Machine learning-based analyses support the existence of species complexes for Strongyloides fuelleborni and Strongyloides stercoralis.

Human strongyloidiasis is a serious disease mostly attributable to Strongyloides stercoralis and to a lesser extent Strongyloides fuelleborni, a parasite mainly of non-human primates. The role of animals as reservoirs of human-infecting Strongyloides is ill-defined, and whether dogs are a source of human infection is debated. Published multi-locus sequence typing (MLST) studies attempt to elucidate relationships between Strongyloides genotypes, hosts, and distributions, but typically examine relatively few worms, making it difficult to identify population-level trends. Combining MLST data from multiple studies is often impractical because they examine different combinations of loci, eliminating phylogeny as a means of examining these data collectively unless hundreds of specimens are excluded. A recently-described machine learning approach that facilitates clustering of MLST data may offer a solution, even for datasets that include specimens sequenced at different combinations of loci. By clustering various MLST datasets as one using this procedure, we sought to uncover associations among genotype, geography, and hosts that remained elusive when examining datasets individually. Multiple datasets comprising hundreds of S. stercoralis and S. fuelleborni individuals were combined and clustered. Our results suggest that the commonly proposed 'two lineage' population structure of S. stercoralis (where lineage A infects humans and dogs, lineage B only dogs) is an over-simplification. Instead, S. stercoralis seemingly represents a species complex, including two distinct populations over-represented in dogs, and other populations vastly more common in humans. A distinction between African and Asian S. fuelleborni is also supported here, emphasizing the need for further resolving these taxonomic relationships through modern investigations.

Implementation of a Strongyloides screening strategy in solid organ transplant donors and recipients.

BACKGROUND: Strongyloides stercoralis infects 100 million people worldwide. Mortality rates in hyperinfection syndrome exceed 50%. Donor-derived Strongyloides infection has occurred after heart, kidney, kidney-pancreas and liver transplantation; yet, only 10% of the US organ procurement organizations currently screen donors for strongyloidiasis. METHODS: We report a fatal case of donor-derived disseminated Strongyloides infection in a liver transplant recipient. Following this case, we implemented universal screening and treatment of donors and recipients. We reviewed our local epidemiology and outcomes after protocol implementation. RESULTS: From a total of 355 deceased donors accepted at our center between January 2016, and March 2018, 14 (3.9%) had positive Strongyloides serology. Except for the index case, all other recipients of Strongyloides antibody-positive donors within that period (including 10 kidneys, 3 livers, one combined liver/kidney, and one kidney/pancreas from eight seropositive donors) received post-transplant prophylaxis with ivermectin, and to date are alive and doing well without signs of infection. Between October 2015, and September 2016, a total of 441 deceased donor solid organ transplants were performed at our center. 220 of these recipients had pretransplant Strongyloides serology available, and 23 of them were seropositive (10.5%). Within the first two years after the implementation of universal screening and treatment of donors and recipients, we had no cases of Strongyloides reactivation in our center. CONCLUSIONS: Implementation of a Strongyloides screening and treatment protocol in our center was an effective strategy to prevent both recipient- and donor-derived strongyloidiasis. Transplant centers should consider implementation of Strongyloides preventive strategies.

Donor-derived strongyloidiasis after organ transplantation in Norway.

Strongyloides stercoralis is an intestinal helminth which in humans can cause asymptomatic chronic infection maintained for decades through its auto-infective cycle. During solid organ transplantation, recipients may unintentionally receive an organ infected with strongyloides. This is a very rare complication but may have deadly outcome if not detected. We hereby report two transplant recipients whom developed Strongyloides hyperinfection syndrome after organ transplantation from the same deceased donor. Recipient 1 was kidney transplanted and presented at day 65 post engraftment with diarrhea and subsequent septicemia and gastric retention. Larvae were detected in gastric aspirate. Recipient 2 was simultaneously kidney and pancreas transplanted and presented at day 90 post engraftment also with gastric retention and septicemia. Larvae were demonstrated on duodenal biopsy and stool sample. The clinical course was complicated with severe duodenal bleedings, gastric retention, meningitis, and prolonged hospitalization. Retrospective testing of pre-transplant donor serum was positive for Strongyloides stercoralis antibodies. As a result of disease severity and gastric retention albenazole was administered via a jejunal tube and ivermectin subcutaneously in both recipients. S stercoralis was successfully eradicated and the transplants ended up with unaffected graft function. Following these two cases, we started systematic screening of all deceased donors for serum Strongyloides IgG in October 2016. After having screened 150 utilized donors one tested positive for Strongyloides, which initiated prophylactic ivermectin treatment to organ recipients. No symptoms or disease developed. Our center will continue to screen all donors as prophylactic treatment may avert this potentially lethal complication in cases of donor-derived Strongyloides infection.

Prevalence and risk factors of Strongyloides stercoralis infection among Orang Asli schoolchildren: new insights into the epidemiology, transmission and diagnosis of strongyloidiasis in Malaysia.

This cross-sectional study aimed to determine the prevalence and risk factors of S. stercoralis infection among 1142 Orang Asli primary schoolchildren in six different states of Peninsular Malaysia. Fecal samples were examined using direct smear, formalin-ether sedimentation (FES), agar plate culture (APC) and PCR techniques. Overall, 15.8% of the children were found to be infected with S. stercoralis. The prevalence was 0.2, 1.3, 15.2 and 13.7% by direct smear, FES, APC and PCR, respectively. Multivariate analysis showed that an age of >10 years, being male, belonging to a Proto-Malay tribe, belonging to the Senoi tribe, indiscriminate defecation, using an unimproved water source for drinking water and not wearing shoes when outside were the significant risk factors of infection among these children. In conclusion, we provide new evidence on the occurrence of S. stercoralis in Malaysia to show that there is a relatively high prevalence of infection among Orang Asli schoolchildren. Therefore, the use of specific methods for detecting S. stercoralis should be considered when screening these children for intestinal parasites. Moreover, prevention and control measures specific to S. stercoralis should be integrated into the intestinal parasitic infections control programme in Malaysia.

