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

Background: Dog bites in humans are a public health problem worldwide. The issues of increasing stray dog populations, rabies outbreaks, and the risk of dogs biting humans have been frequently reported by the media in Bhutan. This study aimed to estimate the bite incidence and identify the risk factors for dog bites in humans, and to estimate human deaths from rabies in rabies endemic south Bhutan. Methods: A hospital-based questionnaire survey was conducted during 2009–2010 among dog bites victims who visited three hospitals in Bhutan for anti-rabies vaccine injection. Decision tree modeling was used to estimate human deaths from rabies following dog bite injuries in two rabies endemic areas of south Bhutan. Results: Three hundred and twenty four dog bite victims were interviewed. The annual incidence of dog bites differed between the hospital catchment areas: 869.8 (95% CI: 722.8–1022.5), 293.8 (240–358.2) and 284.8 (251.2–323) per 100,000 people in Gelephu, Phuentsholing and Thimphu, respectively. Males (62%) were more at risk than females (P,0.001). Children aged 5–9 years were bitten more than other age groups. The majority of victims (71%) were bitten by stray dogs. No direct fatal injury was reported. In two hospital areas (Gelephu and Phuentsholing) in south Bhutan the annual incidence of death from rabies was 3.14 (95% CI: 1.57–6.29) per 100,000 population. The decision tree model predicted an equivalent annual incidence of 4.67 (95% CI: 2.53–7.53) deaths/100,000 population at risk. In the absence of post exposure prophylaxis, the model predicted 19.24 (95% CI: 13.69–25.14) deaths/year in these two areas. Conclusions: Increased educational awareness of people about the risk of dog bites and rabies is necessary, particularly for children in rabies endemic areas of Bhutan https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222627/pdf/pntd.0001391.pdf

  • Oct/17/2020 2:18 PM
  • Dr Tenzin
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Comparison of mark-resight methods to estimate abundance and rabies vaccination coverage of free-roaming dogs in two urban areas of south Bhutan

In Bhutan, Capture-Neuter-Vaccinate-Release (CNVR) programs have been implemented to manage the dog population and control rabies, but no detailed evaluation has been done to assess their coverage and impact. We compared estimates of the dog population using three analytical methods: Lincoln-Petersen index, the Chapman estimate, and the logitnormal mixed effects model, and a varying number of count periods at different times of the day to recommend a protocol for applying the mark-resight framework to estimate free-roaming dog population abundance. We assessed the coverage of the CNVR program by estimating the proportion of dogs that were ear-notched and visually scored the health and skin condition of free-roaming dogs in Gelephu and Phuentsholing towns in south Bhutan, bordering India, in September–October 2012. The estimated free-roaming dog population in Gelephu using the Lincoln-Petersen index and Chapman estimates ranged from 612 to 672 and 614 to 671, respectively, while the logit-normal mixed effects model estimate based on the combined two count events was 641 (95% CI: 603–682). In Phuentsholing the Lincoln-Petersen index and Chapman estimates ranged from 525 to 583 and 524 to 582, respectively, while the logit-normal mixed effects model estimate based on the combined four count events was 555 (95% CI: 526-587). The total number of dogs counted was significantly associated with the time of day (AM versus PM; P = 0.007), with a 17% improvement in dog sightings during the morning counting events. We recommend to conduct a morning marking followed by one count event the next morning and estimate population size by applying the Lincoln-Peterson corrected Chapman method or conduct two morning count events and apply the logit-normal mixed model to estimate population size Main text here: https://www.sciencedirect.com/science/article/pii/S0167587715000239

  • Oct/17/2020 2:16 PM
  • Dr Tenzin

Rabies virus strains circulating in Bhutan: Implications for control

We report a molecular epidemiological study of rabies virus (RABV) strains circulating in animal populations in Bhutan, and investigate potential origins of these viruses. Twenty-three RABV isolates originating from dogs and other domestic animals were characterized by sequencing the partial nucleoprotein (N) gene (395 bp). Phylogenetic analysis was conducted and the Bhutanese isolates were compared with rabies viruses originating from other parts of the world. Phylogenetic analysis showed that Bhutanese isolates were highly similar and were closely related to Indian strains and South Asian Arctic-like-1 viruses. Our study suggests that the rabies viruses spreading in southern parts of Bhutan have originated from a common ancestor, perhaps from the Indian virus strain. Full text here: https://www.researchgate.net/publication/49636933_Rabies_virus_strains_circulating_in_Bhutan_Implications_for_control

