Pasted

select count(*) as pcr_postive_pcr2_positive_and_pcr1neg__on_arv from (
 select b.* from (
 SELECT id_patient,pcr_result FROM testing_specimen where pcr_result=1 and which_pcr=2 and  id_patient  in ( 
 SELECT ab1.id_patient from (
 SELECT id_patient,pcr_result FROM testing_specimen where pcr_result<>1 and which_pcr=1 
 union select id_patient,result as pcr_result from testing_result where result<>1 and which_pcr=1
 ) ab1
 )
 union select id_patient,result as pcr_result from testing_result where result=1 and which_pcr=2 and  id_patient  in ( 
 SELECT ab2.id_patient from (
 SELECT id_patient,pcr_result FROM testing_specimen where pcr_result<>1 and which_pcr=1 
 union select id_patient,result as pcr_result from testing_result where result<>1 and which_pcr=1) ab2)
    ) b 
 left join tracking_regime r on r.id_patient=b.id_patient
 where r.id is not null group by b.id_patient
    ) a