Improving soil-transmitted helminths detection in chronic kidney disease patients
George Vasquez-Rios, Angelica Terashima & Luis A. Marcos
Infection A Journal of Infectious Disease ISSN 0300-8126 Infection DOI 10.1007/s15010-015-0825-3
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Author's personal copy Infection DOI 10.1007/s15010-015-0825-3
CORRESPONDENCE
Improving soil‑transmitted helminths detection in chronic kidney disease patients George Vasquez‑Rios1 · Angelica Terashima1 · Luis A. Marcos1
Received: 28 May 2015 / Accepted: 15 July 2015 © Springer-Verlag Berlin Heidelberg 2015
We read with great interest the article by Omrani and colleagues [1]. It is estimated that 200 million people are affected by any stage of chronic kidney disease (CKD) worldwide and between 576 and 1121 million people are infected by soil-transmitted helminths (STH) including Ascaris lumbricoides, Trichuris trichiura, hookworm and Strongyloides stercoralis. With regard to this burden of disease, appropriate detection of these pathogenic parasites is of paramount interest not only in the prevention of potentially life-threatening conditions (i.e. hyperinfection syndrome by S. stercoralis), but also to avoid complications such as malnutrition, anemia and gastrointestinal symptoms that may increase morbidity in those patients with an underlying chronic disease such as CKD. In spite of the moderate low prevalence rates of STH reported in East Asia [2], it is quite surprising that not a single STH was detected in stool examinations in the study by Omrani et al. The progressive decline in the incidence of STH in Iran, due to the improvement of the sanitary conditions in the last years, could be implicated in this finding. Nonetheless, in a non-endemic scenario like this, high-sensitive parasitological techniques are especially warranted to improve the detection of these parasites. We hypothesize that the lack of STH detection in this study may be explained in part by the use of a low-sensitive method for detecting eggs and larvae of helminths in stools such as the formalin-ether concentration technique (FECT) [3]. Although FECT may be an alternative in
* George Vasquez‑Rios
[email protected] 1
Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
remote areas with limited access to laboratory instruments, the sensitivity of this method may be compromised in a low-transmission setting for STH in comparison with other parasitological techniques such as Kato-Katz or FLOTAC [4]. Kato-Katz, FLOTAC [3, 4], Mini-FLOTAC [3] as well as DNA-based studies [5] may strength the detection of STH in non-endemic areas. However, these techniques may also present some limitations. For example, a certain level of laboratory infrastructure is required for flotation techniques. Also, the performance of FLOTAC may be influenced by the flotation solution and the preservation medium. Furthermore, the materials used in this technique should be discarded carefully to avoid human and environmental toxicity. In addition, DNA-based testing-PCR may be expensive and not widely available in resource-constrained settings. An appropriate and early STH diagnosis in tropical regions may be challenging but it is necessary as the epidemiological risk factors encountered in these areas, along with the phenomenon of globalization by traveling, may favor the transmission and clinical presentation of these parasites in non-endemic regions. Hence, the diagnosis may be missed if low-sensitive parasitological tests are performed. We propose that the detection of STH may be improved in vulnerable populations such as patients with CKD using highly sensitive parasitological techniques such as FLOTAC or Mini-FLOTAC or DNA-based testing-PCR, when available. Future studies should confirm the results by Omrani et al., by applying a different set of parasitological techniques. Compliance with ethical standards Conflict of interest None.
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Author's personal copy G. Vasquez-Rios et al.
References 1. Omrani VF, Fallahi S, Rostami A, et al. Prevalence of intestinal parasite infections and associated clinical symptoms among patients with end-stage renal disease undergoing hemodialysis. Infection. 2015. doi:10.1007/s15010-015-0778-6. 2. Pullan RL, Smith JL, Jasrasaria R, Brooker SJ. Global numbers of infection and disease burden of soil transmitted helminth infections in 2010. Parasit Vectors. 2014;7:37. 3. Habtamu K, Degarege A, Ye-Ebiyo Y, Erko B. Comparison of the Kato-Katz and FLOTAC techniques for the
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diagnosis of soil-transmitted helminth infections. Parasitol Int. 2011;60:398–402. 4. Nikolay B, Brooker SJ, Pullan RL. Sensitivity of diagnostic tests for human soil-transmitted helminth infections: a metaanalysis in the absence of a true gold standard. Int J Parasitol. 2014;44:765–74. 5. Basuni M, Muhi J, Othman N, et al. A pentaplex real-time polymerase chain reaction assay for detection of four species of soiltransmitted helminths. Am J Trop Med Hyg. 2011;84:338–43.
