Dos and Don'ts of Sendai and SDA Quarantine
From the RMCA web site, August 2002
Sendai infects rats, mice, hamsters, and guinea pigs; SDA infects rats. Sendai and SDA are transmitted by direct contact and aerosol.
DO quarantine your rats, mice, hamsters, and guinea pigs. "Quarantine XXXX" here and herein means XXXX is/are not allowed to (1) touch or (2) share air with (3) any other rat, mouse, hamster, or guinea pig.
Sendai and SDA infections are extremely common. To control Sendai and SDA infections, laboratories use incredibly strict quarantines (workers in gowns, gloves, booties, and respirators; HEPA filters; laminar air exchange systems; filter cages; etc.) coupled with elaborate health surveillance programs (routine serological testing, sentinel animals, etc.), yet Sendai and SDA infections have been found in, respectively, 52% and 68% of US laboratory rat colonies tested.
DON'T think Sendai and SDA can't happen to you.
DON'T think quarantine is a guarantee. While quarantine SIGNIFICANTLY reduces risk of infection, it does not completely eliminate the risk.
Sendai and SDA are often carried subclinically-infected mice and rats exhibit no clinical symptoms and appear to be healthy.
DON'T assume other mice and rats that look and sound healthy are Sendai- or SDA-free.
DO assume all other mice and rats are infected with Sendai and SDA; "new" and "infected" are herein used interchangeably.
Sendai is a respiratory viral disease, and clinical signs include chattering, mild respiratory distress, and poor growth or death in babies. SDA is both a respiratory and digestive system viral disease, affecting primarily the function of the salivary and lacrimal glands, and clinical signs include swelling of the head and neck regions, discharge from the nose and eyes, and eye lesions. Sendai or SDA alone rarely kills.
Both Sendai and SDA, however, act synergistically with Myco to produce severe clinical respiratory disease. Both viruses also suppress immune function, leaving the rats and mice vulnerable to other opportunistic secondary infections. Most often, these secondary infections are what kill. Aggressive antibiotic treatment will do nothing for Sendai, SDA, or other viral infections, but will control these secondary bacterial infections.
DO watch new/infected rodents closely for signs of ANY clinical disease. IMMEDIATELY treat clinical disease with aggressive antibiotics and supportive care (bronchodilators, oxygen, antiinflammatories, etc.) and, in the case of eye lesions, eye ointments.
DO watch all other rodents under your care closely for signs of ANY clinical disease. IMMEDIATELY treat clinical disease with aggressive antibiotics and supportive care (bronchodilators, oxygen, antiinflammatories, etc.) and, in the case of eye lesions, eye ointments.
The Sendai and SDA viruses themselves are eliminated from a single infected mouse or rat within a few days after infection. The Sendai virus remains detectable in a single infected mouse up to ~12 days after infection and in a single infected rat up to ~9 days after infection; the SDA virus remains detectable in a single infected rat up to ~6 days after infection. Once Sendai and SDA viruses are eliminated/no longer detectable, the previously infected mouse or rat is nominally considered to be sendai- and SDA-free and no longer contagious.
DO quarantine a single new/infected mouse for 3 weeks and a single new/infected rat for 2 weeks.
In addition to the time it takes the virus to be eliminated in each individual rodent, there exists a finite time needed for transmission of the virus from one rodent to another. Quarantine must be long enough to assure virus infection and virus elimination in each and every rodent under quarantine. The time needed for this to occur is primarily a function of (1) number of rodents under quarantine, (2) susceptibility of rodents being quarantined, and (3) environmental conditions. In the laboratory setting, each non-breeding group of new/infected rodents is quarantined for 6-8 weeks. Upon completion of this quarantine, the group is nominally considered to be Sendai- and SDA-free.
DO quarantine a non-breeding group of new/infected mice for longer than 3 weeks and a group of new/infected rats for longer than 2 weeks. Quarantine must be long enough to assure virus infection and virus elimination in each and every rodent under quarantine.
Maternal antibodies, temporary antibodies inherited from mom, provide newborn pups with passive immunity to Sendai and SDA. Once levels of maternal antibodies wane, however, babies become susceptible to active Sendai and SDA infection. When this occurs (i.e., when they become infected) is not clear, hence in the laboratory setting, all pups within a breeding group of new/infected rodents are destroyed during the quarantine period. In the laboratory setting, each breeding group of new/infected rodents is quarantined for 6-8 weeks, but all breeding is stopped and all pups are destroyed during the quarantine period. Upon completion of this quarantine, the group is nominally considered to be Sendai- and SDA-free.
DO quarantine a breeding group of new/infected rodents for 2 months longer than you would for a similar-sized non-breeding group, with no breeding during the quarantine period. A breeding group of new/infected rodents is any group of rodents, which, at time of acquisition or infection, includes rodents both older and younger than 4 weeks of age (including unborn).
Sendai or SDA infection confers active immunity to the respective diseases for several (6-15) months after infection, but at a heavy price. Sendai and SDA, when complicated by Myco, results in severe clinical disease. Many lives are lost, and permanent lung and eye damage is common among the survivors.
QUARANTINE SIGNIFICANTLY REDUCES THE RISK OF INFECTION BY SENDAI AND SDA.
In loving memory of Minnie.
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Morein, B., Abusugra, I., and Blomqvist, G., Immunity in Neonates, Vet. Immun. Immunopath. 87, 207-213 (2002).
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