Stool for virus

Objectives: Aetiological diagnosis of poliovirus and other enteroviruses, rotavirus and adenovirus infections by demonstration of the organism in faeces by serological techniques and cell culture.

Test material: Faeces, 4-8 gm (approximately 5 mL).

Collection time: The excretion of virus in faeces is maximal in the first four days of illness, but the virus may still be excreted for several days or weeks (poliovirus). For poliovirus it is recommended that two samples be taken from each patient 24-48 hours apart.

Equipment: Clean specimen tube, viral transport medium (see Appendix 2).

Procedure: 1. The stool should be collected either directly into the container, or in a clean bedpan.

2. It should then be transferred to a suitable specimen tube provided with a leak-proof lid. The specimen should not be contaminated with urine.

3. If a rectal swab has to be used, the swab should be suspended in 2 mL of saline buffer.

Storage: Refrigerated (2-8 °C).

Transportation: Preferably in a cooling box (2-8 °C).

Reporting: In case direct antigen detection methods are available (poliovirus, rotavirus, adenovirus) the results will be ready within hours. The results of cell culture will take at least 7-10 days.

Comments: The antigen detection tests are less sensitive than the cell culture technique. Culture and direct antigen detection for poliovirus should preferably be confirmed by serology. Positive isolation of poliovirus will be sent for intratypic differentiation.

Rotavirus is seen mainly in toddlers and small children, between six months and 2 years of age. The disease decreases in prevalence up to 10-12 years of age. It is rare in newborns and adults.