Evaluation of an immunodot blot technique for the detection of antibodies against Taenia solium larval antigens

An Unusual Presentation of Intramuscular Cysticercosis in a Vegetarian Patient: A Case Report

Cysticercosis is a parasitic infection. It can involve any tissue in the body, the brain being the most common site. Intramuscular cysticercosis is rare, and few cases have been reported. Here, we are reporting a case of incidental finding of intramuscular cysticercosis in a 22-year-old male having a purely vegetarian diet presented with pain, swelling, and tingling sensation in the forearm without any other systemic involvement after taking Albendazole for unrelated reasons. Diagnosis of intramuscular cysticercosis remains a challenge and should be considered in the differential diagnosis of intramuscular swelling, especially in endemic areas.

Further evaluation of recombinant Tsol-p27 by enzyme-linked immunoelectrotransfer blot for the serodiagnosis of cysticercosis in pigs from Mozambique

BACKGROUND

Porcine cysticercosis has a negative impact on human health and the meat industry, as it makes infected meat unaproprieted for consuption and it is the main etiology of epileptic seizures in developing countries. There are multiple serological assays that use crude antigens with high sensitivity and specificity for the diagnosis of both porcine and human cysticercosis. Nonetheless, antigen preparation is time-consuming, needs a well-equipped laboratory and trained personnel and places those manipulating the meat at great risk for infection. New serodiagnostic approaches to the diagnosis of porcine and human cysticercosis have been directed towards the development of recombinant deoxyribonucleic acid technology for the generation of synthetic proteins that can serve as simplified, low-cost and harmless substitutes for native antigens. The aim of the present study was to further evaluate the recombinant Tsol-p27 protein as a target molecule in immunoassays for the serodiagnosis of porcine cysticercosis. From these data, we hoped to develop recommendations regarding its use in the serodiagnosis of porcine cysticercosis.

RESULTS

We studied a panel of 83 naturally infected pig sera from Angónia District, Mozambique, an endemic area for porcine and human cysticercosis. These sera were previously tested by antigen enzyme-linked immunosorbent assay (Ag-ELISA) to detect antigens of T. solium. The serum panel was processed by enzyme-linked immunoelectrotransfer blot (EITB) assay against the recombinant Tsol-p27 protein and the Ag-ELISA assay results were used to compare and evaluate the performance of Tsol-p27 for the diagnosis of cysticercosis. Out of 83 sera, 24 (29.0%) were positive for Tsol-p27 and 59 (71%) were negative in the same assay. From the 37 sera that tested positive to Ag-ELISA, 11 (13.3%) were positive to Tsol-p27, while from 46 sera that tested negative to Ag-ELISA, 33 (39.7%) also tested negative to Tsol-p27. The sensitivity and specificity of Tsol-p27 was 29.7% and 71.7%, respectively, while the positive predictive value and negative predictive value were 45.8% and 55.9%, respectively, as calculated using Medcalc® version 15.0 software (MedCalc Software, Ostend, Belgium).

CONCLUSION

While Tsol-p27 recombinant protein might be suitable for testing human sera, its performance in pigs is not acceptable, so other recombinant proteins should be evaluated alone or multiplexed.

Performance of Tsol-p27 antigen for the serological diagnosis of cysticercosis in Mozambique

The diagnosis of neurocysticercosis (NCC) requires expensive neuroimaging techniques that are seldom affordable for people in endemic countries. Accordingly, there is a need for new low-cost diagnostic methods that offer high sensitivity and specificity. In this study, we evaluated Western blot analysis of the previously described recombinant antigen Tsol-p27 in relation to a commercial or in-house enzyme-linked immunosorbent assay (ELISA) for NCC, and compared the results with those provided by a commercial enzyme-linked immunoelectrotransfer blot (EITB) assay, which was regarded as the reference standard method. The analysed serum samples were obtained from 165 people, 18 of whom were confirmed to be NCC positive by EITB. Comparing our Western blot analysis of Tsol-p27 with a previous evaluation performed in Central America showed similar specificity (96.69% versus 97.8%) and sensitivity (85.71% versus 86.7%). The present results indicate that the recombinant Tsol-p27 antigen provides good sensitivity and specificity, and might be preferable as a diagnostic antigen in poorly equipped laboratories in endemic countries.

