterium primarily infects could be isolated from 11.67% (n=14/120) of the soil herbivores such as cattle, sheep, goats, horses and pigs samples collected from the study areas. The present after entering the body through feed and water study revealed that poor knowledge, lack of contaminated with viable spores (Ahsan et al., 2013). awareness, improper carcass disposal, inadequate Anthrax is transmitted from the affected animals to vaccination, high Ca content and moisture in the soil humans through food or other material originated from along with high ambient temperature and rainfall an animal that is contaminated with B. anthracis or its during the anthrax prone season were the possible spores (Cieslak and Eitzen, 1999; WHO, 2008). influencing factors of repeated outbreaks of anthrax in the study areas. Intensive propaganda to create Anthrax naturally occurs in almost all countries in the public awareness of anthrax together with proper world; however, the disease is mostly prevalent in vaccination may reduce anthrax outbreaks in tropical and sub-tropical countries (Biswas et al., 2011). Bangladesh. In recent years, the disease has been reported in Sweden (Lewerin et al., 2010), USA (Mongoh et al., 2008), Italy (Fasanella et al., 2010), Australia (Durrheim eISSN 2311-7710 Hassan et al./ J. Adv. Vet. Anim. Res., 2(2): 158-164, June 2015 158 et al., 2009), and many places in Europe. In many Asian Bogra, Veramara Upazila of Kushtia, Sadar Upazila of and African countries, anthrax outbreak occurs Tangail and Mymensingh districts. Each time, the periodically in animals and humans (WHO, 2008). In study team visited the reported areas and collected Bangladesh, the disease was found periodically in information and susceptible samples for subsequent animals and humans until 2009 (Ahmed et al., 2010), analysis. To ascertain the outbreak and outbreak areas, but in recent years the disease has occurred repeatedly; the study team firstly visited the human and livestock the outbreaks indicate that the disease is no longer officials of the particular areas. The animal owners and sporadic rather than enzootic in Bangladesh (Ahmed et their family members, people associated with al., 2010; Fasanella et al., 2012; Ahsan et al., 2013). slaughtering, butchering, handling and eating the meat of affected animals, people who developed lesions of In Bangladesh, anthrax outbreak is mostly prevalent in cutaneous anthrax, people who were neither associated Sirajganj and nearby districts (Ahmed et al., 2010; with processing of carcass nor had developed lesions, Biswas et al., 2011). Along with animal infections, more the community leader, livestock and health officials of the outbreak areas were considered as the key than 600 people have been diagnosed with anthrax in informants. Bangladesh until the year 2011 (Fasanella et al., 2012). Inadequate livestock vaccination coverage, butchering Environmental factors associated with anthrax sick animals, disposing butchering wastes and carcass outbreak: The environmental factors such as soil type, in the environment where animals graze, handling raw moisture, pH, Ca content and organic carbon contents meat, contact with sick animals, social norms, and were determined following continuous collection and examination of the soil samples (n=120) from the study poverty contributed to the outbreaks of anthrax in areas throughout the year. Approximately 400-gm of Bangladesh (Chakraborty et al., 2012; Islam et al., 2013). surface soil from a maximum depth of one-foot was Favorable environmental conditions such as, soil pH, collected according to the procedure mentioned by Ca content, moisture, soil type, high ambient Ahsan et al. (2013). Soil samples were collected from temperature and rainfall and topography are positively the areas where the suspected animals died, correlated with the persistence of anthrax spores and slaughtered and butchered or buried. One blood subsequent outbreaks (Van Ness, 1971; Hugh-Jones, sample (5 mL in a disposable plastic syringe) from the jugular vein of affected animal and four swab samples 2002; Ahsan et al., 2013). In our previous study (Ahsan from the ulcerative lesions of affected human were also et al., 2013), we investigated the environmental factors collected. The swab samples were immediately dipped related to repeated anthrax outbreak in Bangladesh. in screw capped vial containing nutrient broth. The Though there is discrete information regarding the samples were carried to the laboratory in ice box within social norms, poverty and ignorance, there is no possible earliest period. Physico-chemical analysis of comprehensive data on the knowledge and behavior of the soil samples were performed in the Soil Science the people, environmental parameters (soil factors and Laboratory at the Department of Soil Science, Faculty of Agriculture, Bangladesh Agricultural University. ambient temperature and rainfall) that might positively The changes in the soil parameters with time were influence on the outbreaks of anthrax. Here, our determined and recorded accordingly. The weather investigation focused on the present status of related data (ambient temperature and rainfall) of the knowledge and behavior of people along with the study districts were collected from the official website management of livestock and related environmental of world weather (http://www.worldweather parameters in order to understand how they might online.com and http://www.accuweather.com). According to the history of outbreak, anthrax outbreaks influence the repeated anthrax outbreaks in in Bangladesh mostly occurred during the months of Bangladesh. May to November. Based on the histories, a year was divided into two seasons, anthrax prone season (May MATERIALS AND METHODS to November) and anthrax dry season (December to April). Data derived from the soil sample analysis, Selection of study area and study population: The ambient temperature and rainfall were processed and study areas were selected by assessing the risk of analyzed based on the seasons mentioned. anthrax and from reports published in daily newspapers. The study was conducted in Shahjadpur Host and managerial factors associated with anthrax and Ullahpara Upazila of Sirajganj, Sadar Upazila of outbreak: Some tools of qualitative research were used Hassan et al./ J. Adv. Vet. Anim. Res., 2(2): 158-164, June 2015 159 with the aim of unfolding the possible causes of areas. In our study, we found that 81.25%, 81.25% and repeated anthrax outbreak or transmission to human in 63.64% people at Ullahpara, Shahjadpur and Bogra the areas relating to the knowledge, behavior and sadar upazila fed their animals unwashed grass (Figure managerial factors (i.e., feeding, vaccination, treatment 3). Among the people who washed grass before feeding etc.). Data related to host and managerial factors were to their animals, most (75.71%) used river water (Figure collected from the people interviewed in the study 4); thus possibly making the animals vulnerable to area. Qualitative research tools used in this study were- anthrax. (a) Direct Observation, (b) Focus Group Discussion, and (c) In-depth interview of key

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