Jaipur ABC costs greatly outweighed by benefits in dog bites and human rabies deaths

An economic analysis of dog population management (DPM) is a rare and valuable commentary. So when ICAM read Andrew Larkin’s peer-review publication reporting a net benefit of many millions USD resulting from Help In Suffering’s DPM work in Jaipur, we felt excited to share these findings with the wider DPM field.

Watch ICAM’s interview with lead author Andrew Larkins, Jack Reece (co-author and HIS) and Sanjay Singh (HIS):

Help In Suffering have been running an ABC project (Animal Birth Control of free-roaming dogs, also known as Catch, Neuter, Vaccinate and Release) in Jaipur, India since 1994. This has involved sterilisation and vaccination of an average 3,000 dogs per year and just vaccination of a further 5,000 dogs per year. This has reduced the roaming dog population by around a half and reduced the percentage of puppies from 19% to just 2% of the population. However, Andrew’s focus was on the impact of this work on human dog bites and human rabies deaths, because this is where much of the financial benefits could be calculated.

The economic assessment looked at the 23 year period 1994-2017. The approach was to look at the prevalence of dog bites and human deaths rabies in Jaipur in 1994 and estimate how many would have occurred over the coming 23 years if there had been no intervention. This is called the ‘counterfactual scenario’. Then look at the evidence of what actually happened with dog bites and human rabies in Jaipur over those 23 years, under the influence of Help In Suffering’s ABC work.

In 2013, Help In Suffering’s long-term veterinary surgeon and ABC expert, Jack Reece and his veterinary surgeon colleague Sunil Chawla, had published on the significant reduction in reported dog bites following ABC. Comparing this to the predicted dog bites under the counterfactual scenario, Andrew could calculate that ABC had averted over 360,000 dog bites at a cost of 5.62 million USD, an impressive saving for local health service budgets and improvements in community safety.

But the benefits don’t stop there. Andrew also looked at Jack and Sunil’s earlier 2006 publication on the reduction in human rabies deaths following the implementation of ABC. Again, comparing the predicted deaths under the counterfactual scenario, Andrew was able to estimate that nearly 500 human rabies deaths had been averted by ABC over the 23 year period. He was also able to use what are called DALYs (Disability Adjusted Life Years) and India’s GDP to estimate the economic benefit of those lives save from rabies. When added to the 5.62 million USD saved from bites averted, this becomes a total societal economic benefit, estimated to be 38.48 million USD.

These sizeable financial benefits can then be compared to the 658,744 USD cost of Help In Suffering’s ABC work over 23 years (value adjusted for inflation). ‘Benefit-cost ratios’ are the formal way to make this comparison and show that for every $1.00 spent on ABC, $8.50 was saved in dog bite treatment and $58.40 in total societal economic losses from both rabies and bites.

This analysis has shown a clear and sizable economic benefit for the local health service and economic productivity resulting from Help In Suffering’s ABC work. But what factors in Jaipur led to this result? For one, Help In Suffering’s ABC activities are run very efficiently at an average cost of just $10.78 USD per dog sterilised and vaccinated and only $1.86 for solely vaccinating a dog. Jaipur was also suffering from a high burden of rabies when ABC was launched, so there was plenty of ground to be made up in bites averted and lives saved from rabies. It is also important to highlight that Help In Suffering have persisted in diligently and professionally monitoring their intervention effort and impact since ABC was started; this dataset was crucial for the analysis and Help In Suffering should be celebrated for their outstanding monitoring efforts.

Importantly, this analysis focused on rabies control benefits and the costs of vaccination only activities were less than 1/5 of sterilisation plus vaccination. Sterilisation would have contributed to rabies control, through mechanisms such as reducing contact rates during breeding seasons, but most of the reduction in human rabies deaths can be attributed to vaccination. So this economic analysis could have been even more positive following a vaccination only intervention with lower costs. However, the reduction in dog bites may well have been far less significant following vaccination only. We know that only a small proportion of the bites treated for rabies exposure actually involve a bite from a rabid dog, treatment is rightly given with an abundance of caution; rabies is not a disease to be taken lightly. So this reduction is not driven solely by a reduction in biting rabid dogs, this appears more closely linked to the reduction in dog population size, and avoiding maternal defensive aggression, both requiring sterilisation and not vaccination alone. Help In Suffering used the ABC approach including sterilisation and vaccination because this is what is legally mandated in the Indian legislation, but they were also wisely flexible in their addition of vaccination only activities to boost herd immunity in the roaming dog population.

 

Within India, these findings will be valuable support for those organisations and municipalities implementing, or lobbying for, ABC. But what about outside India? Where a reduction in human rabies deaths is the leading priority, mass dog vaccination will still be the most cost-effective solution, as Andrew states in the conclusion. But where dog bites matter, and those bites are at least sometimes by roaming dogs, this economic analysis provides support for the important and cost-effective role sterilisation can play in bringing down costs to the health service.

