جستجوی مقالات مرتبط با کلیدواژه « strongyloides stercoralis » در نشریات گروه « پزشکی »

Strongyloides stercoralis is one of the soil-transmitted helminths (STH) in tropical and subtropical regions. The role of lipid profile has been investigated in the survival of larval stages of helminths, but there is limited information about the role of lipid profiles and strongyloidiasis. Hence, we aimed to investigate the seroprevalence of S. stercoralis infection in patients with hyperlipidemia is compared with the nonhyperlipidemia.

In 2023, participants were selected from the laboratory of Porsina Hospital in Guilan Province, northern Iran and their lipid profiles including TG, CHOL, LDL, HDL, and VLDL were measured. They were divided into two groups of case and control and matched based on sex and age. S. stercoralis Ab (IgG) was measured by ELISA methods, using the NovaTec kit. Finally, statistical analysis was performed.

Each case and control group consisted of 105 participants, from 13 to 80 years old. 56.66% were female and 43.33% were male. The sero-prevalence of S. stercoralis was found 4.76% in the case group compared to 0.95% in the control group. We found an association between TG fall and VLDL with sero-prevalence of S. stercoralis in hyperlipidemia group (P= 0.034), but other lipid profiles did not show a significant association. A significant relationship was found between contact with dogs and seroprevalence of S. stercoralis (P=0.001).

The sero-prevalence of S. stercoralis in the case group was 5 times higher than the control group. A significant association between TG and VLDL fall with S. stercoralis Ab (IgG) was observed, but future studies with more sample sizes are suggested to investigate the anti-atherogenic effect of S. stercoralis. Also, a genetic assessment of S. stercoralis and the host (humane and dogs) is recommended to research zoonotic potential in epidemic areas.

Uncovering the roles and characteristics of pathogenesis-related molecules can help us develop novel management methods in parasitology. In this study, we studied the expression levels of Strongyloides stercoralis heat shock protein70 (HSP70) (Sst-hsp-70) and astacin (Sst-ast) as pathogenesis-related genes as well as the expression of S. ratti HSP70 and HSP17.1 (Sra-hsp-70, Sra-hsp-17.1) in the larvae and adult stages of S. stercoralis.

A hyperinfection isolate of S. stercoralis from Gilan Province, northern Iran was cultivated on nutrient agar. After a couple of days, parasites in different stages of life were collected, and total RNA was extracted. The expression levels of astacin and HSP genes were compared by real-time PCR.

Statistically higher expression levels of Sst-ast, Sst-hsp-70, and Sra-hsp-70 genes in L3 larvae than in adults were observed. However, the expression level of Sra-hsp-17.1 was non-significantly lower in the larval stage than in adult worms.

Higher expression levels of Sst-ast, Sst-hsp-70, and Sra-hsp-70 genes in the larval stages of S. stercoralis suggest the potential role of these enzymes in parasite cutaneous invasion and pathogenesis. However, higher expression of Sra-hsp-17.1 in adult forms is probably involved in resistance and survival mechanisms. The similarity in gene expression between S. stercoralis and S. ratti can provide helpful hints to better understand strongyloidiasis from various perspectives, including pathogenesis, proper diagnosis, and targeted treatment.

Strongyloides stercoralis a globally widespread human intestinal nematode. Hyperinfection mainly appears in patients with defective immune systems . This study intended to investigate the prevalence of serum positive Strongyloides stercoralis in cancer patients who have never undergone chemotherapy and those who received at least one cycle of chemotherapy.

This study targeted cancer patients, referred to Rasht hospital, and assigned them to two groups of cancer patients with no history of chemotherapy and cancer patients with at least one cycle of chemotherapy. Patient’s demographic information, underlying diseases and chemotherapy regimen were recorded, and their serum sample was examined.

410 patients were included in this study. the majority were female ( 51/7% ). About 40 patients tested positive for serology, out of which 14 were in the chemotherapy-treated group and 26 in chemotherapy-untreated group, indicating that the prevalence of serum positive Strongyloides stercoralis was significantly higher in patients with no history of chemotherapy. Moreover, eosinophilia significantly correlated with the prevalence of seropositivity. The chemotherapy protocol containing high doses of corticosteroids could multiply the risk of positive serology by 12.7 times.