  • Oct/17/2020 2:12 PM
  • Dr Tenzin

Emergency surveillance for novel influenza A(H7N9) virus in domestic poultry, feral pigeons and other wild birds in Bhutan

Following the March 2013 outbreak of novel avian influenza A(H7N9) virus in humans and the subsequent isolation of the virus from chickens, ducks and pigeons in China, concerns were raised that the H7N9 virus would spread beyond China through the poultry value chain linking to a number of bordering countries. For this reason, a rapid emergency surveillance exercise took place in Bhutan between May and July 2013 with the objective of determining whether influenza A(H7N9) virus was silently circulating in domestic poultry and wild birds in Bhutan. A total of 1,716 oropharyngeal, tracheal and cloacal swabs together with faecal droppings were collected from poultry, wild birds and feral pigeons throughout the country; these samples included 150 that had been previously collected for surveillance of influenza A(H5N1) virus. Overall, 733 of the samples were tested. A QIAamp(R) Viral RNA Mini Kit was used to extract viral RNA from a mix of oropharyngeal, tracheal and cloacal swabs and faecal droppings. The matrix gene of avian influenza type A virus was detected using a specific real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assay, and positive samples were further tested in qRT-PCR for simultaneous detection of the H7 and N9 genes. Among the 733 samples tested, 46 (26 prospective, 20 retrospective) were confirmed positive for influenza A, a prevalence of 6.3% (95% CI: 4.6 to 8.3). The influenza A-positive samples were from areas in the south of Bhutan that had experienced previous outbreaks of highly pathogenic influenza A(H5N1). None of the samples tested positive for H7N9 strains, providing evidence that influenza A(H7N9) virus was not present in the sampled population. A risk-based approach for surveillance of influenza A(H7N9) and H5N1 is recommended in Bhutan, based on the epidemiology of the disease in China and other countries in South and Southeast Asia https://www.researchgate.net/publication/283634602_Emergency_surveillance_for_novel_influenza_AH7N9_virus_in_domestic_poultry_feral_pigeons_and_other_wild_birds_in_Bhutan

  • Oct/17/2020 2:12 PM
  • Dr Tenzin
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Human and animal rabies prevention and control cost in Bhutan, 2001−2008: the cost‐benefit of dog rabies elimination

The aim of this study was to understand the use and distribution of human rabies post exposure prophylaxis (PEP) vaccine in Bhutan and to identify risk factors for receiving an incomplete course of the vaccine. We analysed post exposure treatment records from 28 medical hospitals from 2005 to 2008. Males (59%) accounted for significantly more PEP events than females (41%) across all age groups (P < 0.001). Children–particularly 5–9 years of age – received more rabies PEP than other age groups. Animal bite and non-bite accounted for 27% (n = 2239) and 16% (n = 1303) of rabies PEP, respectively, whilst 57% (n = 4773) of the PEP events had no recorded information about the reasons for post exposure treatment. Post exposure treatment was provided throughout the year with a higher number during the winter and spring months. The number of PEP events significantly (P < 0.001) increased between 2005 and 2008, from <1000 to >2800 events, respectively. Significantly (P < 0.001) more PEP events were reported from the southern parts of Bhutan that are endemic for rabies or those areas in eastern Bhutan that have reported rabies outbreaks than other parts of Bhutan. Forty percent (n = 3360) of the patients received an incomplete course of vaccine (<5-doses of vaccine intramuscular). Results suggest that patients with animal bite injury were less likely to receive an incomplete vaccine course than non-bite recipients, and patients presented to hospitals in rabies endemic or outbreak areas were less likely to receive an incomplete course than in non-rabies areas or rabies free areas. Similarly, patients presenting to hospitals for PEP during spring and summers months were less likely to receive an incomplete vaccine course than those during other seasons. Public education campaigns need to be conducted in Bhutan to reduce dog bite incidents and also to prevent mass exposures to rabies. A thorough assessment of each individual case based on the WHO guidelines would reduce unnecessary PEP (and therefore costs) in Bhutan. Full text here: https://ses.library.usyd.edu.au/handle/2123/14836

  • Oct/17/2020 2:04 PM
  • Dr Tenzin

A One Health Approach to Disease Investigation, Prevention & Control in Bhutan: Anthrax Case Study