We must also see the rarity of such an important economic analysis as a rallying cry to our DPM field. As Andrew points out in his discussion, this analysis did not try to capture the economic benefits relating to other potential impacts of ABC, including a “smaller, healthier dog population with improved welfare…and an enhanced human-dog relationship”. Further, recognising that 75% of puppies born on the streets of Jaipur will die in their first year (Reece at al 2008), the reduction in breeding also presents a significant welfare benefit from preventing the suffering and death of many puppies. It’s up to our DPM community to improve and value our monitoring so that we have the data ready to support economic evaluations with broader scope in future.

You can find a summary of the paper on the ScienceDirect website, including figures and section snippets. However, if you would like to read the full paper, send an email to info@icam-coalition.org and we’ll request the authors send you a copy.

Publications discussed in blog and vlog:

Larkins et al (2020) An economic case study of the control of dog-mediated rabies by and animal welfare organisation in Jaipur, India. In Preventative Veterinary Medicine, volume 183.

Reece et al (2013) Decline in human dog-bite cases during a street dog sterilisation programme in Jaipur, India. In Vet Record, volume 172, issue 18.

Reece and Chawla (2006) Control of rabies in Jaipur, India, by the sterilisation and vaccination of neighbourhood dogs. In Vet Record, volume 159, issue 12.

Reece, Chawla, Hiby and Hiby (2008) Fecundity and longevity of roaming dogs in Jaipur, India. BMC Veterinary Research, volume 4.

Hasler et al (2014) A One Health Framework for the Evaluation of Rabies Control Programmes: A Case Study from Colombo City, Sri Lanka. PLoS Negl Trop Dis 8(10): e3270.

Yoak et al (2014) Disease control through fertility control: Secondary benefits of animal birth control in Indian street dogs. Preventive Veterinary Medicine 113 (2014) 152– 156

 


About International Companion Animal Management (ICAM) Coalition

ICAM supports the development and use of humane and effective companion animal population management worldwide. The coalition was formed in 2006 as a forum for discussion on global dog and cat management issues.

Our key goals are to:

  • Share ideas and data
  • Discuss issues relevant to population management and welfare
  • Agree definitions and hence improve understanding
  • Provide guidance as a collegial and cohesive group

Contact information: info@icam-coalition.org

Twitter: @ICAMCoalition

ICAM calls for One Health action this World Rabies Day

This World Rabies Day, the International Companion Animal Management Coalition urges governments around the world to adopt and strengthen the One Health approach with a clear and unmitigated focus on mass dog vaccination for eliminating rabies by 2030 – the United Nations Sustainable Development Goal target that all member states signed up to.

Every year 59,000 people die from rabies and millions of dogs are inhumanely culled in a misguided attempt to stop the spread of rabies. We know that killing dogs does not stop the disease. Removal of dogs through culling or for consumption undermines rabies control efforts. Indiscriminate culling and removal of dogs inadvertently targets the more accessible vaccinated dogs and brings down vaccination coverage (the number of vaccinated dogs as a proportion of the total dog population). It destabilises the population leading to a younger population of rabies susceptible dogs and leads to public upset and resistance against rabies control.  What works is mass dog vaccination – the only efficient and proven way to eliminate rabies.

Humane Dog Population Management (DPM) can further contribute to rabies control by reducing unwanted or unmanaged dogs and reducing population turnover, keeping vaccination coverage high and therefore achieving herd immunity (when enough of the population is resistant so the virus cannot spread and dies out) to protect dogs and people. DPM is important to sustain the gains of mass dog vaccination.

Efforts to eliminate rabies not only has an impact on bite cases and mortality, but also a psychological impact, changing perceptions of dogs from animals to be feared to companions. Therefore, by eliminating rabies through mass dog vaccination, animal welfare and the treatment of dogs will also improve in addition to the human health benefits.

The ongoing global COVID-19 crisis has highlighted the interconnect between animal, human, and environmental health. The significance of the One Health approach to address current and future challenge cannot be overstated – with multiple sectors and stakeholders stepping outside their silos to collaborate towards common health goals. Rabies elimination is the perfect example of One Health in action – a focus on dog health that saves the lives of people and the enormous financial burden of this disease.

Rabies, despite being one of oldest known zoonotic diseases, continues to be one of the major public health problems in around 150 countries around the world. This is the disease that impacts the poorest countries and the poorest communities within them. Truly a disease of poverty that needs to be consigned to history books.

Search for an event or register your own World Rabies Day event on the GARC website.