Before chemotherapy, in areas with a higher prevalence of Strongyloides stercoralis, especially in high corticosteroids protocols, it may make sense to study Strongyloides stercoralis . It becomes more vital in men and eosinophilic patients. Since serologic testing may display false negative rates in patients with defective immune systems, subsequently, alternative complementary methods such as fecal larval examination and fecal PCR test are highly suggested to be carried out along with serology.

Strongyloides stercoralis (S. stercoralis) is a helminth, which infects humans widely in tropical and subtropical countries. This parasitic infestation usually does not produce symptoms in humans; however, severe and life-threatening forms of this infection can occur in immunocompromised individuals. Patients with Coronavirus disease 2019 (COVID-19) with concurrent immunosuppressive therapy are at risk of developing Strongyloides hyperinfection syndrome (SHS). We present a 70-year-old male with a history of high-dose dexamethasone therapy due to severe COVID-19 who was referred to our hospital with chest discomfort, nausea, and anorexia. Histological assessment of the gastric and duodenal mucosae revealed numerous eggs and filariform larvae of S. stercoralis indicative of SHS. Ivermectin and albendazole were administered to the patient. Following the treatment, the patient's symptoms improved. Clinicians must be aware of the risk of SHS, especially in S. stercoralis endemic countries before and during corticosteroid therapy for COVID-19 because early diagnosis and appropriate treatment can significantly reduce mortality in these patients.

Serological diagnosis of Strongyloides stercoralis (S. stercoralis) is frequently challenging because of cross-reactivity with other parasitic nematodes. Therefore, it is necessary to introduce novel serological tests with high performance to properly diagnose this neglected parasitic infection. The purpose of the current study was to design a multi-epitope construct for the diagnosis of S. stercoralis.

For the purpose of this study, first, highly antigenic segments and potential immunodominant epitopes of S. stercoralis were identified from two antigenic proteins, and then all of the selected parts were linked by an appropriate linker. Next, the physico-chemical features of the designed construct were analyzed. Then, tertiary structures of the construct were built and evaluated to find out the best one. Lastly, the amino acid sequence was reverse-translated and optimized for over-expression in Escherchia coli (E. coli).

The bioinformatic evaluation indicated that the designed protein construct could be hydrophilic, thermostable, and acidic and the estimated half-life was more than 10 hr in E. coli.

According to the results of the study, the designed construct could be used as an efficient antigen in the ELISA system for serological diagnosis of human strongyloidiasis.

Strongyloidiasis is a neglected disease caused by Strongyloides stercoralis. Fast and robust detection of this parasite can avoid its auto-infection cycle and therefore from the high parasitic load. The culture of stool and stool-based microscopy techniques are the most used methods for parasite diagnosis; however, these methods are not sensitive enough. Immunological methods are more sensitive diagnostic tools and can be employed for the detection of this parasite. Since IgG4 immunoreactive protein (NIE) is a major pathogenicity factor of the parasite, in the present study, an IgM-ELISA method was developed to investigate the efficiency of anti-NIE IgM antibodies in the detection of Strongyloides stercoralis. For this aim, 50 serum samples were gathered from positive patients along with 50 serum patients from healthy people. IgM antibodies were detected by using the ELISA technique and the data were analyzed by statistical analyses. Statistical analyses showed that IgM-ELISA was able to diagnose the disease with the sensitivity and specificity of 65.0%. The developed IgM-ELISA method was relatively but not sufficiently successful at a robust diagnosis of strongyloidiasis. However, the sensitivity and specificity of this method were not good enough to be considered a reliable test for the diagnosis of the disease compared to the IgG- ELISA.

