Insights from Dr. Rahul K Nelli on Veterinary Surveillance
Dr. Rahul Kumar Nelli is a Research Assistant Professor at Iowa State University’s Veterinary Diagnostic Laboratory. He holds a PhD from the University of Nottingham and an MVM from the University of Glasgow. His research focuses on immune responses to influenza and coronaviral infections, utilizing advanced 3D cell-culture systems. Dr. Nelli has received numerous accolades, including the Postdoctoral Scholar of the Semester at Michigan State University. Based on his recent research study, Naresh Nunna of Neo Science Hub interviewed him online, discussing the implications of avian flu transmission from birds to dairy cattle.
Dr. Rahul, please tell us about your research “Sialic Acid Receptor Specificity in Mammary Gland of Dairy Cattle Infected with Highly Pathogenic Avian Influenza A(H5N1) Virus”?
The essence of our research lies in identifying specific sialic acid receptors in the mammary gland and respiratory tissues of dairy cattle infected with HPAI H5N1. These receptors, particularly alpha 2,3 and alpha 2,6, facilitate the virus’s attachment and entry into host cells, indicating a higher susceptibility of cattle to avian influenza viruses. This finding underscores the potential for cross-species transmission, raising significant public health concerns and highlighting the need for enhanced surveillance and preventive measures to mitigate the risk of future pandemics.
How do you think the Indian dairy industry, which is largely unorganized, can adapt to prevent the spread of avian flu among cows, considering the milking process as a potential mechanism of transmission?
To adapt and prevent the spread of avian flu, the Indian dairy industry should implement several measures. First, establish robust surveillance systems to regularly screen dairy cattle for avian influenza and other diseases. Second, enforce strict hygiene practices during the milking process, including sanitizing equipment and facilities. Third, provide personal protective equipment (PPE) such as masks and goggles to dairy workers to reduce exposure to potential viral aerosols. Additionally, promoting pasteurization of milk can help inactivate viruses, ensuring that the milk supply remains safe for consumption. Collaboration with government bodies to provide training and resources to small-scale farmers is also essential for effective disease management.
What prompted the immediate alerts to your veterinary colleagues in Andhra Pradesh?
The recent avian flu outbreak in US, identified by our diagnostic lab in March, prompted immediate alerts to my veterinary colleagues in Andhra Pradesh due to the significant concerns it posed, especially for farmers facing similar challenges globally.
What are some of the global agricultural challenges mentioned?
The global agricultural landscape is undergoing significant challenges, including a decline in the farming population, inadequate subsidies, and the pursuit of cheap food impacting farmers’ livelihoods. Small-scale farmers face immense pressure to conform to corporate demands, such as adopting genetically modified crops, highlighting the complexities of modern agriculture and the need for a comprehensive understanding of interconnected systems.
How is the attitude towards such issues in India described?
In India, people often do not take issues seriously until they witness them first-hand. This casual approach is concerning, especially in regions like coastal Andhra, which is abundant with migratory birds. Places like Koringa and Kolleru are pivotal as they serve as stops for birds traveling long distances, interacting with various bird colonies worldwide.
Why are migratory birds significant in the context of avian flu?
Birds are natural carriers of influenza, often harbouring the virus without obvious symptoms. In the presence of a highly pathogenic strain, affected birds may show clinical signs and die, but often the infection remains subclinical, without visible symptoms. The virus continues to mutate quietly, and a single mutation could potentially trigger a pandemic virus, leading to widespread outbreaks, which was my primary concern upon learning about the situation.
What was your experience with cattle in coastal Andhra and its potential health risks?
My first experience with cattle in coastal Andhra highlighted the high density of animals, including robust milk-producing cattle. Our predominantly open farms expose people, animals, and birds to each other. Paddy farms attract numerous cranes and other birds, increasing the possibility of disease transmission, such as influenza or coronavirus among animals. However, the likelihood of such transmission is uncertain due to the lack of comprehensive studies.
