Butler (Reference Butler2006) emphasises the importance of psychiatrists being aware of prion disease. We feel that psychiatrists in low- and middle-income countries also need to be aware of these disorders. The low prevalence rate in such countries might be attributable to underdiagnosis and underreporting. Prion diseases are not included in the list of notifiable diseases in countries such as Sri Lanka and even diagnosed cases are not notified.

Butler & Fleminger (Reference Butler and Fleminger2001) stated that approximately two-thirds of patients with new-variant Creutzfeldt–Jakob disease (CJD) present with psychiatric symptoms such as anxiety, depression, apathy and withdrawal. Somatic symptoms are a common presentation of depression in countries such as Sri Lanka. Even neurological symptoms such as pain and headache can be features of depression and the diagnosis of prion disease might be easily missed.

Two cases of prion disease have been diagnosed in the psychiatry unit at North Colombo Teaching Hospital over the past 10 years. Both patients were referred for the assessment of depression and later developed neurological symptoms such as myoclonus. Electroencephalography revealed a characteristic pattern of CJD (further details available from the authors). Other patients with CJD who presented with psychiatric symptoms have been reported from different units in Sri Lanka (Reference Gunathilake, de Silva and JayamanneGunathilake et al, 1998). All these cases appear to be of the sporadic type.

Although CJD is a known cause of dementia, a patient presenting with dementia might not always be investigated for prion diseases because of the perceived low prevalence of the disease in low- and middle-income countries.

Moreover, CJD is a transmissible disease, and a lack of awareness of its true prevalence might lead to a lax attitude regarding precautions against spread. Prion protein is not destroyed by ordinary sterilisation procedures but requires sophisticated methods of sterilisation which might not be available in low- and middle-income countries. Prion diseases can also be transmitted through meat. Although there are regulations regarding meat production and sale, these are not strictly adhered to in most low- and middle-income countries, so although prion diseases might not be common in these countries, the risk of transmission might be higher. Furthermore, the healthcare systems might be unprepared to meet the challenges of an epidemic. Therefore, it is important to raise awareness of prion diseases among clinicians worldwide.