Human African trypanosomiasis (HAT) is a vector-borne parasitic zoonotic disease. The disease caused by Trypanosoma brucei gambiense is the most prevalent in Africa. Early diagnosis is hampered by lack of sensitive diagnostic techniques. This study explored the potential of loop mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR) in the detection of T. b. gambiense infection in a vervet monkey HAT model. Six vervet monkeys were experimentally infected with T. b. gambiense IL3253 and monitored for 180 days after infection. Parasitaemia was scored daily. Blood, cerebrospinal fluid (CSF), saliva, and urine samples were collected weekly. PCR and LAMP were performed on serum, CSF, saliva, and urine samples. The detection by LAMP was significantly higher than that of parasitological methods and PCR in all the samples. The performance of LAMP varied between the samples and was better in serum followed by saliva and then urine samples. In the saliva samples, LAMP had 100% detection between 21 and 77 dpi, whereas in urine the detection it was slightly lower, but there was over 80% detection between 28 and 91 dpi. However, LAMP could not detect trypanosomes in either saliva or urine after 140 and 126 dpi, respectively. The findings of this study emphasize the importance of LAMP in diagnosis of HAT using saliva and urine samples.

This vervet monkey model can only be used for early-stage disease Gambian sleeping sickness.

Porcine cysticercosis is a neglected and underestimated disease caused by metacestode stage of the tapeworm, Taenia solium (T. solium). Pigs are the intermediate hosts of T. solium while human are the only known definitive host. The disease has an economic consequence because the affected farmers lose 50−100 percent of the value of pigs if they are infected. Lack of affordable, easy to use, sensitive, and specific molecular diagnostic tools for detection of infections at the farm level hinders the control of porcine cysticercosis in endemic areas. A number of DNA based diagnostic assays for the detection of T. solium infections in pigs have been developed and evaluated but none is applicable at low-resource areas where this disease is an endemic. This review focuses mainly on DNA based diagnostic methods, their sensitivity, specificity, and utilization at low-resource areas. We summarized data from 65 studies on the current DNA-detection based diagnostic techniques for T. solium cysticercosis in porcine, published in English between the years 2000–2018, identified through PubMed search engine. Of the different polymerase chain reaction (PCR) assays developed for identification of T. solium, the most sensitive (97−100%) and specific (100%) one is nested PCR. One study utilized loop-mediated isothermal amplification (LAMP) as a diagnostic tool for the detection of T. solium infections though its field use was never determined. Recombinase polymerase amplification (RPA) has been evaluated as a diagnostic tool for a variety of diseases, but has never been exploited for the diagnosis of cysticercosis/taeniasis. In conclusion, several molecular methods have been developed and evaluated in lab settings. However, there is need to validate these methods as a diagnostic tool to diagnose porcine cysticercosis in low-resource areas.

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BackgroundThere are three subspecies of Trypanosoma brucei: T. b. gambiense, T. b. rhodesiense and T. b. brucei. The first two are infectious to humans, whilst T. b. brucei is not. Identifying an animal model of T. b. brucei that mimics human African trypanosomiasis (HAT) would enable researchers to study HAT without subjecting themselves to undue risks such as accidental infection.ObjectivesThis study assessed the sequential clinical, parasitological and haematological changes in vervet monkeys infected with T. b. brucei.MethodsThree vervet monkeys were infected with a 104 inoculum of T. b. brucei (isolate GUTat 1). Late-stage disease was induced by subcurative treatment with diminazene aceturate 28 days post-infection. The animals were treated curatively with melarsoprol upon relapse. Parasitaemia and clinical signs were monitored daily and, at weekly intervals, the monkeys’ blood and cerebrospinal fluid (CSF) were sampled for haematology and parasitosis assessments, respectively.ResultsThe first-peak parasitaemia was observed between seven and nine days post-infection. Clinical signs associated with the disease included fever, dullness, pallor of mucous membranes, lymphadenopathy, splenomegaly and oedema. Late-stage signs included stiffness of joints and lethargy. The monkeys developed a disease associated with microcytic hypochromic anaemia. There was an initial decline, followed by an increase, in total white blood cell counts from early- to late-stage disease. Trypanosomes were detected in the CSF and there was a significant increase in white cell counts in the CSF during late-stage disease. Infected vervet monkeys displayed classical clinical symptoms, parasitological and haematological trends that were similar to monkeys infected with T.b. rhodesiense.ConclusionThe T. b. brucei vervet monkey model can be used for studying HAT without putting laboratory technicians and researchers at high risk of accidental infection.