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| Causative Agent | Transmission | Incubation Period1 | Signs/Symptoms | Zoonosis2 | |
| African Swine Fever (ASF) | African Swine Fever virus (ASFv) | Direct contact with infected; indirect contact via fomites3; tick bite; "swill feeding" | 4-19 days |
100% mortality, red or bluish- purple skin discoloration esp. on extremities, hemorrhages |
None; Only infects pigs |
Coronavirus Disease 2019 (COVID-19) |
SARS-CoV-2; nCoV |
Direct contact with infected (via respiratory droplets from coughing and sneezing) |
2-14 days |
Fever, cough, shortness of breath |
Yes; Bats as reservoir |
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Avian Influenza (AI) |
Influenza virus A (recent: HPAI H5N6) |
Direct contact with infected; feco-oral4; indirect contact via fomites |
Up to 14 days |
Depression, swollen & congested comb & wattle, swelling under the eye, coughing, sneezing, diarrhea, red shanks, nervous signs, death |
Yes |
1Incubation period – between exposure to an infection and the appearance of the first sign; 2Zoonosis – disease transmissible from animals to humans 3Fomites – objects that carry a disease (vehicle, equipment, clothes, feeds); 4Feco-oral – transmission of disease through ingestion of contaminated feces
Prevention and Control
The causative agent of COVID-19 belongs to the family of Coronaviruses, as are Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) in humans, Porcine Epidemic Diarrhea (PED) and Transmissible Gastroenteritis (TGE) in pigs, and Infectious Bronchitis (IB) in chickens. Coronaviruses are highly contagious, yet can be easily inactivated by alcohol and common disinfectants like bleach in water. The World Health Organization (2020) recommends the use of 70% alcohol and 0.1% sodium hypochlorite (bleach), as effective and sufficient disinfection procedures against Coronaviruses. Soap and detergent for cleaning also effectively decrease viral load before disinfection. Table 2 lists down the recommended disinfectants for the three viral diseases. As shown, Influenza viruses, responsible for bird flu and common flu in humans, are susceptible to all compounds used against ASF and COVID-19. Influenza viruses are relatively unstable in the environment, thus, can be readily killed (Swayne, 2019). On the other hand, ASF virus tends to be more resistant to common disinfectants as it is large and can withstand fairly extensive changes in pH (Juszkiewicz et al., 2019). Thus, it requires stronger compounds such as aldehydes and potassium monopersulfate (PMPS) for effective disinfection.
In all disease-free regions, a quick response is vital for containing outbreaks whether it be a human or animal disease. The Bureau of Animal Industry (BAI) requires veterinarians who encounter or suspect ASF and AI to follow the national and/or local guidelines for disease reporting. The same is true for COVID-19 under the order of the Department of Health (DOH). Upon confirmation of any disease, control strategies are readily implemented. Detailed investigation, with tracing of possible sources and possible spread of infection, is performed (OIE, 2013). Infected zones are identified and are paired with movement control. For animal diseases like ASF and AI, a quarantine area is designated within the 1 km radius from the infected premise (AIPP, 2016; DA, 2019). Transportation of live animals, products and by-products out of the infected premises and quarantine areas is prohibited. Movement is only permitted in non-infected zones provided that there is a shipping permit. As for COVID-19, an enhanced community quarantine was implemented by the DOH to control human traffic (Medialdea, 2020). For all these diseases, checkpoints along the borders of quarantine areas should be in place to ensure compliance (AIPP, 2016; DA, 2016; Medialdea, 2020).
Table 2.
Similarly, movement or importation of live pigs, pork products, and by-products from ASF-positive countries have been banned by BAI. Undocumented shipments are confiscated and condemned. This is also true for bird flu (AIPP, 2016). In a similar manner, the Office of the President imposed an international travel ban to all countries affected with COVID-19. An exception would be Filipino citizens, their foreign spouse and children, permanent residents and holders of diplomatic visas (CNN Philippines, 2020a). Upon arrival, monitoring of body temperature is a must. Suspected individuals and their immediate co-passengers are then directed to quarantine and isolation.
