We work with a number of clinical labs and don't know of any lab that test for all three strains of polio. Why has polio type 2 testing been dropped by most labs?
Since October, 1999, wild poliovirus type 2 has not been detected in community-acquired infection anywhere.
Every major lab we work with do not have testing polio 2 as an option. Only 1 and 3 are tested for because as of the global eradication of polio 2. Last case was found in 1999. Local schools and health departments may ask for all 3 but its only because they have not updated their policies. Below are links to articles regarding the eradication of polio 2.
Global Commission for the Certification of Poliomyelitis Eradication (GCC) today concluded that wild poliovirus type 2 (WPV2) has been eradicated worldwide. The GCC reached its conclusion after reviewing formal documentation submitted by Member States, global poliovirus laboratory network and surveillance systems. The last detected WPV2 dates to 1999, from Aligarh, northern India.
Among the remaining polioviruses, WPV3 was last reported in Nigeria in 2012. The only remaining WPV1 strains are now restricted to Pakistan and Afghanistan. The Global Commission for the Certification of Poliomyelitis Eradication met on 21 September in Bali, Indonesia, and after reviewing formal documentation submitted by Member States, global poliovirus laboratory network and surveillance systems officially declared the worldwide eradication of WPV2. This is a significant step towards the phased removal of oral polio vaccines (OPVs), beginning with a planned switch from trivalent OPV (for all three polioviruses) to bivalent OPV (for polioviruses type 1 and type 3) in April 2016.