Donor-derived strongyloidiasis in a Saudi pediatric kidney transplant recipient: A case report and mini-review.

S. stercoralis infection has been identified as a donor-derived infection in cases of solid organ transplant among recipients with no prior risk factor for parasitic exposure. Worldwide and regional reports from the adult kidney transplant population highlight this indirect method of infection and caution about delayed diagnosis, severe complications, and death related to donor-derived S. stercoralis infection. We report a deceased-donor-derived S. stercoralis infection in a 12-year-old Saudi girl who underwent kidney transplantation. This is the first pediatric case reported outside the United States of America. Although she presented with mild bouts of gastrointestinal symptoms, the need for additional immune suppression put her at risk of serious complications. A literature review highlights the importance of awareness about S. stercoralis infections and complications in kidney transplant recipients, pretransplant screening of donors based on risk assessment, and the challenges with treatment availability and duration in this vulnerable population.

Dogs are reservoir hosts for possible transmission of human strongyloidiasis in Thailand: molecular identification and genetic diversity of causative parasite species.

Human strongyloidiasis is a deleterious gastrointestinal disease mainly caused by Strongyloides stercoralis infection. We aimed to study the possible transmission of S. stercoralis between humans and pet animals. We isolated Strongyloides from humans and domestic dogs in the same rural community in north-east Thailand and compared the nucleotide sequences of derived worms using portions of the mitochondrial cytochrome c oxidase subunit 1 (cox1) and 18S ribosomal RNA (18S rRNA) genes. Twenty-eight sequences from the 18S rRNA gene were obtained from worms derived from humans (n = 23) and dogs (n = 5), and were identical with S. stercoralis sequences (from Thailand, Cambodia, Lao PDR and Myanmar) published in the GenBank database. The 28 cox1 sequences from humans and dogs showed high similarity to each other. The available published cox1 sequences (n = 150), in combination with our 28 sequences, represented 68 haplotypes distributed among four clusters. The 28 samples from the present study represented eight haplotypes including four new haplotypes. Dogs and humans shared the same haplotypes, suggesting the possibility of zoonotic transmission from pet dogs to humans. This is of concern since dogs and humans live in close association with each other.

MaxEnt modeling of soil-transmitted helminth infection distributions in Thailand.

Infections due to soil-transmitted helminths (STHs), i.e. Ascaris lumbricoides, Trichuris trichiura, hookworms, and Strongyloides stercoralis, are widely distributed in tropical and subtropical areas in which approximately 1.5 billion people are infected. A clear understanding of the epidemiology and distribution of diseases is an important aid for control and prevention. The aim of our study was to identify the effects of environmental and climatic factors on distribution patterns of STHs and to develop a risk map for STH infections under current environmental and climate regimes in Thailand. Geographical information systems (GIS), remote sensing, and Maximum Entropy (MaxEnt) algorithm software were used to determine the significant factors and to create predictive risk maps for STH infections in Thailand. The disease data from Thailand covered the years from 1969 to 2014, while environmental and climatic data were compiled from the Worldclim database, MODIS satellite imagery, Soilgrids and ISCGM. The models predicted that STHs occur mainly in southern Thailand. Mean annual precipitation was the factor most affecting the current distribution of A. lumbricoides, T. trichiura, and S. stercoralis. Land cover class was the main predictor for distribution of S. stercoralis and important for hookworms. Altitude was the dominant factor affecting the distribution of hookworms, and mean temperature of the wettest quarter was significantly associated with A. lumbricoides distribution. A predicted distribution map of STHs to identify environmental risk factors in Thailand is presented. This work provides a model for use in STH monitoring and health planning not only in Thailand but also in other countries with similar disease conditions.

Seroepidemiological trend of strongyloidiasis in the Bolivian Chaco (1987-2013) in the absence of disease-specific control measures.

OBJECTIVES: The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013. METHODS: Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland). RESULTS: Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987. CONCLUSIONS: The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections.

First molecular identification and report of genetic diversity of Strongyloides stercoralis, a current major soil-transmitted helminth in humans from Lao People's Democratic Republic.

Strongyloidiasis is a major soil-transmitted helminth (STH) disease that affects people worldwide. We present updated data on prevalence in the Lao People's Democratic Republic (Lao PDR) in 2015, arising from a community cross-sectional helminthiasis survey. Fecal samples were collected from 327 individuals across three provinces in Lao PDR (Luang Prabang in the north, Khammouane in the center, and Champasack in the south). Agar plate culture and Kato-Katz methods were used to examine duplicate stool samples from each participant to detect Strongyloides stercoralis and co-infecting helminths. Overall prevalences of S. strercoralis human hookworm, Taenia spp., Trichuris trichiura, Ascaris lumbricoides, and Enterobius vermicularis were 41.0, 28.1, 4.9, 4.0, 1.5, and 0.9 %, respectively. The prevalence of miscellaneous trematodiases (including opisthorchiasis) was 37.9 % and of Schistosoma mekongi infection was 0.3 %. