High Prevalence of Calcified Silent Neurocysticercosis in a Rural Village of Mexico

Abstract

Human neurocysticercosis (NC) is a parasitic disease caused by Taenia solium when its larvae lodge in the central nervous system. NC prevalence estimates are obscured by the variable and often asymptomatic clinical picture. While infection depends on exposure, severity is possibly related with various host factors (immunity, genes and gender). This epidemiological study of cranial CT scans in an endemic rural community found that 9.1% of apparently healthy subjects had calcified lesions and were completely asymptomatic. Silent NC cases did not correlate with the exposure factors tested but showed family aggregation and higher rates of positive serology. Thus, NC prevalence may be higher than currently considered and host-related factors appear to be involved in infection and pathogenesis.

Therapy for neurocysticercosis

“…The descriptions of spontaneous resolution of parenchymal cysticercosis with benign evolution, risks of complications and reports of no long-term benefits have reinforced the debate over the usefulness and safety of anticysticercal therapy [39,41,42,44,45]. Some authors are of the opinion that most of the available data describing the effectiveness of anticysticercal treatment are from retrospective studies and that these studies have a significant selection bias.…”

Edema surrounding calcified intracranial cysticerci: clinical manifestations, natural history, and treatment

“…4 Although there is considerable variability in size and shape, calcifications are typically small and round. The number of calcified cysts varies considerably in any individual: 1-2 is usual, [5][6][7] but there may be hundreds.…”

The Role of Sex Steroids in the Host-Parasite Interaction

“…Human's immunological contact with any of T. solium's developmental forms is likely to induce an immune response. The high mean prevalence of seropositive individuals in the open population of Mexico (~1%) , when compared with the presumed prevalence of neurocysticercosis (~0.1 to 10%) (Fleury et al, 2003;, is taken to indicate that very few of the contacts result in the establishment of the cysticercus in the tissues of humans and less so in their brains. In view of the many weaknesses of such numbers and assumptions lacking the objective finding of the parasite in the suspected human cases it's somewhat adventurous to interpret them as signs of sexual dimophism in human disease, even if significant differences in serological prevalence favor women over men in Mexico .…”