Strongyloides stercoralis hyperinfection in an unconscious diabetic patient with dermatomyositis

Severe strongyloidiasis: a systematic review and meta-analysis of 339 cases

Strongyloidiasis is a parasitosis representing a significant public health problem in tropical countries. It is often asymptomatic in immunocompetent individuals but its mortality rate increases to approximately 87% in severe forms of the disease. We conducted a systematic review, including case reports and case series, of Strongyloides hyperinfection and dissemination from 1998 to 2020 searching PubMed, EBSCO and SciELO. Cases that met the inclusion criteria of the Preferred Reported Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist were analysed. Statistical analysis was performed using Fisher's exact test and Student's t-test and a Bonferroni correction for all the significant values. A total of 339 cases were included in this review. The mortality rate was 44.83%. The presence of infectious complications, septic shock and a lack of treatment were risk factors for a fatal outcome. Eosinophilia and ivermectin treatment were associated with an improved outcome.

Importance of detection of Strongyloides stercoralis DNA in fecal samples from patients with type 2 diabetes mellitus

OBJECTIVE

The association between diabetes and Strongyloides infection remains controversial. This study aimed to detect Strongyloides stercoralis DNA in the feces of patients with Diabetes Mellitus type 2 (DM2).

METHODS

Fecal samples were analyzed via the Lutz, Rugai, and agar plate culture methods. PCR amplification was performed using two targets (PCR-genus and PCR-species) located on the S. stercoralis 18S ribosomal.

RESULTS

The positivity for S. stercoralis using parasitological methods was 1.1%. PCR-genus (14.13%) demonstrated a higher positivity than PCR-species (9.78%).

CONCLUSION

The results confirm the greater positivity of the molecular diagnosis in relation to parasitological methods, reinforcing its use as an additional tool for the diagnosis of S. stercoralis infection in patients with DM2 living in endemic areas for this helminthiasis.

Screening of Strongyloides stercoralis infection in high-risk patients in Khuzestan Province, Southwestern Iran

BACKGROUND

Strongyloidiasis, one of the neglected tropical diseases (NTDs), can be fatal in immunocompromised patients. Available data on Strongyloides stercoralis infection in high-risk patients in Iran are limited. The aim of the present study was to determine the prevalence of S. stercoralis infection and associated risk factors among high-risk patients as well as to evaluate the sensitivity of the diagnostic tests used in the diagnose of S. stercoralis infection.

METHODS

This cross-sectional study was performed from 2019 to 2020 among 300 high-risk patients in Khuzestan Province, southwestern Iran. Patients with autoimmune diseases, uncontrolled diabetes, HIV/AIDS, cancer, organ transplant, hematological malignancy, asthma and chronic obstructive pulmonary disease (COPD) were examined using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test. Since agar plate culture was considered the reference diagnostic test, culture-positive samples were confirmed by PCR amplification and the sequencing of the nuclear 18S rDNA (SSU) hypervariable region (HVRIV) of the parasite.

RESULTS

The prevalence of S. stercoralis infection was 1%, 1.3%, 2%, 2.7%, and 8.7% using direct smear examination, formalin-ether concentration, Baermann funnel technique, agar plate culture, and ELISA test, respectively. All culture-positive samples were confirmed by SSU-PCR. According to the results, the most sensitive test was ELISA, with 100% sensitivity, followed by the Baermann funnel technique with the sensitivity of 75%. Direct smear examination, formalin-ether concentration technique, and Baermann funnel technique had the highest PPV (100%) while the ELISA test had the highest NPV (100%). Significant eosinophilia was observed in the patients whose culture test was positive (7/8; P < 0.05). In the present study, the majority of the positive cases by the agar plate culture had a history of prolonged exposure to soil and of asthma and COPD and were > 60 years old.

CONCLUSIONS

Given that the ELISA test had the highest NPV, the screening of all high-risk patients for S. stercoralis infection in endemic areas is recommended prior to starting corticosteroid therapy with the ELISA test. The results indicate the importance of paying attention to patients with unknown eosinophilia in endemic areas. Ivermectin should be available to strongyloidiasis patients in the endemic areas.

Zoonotic transmission of Teladorsagia circumcincta and Trichostrongylus species in Guilan province, northern Iran: molecular and morphological characterizations

Background

Parasitic trichostrongyloid nematodes have a worldwide distribution in ruminants and frequently have been reported from humans in Middle and Far East, particularly in rural communities with poor personal hygiene and close cohabitation with herbivorous animals. Different species of the genus Trichostrongylus are the most common trichostrongyloids in humans in endemic areas. Also, Ostertagia species are gastrointestinal nematodes that mainly infect cattle, sheep and goats and in rare occasion humans. The aim of the present study was to identify the trichostrongyloid nematodes obtained from a familial infection in Guilan province, northern Iran, using morphological and molecular criteria.

Methods

After anthelmintic treatment, all fecal materials of the patients were collected up to 48 h and male adult worms were isolated. Morphological identification of the adult worms was performed using valid nematode keys. Genomic DNA was extracted from one male worm of each species. PCR amplification of ITS2-rDNA region was carried out, and products were sequenced. Phylogenetic analysis of the nucleotide sequence data was performed using MEGA 6.0 software.

Results

Adult worms expelled from the patients were identified as T. colubriformis, T. vitrinus and Teladorsagia circumcincta based on morphological characteristics of the males. Phylogenetic analysis illustrated that each species obtained in current study was placed together with reference sequences submitted to GenBank database.

Conclusions

The finding of current study confirms the zoonotic aspect of Trichostrongylus species and T. circumcincta in inhabitants of Guilan province. The occurrence of natural human infection by T. circumcincta is reported for the first time in Iran and the second time in the world.