What is necessary to understand the risk of disease transmission among animals in India?
To understand the risk, robust epidemiological data and trend analysis are essential. Unfortunately, there is no adequate surveillance system in India for animal health. An effective system would involve regularly screening animals for various diseases and certifying them as disease-free. This requires a significant policy overhaul and strengthening infrastructure to facilitate these health safeguards.
Are we prepared for potential disease outbreaks in animals in India?
Most responses indicate a lack of readiness. For example, during the lumpy skin disease outbreak two years ago, we were caught off-guard without reliable diagnostic tests. Bureaucratic hurdles and interpersonal dynamics further complicate collaboration. While Indian cattle might have some resilience, it’s crucial to remain vigilant and prepared.
What sentiments were expressed regarding the resilience of Indian livestock during disease outbreaks?
When anthrax cases were reported, there were similar sentiments about the resilience of Indian sheep, encouraging the belief that they are naturally resistant. However, I caution against complacency. While our cattle and sheep are traditionally believed to have robust immune systems, it’s essential to recognize the difference between bacterial infections and viral infections, which can mutate unpredictably, similar to coronaviruses.
How do the mortality rates of highly pathogenic avian influenza and COVID-19 compare?
Scientific literature indicates that the mortality rate for humans from highly pathogenic avian influenza, based on limited cases observed, is 50%. In contrast, COVID-19, with a significantly larger number of cases, has shown a mortality rate of less than 1%. This stark difference underscores the severity and unpredictability of avian influenza compared to COVID-19.
Why is it important to be proactive in managing public health threats?
It’s imperative to be proactive rather than reactive. Implementing preventive measures before a crisis escalates is crucial. The aim should be to prevent problems rather than trying to solve them after they arise, which is essential for effective public health management.
How did the study draw parallels to the COVID-19 pandemic, and what are the specifics of influenza virus receptors?
The study drew parallels to the COVID-19 scenario because it is fresh in everyone’s mind. During the COVID-19 pandemic, much discussion centered on the ACE2 receptors to which the virus binds. Similarly, for influenza, the virus binds to sialic acid receptors, which are abundant in mucus and sputum across all animal species. Influenza viruses attach to sialic acids known as alpha 2,3 and alpha 2,6. Influenza A viruses, primarily of avian origin, bind to the alpha 2,3 receptors.
What receptors were discovered in dairy cattle, and what do they indicate?
Our research discovered the presence of both alpha 2,6 and alpha 2,3 receptors in dairy cattle, specifically in a hybrid breed. There are more alpha 2,3 receptors than alpha 2,6, indicating a higher affinity for avian viruses. This suggests that viruses like the highly pathogenic H5N1, which originated in birds and has been circulating globally since 2021, could readily bind to these receptors in cattle. This finding underscores the potential risk and transmission dynamics between avian species and livestock.
What is significant about the strain of virus identified in cattle?
The virus originated from a sub-clade of the bird population, representing a new strain capable of binding to avian receptors abundant in cattle. Remarkably, this strain can penetrate deep into the lungs and even the mammary glands, marking the first reported case of influenza A in dairy cattle. No previous study had identified such an infection in cattle before our lab published the initial paper on this finding.
How did the scientific community initially react to your findings?
When we submitted our paper, there was significant scepticism within the scientific community. Reviewers questioned the authenticity of our findings, suggesting possible errors in our control measures and expressing disbelief that cattle could contract influenza. This type of confrontation from reviewers was unprecedented, as it was the first time such a phenomenon had been observed.
What was the outcome of the scepticism during the review process?
I recall first encountering this scepticism in late April to May during the review process of our paper. Repeatedly, we were asked to confirm our results. Ultimately, our findings were validated as both the USDA and CDC confirmed them, reinforcing the credibility of our research. This breakthrough has significant implications for understanding the transmission dynamics of influenza across species.
