There is increasing interest in raising chickens in urban settings across North America. Current regulations on backyard chickens vary by jurisdiction due to concerns about perceived health threats. Proposed negative impacts on public health and community well-being include infectious diseases acquired through rearing practices or consumption of eggs, inappropriate waste management, interaction with pests and predators and nuisance factors such as noise and odour. Proposed benefits are derived largely from the human-animal bond and from feelings of autonomy over food selection. The importance or validity of claims of positive and negative effects cannot be supported by literature specific to the urban agriculture context. Public health practitioners might approach this issue in a manner analogous to concerns over keeping domestic pets.

BackgroundFive cases of severe neutropenia (neutrophil counts < 0.5 per 109 cells/L) associated with exposure to cocaine and levamisole, an antihelimithic agent no longer available in Canada, were identified in Alberta in 2008. Alberta and British Columbia (BC) public health officials issued an advisory and urged health care professionals to report cases to public health. This paper presents the findings of the public health investigations.MethodsCases were identified prospectively through reporting by clinicians and a retrospective review of laboratory and medical examiners data from January 1, 2006 to March 31, 2009. Cases were categorized as confirmed, probable or suspect. Only the confirmed and probable cases are included in this paper.ResultsWe compare cases of severe neutropenia associated with tainted cocaine (NATC) identified in Alberta and BC between January 1, 2008 to March 31, 2009. Of the 42 NATC cases: 23(55%) were from Alberta; 19(45%) were from British Columbia; 57% of these cases reported crack cocaine use (93% of those who identified type of cocaine used); 7% reported using cocaine powder; and the main route of cocaine administration was from smoking (72%). Fifty percent of the NATC cases had multiple episodes of neutropenia associated with cocaine use. Cases typically presented with bacterial/fungal infections and fever. One Alberta NATC case produced anti-neutrophil antibodies, and four were positive for anti-neutrophil cytoplasmic antibody (ANCA). Analysis of two crack pipes and one drug sample obtained from NATC cases confirmed the presence of both cocaine and levamisole. A further 18 cases were identified through the retrospective review of laboratory and medical examiner data in AlbertaInterpretationOur findings support a link between neutropenia and levamisole tainted cocaine; particularly from smoking the crack form of cocaine. Some patients may be genetically predisposed to develop levamisole-related neutropenia. Awareness of the differential diagnosis will assist clinicians with case timely detection and appropriate management.

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