J C Allan

Bio: J C Allan is an academic researcher from University of Salford. The author has contributed to research in topics: Echinococcosis & Echinococcus multilocularis. The author has an hindex of 2, co-authored 2 publications receiving 243 citations.

Detection, screening and community epidemiology of taeniid cestode zoonoses: cystic echinococcosis, alveolar echinococcosis and neurocysticercosis.

Abstract: Publisher Summary This chapter focuses on the public health importance of taeniid cestode zoonoses especially cystic echinococcosis, alveolar echinococcosis and T. solium cysticercosis. The chapter addresses the problem of neurocysticercosis and epilepsy in developing countries particularly Latin America and its public health consequences in the USA and elsewhere. E. multilocularis , which is the cause of one of the most pathogenic of all human parasitic infections, appears to be spreading in parts of western Europe, USA, and Japan. The remarkable development in the past 20 years or so of high resolution imaging technologies, such as computerized tomography (CT) scan and ultrasound have enabled precision detection of taeniid larval cystic infection in humans. Coupled with improvements in immunodiagnostic test sensitivity and antigen specificity, diagnosis of cestode zoonoses is now more accurate than ever before. Although further developments in immunodiagnosis are required, laboratory tests have provided improved capability for screening populations in both epidemiological and community studies. Parallel and recent development of genus specific coproantigen tests for human taeniasis and canine echinococcosis have also provided major new tools for epidemiological and surveillance programs.

Immunoblot evaluation of IgG and IgG-subclass antibody responses for immunodiagnosis of human alveolar echinococcosis.

Abstract: Antigen binding of total-IgG and IgG-subclass antibodies from patients with alveolar or cystic echinococcosis (AE and CE) was assessed by immunoblotting. Antigen extracts were prepared from Echinococcus multilocularis protoscoleces (EmP) or from homogenized E. multilocularis metacestode tissue (EmCH). Antigens of approximately 44, 35, 21, 17.5 and 16.5 were recognized by total-IgG and IgG1- and IgG4-subclass antibodies in some of 50 human AE sera from China, Japan or France. The 44- and 35-kDa polypeptides, present in both EmP and EmCH extracts, were recognized by total-IgG antibodies in sera from 82% and 66% of the AE patients, respectively. However, over 30% cross-reactivity occurred between these two antigens and sera from CE and Taenia solium cysticercosis patients. The immunoblot specificities of the 27-, 21- and 17.5-kDa antigens in EmP for E. multilocularis infection were 73%, 88% and 93%, respectively. Recognition of the 17.5-kDa antigen in the EmP immunoblot was much higher for the Japanese AE cases (11/13; 85%) than for the French (9/19; 47%) or Chinese (9/18; 50%) AE cases. None of the CE cases from Uruguay or Libya, where human AE has not been reported, was seropositive for the 17.5-kDa antigen. Antibodies from three (7.3%) of the 41 Chinese CE cases recognized the 17.5-kDa antigen. Within the 13 Japanese AE sera, the combined detection by IgG1, IgG4 and total-IgG antibodies of the 27-, 21- and 17.5-kDa antigens in either EmP or EmCH immunoblots was greater than that by each class/subclass alone, increasing the overall sensitivity for AE patients. A combined ELISA/immunoblot approach, including IgG-subclass detection using E. multilocularis protocolex or cyst extracts, could be useful for the differential diagnosis of human alveolar echinococcosis. An algorithm for such an approach is given.

Prevention and control of cystic echinococcosis

Abstract: Human cystic echinococcosis (hydatid disease) continues to be a substantial cause of morbidity and mortality in many parts of the world. Elimination is difficult to obtain and it is estimated that, using current control options, achieving such a goal will take around 20 years of sustained efforts. Since the introduction of current (and past) hydatid control campaigns, there have been clear technological improvements made in the diagnosis and treatment of human and animal cystic echinococcosis, the diagnosis of canine echinococcosis, and the genetic characterisation of strains and vaccination against Echinococcus granulosus in animals. Incorporation of these new measures could increase the efficiency of hydatid control programmes, potentially reducing the time required to achieve effective prevention of disease transmission to as little as 5-10 years.

How much human helminthiasis is there in the world

Abstract: The impact of Norman Stoll's presidential address to the American Society of Parasitologists in Boston at Christmas time in 1946 has been and continues to be immense. Since its publication in 1947, have any helminthologists not read it? Have any parasitology text books not cited it since then? Does any parasitology course today not refer students to it? Despite our expanding knowledge of DNA, molecular biology, and immunology and the application of mathematical techniques to our understanding of epidemiology and helminth population biology, Stoll's appraisal of the wormy world still excites and challenges our imaginations. A measure of the influence of Stoll's paper is the fact that we regularly use the title of "This Wormy World" as we seek to draw attention to the global public health significance of human helminth infections. CRC Press reprinted the paper (renamed as "The Wormy World") and supplied a commentary in each of a series of volumes dealing with zoonoses (CRC, 1982). The World Health Organization used the same title for an issue of its official magazine (WHO, 1984) and recently Parasitology Today devoted an issue to revisiting the subject of "This Wormy World" in which Bundy (1997a) explained why Stoll's paper has been supremely important in directing our approach to the study and management of human helminth infections and colleagues evaluated the current status of several major helminthiases. Only last year, Bundy and de Silva (1998) again wrote about this wormy world, this time with themes of optimism and encouragement over prospects for control. In this article, I have sought to place Stoll's evaluation of human helminthiasis in a contemporary setting. I have tried to address some of the questions he asked and to review aspects of current progress in the control of human helminthiasis. Most of all, I hope this paper will be seen as a tribute to Stoll's inspirational leadership and will serve as a reminder of our need to tackle what he saw as an "unremittingly corrosive" burden of disease.

Concepts in Immunology and Diagnosis of Hydatid Disease

Abstract: Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Both CE and AE are both serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review discusses new concepts and approaches in the immunology and diagnosis of CE, but comparative reference has also been made to AE infection and to earlier pivotal studies of both diseases. The review considers immunity to infection in the intermediate and definitive hosts, innate resistance, evasion of the immune system, and vaccination of intermediate and definitive hosts, and it particularly emphasizes procedures for diagnosis of CE and AE, including the value of immunodiagnostic approaches. There is also discussion of the new advances in recombinant and related DNA technologies, especially application of PCR, that are providing powerful tools in the fields of vaccinology and molecular diagnosis of echinococcosis.