Environmental surveillance of Polio and Non-Polio Enteroviruses in Sistan and Balouchestan Province

Enteroviruses can easily circulate in the population through sewage and they are suitable indicators for environmental surveillance. On the other hand, in some countries there are evidences of silent circulation of viruses in sewage specimens despite no virus isolation from clinical specimens. Therefore, WHO has suggested environmental surveillance using surface water and sewage specimens for final confirmation of Poliovirus eradication. In this research, according to wild Poliovirus circulation in Afghanistan and Pakistan and probability of virus entrance to Iran, and also to assure wild Poliovirus eradication, the environmental surveillance was performed in Sistan and Balouchestan Province of Iran. From March 2004 to February 2005, 86 specimens from 2 sewage disposal systems, 5 hospitals and surface water from several villages were collected by Grab Sample method and tested for Enteroviruses directly and using 2 concentration methods: Pellet and Two-phase. Then Poliovirus and Non-Polio Enteroviruses [NPEV] were serotyped by microneutralization method and Polioviruses were intratypically differentiated using ELISA and Probe Hybridization techniques. From a total of 86 specimens, Enteroviruses and Non-Polio Enteroviruses were isolated from 49[56.98%] and 46[53.49%] of specimens respectively. Polioviruses were isolated from 18[20.93%] specimens and none of them was wild Poliovirus fortunately. 13[17.81%], 39[53.42%] and 57[78.08%] of enteroviruses were isolated using Direct, Pellet and Two-phase methods, respectively. The results of this research confirm the validity of environmental surveillance and Polio eradication in Sistan and Balouchestan Province

[Assessment of different methods to remove organic inhibitors in order to create a sensitive method for direct surveillance of enteroviral infectious diseases in sewage specimens]

Enteroviruses in sewage are considered among the most sensitive indicators for virus circulation in society. These are mainly detected by sensitive cell cultures, however, since it is time consuming, molecular direct methods have also been considered as sensitive techniques. This study accomplished to assess different methods of removing organic inhibitors of sewage in order to detect Enteroviruses with RT-PCR. For this cross sectional study, 63 sewage specimens of Tehran were prepared with Grab sample method and concentrated with Pellet and Two-Phase methods and cultured in RD and Hep-2 cells. Then, with 12 different methods, removing organic inhibitors in sewage with RT-PCR method was assessed. Of investigated methods, we succeeded to isolate all of expected viruses only with the use of ICC-RT-PCR method. With respect to 0.01 TCID50 sensitivity of ICC-RT-PCR method, further studies are strongly recommended in order to confirm the utility of this method as one of the most sensitive methods of detecting Enteroviruses