Strongyloides stercoralis is an intestinal nematode with worldwide distribution which is endemic in tropical and subtropical areas. It is unique in its ability to complete its entire life cycle and reinfect its human host via a phenomenon called autoinfection. The majority of infections are clinically asymptomatic or can manifest with gastrointestinal symptoms, such as heartburn, bloating, diarrhea, abdominal discomfort, gastroesophageal reflux disease (GERD), or symptoms related to the penetration of larvae through skin, including dermatitis and eosinophilia. Immunosuppressed patients, such as solid organ transplant patients with untreated strongyloidiasis are at great risk of hyperinfection, dissemination syndromes, and often fatal conditions associated with strongyloidiasis.

In this retrospective single-center cross-sectional study, we evaluated 157 cases (131 heart, lung, and kidney transplant recipients and 26 kidney donors) in Tehran, Iran, from March 2020 to April 2021. Demographic information including age, gender, place of birth, place of residence, underlying disease, being the donor or recipient, history of previous transplant and type of transplant, travel history to endemic regions, and seropositivity for S. stercoralis were evaluated.

Among 157 cases with a mean age of 38.9 years, 40 (25.5%) cases tested positive for S. stercoralis antibodies. Out of 26 donors, eight cases were seropositive, and among 131 recipients, 32 cases were seropositive. There was no significant correlation between birth place and place of residence in endemic areas and seropositivity for S. stercoralis. None of the cases showed hypereosinophilia, hyperinfection, or disseminated syndrome. Also, we found no significant correlation between the type and time of transplant, history of previous transplants, and S. stercoralis infection.

Universal screening for S. stercoralis latent infection is important in immunosuppressed patients, especially in solid organ transplants because of the high risk of hyperinfection and disseminated syndrome, which may culminate in death. Furthermore, screening for latent strongyloides infection in donors seems to be necessary because of the possibility of strongyloides infection being transmitted from donors to recipients.

Strongyloides Stercoralis is a common cause of gastrointestinal (GI) infection. Symptoms are usually mild, but in the setting of impaired host immunity, severe and disseminated illness may occur.

The present report describes a male patient with history of asthma and corticosteroid therapy, now presented with dyspnea and abdominal pain. In examinations show Strongyloides Stercoralis larvae in BAL fluid specimen.

The patients who undergone immunosuppressive therapy, are highly indicated for Strongyloides Stercoralis screening which prevent hyperinfection in endemic areas.

Human infection with Strongyloides stercoralis and hookworm parasites is usually under reported due to less sensitive diagnostic methods. Agar plate culture (APC) is the most sensitive technique for parasites having larval stage. However, using APC in routine diagnosis is uncommon. This study aimed to determine the detection rate and sensitivity of APC in comparison with formal ether concentration technique (FECT) and spontaneous tube sedimentation techniques (STSTs) for S. stercoralis and hookworm larvae.

Stool samples collected from 844 schoolchildren in Amhara Regional State, northwestern Ethiopia in 2019, transported to nearby health institutions and processed by APC, FECT and STSTs. The prevalence of S. stercoralis and hookworm was computed by descriptive statistics and Chi-square. The diagnostic agreement among the three techniques was evaluated using Kappa value.

The overall prevalence of S. stercoralis and hookworm infections by combining the three methods was 13.2% (111/844) and 33.8% (277/844), respectively. Using APC alone, the prevalence of S. stercoralis and hookworm were found to be 10.9% (92/844) and 24.5% (207/844), respectively. Agar plate culture was 5.4 and 2.7 times respectively more sensitive than FECT and STST, with slight and fair agreement in the detection of S. stercoralis. Hookworm diagnostic agreement was moderate between APC and FECT, and APC and STST. The Kappa value between STST and FECT diagnostic methods was substantial.

APC has a better detection rate of S stercoralis and hookworm larvae. Therefore, APC can be used as an alternative routine diagnostic method to S. stercoralis and hookworm co-endemic countries.