During 2010, there was an outbreak of anthrax in which forty three domestic animals died in the Zhemgang district of central Bhutan. There were also eight cases of cutaneous anthrax in humans and one person died following systemic infection. All affected people had a history of contact with the carcasses of infected animals. The outbreak was contained by field staff from the Department of Livestock, Ministry of Agriculture & Forests (MoAF) and the Department of Public Health, Ministry of Health (MoH) using a One Health approach. Concurrent treatment of affected people and sick animals, along with ring vaccination of neighbouring cattle, controlled the outbreak. Enhanced public awareness was created through meetings and a door to door advocacy campaign in the area impacted by the outbreak. Comprehensive disease preparedness and response guidelines were subsequently developed with the aim of ensuring an effective and coordinated approach to dealing with human and animal cases and to enhance regional awareness of anthrax in Bhutan. In the case study presented we illustrate how the Department of Livestock and the Department of Public Health in Bhutan have practiced a One Health approach to the control and prevention of zoonotic diseases such as anthrax. Full text https://www.researchgate.net/publication/315673802_A_One_Health_Approach_to_Disease_Investigation_Prevention_Control_in_Bhutan_Anthrax_Case_Study

  • Oct/17/2020 2:01 PM
  • Dr Tenzin

Seroprevalence and associated risk factors of important pig viral diseases in Bhutan.

A cross-sectional serological study was conducted in Bhutan between October 2011 and February 2012 to determine the prevalence of antibodies to classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), swine influenza virus (SIV) subtype H1N1 and Aujeszky's disease virus (ADV). Furthermore, risk factors for the seropositive status were investigated. Antibodies to SIV, subtype H1N1 (likely pandemic H1N1 2009) were detected in 49% of the pigs in the government farms, and 8% of the village backyard pigs. For PCV2, these percentages were 73% and 37% respectively. For CSFV, the percentages were closer together, with 62% and 52% respectively. It should be taken into consideration that vaccination of piglets is routine in the government herds, and that piglets distributed to backyard farms are also vaccinated. No direct evidence of CSFV infections was found, either by clinical signs or virus isolation. Antibodies to PRRSV and Aujeszky's disease, on the other hand, were not found at all. Risk factors found are mainly related to practices of swill feeding and other biosecurity measures. For CSFV, these were swill feeding (OR = 2.25, 95% CI: 1.01-4.99) and contact with neighbour's pigs (OR = 0.31, 95% CI: 0.13-0.75). For PCV2 this was lending of boars for local breeding purposes (OR = 3.30, 95% CI: 1.43-7.59). The results of this study showed that PCV2 and SIV infections are important in pigs in Bhutan and thus appropriate control strategies need to be designed and applied which could involve strict regulation on the import of live pigs and vaccination against these diseases. https://www.researchgate.net/publication/264123940_Seroprevalence_and_associated_risk_factors_of_important_pig_viral_diseases_in_Bhutan

  • Oct/17/2020 2:00 PM
  • Dr Tenzin

Crimean-Congo Hemorrhagic Fever Virus IgG in Goats, Bhutan

Crimean-Congo hemorrhagic fever (CCHF) is a highly infectious tickborne disease caused by a high-risk group of viruses belonging to the family Bunyaviridae (1,2). In humans, the overall case-fatality rate of CCHF is ≈30%, but in severe and hospitalized patients, fatalities may be up to 80% (3,4). CCHF is widespread in various countries in Africa, Asia, and Europe; the virus had been identified in humans in China, Pakistan, and Afghanistan and has been recently reported for the first time in humans in India (4–7). Humans can be infected by bites from infected ticks, mainly of the Hyalomma genus; by unprotected contact with blood or tissue of viremic patients; or during slaughtering of infected animals. In addition, nosocomial infections are found in humans

  • Oct/17/2020 1:57 PM
  • Dr Tenzin
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Community-based survey during rabies outbreaks in Rangjung town, Trashigang, eastern Bhutan, 2016

