Taenia solium taeniasis/cysticercosis (TSTC) is a foodborne, zoonotic neglected tropical disease affecting predominately low- and middle-income countries. Humans are definitive hosts for T. solium, whereas pigs act as intermediate hosts. Taeniasis, i.e. intestinal infection with adult T. solium in the human host, occurs through ingestion of undercooked pork infected with the larval stage (porcine cysticercosis, PCC). Human cysticercosis occurs after humans ingest T. solium eggs, acting as accidental intermediate hosts. Migration of cysticerci to the human brain results in neurocysticercosis (NCC), manifesting in a variety of clinical symptoms, most notably epilepsy. NCC is the leading cause of acquired epilepsy cases in endemic areas. PCC results in reduced pork value because of condemnation or the risk of condemnation of the meat. Available serological diagnostic tests for porcine and human cysticercosis are characterized by low sensitivity and are not cost-effective. An effective vaccine for T. solium cysticercosis in pigs has been developed, although it is not yet commercially available in all endemic countries, and still no vaccine is available for use in humans. This primer highlights the recent development in the field of diagnostic tests and vaccine production and explores possible strategies for future control and eradication of T. solium. In the absence of highly specific diagnostic tests and human vaccines, treatment of infected pigs and tapeworm carriers and prevention of disease transmission remain the principal means to interrupt the zoonotic cycle of T. solium in endemic countries. Graphical abstract

Cysticercosis is a neglected zoonosis caused by Taenia solium, which involves pigs as intermediate hosts, leading to pig cysticercosis (PCC). Humans are the only definitive hosts, harbouring the mature tapeworm in the small intestines, but they can also act as intermediate hosts upon accidental ingestion of eggs, resulting in human cysticercosis (HCC), called neurocysticercosis (NCC) when the cysts lodge in the central nervous system. Diagnosis of HCC/NCC in humans is based on imaging technologies and serology. The gold standard method for PCC diagnosis is the full carcass dissection and recovery of cysts. However, tongue palpation and meat inspection are the most widely used methods in endemic countries. These methods are specific at the genus level but cannot distinguish mixed infection from other taeniids and are not sufficiently sensitive in pigs with low infection. Available serological tests for human and pig infection are based on parasite-specific immunoglobulin G (IgG). Still, most tests are either cross-reactive with other taeniids or not sensitive enough for single or inactive cysts, particularly for NCC patients. Here, we compare various serological techniques for PCC and NCC published since 2000 and discuss the benefit of IgE-based serodiagnosis as a potential alternative to traditional serology. Considering the diagnostic limitations described above and the need to identify endemic areas to prevent transmission between humans and pigs and monitor control efforts, the development of more sensitive and specific serological tests, followed by a field-applicable point-of-care (POC) test for cysticercosis, is of the utmost importance.

Primers were designed to amplify 18S RNA sequences of Babesia bigemina and B. bovis. Blood samples were collected from naturally infected calves. PCR products of sizes 321 bp and 269 bp, were obtained for B. bigemina and B. bovis, respectively. Infected RBCs (iRBCs) were then, cultured in in vitro to achieve >10% parasitemia of B. bigemina. Splenectomized calf was infected with 1×108 iRBCs. Three intact calves aged 4 to 6 months were infected with iRBCs with B. bigmenia from splenectomized calf. Then, merozoites of B. bigemina were harvested from iRBCs of splenectomized calf and were analyzed through immuno-blotting through homologous and heterologous sera collected from field and experimentally infected calves. SDS-PAGE was performed to analyze the protein bands of native antigens of B. bovis and B. bigemina. The gel was transferred on to nitrocellulose membrane containing native antigens of B. bigemina. The membrane was immuno-blotted with serum sample from B. bigemina-positive animal and it showed a clear band of about 23 kD, while this band was absent on membranes which were incubated with sera from B. bovis-infected calf and negative control animal. Further, native antigens of B. bigemina were coated for optimization of indirect ELISA with homologous serum of experimentally infected intact calves. Cut off point ≥ 0.4893 was considered positive. We obtained antibody titer of 149 ± 97.8 to 299 ± 196 in wells of microtiter plate coated with 5 µg/mL of native antigens while this titer was from 597 ± 391 to 1195 ± 782 in wells coated with 10 µg/mL of antigens. This putative protein would need to be characterized in future to validate its diagnostic value for screening field samples.