Strongyloidiasis is a public health concern in northern regions of Iran, caused by Strongyloides stercoralis. Auto-infection cycle can be resulted in high parasitic load, especially in immunocompromised hosts. Because of low sensitivity of stool culture and stool-based microscopy techniques, detection of antibodies in patient’s sera can be an alternative diagnostic technique for detection of the nematode. In the present study, as the first step of the development of an ELISA kit for the detection of antibodies against the nematode, IgG4 immunoreactive protein (NIE) was expressed in Escherichia coli expression system, purified and verified.

The NIE gene sequence was retrieved from the GenBank. This sequence was codon-optimized for the expression in E. coli BL21 (DE3). The sequence was inserted into the expression vector pET-30b (+). The recombinant vector was then transferred into competent E. coli BL21 (DE3). Transformed colonies were selected and verified by colony PCR. NIE gene expression was induced with IPTG induction. The protein production was evaluated by SDS-PAGE and verified using Western blotting.

The codon-optimized NIE gene had required parameters for expression in E. coli. NIE protein was proved and verified by SDS-PAGE and Western blotting.

NIE recombinant protein was successfully expressed in E. coli expression system in appropriate amounts. The recombinant protein can be used for developing ELISA kit in diagnosis of S. stercoralis.

Soil–transmitted helminth infections constitute a public health problem in the rural areas of tropical and subtropical regions, including Thailand. We aimed to determine the prevalence of soil–transmitted helminth infections and underlying risk factors among the schoolchildren living in the rural areas of southern Thailand.

A cross–sectional survey was conducted between Sep and Nov 2018 in the district of Thasala, Nakhon Si Thammarat, Thailand. A total of 192 children, aged 6–12 yr were enrolled. Each child provided a single stool sample that was subjected to a suite of microscopic diagnoses for soil–transmitted helminth. A questionnaire was administered to determine risk factors of the infections. Logistic regression models were applied to investigate associations.

The overall prevalence of soil–transmitted helminth infections was 3.13%; Strongyloides stercoralis 2.08%; hookworm 1.04% and Trichuris trichiura 0.52%. Children who cutting fingernails short can prevent soil–transmitted helminth infections highly up to 90% (crude OR = 0.1; 95% confidence interval = 0 – 0.8; P = 0.020).

The finding of the study shows a sharp decrease in the prevalence of soil–transmitted helminth among schoolchildren in the southern Thailand in the past two decades with prevalence dropping below 5% for soil–transmitted helminth. However, the prevalence of S. stercoralis remained stable over time. These results suggest that the culture method should be used to access strongyloidiasis situation in the older age group who greater contact with soil for agriculturists.

Intestinal parasitic infections (IPIs) are among the most important etiologies of gastrointestinal disorders in developing countries. The present study was performed to determine the prevalence of IPIs in rural inhabitants of Fouman, northern Iran.

Overall, 31 villages were randomly selected during 2015-2016. Stool samples were collected from 1500 inhabitants aged 2-87. The samples were examined by direct wet smear, formalin ethyl-acetate concentration and agar plate culture. Trichrome staining and modified acid-fast staining were used as confirmatory tests for intestinal amoeba and flagellates and cryptosporidium spp., respectively. Data were analyzed with Chi-Square and Fisher exact tests using SPSS.

8.06% of participants were positive for at least one intestinal parasite. The prevalence of mixed parasitic infections was 0.87%. The most prevalent IPIs were caused by Trichostrongylus spp. (3.13%), followed by Strongyloides stercoralis (1.5%), Giardia lamblia (1.3%), and Entamoeba coli (1.0%), Blastocystis hominis (0.86%), E. histolytica/dispar (0.53%), Endolimax nana (0.26%), Iodamoeba butschlii (0.13%), Trichuris trichiura (0.07%), Enterobius vermicularis (0.07%), Hook worm (0.07%) and E. hartmani (0.07%). Statistically, the prevalence of IPIs showed significant differences regarding the age groups, education status, occupation (P<0.001), and the habit of eating raw vegetables (P<0.007), whereas, the differences were insignificant with regard to sex (P=0.924) and water supply (P=0.088).

