Anthrax is a zoonotic disease of antiquity caused by Bacillus anthracis
, an aerobic, spore-forming, large gram-positive rod [1
]. The incidence of anthrax infection is diminishing in developed countries; however, it still remains a public health problem in developing countries, especially in areas where farming is the main source of income. Soil is contaminated with anthrax spores from the carcasses of dead animals and spores can survive for decades, even under adverse conditions, to serve as a source of infection for animals [2
]. Humans are relatively resistant to cutaneous invasion, but the organisms may gain access through microscopic or gross breaks in the skin by contact with infected animals or their products like meat, hides, hair and bristles. There are three main forms of human anthrax, depending on the route of exposure: cutaneous, gastrointestinal and pulmonary or inhalational [3
]. Cutaneous forms account for 95% of anthrax worldwide [4
] and is characterized by rapidly developing necrotizing painless eschar (malignant pustule) with suppurative regional adenitis. Cutaneous infection starts as one or more painless, itchy papules or vesicles on the skin, typically on exposed areas such as the face, neck, forearms or hands. Within 7-10
days of the initial lesion, the papule forms an ulcer. The ulcer subsequently crusts over, forming a painless black eschar that is the hallmark of cutaneous anthrax. In addition, localized swelling, painful swollen regional lymph nodes and systemic symptoms can occur [5
]. There is no report of direct human-to-human transmission in the literature and also there is no racial, sexual, or age predilection for anthrax. However, because anthrax is often related to industrial exposures and farming, the disease most often affects young and middle-aged adults. Death is rare with appropriate therapy, but untreated, the case fatality rate may reach up to 20%.
Anthrax was described in the early literature of the Greeks, Romans, Egyptians, and Hindus. The term anthrakis
means coal in Greek, and the disease is named after the black appearance of its cutaneous form [6
]. Until the twentieth century, anthrax infections killed hundreds of thousands of animals and people each year in Australia, Asia, Africa, North America, and Europe, particularly in the concentration camps during World War II [7
]. Today there is concern about the use of anthrax as a biologic warfare agent. The disease is more common in developing countries without widespread veterinary or human public health programs.
Anthrax was reported in Bangladesh from 1980 to 1984 affecting both cattle and man [8
], but it re-emerged in 2009-2010 with wider involvement. The animal anthrax, locally known as ‘Torka’,
is believed to have been enzootic in Bangladesh for a long time, and historically human outbreaks were always preceded by animal outbreaks. The Government of Bangladesh declared a red alert due to a sudden explosive outbreak of anthrax in 2010 that hit 12 districts and affected 607 people. The outbreak was investigated and thought to have been caused by the slaughter of infected cattle and selling or eating contaminated meat. The outbreak was most prevalent in the districts of Pabna, Sirajganj, Rajshahi, Kushtia and Tangail, which have greater cattle populations [9
Health and livestock officials in Bangladesh have expressed great concern over a fresh outbreak of human anthrax prevailed from April to September 2011, mostly affecting two North-Western districts of Sirajganj (61 cases) and Pabna (32 cases). Additionally, districts of Bogra, Meherpur and Tangail had 28, 39 and 14 cases of anthrax respectively. Due to vaccine coverage in the preceding years, the number of livestock deaths was minimal and only a few infected slaughtered animals were held responsible for human transmission during the 2011 outbreak [12
]. Fortunately there were no anthrax-related human deaths but meat sales drastically declined due to a lack of consumer confidence, and anthrax created mass havoc with significant economic losses related to cattle farming. Although there was no known case fatality, people panicked and mass immunization of livestock was demanded by concerned sections. Considering the overall impact of the recent outbreak of human cutaneous anthrax in Bangladesh, this study was conducted to examine its clinico-demographic profile and treatment outcomes of the affected population with the aim to generate awareness regarding the disease.