Comparison of Kato-Katz, PCR and coproantigen for the diagnosis of Taenia solium taeniasis.

Four methods were compared for the diagnosis of human taeniasis caused by Taenia solium. Fecal samples from persons living in a T. solium endemic region of Madagascar were examined for taeniid eggs by the Kato­Katz method. Subsequently, samples positive (n = 16) and negative (n = 200) for T. solium eggs were examined by (i) amplification of the fragment of small subunit of the mitochondrial ribosomal RNA (rrnS) gene using conventional polymerase chain reaction (PCR) and (ii) a nested PCR of a fragment of the T. solium Tso31 gene. Additionally, 12 egg-positive and all egg-negative samples were tested for coproantigen detection. A further 9 egg-positive fecal samples were examined using both PCRs. Of the 12 egg-positive samples tested by PCRs and coproantigen methods, 9 (75%) were positive by rrnS PCR, 3 (25%) using Tso31-nested PCR and 9 (75%) by coproantigen testing. None of the 200 egg-negative fecal samples was positive in either rrnS or Tso31-nested PCR. Twenty of the 25 egg-positive samples (80%) were positive in rrnS PCR, and DNA sequencing of PCR amplicons was obtained from 18 samples, all confirmed to be T. solium. Twelve of the 25 egg-positive samples (48%) were positive in the Tso31-nested PCR, all of which were also positive by rrnS PCR. It is suggested that species-specific diagnosis of T. solium taeniasis may be achieved by either coprological examination to detect eggs or coproantigen testing, followed by rrnS PCR and DNA sequencing to confirm the tapeworm species in egg-positive or coproantigen-positive samples.

Impact of a 3-year mass drug administration pilot project for taeniasis control in Madagascar.

Taenia solium is endemic in Madagascar and presents a significant burden on the population and the health system. The parasite cycles through humans who host the adult tapeworm, and pigs that host the larval stages. Accidental infection of humans may occur with the larval stages which encyst in the nervous central system causing neurocysticercosis, a major cause of seizure disorders and a public health problem. One of the interventions to facilitate the control of the disease is mass drug administration (MDA) of the human population with taeniacide. Here we describe a pilot project conducted in Antanifotsy district of Madagascar from 2015 to 2017 where three annual rounds of MDA (praziquantel, 10mg/Kg) were undertaken in 52 villages. Changes in the prevalence of taeniasis were assessed before, during and after the treatments. A total of 221,308 treatments were given to all eligible people above 5 years of age representing a 95% coverage of the targeted population. No major adverse effects were notified related to the implementation of the MDA. The prevalence of taeniasis was measured using Kato-Katz and copro-antigen techniques. Analyses undertaken combining the results of the Kato-Katz with copro-antigen, or using the Kato-Katz results alone, showed that there was a significant reduction in taeniasis 4 months after the last MDA, but 12 months later (16 months after the last MDA) the taeniasis prevalence had returned to its original levels. Results of the pilot project emphasize the need of a multi-sectorial One-Health approach for the sustained control of T. solium.