The prevalence of IPIs, especially soil-transmitted helminthes (STHs) has sharply decreased in northern Iran. Excluding Trichostrongylus spp. and S. stercoralis, other intestinal parasites only produce a marginal and unnoticeable health problem in this area, today.

Strongyloides infection is usually asymptomatic in healthy individuals; however, immunocompromised patients are subject to potential hyperinfection involvement. Hereby, we report disseminated and hyperinfection strongyloidiasis in two immunosuppressed patients from north of Iran, an endemic region for Strongyloides stercoralis.
        

After assessment of clinical symptoms, disseminated strongyloidiasis was identified in the first case with pemphigus vulgaris by the presence of abundant larvae in direct stool smears and gastric biopsy. The second patient had metastatic carcinoma and was hospitalized with complicated symptoms. The infection was diagnosed by detection of numerous first-stage larvae in wet mount stool smears and agar plate analysis. Despite antiparasitic treatment, both patients died during the hospitalization.
          

Delayed diagnosis of active strongyloidiasis in immunosuppressed patients can lead to hyperinfection syndrome. Thus, screening for S. stercoralis infection in these patients is recommended in endemic regions to reduce mortalities.

Strongyloides stercoralis, a soil transmitted helminth, is well known as a potentially fatal parasite in immunosuppressed patients.

The current study aimed to evaluate the prevalence of strongyloidiasis in diabetic patients, in the central parts of Mazandaran province, Iran, using coprological examination and enzyme-linked immunosorbent assay (ELISA).

Fresh stool and serum samples were obtained from diabetic patients. The stool samples were examined using direct smear and formalin-ether concentration methods. The serum samples were tested for the existence of Strongyloides sp. antibodies using a commercial diagnostic kit (Strongyloides - ELISA).

The overall prevalence rates were 13.3% (4/30) and 25.6% (46/180) using parasitological and ELISA methods, respectively. The sensitivity and specificity of ELISA compared with stool examination were 100% and 84.6%, respectively. The seroprevalence rate of this infection was higher in females (27.3%) than males (19.5%), and among participants living in rural regions (31%) compared with urban areas (20%). The prevalence rate of Strongyloides sp. infection was higher in patients with diabetic foot (39.1%) compared with cases with non-diabetic foot (23.6%). It also was higher in insulin dependent patients (29.9%) compared with non-insulin dependent subjects (23%). However, these differences were not statistically significant which may have resulted from the small sample size.

Our findings demonstrated a high seroprevalence of Strongyloides sp. infection in diabetic patients. Furthermore, this is the first seroprevalence study of strongyloidiasis in diabetic patients from Iran. It seems that the ELISA technique can be used for the diagnosis of individual cases and is a good screening assay to rule out strongyloidiasis in diabetic patients.

The present study aimed to evaluate the prevalence of intestinal parasitic infection among mentally retarded individuals and the staff of the center in Bandar Abbas, south of Iran.

This cross-sectional study was conducted in central institution for mentally retarded in Bandar Abbas, Hormozgan Province, from 2016 to 2017. A triple fecal specimen was collected from each one of the 163 participants and were evaluated using wet mount and formalin-ethyl acetate methods. Trichrome and Ziehl-Neelsen staining were used to confirm suspected cases of protozoa. As well as Baermann and Harada-Mori techniques and agar plate culture were implemented to diagnosis of Strongyloides stercoralis.

Overall, 163 subjects were examined including 126 mentally retarded individuals and 37 personnel. Ninety (55.2%) cases of participants were infected with at least one of the intestinal parasites, 69 (54.7%) of mentally retarded and 21 (56.7%) of personnel. Twenty-six mentally retarded individuals were infected with S. stercoralis (20.6%), Blastocystis hominis 30.2%, Entamoeba coli 25.4%, Giardia lamblia 5.6%, Enterobius vermicularis 1.6%, Hymenolepis nana 0.8% and Iodamoeba butschlii 1.6%. Twelve staff (32.4%) harbored B. hominis, E. coli 27%, S. stercoralis 2.7%, G. lamblia 10.8%, H. nana 2.7% and Endolimax nana 2.7%.