How did the scientific community react to your findings initially?
The initial scepticism we encountered is a typical human reaction. When presented with unfamiliar information, people often respond with disbelief. This reaction isn’t malevolent; it’s a natural human inclination to question anomalies. We detailed our methodologies thoroughly, and ultimately, the scientific community accepted our evidence.
What was an intriguing aspect of your study regarding virus replication?
An intriguing aspect of our study is why the virus replicates more in the mammary gland than in the respiratory tract. Typically, influenza symptoms are associated with the respiratory system. However, in this case, the virus predominantly affects the mammary gland. This prompted further investigation by our team, leveraging my PhD research on influenza receptors in pigs.
What were your findings regarding virus replication in the mammary gland?
Our findings confirmed that the virus replicates more efficiently in the mammary gland than in the lung and trachea. We are currently seeking grants to fund additional research on how the virus infects the mammary gland, specifically targeting the epithelial cells. Another key discovery is the presence of the virus in macrophages within the mammary gland tissue, raising critical questions about their role in the infection process.
What potential systemic implications does H5N1 infection in macrophages have?
Historically, H5N1 has been known to infect macrophages, potentially allowing the virus to spread systemically from the mammary gland to the bloodstream and other organs. Whether this occurs in our case is still uncertain and warrants further investigation.
Why is funding essential for advancing your research?
Funding is crucial to understand the implications of our findings for dairy production. During the milking process, milk is often collected along with some cells, raising concerns about viral transmission. Understanding these risks highlights the urgency and importance of our research.
What is the role of somatic cell count in dairy production, and what risks does it pose?
Somatic cell count is a key parameter in dairy production to prevent mastitis. It reflects the number of epithelial cells in the milk, and if these cells are infected, there’s a heightened risk that the milk could carry viruses. This practice is standard worldwide, including in India.
How does pasteurization and boiling of milk ensure safety?
Consuming such milk could be safe if pasteurized or boiled, as these processes neutralize pathogens. Not all countries mandate pasteurization for every milk product, and some dairy products are consumed without this treatment. In India, it is customary to boil milk at home for further safety, even if it has already been pasteurized, ensuring food safety through cultural practices.
What is somatic cell count, and why is it important in dairy production?
The term “somatic cell count” refers to counting the cells in milk to determine if it falls within acceptable limits for consumption. This measure is standard in dairy units globally, including in India, primarily to monitor and prevent mastitis, a significant concern in the region. The somatic cells counted are typically epithelial cells. If these cells are present in the milk and are infected, there’s an increased risk that the milk may also carry viruses.
How does pasteurization and boiling milk help in ensuring its safety?
To mitigate the risk of viral transmission, pasteurization or boiling the milk is crucial, as these processes can destroy potential pathogens. Not all countries require pasteurization for all milk products, and some products are consumed without undergoing this process. In contrast, it is common in Indian culture to boil milk at home for additional safety, even if it has already been pasteurized. This practice effectively reduces the viral load, providing a measure of protection. Most people in India consume only pasteurized milk, typically boiling packet milk or fresh milk from local vendors to 100 degrees Celsius, sufficient to inactivate the virus, which can be neutralized at around 68 degrees Celsius in less than 10 minutes.
What additional concerns do you have beyond milk consumption?
My concern extends to milk products and the trend of consuming raw milk, popularized by social media influencers. There’s a misconception that raw milk consumption makes one stronger, akin to the health of our ancestors. This practice poses a significant risk, as even a small number of people consuming raw milk could potentially facilitate virus transmission. If the virus mutates within these individuals, it could lead to a more infectious strain, posing a substantial public health risk, especially given India’s large population.
How does the milking process contribute to the risk of virus transmission?
The milking process can generate aerosols—fine droplets that may carry the virus. At our dairy farms, people involved in milking have experienced symptoms like conjunctivitis, possibly due to these aerosols. They might also inadvertently touch their face with contaminated hands, increasing the risk of transmission. Protective measures such as wearing goggles and masks are crucial, but these precautions are often not taken, especially in resource-limited areas like India, highlighting a gap in preventive strategies.
