@phdthesis{vanEckert2020,
  author    = {van Eckert, Viviane Roxann},
  title     = {Prevalence of Strongyloides stercoralis infection in adult HIV-positive patients and comparison of specificity and sensitivity of five different methods to detect a current infection in Mwanza Province /Northern Tanzania},
  doi       = {10.25972/OPUS-20530},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-205306},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {S. stercoralis is a helminthic parasite which is common in tropical and subtropical regions. It causes a persistent but often inapparent infection in humans. In the state of a protracted immunosuppression this parasite can cause a life-threatening hyperinfection syndrome. Most often the hyperinfection syndrome was found after prolonged high dose corticosteroid treatment. In HIV-infected individuals high dose corticosteroids are used for the treatment of the immune reconstitution inflammatory syndrome (IRIS) or as adjunct treatment in the treatment of meningeal or pericardial tuberculosis. Case reports from Tanzania demonstrate that Strongyloidiasis is prevalent not only in coastal regions but also in the Lake province of Tanzania. However, data on the local prevalence of S. stercoralis infection based on sensitive techniques are scanty, especially in HIV-infected individuals. The main objective of this study is to provide data on the prevalence of S. stercoralis infections in the adult HIV-infected population attending the Bugando Medical Centre for medical care. Specific objectives of the study are the comparison of the sensitivities and specificities of five different methods in detecting S. stercoralis. Four methods to detect S. stercoralis larvae used stool samples; one method to detect S. stercoralis antibodies required blood samples. The study used the Agar-plate-culture-technique and a modified Harada-Mori-culture-technique for the direct detection of helminthic larvae in the collected faecal samples. In addition, a recently described PCR-assay from faecal specimens and an ELISA for S. stercoralis antibodies have been applied. The Faecal Parasite Concentrator (FPC) stool concentration technique was used for the differential diagnosis of other intestinal helminthic parasites. The results of the study may influence the current treatment guidelines for HIV-infected patients in case that a relevant prevalence of S. stercoralis infection is found. Then, prior to a prolonged iatrogenic immunosuppression -like the high dose corticosteroid treatment for IRIS- a prophylactic anthelminthic treatment capable to eradicate a S. stercoralis infection could be recommendable. The prevalence of a current S. stercoralis infection using the PCR as a gold standard was 5.4\%. The Agar plate method showed positive results in 19 out of 278 cases (6.1\%), the modified Harada Mori technique in 13 of 278 (4.7\%) cases. With PCR as gold standard the sensitivity of the agar plate method was 60\%, the positive predictive value 47.4\%, the specificity 96.2\% and the negative predictive value 97.7 \%. The sensitivity of the Harada Mori technique was 36.4\%, the positive predictive value 30.7\% with a specificity of 96.4\% and negative predictive value 97.1\%. The modified Harada Mori technique allowed in principal the morphological identification of nematode larvae. Microscopic analysis showed a specificity of 100\% and a sensitivity of 46.7\%. Antibodies were detected in 45 of 278 cases 16.2\% by ELISA, with a sensitivity of 92.9\% and a specificity of 87.8\%. The findings of this study show that none of the diagnostic tests can be implemented as a routine diagnostic procedure to diagnose a current infection. This leads to the conclusion that it is high time to consider the provision of a prophylactic treatment within patients who are either HIV positive patients who could develop an IRIS after receiving ART, patients with a HTLV-1 infection and the growing number of patients under iatrogenic immunosuppression for various reasons.},
  subject      = {Strongyloides stercoralis},
  language  = {en}
}