Stray Dogs and Public Health: Population Estimation in Punjab, India.

The overpopulation of stray dogs is a serious public health and animal welfare concern in India. Neglected zoonotic diseases such as rabies and echinococcosis are transmitted at the stray-dog human interface, particularly in low to middle-income countries. The current study was designed to estimate the stray dog populations in Punjab to enhance the implementation of animal birth and disease (for example, rabies vaccination) control programs. This is the first systematic estimation of the stray dog population using a recommended method (mark-re-sight) in Punjab, India. The study was conducted from August 2016 to November 2017 in selected villages or wards in Punjab. For the rural areas, 22 sub-districts in each district were randomly selected, then one village from each of the 22 selected sub-districts was selected (by convenience sampling). For urban areas, 3 towns (less than 100,000 human population) and 2 large cities (more than or equal to 100,000 human population) were randomly selected, followed by convenience selection of two wards from each of the 5 selected towns/cities. To estimate the dog population size, we used a modified mark-re-sight procedure and analysed counts using two methods; the Lincoln-Petersen formula with Chapman's correction, and an application of Good-Turing theory (SuperDuplicates method; estimated per km2 and per 1000 adult humans and were compared between localities (villages vs. towns), dog sex (male vs. female) and age group (young vs. adult) using linear mixed models with district as a random effect. The predicted mean (95% CI) count of the dogs per village or ward were extrapolated to estimate the number of stray dogs in Punjab based on (a) the number of villages and wards in the state; (b) the adult human population of the state and (c) the built-up area of the state. Median stray dog populations per village and per ward using the Lincoln-Petersen formula with Chapman's correction were estimated to be 33 and 65 dogs, respectively. Higher estimates of 61 per village and 112 per ward are reported using the SuperDuplicates method. The number of males was significantly higher than the number of females and the number of adult dogs was about three times the number of young dogs. Based on different methods, estimates of the mean stray dog population in the state of Punjab ranged from 519,000 to 1,569,000. The current study revealed that there are a substantial number of stray dogs and a high number reside in rural (versus urban) areas in Punjab. The estimated stray dog numbers pose a potential public health hazard in Punjab. This impact requires assessment. The estimated stray dog numbers will help develop a dog population and rabies control program in which information about the logistics required as well as costs of implementing such programmes in Punjab can be incorporated.

Estimation of the incidence of animal rabies in Punjab, India.

BACKGROUND: Rabies is a devastating zoonotic disease of mammals that causes encephalitis and death. It is endemic in India, with an estimated annual 20,000 human deaths (one-third of the global rabies burden). The magnitude of animal rabies incidence is unknown. METHODS: In four sub-districts of Punjab, India, we monitored canine and livestock populations from August 15, 2016 to August 14, 2017. Demographic, clinical and rabies diagnostic laboratory (RDL) data were collected from suspected cases of rabies. The annual incidence rate / 10,000 animal years at risk (95% CI) in each sub-district was estimated for each species. RESULTS: During 2016-2017, a total of 41 suspected rabies cases were detected in the four selected sub-districts in Punjab. Laboratory confirmed rabies (LCR) incidence was 2.03/10,000 dog years (0.69, 5.96) and 2.71/10,000 dog years (1.14, 6.43) in stray and pet dogs, respectively. The LCR incidence in farmed buffalo and cattle was 0.19/10,000 buffalo years (0.07, 0.57) and 0.23/10,000 cattle years (0.06, 0.88), respectively. The LCR incidence amongst equine was 4.28/10,000 equine years (0.48, 38.10). Stray cattle rabies incidence in the selected sub-districts was 9.49/10,000 cattle years (3.51, 25.67). If similar enhanced surveillance for rabies was conducted state-wide, we estimate that 98 (34-294) buffalo, 18 (2-156) equine, 56 (15-214) farmed cattle, 96 (35-259) stray cattle, 128 (54-303) pet dogs and 62 (21-182) stray dogs would be expected to be confirmed with rabies in Punjab annually. CONCLUSION: These results indicate that rabies incidence in animals, particularly in dogs and stray cattle, is much higher than previously suspected. We recommend that statewide enhanced disease surveillance should be conducted to obtain more accurate estimates of rabies incidence in Punjab to facilitate better control of this important disease.

Challenges to human rabies elimination highlighted following a rabies outbreak in bovines and a human in Punjab, India.

In August 2015, a rabies outbreak occurred in bovines in a Punjab village, India; subsequently, a farmer in the same village died of rabies in October 2015. We surveyed farmers to describe the outbreak, the demographics and rabies prophylaxis administered to householders on case farms, and farmers' knowledge of rabies prevention and treatment. We used multiple correspondence analysis to guide investigation of associations between demographics, farm status and rabies knowledge, attitudes and practices. The number of affected bovines was unusually high; 15 cattle and buffalo died on 13 smallholder farms (attack rate 4%). Post-exposure vaccinations were administered to 24 people (median 2 doses). Affected farms had significantly larger households and were more likely to keep their livestock outside (therefore, accessible by stray dogs), suggesting that the impact of the outbreak was disproportionally borne by households of lower socio-economic status. Primary sources of rabies information were friends and neighbours, not health authorities or media. Women who had not received formal education were less likely to have heard of rabies. Although case farm participants were more likely to have heard about rabies from a veterinarian, their knowledge and practices to prevent rabies did not reflect the level expected considering their contact with a health professional; they were more likely to believe that traditional remedies prevent rabies and less likely to tell their children to avoid playing with stray dogs than participants from other farms. This study highlights knowledge dissemination disparities that, if typical of rural locations, could obstruct attempts to eliminate canine-mediated human rabies in India. Therefore, understanding the pervasiveness and influence of traditional medical beliefs on treatment-seeking behaviour, communication structures within villages and the impact of local practices such as carcass disposal on dog populations will be essential to ensure that rabies control strategies are effective in rural India.