Julio Sotelo

A proposal to declare neurocysticercosis an international reportable disease

Neurocysticercosis is an infection of the nervous system caused by Taenia solium. It is the most important human parasitic neurological disease and a common cause of epilepsy in Africa, Asia, and Latin America, representing enormous costs for anticonvulsants, medical resources and lost production. Neurocysticercosis is a human-to-human infection, acquired by the faecal-enteric route from carriers of intestinal T. solium, most often in areas with deficient sanitation. Intestinal tapeworms cause few symptoms, but adult taeniae carried by humans release large numbers of infective eggs and are extremely contagious. Ingestion of poorly cooked pig meat infested with T. solium larvae results in intestinal taeniosis but not neurocysticercosis. With a view to hastening the control of taeniosis and neurocysticercosis we propose that neurocysticercosis be declared an international reportable disease. New cases of neurocysticercosis should be reported by physicians or hospital administrators to their health ministries. An epidemiological intervention could then be launched to interrupt the chain of transmission by: (1) searching for, treating and reporting the sources of contagion, i.e. human carriers of tapeworms; (2) identifying and treating other exposed contacts; (3) providing health education on parasite transmission and improvement of hygiene and sanitary conditions; and (4) enforcing meat inspection policies and limiting the animal reservoir by treatment of pigs. We believe that the first step required to solve the problem of neurocysticercosis is to implement appropriate surveillance mechanisms under the responsibility of ministries of health. Compulsory notification also has the major advantage of providing accurate quantification of the incidence and prevalence of neurocysticercosis at regional level, thus permitting the rational use of resources in eradication campaigns.

Comparison of therapeutic regimen of anticysticercal drugs for parenchymal brain cysticercosis

SummaryThe efficacy of different regimens of therapy for parenchymal brain cysticercosis either with praziquantel (PZQ) or with albendazole (ALB) was compared in 114 patients. Four schemes of treatment were used: PZQ 50 mg/kg per day for 15 days, PZQ 50 mg/kg per day for 8 days, ALB 15 mg/kg per day for 30 days, and ALB 15 mg/kg per day for 8 days. Three months after therapy, it was apparent that both PZQ and ALB were effective, as shown by the disappearance of cystic lesions in computed tomographic scans. Thirty-three control patients followed for a mean of 11 months had no spontaneous remission of lesions. When comparing PZQ with ALB, the latter was found to be more effective than the former for both the full and the short course of treatment: 85% vs 60% and 85% vs 48% disappearence of lesions, respectively (P<0.001). Comparison of the full vs the short course of PZQ showed that the short course had a further 12% reduction in durg effectiveness. In contrast, the length of ALB therapy could be shortened without lessening its efficacy. Based on these results, an 8-day course of ALB is recommended as treatment for parenchymal brain cysticercosis; a 15-day course of PZQ could be subsequently used in those patients who show only partial response to ALB.

A new complement fixation test for the diagnosis of neurocysticercosis in cerebrospinal fluid.

SummaryAs a modification of the classical complement fixation test, a new test for immunodiagnosis in cerebrospinal fluid (CSF) was developed. When the assay was used for the diagnosis of neurocysticercosis in 149 CSF samples from patients and 1036 from controls, results showed 93% concordance with positives and 97% with negatives when compared with the results obtained by ELISA; in addition, it was positive in 12 of 16 cases of neurocysticercosis in which negative results had been obtained by ELISA. The new complement fixation test is particularly useful in CSF because of the immunological peculiarities of the subarachnoid space, where local synthesis of oligoclonal antibodies is induced by infectious agents. Reagents used for the assay are easy to produce and preserve, and the test is inexpensive, reliable and easy to perform. As this test detects the immunobiological consequence of the antigen-antibody reaction, it can be used in conjunction with other assays, such as ELISA, that measure the reaction directly, thus increasing the diagnostic possibilities. It may also be used where financial or technical limitations hinder access to other immunodiagnostic tests.

Therapy of neurocysticercosis

The different manifestations of neurocysticercosis are classified and the appropriate therapy in each group is described.

NEUROCYSTICERCOSIS: AN UPDATE

Cysticercosis is the commonest parasitic disease of the central nervous system and is endemic not only in developing countries but in industrialized nations with high rates of immigration from endemic areas. Clinical manifestations of neurocysticercosis are non-specific and depend mainly on the number and the topography of the lesions, the host immune response to the parasite, and the sequelae of previous infections. Diagnosis is difficult on clinical grounds, but integration of data from computed tomography and cerebrospinal fluid analysis permits accurate diagnosis of most cases. Therapy for neurocysticercosis is also varied and must be individualized according to the activity of the disease and location of cysticerci. In this paper, the experience of the authors with neurocysticercosis is summarized and current information on several controversial aspects of this disease is reviewed.