Human cysticercosis is a neglected tropical parasitic zoonotic disease with high public health concerns. Infection of Taenia solium cysticerci in the brain commonly known as neurocysticercosis is a cause to over 29% of all epileptic cases in endemic countries. Unfortunately, this infection can go unnoticed for over 10 years. The objective of this review was to characterize the diagnostic approaches accessible in endemic poor resource countries. The review sought literature from library catalogues and public databases for studies on epidemiology and diagnosis challenges of human cysticercosis. The search key words included “ Taenia solium, T. solium cysticercosis, human cysticercosis, neurocysticercosis and diagnosis”. Most of the diagnostic procedures rely on serology. Neuroimaging tools which would confirm and thus enable the assessment of the burden of the disease in endemic countries are rarely used. Therefore assessing the estimate on prevalence and burden of the disease fallacious is owing to the low sensitivity of serological tools and the inhibition of humoral, cellular immune responses, inflammatory reaction and cytokines by the living cysticerci.
Human cysticercosis (HCC) refers to the infection by the larval form of Taenia solium, the pork tapeworm. Records on pork tapeworm date back to 1500 BC and it has been recognized as one of the earliest human parasites which possibly evolved before the domestication of pigs [
The review was based on life databases (HINARI and AGORA), library catalogues and electronic databases such as PubMed, Google Scholar using the key words “Taenia solium, T. solium cysticercosis, human cysticer- cosis, neurocysticercosis and diagnosis”. Only those articles or publications in English or Kiswahili language were considered however, final reporting was in English. 282 citation articles were screened and selected for re- view of their abstracts. A total of 98 publications were selected for full review. The inclusion criteria considered all articles that reported on the epidemiology of Taenia solium cysticercosis (TSC), prevalence, diagnosis and control of HCC. After reviewing the full texts, only 58 studies fully met the inclusion criteria.
Human cysticercosis is one of the neglected tropical diseases alongside echinococcosis, filariasis, rabies, brucellosis, anthrax, leptospirosis and several others [
Human cysticercosisis endemic in China, Southeast Asia, India, Africa and Latin America [
The epidemiology of HCC is associated with residence in endemic areas, frequent travel to endemic areas and or household contact [
High incidences of HCC have been reported in Latin America, Asia and Africa. In some regions of Mexico, HCC prevalence reaches 3.6% in the general population [
The detection of human cysticercosis is one of the keys to the management of the disease [
With regard to
Despite the problems related to awareness and neuroimaging diagnostic tools in endemic poor resource coun- tries, this review shows that the T. solium cysticerci inhibit IFN-γ and IL-2, and to a lesser degree IL-4 production [
Test | Case | Country/Region | Source |
---|---|---|---|
Sero-Screening, CT Scan | Neurocysticercosis | Nepal | [ |
CT Scan, MRI and Biopsy | Multiple tonics-chronic seizures vs neurocysticercosis | United States of America | [ |
Sero-Screening | Epilepsy as indirect marker for neurocysticercosis | Laos, South-East Asia | [ |
Autopsy and Sero-Screening | Human cysticercosis | Central and West Africa | [ |
Sero-Screening, X-Ray and Autopsy | Human cysticercosis | Togo and Benin | [ |
Sero-Screening and CT Scan | Human cysticercosis | Cameroon | [ |
Sero-Screening | Human cysticercosis | Burundi | [ |
Sero-Screening, CT Scan and Autopsy | Human cysticercosis | Eastern and South Africa | [ |
X-Ray and Sero-Screening | Human cysticercosis | Zimbabwe | [ |
Sero-Screening | Human cysticercosis | Mozambique | [ |
Sero-Screening | Human cysticercosis | Madagascar | [ |
Sero-Screening | Human cysticercosis | Kenya | [ |
Serology and Cerebral Spinal Fluid (CSF)-Screening, CT Scan | Human cysticercosis/neurocysticercosis | Tanzania | [ |
The literature reviewed has shown that limitations on facilities required for diagnosis of HCC, the unnoticed long-life of the parasite in the human body and low public awareness on the transmission drivers for the disease contribute to its persistence. However, even if neuroimaging tools were available, they are unaffordable and inaccessible to the common person from endemic developing countries. Furthermore, the inconsistence of the sero-screening technique(s) widely used in endemic poor resource countries undermines the resulting estimates on prevalence of the disease. This is because of the low sensitivity of the tools for the diagnosis of HCC. Efforts must therefore, be invested in developing cheap, easily accessible, reliable, sensitive, specific and environmentally stable tools for the diagnosis of T. solium cysticercosis in both definitive host, humans and intermediate host, pigs. Also awareness creation among the medical, veterinary and community development sectors and the general public on the epidemiology and risk factors of HCC is of paramount importance.
This review was carried out within the framework of the consortium Afrique One “Ecosystem and Population Health: Expanding Frontiers in Health”. Afrique One is funded by the Wellcome Trust (WT-087535MA) and the University of Dar es Salaam hosted and facilitated the project. The contents are the responsibility of author and do not necessarily reflect the views of sponsors.