Such claims have been examined extensively in the peer-reviewed medical and scientific literature; a scientific consensus has arisen that denialist claims have been convincingly disproved, and that HIV does indeed cause AIDS. In the cases cited by Duesberg where HIV "cannot be isolated", PCR or other techniques demonstrate the presence of the virus, and denialist claims of HIV test inaccuracy result from an incorrect or outdated understanding of how HIV antibody testing is performed and interpreted. Regarding Koch's postulates, "New Scientist" reported: "It is debatable how appropriate it is to focus on a set of principles devised for bacterial infections in a century when viruses had not yet been discovered. HIV does, however, meet Koch's postulates as long as they are not applied in a ridiculously stringent way". The author then demonstrated how each postulate has been met – the suspected cause is strongly associated with the disease, the suspected pathogen can be both isolated and spread outside the host, and when the suspected pathogen is transmitted to a new and uninfected host, that host develops the disease. The latter was proven in a number of tragic accidents, including an instance when multiple scientific technicians with no other known risk factors were exposed to concentrated HIV in a laboratory accident, and transmission by a dentist to patients, the majority of whom had no other known risk factor or source of exposure except the same dentist in common. In 2010, Chigwedere and Max Essex demonstrated in the medical journal "AIDS and Behavior" that HIV as the cause of AIDS fulfills both Koch's postulates and the Bradford Hill criteria for causality.