Further characterization of Tsol-p27 as a diagnostic antigen in sub-Saharan Africa

Commercial antigens used to diagnose human neurocysticercosis are obtained from either a soluble parasite extract or a parasite-derived glycoprotein fraction. The aim of the present study was to identify antigenic proteins as potential diagnostic candidates in Mozambique. Soluble proteins from Taenia solium cysticerci were separated by two-dimensional electrophoresis and blotted onto nitrocellulose membranes. Subtracted hybridization was performed with serum samples obtained from patients with neurocysticercosis (NCC) and from a NCC-negative control group. Six antigenic proteins were identified and sequenced by liquid chromatography–mass spectrometry. Among these we found Tsol-p27, which was previously identified as a diagnostic candidate in a study conducted in Nicaragua, Central America. Here, we evaluated Tsol-p27 and the antigen cC1 as potential recombinant diagnostic reagents, and also investigated the localization and partial function of Tsol-p27. Immunoblotting demonstrated that Tsol-p27 was recognized by all 10 serum samples from NCC-positive individuals, whereas cC1 was identified by only five of the 10 positive sera. None of the antigens were recognized by negative control sera. Despite the limited number of serum samples evaluated in this study, the results suggest that Tsol-p27 can be a suitable candidate for diagnosis of human NCC, not only in Central America but also in sub-Saharan Africa.

Antiparasitic treatment of cerebral cysticercosis: lessons and experiences from China

Cysticercosis is a tropical disease caused by infection with the larval stage of the pork tapeworm, Taenia solium. Humans and pigs acquire cysticercosis by ingesting T. solium eggs shed in the feces of humans with taeniasis (i.e., infected with an adult intestinal tapeworm). Cerebral cysticercosis occurs when the cysts of T. solium develop within the central nervous system, and it is the primary cause of illness in T. solium infection. Currently, cerebral cysticercosis is endemic worldwide, and it is a leading cause of adult-onset epilepsy in developing countries. However, it is now increasingly detected in developed countries due to the immigration of T. solium carriers from the endemic areas. The antiparasitic treatment of cerebral cysticercosis remains controversial till now. In China, except a few cases who conform to the contraindicated criteria of antiparasitic therapy, most cerebral cysticercosis patients with symptoms and signs are given etiological treatment. This paper reviews the antiparasitic therapy of cerebral cysticercosis in China during the past several decades. Praziquantel treatment with different regimens has been used, and various efficacies are achieved. In the early stage, unsatisfactory therapeutic efficacy was achieved due to small doses and short treatment courses. Afterwards, the therapeutic efficacy became increasingly remarkable in both adults and children with the increases in dosage and courses. Albendazole also presents activity against cysticercosis with slow and moderate action, and it has been widely used in the treatment of the infection. The comparison between praziquantel and albendazole treatments showed that the immediate and short-term effects of albendazole treatment were better than those of praziquantel treatment, but similar mid- and long-term efficacies were observed following albendazole and praziquantel treatments. The combination of albendazole and praziquantel treatments can increase the therapeutic efficacy, and now, from the massive clinical practices, most of Chinese clinical specialists propose the combination therapy of albendazole and praziquantel for cerebral cysticercosis with simultaneous administration of steroids, especially in the first course. In addition, administration of praziquantel at a high dose can become a diagnostic treatment for suspected cerebral cysticercosis and serve as a supplement of the currently available diagnostic methods, such as diagnoses based on the clinical features, immunology, CT and MRI imaging, etc., in some atypical cerebral cysticercosis patients. Praziquantel and albendazole treatments have some adverse reactions, and to control these adverse effects, all the cerebral cysticercosis patients should be treated in hospital. According to the type of cerebral cysticercosis, especially for intracranial hypertension type and meningocephalitis type, the dosages of anti-cysticercus drugs need to follow a gradually increasing pattern. During the period of anti-cysticercosis treatments, steroids and/or dehydrating agents need be administered which can alleviate the intracranial hypertension and so on. Traditional Chinese medicines have been also used in the treatment of cerebral cysticercosis and achieve satisfactory outcomes. However, the compound prescription of traditional Chinese medicines is very complex, and the effective components are not fully clear. Some cerebral cysticercosis patients with very high intracranial tension could not receive antiparasitic treatment immediately, and surgical treatment is required. Chinese surgeons also achieve some successful experiences, but not all the cysticercus can be removed completely during the surgery. Therefore, antiparasitic drugs are still needed after the operation. The rehabilitative treatment is supplementary in the therapy of cerebral cysticercosis. In China, the rehabilitative treatment of cerebral cysticercosis is still at the initial stage. These lessons and experiences in China can be shared with medical staff and researchers from other countries where the disease is endemic.