Should outbreaks occur, the fastest and most efficient response enacted by the government against ASF and AI is “stamping out” or depopulation of positive herds and flocks by the most humane manner possible (DA, 2019). For HPAI outbreaks, special protocol is observed during depopulation given the zoonotic potential of the disease. Persons involved must wear personal protective equipment such as coveralls, masks, headgears, rubber boots and waterproof gloves (AIPP, 2016). As for COVID- 19, stamping-out is absolutely unacceptable. Instead, wearing of face mask and/or avoiding close contact about 1 meter away from another person or “social distancing” is enforced to prevent spread of the disease in a community (CDC, 2020).
Proper disposal and adequate cleaning and disinfection must follow immediately. Using the recommended disinfectant, as discussed earlier (Table 2), will enable complete and effective disinfection. In the case of ASF, disinfection is done daily for 30 days. Before repopulation, farm downtime should not be less than 90 days (DA, 2019). As for AI, a final disinfection is performed 14 days after the first disinfection. This is followed by a 21- day resting period, and only then can the farm be restocked (AIPP, 2016). During disinfection, ASF- and AI- infected farms should be closed and remain unloaded. On the other hand, the Centers for Disease Control and Prevention (2020) recommends cleaning and disinfection of frequently touched surfaces (e.g. door knobs, handles, desks, etc.) to address COVID-19. Washing of hands for 20 seconds with soap and water or alcohol-based hand rub is also part of the disinfection protocol.
As of today, no practical, specific treatment for AI, ASF, or COVID-19 exists. Supportive care and antibiotic treatment have been employed to reduce the effects of concurrent bacterial infections. There are no known effective vaccines for these diseases except for AI. In the country, vaccination is considered as a last resort in case stamping out is not successful or cannot be implemented for whatever reason (i.e. successive infections) (AIPP, 2016).
Economic impact
The emergence of threatening diseases in the country has mutated from a health problem to an economic one. During the peak of ASF late last year, the industry is under pressure from consumer avoidance of pork and sudden panic to dispose growers and fatteners before the farm gets hit by the disease (Galang, 2019). This caused hog raisers to market them at a very low price. The incidence of ASF has also made the dynamics of supply and demand in the local pork industry pretty strange. While infected areas are limiting the movement of pigs, non- infected areas are enacting pork and pork products ban as a preventive measure. This has resulted in an undersupply in the latter and an oversupply in the former (Mirasol, 2020).
On a similar note, sudden panic from COVID-19 outbreak has caused people to buy and even hoard face masks and alcohols reaching to a point of shortage. There were unscrupulous traders reported to be hoarding these supplies and selling them beyond their regular prices (Geducos, 2020). But a more significant economic impact of this disease includes sharp decline in trade and tourism (CNN Philippines, 2020b)
Meanwhile, the case of bird flu this year was emphasized by the Department of Agriculture to be an isolated case which affected a quail farm (Reuters, 2020). Given this, there was no evident effect in the supply, demand and price of poultry products particularly chicken.
What the industry can learn
As we know, a disease can successfully enter a farm with breach in its biosecurity. Being a farm’s first line of defense, biosecurity should always be given importance. As the saying goes, “Prevention is better than cure”, there is no better and more efficient mode of prevention than strict biosecurity practices and proper human hygiene especially in cases of diseases without primary treatment like ASF, AI and COVID-19.
During a disease, fear and panic seems to be the first response. Fake news is becoming more and more rampant as people are not well-informed. Industry personnel and the general public alike must be educated on how a disease is introduced, how it spreads, and how it can be prevented. They must also know its zoonotic potential in the case of an animal disease to avoid fear among consumers.
Most importantly, sick or affected individuals or population, whether animals or humans, must be reported. This is becoming a problem in the country as disease reporting is largely withheld to avoid panic. The current trend of disease detection and reporting in the country still relies on the presence of a large population of affected flocks, herds, or people. It must be realized that diseases are easiest to control when the affected are minimal in number.
References are available upon request.
Editor-in-Chief: Emily Angeles
Assistant Editor-in-Chief: Francis Carlo Reyes
Research Team: Harrah Grace Magsino, Lawrence Patrick Amistoso, Kristiana Jil Meg De Castro, Medallaine Dimaiwat
Dixie Grace Mendoza
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