Module 5: Management and Prevention of Disease Outbreaks
Successful life-saving strategies for managing disease outbreaks include the following basic steps.
Steps for Management of Disease Outbreaks
- Diagnosis of the disease
- Isolation of sick animals
- Quarantine of exposed asymptomatic animals
- Assessment of infection risk in exposed animals
- Create a clean break to prevent exposure of more animals
- Biosecurity and environmental decontamination
Please note that while these are listed as steps, the responses occur simultaneously. The overarching goal of the management strategy is to create an effective break between the infected/exposed population and the unexposed population without resorting to mass depopulation via euthanasia. This strategy is effective in minimizing in-shelter transmission of infection. The success is totally dependent on staff adherence to the necessary steps involved. Staff that disregard or “make exceptions” to the decisions required for each step will undermine any success by assuring continual transmission of disease, prolonged resolution, increased financial burden, public scrutiny, and ultimately the loss of more lives than was necessary.
Review the Disease Outbreak Management in Shelters document to learn more about common causes of disease outbreaks in shelters and the strategic steps for successfully managing these outbreaks while maximizing the saving of lives.
- Crowding caused by ineffective population management is the most important and common risk factor for a disease outbreak.
- Leaving sick animals in the general population is another important and common cause of disease outbreaks.
- Canine parvovirus, feline panleukopenia, canine and feline viral respiratory pathogens, and feline ringworm are the most common causes of disease outbreaks in shelters.
- The overarching goal of a successful disease outbreak management strategy is creation of an effective break between the infected/exposed population and the unexposed population without resorting to mass depopulation via euthanasia.
- Diagnosis is essential for successful control and resolution of disease outbreaks. All the steps for management and resolution depend on knowing the pathogen and its properties.
- Diagnostic testing should be conducted on sick animals and asymptomatic exposed animals at a time when pathogen shedding is highest. For parvoviruses and respiratory pathogens, the largest amounts of shedding occur during the preclinical incubation period and the acute phase of illness (sick for ≤4 days).
- Diagnostic tests that detect the pathogen in some body secretion or excretion are more desirable than those that detect antibodies to the pathogen since this approach is easily confounded by prior vaccinations or exposures.
- Prompt relocation of sick animals from the general population to isolation housing is the single most important step in containing a communicable disease outbreak.
- Infected animals should be isolated for the duration of pathogen shedding.
- All exposed animals should be considered an infectious risk regardless of vaccine status and quarantined to protect other animals from exposure.
- The quarantine time is equal to the pathogen’s maximum incubation period.
- Quarantined animals should be monitored twice daily for clinical signs. Sick animals should be promptly moved to isolation and the quarantine clock re-started for the remaining animals since there was a new exposure.
- Quarantined animals can be assessed for their risk of infection based on testing for protective levels of antibodies to the pathogen or testing for the pathogen itself. This provides a humane and cost-effective strategy for quickly moving animals out of quarantine, thereby relieving the strain created by utilizing housing for quarantine.
- When caring for animals in quarantine and isolation, staff must wear PPE consisting of full-length gowns or scrubs that completely cover arms and legs, hair cover for long hair, rubber boots, and gloves.
- The cornerstone for prevention of further spread of infection is creation of a clean break. This is defined as protection of unexposed animals and new arrivals from exposed or infected animals.
- Disinfectants that kill the parvoviruses, feline calicivirus, and feline ringworm should be used in all housing areas – household bleach, Wysiwash, and Accel/Rescue are 3 reliably effective disinfectants.
- Several disease outbreak parameters should be documented to aid in diagnosis, to determine whether the infection was contracted outside of the shelter or acquired in the shelter, for containment strategy planning, to assess the effectiveness of the strategy, and identification of the weakness in the system that enabled the outbreak.
- Proactive transparent communication about a disease outbreak within the shelter and the control strategy being used provides an opportunity to disseminate accurate information to shelter staff as well as community stakeholders such as adopters, rescue groups, and veterinarians.
- A written statement describing the disease, what animals are at risk, and the transmission modes should be provided to all shelter staff, including managers, directors, and public information officers.
- By convention, a disease outbreak is declared over when a period of twice the incubation period of the pathogen has elapsed without identification of any new cases.