With a very low mudcake permeability, e.g., 10−3 mD, the stresses become very close to those of an impermeable wellbore, implying a lower risk of lost circulation.
This may lower the risk of lost circulation, and also improve the chance of successfully cementing casing and achieving zonal isolation.
This result qualitatively agrees with the observation of experimental studies that a mudcake can effectively increase the sustainable pressure of a wellbore and reduce the risk of lost circulation (Cook et al. 2016).
Correlation between the populations at greatest risk of undetected circulation and poor surveillance quality suggest the need to specifically focus on underserved areas.
Some sera from farms with a long history of immunization with DIVA vaccines and where the risk of viral circulation was very low produced positive results when tested with a commercial gE blocking ELISA.
Although the risk for further transmission of iVDPV is relatively low, potential risk for circulation of iVDPV strains always remains.
As in the case of the chikungunya outbreak in 2005 2006 in Mayotte, thought to have started in Lamu, Kenya (13 ), RVFV circulation illustrates once again the risk of introduction or circulation in Mayotte or other Comorian islands of infectious agents involved in outbreaks in neighboring eastern African coastal countries (14 ).
Countries will need to maintain vigilance in their surveillance for polioviruses and recognize that their risks of undetected circulation may differ as a function of their efforts to manage population immunity and to identify cases or circulating live polioviruses.
As we consider the prerequisites for OPV cessation and approach key decision points, countries will need to recognize that increasing population immunity and the actual quality of surveillance will impact the risks of undetected circulation and the confidence associated with different time periods of no observed cases.
The authors stated a possible explanation; older patients have wider subarachnoid spaces which can hold larger amounts of subarachnoid blood, thus increasing their risk of developing CSF circulation disturbances.
