DIAGNOSIS OF Strongyloides stercoralis INFECTION IN IMMUNOCOMPROMISED PATIENTS BY SEROLOGICAL AND MOLECULAR METHODS

Abstract

SUMMARYStrongyloidiasis is a potentially serious infection in immunocompromised patients. Thus, the availability of sensitive and specific diagnostic methods is desirable, especially in the context of immunosuppressed patients in whom the diagnosis and treatment of strongyloidiasis is of utmost importance. In this study, serological and molecular tools were used to diagnose Strongyloides stercoralis infections in immunosuppressed patients. Serum and stool samples were obtained from 52 patients. Stool samples were first analyzed by Lutz, Rugai, and Agar plate culture methods, and then by a quantitative real time polymerase chain reaction (qPCR). Serum samples were evaluated by an enzyme-linked immunosorbent assay (ELISA) using a soluble (AS) or a membrane fractions antigen (AM) obtained from alkaline solutions of the filariform larvae of Strongyloides venezuelensis. Of the 52 immunosuppressed patients, three (5.8%) were positive for S. stercoralis by parasitological methods, compared to two patients (3.8%) and one patient (1.9%) who were detected by ELISA using the AS and the AM antigens, respectively. S. stercoralis DNA was amplified in seven (13.5%) stool samples by qPCR. These results suggest the utility of qPCR as an alternative diagnostic tool for the diagnosis of S. stercoralis infection in immunocompromised patients, considering the possible severity of this helminthiasis in this group of patients.

Microfilaria and Strongyloides larva diagnosed in cerebrospinal fluid and ascitic fluid, respectively: Approach to their morphology on cytology

“…Here the female adult worms produce eggs, which later hatch in the mucosa, and larvae are then excreted in the feces. Most infected people are asymptomatic or have minor gastrointestinal or respiratory symptoms . In immunocompromised individuals, hyperinfection or disseminated infection is common which includes organs other than GIT and lungs.…”

“…Sometimes, gastric or duodenal biopsies can show the parasite as in our case. Serological tests and polymerase chain reaction (PCR) tests are also available for diagnosis in specialized centers . Few cases having Strongyloides hyperinfection with ascites and pleural effusion has been reported earlier.…”

“…Most infected people are asymptomatic or have minor gastrointestinal or respiratory symptoms. 3,9 In immunocompromised individuals, hyperinfection or disseminated infection is common which includes organs other than GIT and lungs. With effective treatment, the fatality is 60% and without treatment, it is almost 100%.…”

Strongyloides Infection in a Man with Abdominal Pain and a History of Rheumatoid Arthritis

“…Also, it seems that the interactions of gut microbiome [5 -7], pathological mechanisms, host defense pathways and effect of systemic corticosteroids [8] impacts on its manifestations. There are several desirable parasitological diagnostic methods in detection of S. stercoralis in particular among immunosuppressed patients such as serological and molecular tools [9]. As S. stercoralis colonize in the duodenum, in certain situations the diagnosis by endoscopy and biopsy may be essential for the diagnosis of this parasitosis thus reducing the risk of death of the hosts in cases of immunosuppression [10 -12].…”

Anticorpos IgY anti-Strongyloides venezuelensis: produção, caracterização e aplicação no imunodiagnóstico da estrongiloidiase humana

“…O diagnóstico molecular é baseado na identificação e amplificação do material genético do parasito em amostras biológicas dos pacientes. A principal ferramenta utilizada nesses casos é a reação em cadeia da polimerase (polymerase chain reaction, PCR) (VERWEIJ et al, 2009;LOK, 2014;SAUGAR et al, 2015;O'CONNELL;NUTMAN, 2016;PAULA et al, 2016). As sequências gênicas foram analisadas principalmente em amostras fecais de pacientes como as regiões internal transcribed spacer 1 e 2 (ITS 1 e ITS 2) do gene de rRNA (ribossomal ribonucleic acid) (NILFOROUSHAN et al, 2007;MOGHADDASSANI et al, 2011), a região 18S do gene de rRNA (VERWEIJ et al, 2009), o gene da cytochrome c oxidase, subunit 1 (VERWEIJ et al, 2009;SHARIFDINI et al, 2015), e a sequência repetida AYO28262 Strongyloides-específica, recentemente detectada em amostras de urina de pacientes (LODH et al, 2016).…”