Global Health Vet – A One Health approach to public health

I just came back from a very interesting conference in Hyderabad, India. The International Congress on Infectious Diseases (ICID) was held between March 2^nd & 3^rd, 2016. As usual, there were a lot of great talks, discussions and posters. Due to its location, a large number of representatives from Asian countries were presenting – it was nice to see new faces and learn about global health in that part of the world (plus it was my first time in India – so there’s another benefit…).

Conferences are always a good opportunity to get up-to-date information on disease situations from the experts who are on the frontlines. The Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) and Zika virus aretwo interesting situations to compare and contrast. I’ve talked about MERS-CoV in the past, responsible for an outbreak since 2013, and Zika has been the source of much attention lately. Because these topics generate much discussion, I’ve broken down my notes from ICID into two posts (look at that, 2 posts for the price of one!) – the 1^st one focusing on MERS-CoV and other interesting aspects of the conference, and the 2^nd one exclusively about Zika virus (but I’ll also sprinkle some other mosquito-borne diseases here and there…).

MERS-CoV update

Transmissibility of MERS-CoV

This is an emerging disease that appeared in the Arabian Peninsula in 2012 which causes acute respiratory disease in those affected. Since then, it has spread to other countries, mostly through movement of travelers who became infected in places where the disease is prevalent. Few local clusters of infections were then seen in the destination countries, most often associated to nosocomial (hospital-acquired) infections. Because of this, it was thought that the “superspreading” potential of this disease was limited. In 2015, a large outbreak of MERS-CoV in South Korea challenged that idea. The index case was an infected traveler who flew from Saudi Arabia to South Korea. The individual became ill and was hospitalized in Seoul, the infection spread to 186 people – the largest number of MERS-CoV cases outside of the Arabian Peninsula. Because of the robust video surveillance used in the affected hospital, it was possible to have a close look at the risk factors for disease transmission from contact with an infected person. It was determined that a 10-minute stay within 5 feet (1.5 meters) and 2minute talk with an infected person had the potential to spread the disease. This estimate shows that MERS-CoV could potentially be more transmissible than initially thought.

Animal origin

Bats may be a source of MERS-CoV infection to both camels and humans. (Photo source)

Another interesting discussion around this disease revolves around its origin. The search for the animal origin of MERS-CoV continues and a lot of attention has been put on camels as a potential source of infection in humans. Our speaker supported the idea that, while they can transmit the virus to humans, both camels and people get infected from another animal source – most likely bats. This was supported by the fact that only 1/3^rd of human cases had contact with camels. Interesting research has been done on the disease in camels and it was found that camels in many countries had positive antibodies to MERS-CoV and, and were thus exposed to the virus at one point in their life – the geographic range of these positive antibiodies is well beyond the region where MERS-CoV occurs in people. Another highlight is that camel serum from the Kingdom of Saudi Arabia which was frozen in 1985 tested positive for MERS-CoV antibodies. This shows that, although spillover into human populations seems like a somewhat recent event, the virus has been in circulation in animal populations for some time. Parts of the virus were also found in a bat, however, the specimen was damaged during transport so the search for the definitive animal reservoir continues. This may take some time; after all it was only in 2013 (11 years after the Severe Acute Respiratory Syndrome (SARS) outbreak) that researchers found evidence of that virus in bats.

Other interesting tidbits about MERS-CoV

• A person who is not symptomatic for MERS-CoV is not infectious to others.
• About 25% of infected people may be asymptomatic (this is an estimate as those who are not sick don’t tend to go to the hospital – where the diagnosis can be made).
• A visibly sick patient can spread the virus for up to 30 days.
• A human who recovered from the disease will have positive antibodies for up to 3 months – after which serologic testing may be negative. This complicates historical investigation of the disease in humans since antibodies are so short-lived.
• Most nurses who became infected in Saudi Arabia from their patients were involved in intubation procedures of infected patients.
• Cleaning is key – in hospital settings, the virus was found on surfaces about 28 days after the patient recovered.
• It is unknown if dogs and cats can become infected with MERS-CoV.

Miscellaneous cool topics of ICID

Although not a specifically “One Health-oriented” conference, One Health is always around. This was evident as a lot of presentations discussed the relationships between humans, animals and their shared environment, especially when it comes to infectious diseases.

Flooding and contact with carrier animals are risk factors for human leptospirosis infection (Photo source)

Leptospirosis challenges in India. In India, whenever there are cattle, rats and children in the same environment, then leptospirosis is usually present. Leptospirosis is a bacterial disease that usually infects its hosts through contact with mucous membranes (gums, conjunctiva) or open wounds. Infection with the bacteria can lead to severe liver disease. It was interesting to learn about the local epidemiology of the disease, as well as get examples of potential simple interventions that can help reduce cases of the disease in children, such as wearing long shoes. The speaker also covered some of the challenges in creating a vaccine for the disease that cover all serotypes of Leptospira bacteria, and mentioned hopes that a DNA-based vaccine may provide more coverage.

Integrated human and animal vaccinations in Nigeria. A very interesting presentation described efforts to jointly vaccinate people and livestock in pastoralist communities of Nigeria using multi-disciplinary teams. The speaker went on to say that the communities were very responsive to the program and that the group is looking to publish about their experiences soon. This presentation was truly a great example of One Health in action, leveraging the relationships between humans and livestock to improve health on both ends.

Stray dog on the beach of Goa, where the highest numbers of rabid dogs are reported in India

Dog bites to humans and animals. This poster measured the impact of dog bites on both humans and other animals in a region of India. Emphasis was on the rabies risk for both people and animals after they were bitten by stray dogs in an area endemic for canine rabies – and the cost associated with treatment of those affected. This is leading the government of India to recognize the need for surgical spay/neuter of stray dog populations as an integral part of canine rabies control.

This about wraps it up for part one of my ICID report – I will upload part two in the next few days.

This was my first time in India so I had to see more of this beautiful country. Sunset on the Ganges.