Join the webinar on Monday September 28

Join the WSAVA’s 2 part webinar on September 28 to mark this year’s World Rabies Day. Bringing together stakeholders and experts, including the OIE, GARC and World Animal Protection to discuss the importance of humane management and animal welfare in the global fight against rabies.

Read ‘All eyes on dogs’

Read World Animal Protection’s ‘All eyes on dogs’ report on why dogs hold the key to rabies elimination. And what actions stakeholders must do to achieve the goal of ending human rabies by 2030.

Download the report in EnglishPortuguese/PortuguêsSpanish/EspañolThai/??? or Mandarin/???.

 


About International Companion Animal Management (ICAM) Coalition

ICAM supports the development and use of humane and effective companion animal population management worldwide. The coalition was formed in 2006 as a forum for discussion on global dog and cat management issues.

Our key goals are to:

  • Share ideas and data
  • Discuss issues relevant to population management and welfare
  • Agree definitions and hence improve understanding
  • Provide guidance as a collegial and cohesive group

Contact information: info@icam-coalition.org

Twitter: @ICAMCoalition

Infected not infectious: How dogs and cats have become the victims of COVID-19

Those of us who work with companion animals will be all too aware of zoonotic diseases. These are diseases that are passed between animals and people, including rabies. Using vaccination and deworming to prevent these diseases in dogs and cats, and therefore also protect people, is a constant drive within our work.

COVID-19 is different. There are competing hypotheses for where it originated, including transmission from animals (possibly bats or pangolins) to people, we may never know the truth. But since the original ‘case zero’ in Wuhan, China, the transmission appears to have been entirely person to person. Except we have seen the odd rare case of SARS-CoV-2 infection in companion animals. Importantly, all these cases suggest the transmission was from an owner to their pet and not the other way; the person is sick, and some days later their animal shows similar signs or is tested positive during quarantine by public health officials. ‘Reverse zoonosis’ is a relatively rarely used term in companion animals but may be suitable with COVID-19. This is where an animal is the victim of a disease hosted by the human population; it has become infected, but it is not infectious

Infected: Can dogs and cats be infected by SARS-CoV-2?

Since the outbreak of the COVID-19 pandemic we have seen a number of positive cases in companion animals (see our blog on why testing in companion animals should be limited). But equally as important, are the negative results. The following is a summary of both. See the footnote for an explanation of the different diagnostic tests used¹:

Pets in homes with COVID-19 tested using RT-PCR:

Positive cases

  • 2 dogs in Hong Kong (one Pomeranian, one German Shepherd)
  • 1 cat in Hong Kong
  • 1 cat in Belgium
  • 2 cats in New York, USA (one home had no history of COVID-19 symptoms, but very mild or asymptomatic infection was not ruled out)
  • 1 dog in North Carolina, USA (Pug)
  • 1 cat in Spain
  • 2 cats in France
  • 1 cat in Germany
Negative

  • 60+ companion animals in Hong Kong, have been quarantined from COVID-19 homes, only 3 have shown positive test results
  • 12 pet dogs and 9 pet cats in France, belonging to 20 vet students (2 tested positive for COVID-19, 11 suffered symptoms and remainder exposed to those that were sick) were tested and none were found positive. Antibody tests also returned negative results. Temmam et al (2020)

Studies of infection in real-world samples:

Positive

  • 15 of 102 cats tested after the outbreak in Wuhan were found to have antibodies to SARS-CoV-2, none had positive PCR results so there was no longer any virus present. 3 cats were from COVID-19 households, 6 were from pet hospitals and 6 were stray cats brought to shelters after the outbreak. The authors concluded all were likely to have been exposed to people with COVID-19. Zhang et al (2020)
Negative

  • IDEXX have tested 5,000+ animals (cats, dogs and horses) with respiratory signs from 17 countries. None of these tests have returned a positive PCR result.
  • 147 pet dogs (15 from Wuhan, 1 had an owner with COVID-19), 250 street dogs (99 from Wuhan), 87 pet cats and 21 street cats (some from Wuhan, unclear how many); all had negative antibody results. Deng et al (2020)

Studies of infection in the laboratory:

Studying infection in a laboratory involves inoculation of animals with virus. Two laboratory-based experimental studies have produced the following results; Shi et al (2020) in China and Halfmann et al (2020) in USA/Japan.

Positive

  • 7 sub-adult cats and 7 juvenile cats were inoculated with virus and all showed positive results (Shi et al). 
  • 3 juvenile cats were inoculated with virus and all showed positive results (Halfmann et al).
Positive and negative

  • 5 dogs were inoculated with virus, only 2 showed positive results (Shi et al).

These studies involved placing large doses of virus onto susceptible tissues deep inside nasal passages, mouths and eyes; this may be very different to the viral loads and exposure experienced in the real-world. The type of laboratory animals used and the way they are kept may also contribute to reduced immunity. Hence, ICAM advises caution in applying the results of such experimental studies to real-world disease control. These studies may be more suited to comparing responses between species or individuals within the confines of the study.

