Prof Emeritus Peter Windsor
It’s now mid-April 2021, and citizens of many countries around the world remain in relative isolation, having adopted a huge behavioural change to reduce the risks of being infected by the Covid-19 virus. The priority intervention in controlling pandemic and epidemic disease is enhanced biosecurity, with effective quarantine and movement controls necessary to prevent transmission between the infected and susceptible populations. There has been impressive compliance with this within Australia, where life has been pretty much back to normal for a considerable time now. Mass gatherings for sporting events and even music festivals are now permitted as recent cases of Covid-19 have been confined within the quarantine hotels and restricted to returning citizens from overseas.
However, in most countries, the need for people to socialise has been overwhelming, and Covid-19 outbreaks have readily spun out of control. Globally, the statistics remain alarming, with currently over 141million people having been infected with over 3.1million deaths. Fortunately, vaccination programs are now rolling out worldwide, bringing increasing optimism that life in other countries will also be returning to ‘normal’ before too long. The vaccination program is essential for Cambodia, as it is currently in ‘lockdown’ with the streets of Phnom Penh largely deserted in an attempt to reduce virus transmission. As Covid-19 surveillance in most countries is ‘passive’ and relies on reporting of clinical cases, there are always concerns of under-reporting and that the actual prevalence is higher than the number of cases reported daily. Surveillance through the testing of sewage for molecular remnants of Covid-19 has been adopted in Australia to create a more ‘active’ surveillance system that provides an early warning of where unrecognised infection may be occurring.
The Covid-19 experience has increased the global understanding of ‘biosecurity in action’. There has been much discussion and debate in most households and regularly in the media on ways to improve the effectiveness of quarantine & human movement controls, methods for increasing levels of disease surveillance and reporting, and more recently, challenges with vaccination efficacy. A feature of the pandemic is the overwhelming public awareness of these issues. Covid-19 has certainly reinforced understanding of the four key interventions required for transboundary disease (TAD) control programs into sharp focus: quarantine/movement control, surveillance, vaccination and public awareness. However, what does this global understanding of these interventions for a human disease (albeit having likely originated from wildlife transmission) mean for the understanding of TAD control in livestock populations? These interventions were successfully applied in Indonesia and then The Philippines to eradicate Foot-and-Mouth-Disease (FMD). However, despite many efforts to transport these lessons to the Mekong region, FMD remains out of control and the region at significant risk of TAD incursions, as has occurred with African Swine Fever (ASF). The history of the FMD challenges in Se Asia has been reviewed: doi:10.1017/S0950268819000578.
Much of the impetus for improving livestock disease control in the Mekong is the demand for red meat in China, producing an annual movement of over a million cattle from Myanmar and elsewhere into China, with many passing through northern Laos. China is seeking to reduce the risks of TADs and FMD, particularly from this trade, with discussion on creating a Disease Control Zone (DCZ) in border provinces. With recent political upheavals in Myanmar, the status of a DCZ proposal there is uncertain. However, in Laos, efforts to progress this initiative and work conducted in Laos in the last decade suggest this may be achievable. A preliminary attempt to collaboratively work towards the first FMD DCZ in the Mekong was the efforts in northern Laos 2012 and 2016 when over 1.6million doses of FMD vaccine were administered across the northern provinces, supported by OIE through SEACFMD program support (i.e. STANDZ funded program from Australia). This program appeared effective in suppressing clinical FMD, although when the donor funds for vaccine expired, the disease re-emerged in 2017. Many lessons were learned from this program, as were documented in the paper: doi:10.1017/S0950268818002443.
An important lesson from these mass vaccination programs was that sustainability of vaccination for prolonged FMD suppression is critical and is likely a >10yr commitment. As described in the final paragraphs of this paper, another key lesson was that there was insufficient time budgeted for the village visits, both to reach enough of the livestock population receiving the vaccine and the training of farmers on improving village-level biosecurity. A recommendation was that the first issue could be resolved by an extra vaccine day/site and the second by holding biosecurity information meetings separate from the vaccine day(s). Gender issues were also an important consideration. As females dominate the household finances, we have learned the importance of separate meetings with females to ensure they were aware of what the program was all about and that livestock biosecurity is a family household sustainability and resilience activity. Finally, closing the porous unregulated border areas for animal movement, improving the surveillance capacity, and developing an emergency disease response capability are essential components for developing an effective DCZ in the Mekong, described in detail in the FMD eradication program in The Philippines: doi:10.1111/j.1865-1682.2011.01225.
It is hoped that the important lessons from Covid-19 awareness can also assist understanding of disease control in animal populations and result in more sustainable progress in achieving TAD control, particularly for FMD in the Mekong region.