High rate of intestinal parasites particularly, S. stercoralis compared to the most recent studies of general population. Therefore, regular screening and tracking the positive cases, disinfection of the living environment, training and financing of the staff, increasing the number of the workers, recruiting of professionals and trained personnel in these centers are suggested.

It is estimated that 100 - 300 million people in the world are infected with Strongyloides stercoralis. Although there are several laboratory diagnostic methods for detection of this parasite, there is still no gold standard diagnostic method. The need for an application test with high sensitivity and specificity is highly felt, especially in people with immune deficiency or organ transplant volunteers.
The diagnostic sensitivity of five parasitological methods, including direct smear of feces in saline and Lugol iodine stain, Baermann technique, formalin-ethyl acetate concentration, Harada-Mori filter paper, agar plate culture and molecular method was evaluated by stool specimens collected from the central mentally retardation institute of Bandar Abbas, to find out an easy, practical and cost-effective method for detecting Strongyloides stercoralis.
Five parasitological and molecular methods were investigated using 163 stool samples. Considering the employed methods, there found to be 30 cases of S. stercoralis. The total positive cases of S. stercoralis using different methods was considered as golden standard. The highest sensitivity of parasitological methods was associated with the Baermann 27 (90%) and the least positive results obtained with Harada-Mori method, 1 (3.3%). In this study 9 positive cases were detected by PCR method (30%).
Highest sensitivity was observed when different diagnostic approaches were combined where Baermann technique proceeded it. Therefore, this technique is recommended as a selective method for detecting S. stercoralis due to its easy, practical and inexpensive nature

Aim: This study is aimed to diagnose and analyze strongyloidiasis in a population of an endemic area of Iran using nested-PCR, coupled with parasitological methods.
Screening of strongyloidiasis infected people using reliable diagnostic techniques are essential to decrease the mortality and morbidity associated with this infection. Molecular methods have been proved to be highly sensitive and specific for detection of Strongyloides stercoralis in stool samples.
A total of 155 fresh single stool samples were randomly collected from residents of north and northwest of Khouzestan Province, Iran. All samples were examined by parasitological methods including formalin-ether concentration and nutrient agar plate culture, and molecular method of nested-PCR. Infections with S. stercoralis were analyzed according to demographic criteria.
Based on the results of nested-PCR method 15 cases (9.7%) were strongyloidiasis positive. Nested-PCR was more sensitive than parasitological techniques on single stool sampling. Elderly was the most important population index for higher infectivity with S. stercoralis.
In endemic areas of S. stercoralis, old age should be considered as one of the most important risk factors of infection, especially among the immunosuppressed individuals.

We aimed to determine the status of strongyloidiasis in mentally disabled population in the institutional places in Rasht City, the capital of Guilan Province, northern Iran.
This cross-sectional study was conducted in 8 institutions for mentally retarded population in Rasht in 2013. Before collecting the samples, a questionnaire was filled out for each participant by an expert person. A single stool sample was obtained from each of the 173 subjects and examined using direct wet mount, formalin-ether concentration technique and agar plate culture method.
A total of 173 mentally disabled individuals aged 2-57 (25.69±11.56) yr old were studied. Stool examination showed that 51 (29.5%) cases were infected with at least one parasite. Of 173 studied cases only 10 (5.8%) individuals were infected with pathogenic parasites, of which 2 (1.2%) cases were infected with Strongyloides stercoralis and 8 (4.6%) with Giardia lamblia. On the other hand, 42 (24.3%) of the studied population were infected with non-pathogenic intestinal protozoa such as Blastocystis hominis (n=29, 16.8%), Entamoeba coli (n=16, 9.2%) and Endolimax nana (n=4, 2.3%). Mixed protozoal infections were observed in 8 (4.6%) individuals.
The prevalence rate of S. stercoralis in mentally disabled individuals in Rasht was somewhat higher than those of normal population of the province. The same picture was seen when the prevalence of G. lamblia and non-pathogenic protozoa in normal and mentally disabled populations were compared.