Why are protective measures during milking important, and what challenges exist?
Protective measures such as wearing goggles and masks are essential to prevent virus transmission during milking. However, these precautions are often not taken, particularly in places like India where resources may be limited, and safety practices are not standard. This oversight highlights a significant gap in our current preventive strategies and underscores the need for enhanced safety protocols in these environments.
What should the government do to protect those involved in dairy farming?
The government should provide personal protective equipment (PPE) to those involved in dairy farming. The goal of PPE is not to eliminate exposure completely but to significantly reduce it. For instance, if a thousand viral particles might reach someone’s eye without protection, wearing PPE like masks and goggles could reduce that number to ten. This reduction means the immune system can manage the fewer particles effectively, whereas it could be overwhelmed by a larger number.
How should people understand the use of PPE in reducing risk?
People need to understand that PPE reduces risk to a level where the body’s natural defenses can function effectively. It’s about lowering the number of viral particles that reach the body, allowing the immune system to manage them better.
What are the potential risks associated with traditional practices involving cow dung and cow urine in India?
Traditional practices involving cow dung and cow urine, which hold sacred value for many, could pose risks as preliminary data suggest potential contamination from these substances. The virus has been found in the gastrointestinal tract, indicating that dung and urine could harbour the virus. This information needs to be published to inform and possibly recalibrate these practices for health safety.
What concerns exist regarding the consumption of cow urine in North India?
In North India, many people consume cow urine for various reasons, some considered auspicious. While respecting cultural practices is important, there’s a potential public health risk that cannot be overlooked. The COVID-19 pandemic demonstrated how a solitary event can have global repercussions, underscoring the importance of collective responsibility in preventing such incidents.
Why are preventive measures crucial in handling potential outbreaks?
Preventive measures are crucial because they help delay and mitigate the impact of incidents while preparations are made, such as developing vaccines, stocking antivirals, and ensuring hospitals are equipped to handle outbreaks. Being prepared is far more effective than having to react to a crisis.
Have your studies included buffaloes, and what are the implications of this?
Our studies have been conducted on Holstein Friesian cattle, not buffaloes. The susceptibility to diseases can vary between species, so there might be differences in how buffaloes respond to these viruses. We have not yet studied buffaloes but are open to collaborating with researchers in India to explore this area. This research is necessary to understand the risks fully and develop appropriate preventive strategies.
What shift is occurring in South India regarding livestock, and what concerns does it raise?
In South India, while buffalo use is predominant, there’s a noticeable shift towards high milk yield cows from regions like Punjab. This raises questions about disease resistance and necessitates prompt research to understand the health implications fully. The Indian government and the Ministry of Animal Health must fund and conduct these studies to ensure livestock are not assumed to be resistant without concrete data.
Why is it crucial for policymakers to be vigilant about cattle health?
Given the current government’s favourable stance towards cattle, acknowledged as sacred animals, policymakers must be vigilant to safeguard animal health and political interests. Any outbreak could have severe repercussions, and preparation poses no disadvantage. This includes managing practices such as the disposal of cow dung, which can exacerbate virus spread.
What are the challenges in managing an outbreak among livestock compared to humans?
The logistics of culling large animals involve significant ethical, political, and practical challenges, such as the energy required for cremation and the land needed for burial. Unlike smaller poultry, dealing with livestock requires considerable resources and planning. Strategic thinking and comprehensive resource planning are essential for effective containment and management of potential outbreaks.
What approach is essential for readiness in case of a potential outbreak?
Beyond vaccination, strategic thinking and comprehensive resource planning are crucial. This includes ensuring adequate resources for containment and management of the virus, should an outbreak arise. Preparation is key to mitigating the impact and ensuring readiness for any potential threat.