Infectious: Can dogs and cats transmit SARS-CoV-2 to other dogs and cats? 

There is no real-world evidence of transmission between animals, on the contrary, some of the positive cases mentioned previously lived with other animals that tested negative. However, there is evidence of transmission between cats from the two laboratory-based studies mentioned previously (Shi et al 2020 and Halfmann et al 2020). These studies exposed naive animals (animals that had not been infected with virus) to inoculated animals to see if these naive animals would then ‘catch’ the virus.  

  • Shi et al. 6 pairs of inoculated and exposed cats were housed in neighbouring cages. The exposed cats in 2 pairs had positive results for PCR and antibodies, the other 4 exposed cats were negative. The same scenario with 2 pairs of dogs showed the exposed dogs had no positive test results. This suggests that transmission between dogs is not possible, but transmission between cats might be possible. 
  • Halfmann et al repeated this study but just with 3 pairs of cats who were co-housed in small cages. They found all 3 exposed cats became infected. None of the cats showed symptoms and there was no evidence of viral shedding after 5 days. 

As described above, these laboratory-based studies have limitations when extrapolating to real-world disease control. In addition to concerns about viral loads and immune system health, these pairs of cats were kept in constant close proximity in small cages. ICAM believes these factors in experimental studies combine to increase the chances of infection far higher than would occur in the real-world between pets or roaming animals.

Negative test results from real-world infections also provide some evidence that transmission between animals may not be occurring: 

  • The German Shepherd in Hong Kong that tested positive for SARS-CoV-2 also lived with a mixed-breed dog that repeatedly tested negative. 
  • The cat in New York, USA from a COVID-19 home lived with another cat that tested negative.
  • The Pug in North Carolina, USA lived with another dog and cat, neither tested positive for SARS-CoV-2.
  • The cat in Germany lived in a retirement home with her owner who died of COVID-19, two other cats that lived in the same home tested negative.

In each of these real-world scenarios is a test of potential transmission between animals AND from people to animals, as they were all in the same household with people who were sick with COVID-19. That transmission did not occur is evidence that sick owners infecting their pet is not inevitable, it appears to be very rare. It also suggests transmission is not occurring between animals.

Infectious: Can dogs and cats transmit SARS-CoV-2 to people? 

“Currently, there is no evidence that animals are playing a significant epidemiological role in the spread of human infections with SARS-CoV-2.” OIE. Evidence of transmission from dogs or cats to people would require clarity on two factors; timing and other transmission routes. A person would need to become sick with COVID-19 after their dog or cat had shown signs of infection AND all other possible routes of transmission from people would need to be excluded. Because they are in contact with many more dogs and cats than most people, veterinarians and shelter workers would be most at risk for this kind of transmission. Thankfully, there appears to be no greater prevalence of COVID-19 in these workforces. 

With over 4 million human cases worldwide we have an abundance of complex, uncontrolled but undeniably valuable epidemiological evidence about transmission. The extremely small number of infections from people to dogs and cats, and the lack of any examples of transmission to people, is meaningful. Dogs and cats are not playing a role in transmission of SARS-CoV-2 to people. These companion animals are the victims of this reverse zoonosis; they are (rarely) infected but not infectious.

Footnote 1: What testing methods are available for companion animals?

In the majority of cases, the tests offered for companion animals will be RT-PCR tests for viral genetic material. The following explains this test and its limitations in more detail and two other tests that are being used for companion animals, usually in research contexts:

  • RT-PCR: Uses oral, nasal or fecal/rectal samples. Amplifies available genetic material so is very sensitive. However, a positive test doesn’t prove the virus is live, just there is viral genetic material there, which can occur after live virus has been cleared or if there have been contamination of the animal or sample by viral particles. Need to show persistent positive RT-PCR results to show an active infection. 
  • Virus isolation: This attempts to culture (grow) live virus from swabs, so a positive result implies there is an active infection and there may be a chance of infectiousness, although this depends on viral ‘load’ (amount of virus) and closeness of contact.
  • Serology: Uses blood samples to test for the presence of antibodies. A positive result proves there was infection at some point. However, antibodies are slow to become detectable, so not the best markers for active or acute infection. 

Resources

About International Companion Animal Management (ICAM) Coalition

ICAM supports the development and use of humane and effective companion animal population management worldwide. The coalition was formed in 2006 as a forum for discussion on global dog and cat management issues.

Our key goals are to:

  • Share ideas and data
  • Discuss issues relevant to population management and welfare
  • Agree definitions and hence improve understanding
  • Provide guidance as a collegial and cohesive group

Contact information: info@icam-coalition.org

Twitter: @ICAMCoalition