Tenzin Tenzin, Jamyang Namgyal and Sangay Letho Background Rabies is a highly fatal disease transmitted through the bite of a rabid animal. Human deaths can be prevented by prompt administering of rabies vaccine and rabies immunoglobulin following the exposure. An assessment of community knowledge, awareness and practices on rabies is important during outbreak to understand their preparedness and target educational messages and response activities by the rapid response team. Methods: A rabies outbreak has occurred in Rangjung town, eastern Bhutan on 4 October 2016. A rapid response team was activated to investigate outbreak and to establish a control program. A community-based questionnaire survey was conducted from 20 to 21 October 2016 to assess the community knowledge of rabies to guide outbreak preparedness and also target educational messages and response activities by the RRT. Results: A total of 67 respondents were interviewed, of which 61% were female and 39% male. All the respondents have heard of rabies (100%), have knowledge on source of rabies (dog) and its mode of transmission in animals and humans. Most (61%) respondents were aware and also indicated that they would wash the animal bite wound with soap and water and seek medical care on the same day of exposure (100%). Majority (94%) of the respondents have indicated that they would report to the government agencies if they see any suspected rabid dogs in the community and suggested various control measures for dog population management and rabies in Rangjung including neutering procedure and mass dog vaccination. Although only few (10%) of the respondents households owned dogs and cats, but 50% of them have indicated that their dogs were allowed to roam outside the home premises posing risk of contracting rabies through rabid dog bites. Conclusions: Although this study indicates a high level of knowledge and awareness on rabies among the community, there exists some knowledge gaps about rabies and therefore, an awareness education should be focused on the source of rabies and rabies virus transmission route to reduce public concern on nonexposure events thereby reducing the cost on unnecessary postexposure treatment. For the full text click continue reading

  • Oct/17/2020 1:41 PM
  • Dr Tenzin
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Comparision of antibody responses after vaccination with two inactivated rabies vaccines in dogs in Thimphu, Bhutan.

We compared the antibody responses after vaccination with two commercially available inactivated rabies vaccines-Rabisin (Merial, France) and Raksharab (Indian Immunologicals) in dogs in Thimphu city, Bhutan. Fifty puppies were randomly assigned to two groups of 25 each and one group was subcutaneously vaccinated with a single dose of Rabisin and other group with Raksharab rabies vaccines as primary vaccination on day 0. Similarly, 50 adult dogs were also randomly assigned to two groups of 25 each and each group was subcutaneously vaccinated with a single dose of Rabisin and Raksharab vaccines as booster vaccination. Serum samples were collected on day 0 (prior to vaccination), 14 and 28 from all the dogs. Rabies antibodies were measured over a period of 28 days using SERELISA® Rabies Ab Mono Indirect enzyme-linked immunosorbent assay (ELISA). A total of 198 blood samples from 66 dogs (3 sample each on day 0, 14 and 28) were collected and analyzed. Eight puppies (8/35; 22.86% belonging to Raksharab (n=7) and Rabisin vaccination group (n=1) demonstrated a minimum protective antibody titre (≥0.5 IU/ml) ranging from 0.6 to 2.75 IU/ml while the remaining puppies (n=27) demonstrated an antibody titre ranging from 0.1 to 0.45 IU/ml on day 0 (prior to primary vaccination). The antibody titre level increased after primary vaccination ranging from 0.21 to 4.78 IU/ml and 0.16 to 7.38 IU/ml under Rabisin group on day 14 and 28, respectively, and from 0.59 to 5.80 IU/ml and 1.19 to 6.76 IU/ml under Raksharab group on day 14 and 28, respectively. In adult dogs under Rabisin booster vaccination group, 56% (9/16) of the dogs had ≥0.5 IU/ml of antibody titre (ranges: 0.25 to 6.45 IU/ml) on day 0 (before vaccination) and all dogs attained protective titre on day 14 (ranges: 1.07 to 6.46 IU/ml) and on day 28 (ranges: 2.22 to 10.26 IU/ml). Similarly, under Raksharab booster vaccination group, 56% (9/16) of the dogs had ≥0.5 IU/ml of antibody titre (ranges: 0.27 to 5.39 IU/ml) on day 0 (before vaccination). Excepting one adult male dog, all other dogs attained protective titre (≥0.5 IU/ml) on day 14 (ranges: 0.62 to 5.59 IU/ml) and on day 28 (ranges: 1.86 to 6.66 IU/ml). The findings showed that both the inactivated vaccines have elicited minimum threshold level for protection (≥0.50 IU/ml) responses as per the recommendation of the World Animal Health Organization (OIE) and World Health Organization (WHO), indicating that the vaccines used in Bhutan are potent and efficient and thus, acceptable for primary and booster vaccination against rabies in dogs. Full text here: https://www.researchgate.net/publication/333105449_Comparison_of_Antibody_Responses_after_Vaccination_with_Two_Inactivated_Rabies_Vaccines_in_Dogs_in_Thimphu_Bhutan

  • Oct/17/2020 1:33 PM
  • Dr Tenzin
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