SOPs

Sample Collection, Management and Treatment Procedures for Pinworm Outbreaks in Mice and Rats

Unit for Laboratory Animal Medicine
Apr 15, 2016 12:00 am

Syphacia sp. and Aspiculuris sp. are different species of pinworms, a parasite that can infest rodents. Both can be eradicated using an ivermectin or fenbendazole treatment regimen.

  • Procedures

    1. Background

    Species of Pinworm

    Time to Egg Infectivity

    Prepatent Period

    Aspiculuris tetraptera

    5 - 8 days

    21 - 25 days

    Syphacia muris

    5 - 20 hours

    7 - 8 days

    Syphacia obvelata

    5 - 20 hours

    11 - 15 days

    1. The use of individually ventilated caging (IVC) and microisolation technique reduces transmission and propagation of pinworm eggs.
    2. Treatment start date will be indicated on the bottom of the red contamination sign on the room door. Once finished, a yellow contamination sign is posted.
    3. New entry procedures are as follows: All new personnel protection equipment must be donned before entering the animal housing room including gown, gloves, hair bonnet and shoe covers. Nothing unnecessary should be worn or taken into the room (hats, book bags etc.). This will help reduce the spread of pinworm eggs. Gown, gloves, hair bonnet, and shoe covers should be discarded prior to leaving the contaminated room.
      1. If an employee is unable to wear PPE as required, departments provide alternate PPE if deemed to be at least as effective as the required equipment. If the employee is unable to wear PPE or an alternate is not acceptable to either party,then the employee will not be able to conduct the work tasks in which PPE is deemed necessary.
    4. Appendix A: Flowchart for Pinworm Outbreaks at the end of this document describes the procedures for the treatment and management of pinworm outbreaks.

    2. Sampling

    1. Routine sample collection, testing, and the issuing of outbreak reports will be performed according to the Rodent Health Surveillance SOP. The veterinarians will contact laboratories to inform them of the outbreak and determine a course for treatment according to the Procedures for Veterinary Outbreaks SOP.

    3. Treatment

    1. The following options are routinely used for treatment of pinworms:
      1. Ivermectin Oral Formulation:
        1. The source of oral ivermectin must be 10mg/ml concentration.
        2. Dilution: Each 8- and 16-ounce water bottle receives 0.5 ml and 1 ml ivermectin solution, respectively. A 1L carboy will receive 2.2ml ivermectin. 
        3. Table 1: Ivermectin Water Treatment Schedule (6 weeks) 

             Week   

             Friday

             1   

             Add treated water to cages. Water will stay on the cage throughout the week-end.   

             2   

             Add treated water to cages. Water will stay on the cage throughout the week-end.   

             3   

             Add treated water to cages. Water will stay on the cage throughout the week-end.   

             4   

             No Treatment. Complete Room Change Out. a Disinfect room.   

             5   

             Add treated water to cages. Water will stay on the cage throughout the week-end.   

             6   

             Treatment is complete.   

          a See Procedures section 4 below for further information on complete room change out.
    1. Fenbendazole Chow:
      1. The Harlan Teklad TD.01432 FB 150 ppm diet does not require refrigeration (standard non-irridiated diet ordered).
      2. Label the Fenbendazole chow with the expiration date.
      3. Take only what is needed for a change out into the room. 
      4. Table 2: Fenbendazole Chow Treatment Schedule (6 weeks) 

           Week   

           Monday

           1   

           Fenbendazole chow to be put in cage as sole source of food, enough until next Monday (half of hopper).   

           2   

           Change back to regular food.   

           3   

           Fenbendazole chow to be put in cage as sole source of food, enough until next Monday (half of hopper).   

           4   

           Change back to regular food. Complete Room Change Out. Disinfect room.   

           5   

           Fenbendazole chow to be put in cage as sole source of food, enough until next Monday (half of hopper).   

           6   

           Dump Febendazole chow and add regular chow. Treatment complete.   

        a See Procedures section 4 below for further information on complete room change out.

    4. Room Decontamination

    1. Complete change of room means changing the following:
      1. Cage bottoms
      2. Cage tops and accessories (including feeders, wire tops, micro isolator tops, cage card holders)
      3. Food
      4. Water bottles and sipper tubes
      5. Bedding, nesting and other enrichment material
      6. All room filters including wall, laminar flow hood and rack blowers
      7. Cleaning supplies including mop and broom
      8. All protective clothing such as gowns, gloves
      9. Racks and associated accessories (like hoses)
      10. Replacement of any other supplies which cannot be sanitized
    2. Husbandry performs a complete room change out during the fourth week of treatment. Based on preliminary environmental testing performed at the University of Michigan, only one complete change out is necessary to eliminate environmental pinworm contamination during the treatment phase.
    3. At the completion of treatment (after week 6), routine cage changing (i.e. cage bottom and feeders) every two weeks will resume.
    4. Vaporized hydrogen peroxide is another decontamination option that may be considered to sterilize or disinfect the animal room and/or equipment after treatment is completed. This method will kill pinworm eggs and effectively disinfect everything. When it is time to disinfect the room, place the animals in the hallway and cover them. Flowhoods may remain in the room during the decontamination process.
    5. Investigators are not allowed to remove animals on the day of change out. Animal care supervisors will notify labs of this prior to the change out day.
    6. Sentinel animals will be placed after treatment and room decontamination is complete and will be processed as per usual time frame.
    7. The husbandry supervisor will post room as Potentially Contaminated (yellow) status after treatment is completed. The husbandry supervisor or veterinary resident may contact labs to update them of the change in room contamination status. Once quarterly sentinel surveillance is performed and comes back negative, the room contamination status may be lowered to green (normal; white sign on door).
  • Related Documents

  • Appendix A: Flowchart for Pinworm Outbreaks

Species: Mice Rats