Dog Bites in Humans and Estimating Human Rabies Mortality in Rabies Endemic Areas of Bhutan

Dog bites in humans are a public health problem worldwide. We conducted a hospital based questionnaire survey and described the incidence and risk factors for human dog bites in Bhutan. We also estimated the human death rate attributable to rabies in two rabies endemic areas of south Bhutan. Our study shows that dog bites incidents in humans are common in the survey areas. There were significant gender and age differences in bite incidents; males and the children are affected the most. The majority of the victims were bitten by stray dogs, increasing the risk of rabies infection if not treated in time. Our decision tree model predicted 2.23 (95% CI: 1.20–3.59) human deaths from rabies/year, equivalent to an annual incidence of 4.67 (95% CI: 2.53–7.53) deaths/100,000 in the two rabies endemic areas of south Bhutan. In the absence of post exposure prophylaxis, the model predicted 19.24 (95% CI: 13.69–25.14) deaths/year in these two areas. The public should be encouraged to visit hospitals for post exposure prophylaxis following dog bite injury in south Bhutan

Standardized morbidity ratio (SMR) of reported dog bite incidents according to gender and age of victims in three hospital catchment areas (Jigme Dorji Wangchuk National Referral hospital, Phuentsholing General hospital, Gelephu Regional Referral hospital) in Bhutan, 2009–2010.

<p>N = number of reported dog bite victims in each group.</p><p>*SMR >1 means that they are more likely to report bites than expected, a value <1 means that they are less likely to report bites than expected and a value of 1 means that they are equally likely to reported than expected. Children in age group 5–9 are 2.3 times more likely to report dog bites than expected comparing to other age groups.</p

Annual incidence of dog bites/100,000 population classified by age and gender.

<p>Data is based on a survey of dog bite victims attending three hospitals (Jigme Dorji Wangchuk National Referral hospital, Phuentsholing General hospital, Gelephu Regional Referral hospital) in Bhutan, 2009–2010.</p

Annual predicted death counts and incidence rate from rabies for different age groups in Phuentsholing and Gelephu areas of south Bhutan, calculated using the decision tree model.

<p>Annual predicted death counts and incidence rate from rabies for different age groups in Phuentsholing and Gelephu areas of south Bhutan, calculated using the decision tree model.</p

Decision tree model outlining the probability of rabies deaths.

<p>The model is adapted from Cleaveland et al., 2002 (reference number 11). Probabilities (P1–P10) are defined in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001391#pntd-0001391-t004" target="_blank">Table 4</a> and described in the <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001391#s2" target="_blank">methods</a> section. The probability calculated represents the probability of death following the bite of a suspect rabid dog.</p

Distribution of bite injuries on the body according to age group of dog bite patients in Phuentsholing and Gelephu hospital areas of south Bhutan.

<p>In the case of multiple bites, the site of the most severe bite is given. The row proportions (point estimate) are calculated for each group.</p

Anatomic location and severity of dog bite wounds.

<p>Data is derived from victims attending three hospitals (Jigme Dorji Wangchuk National Referral hospital, Phuentsholing General hospital, Gelephu Regional Referral hospital) in Bhutan, 2009–2010 (the number in the figure indicates the number of bite victims).</p

Anatomic location of dog bite wounds according to age group.

<p>Data is derived from victims attending three hospitals (Jigme Dorji Wangchuk National Referral hospital, Phuentsholing General hospital, Gelephu Regional Referral hospital) in Bhutan, 2009–2010 (the number in the figure indicates the number of bite victims). Age was categorized into the two groups indicated.</p

Model parameters, probability distributions and data sources used in the prediction of human deaths from rabies in Phuentsholing and Gelephu areas of south Bhutan from dog bite survey data.

<p>Model parameters, probability distributions and data sources used in the prediction of human deaths from rabies in Phuentsholing and Gelephu areas of south Bhutan from dog bite survey data.</p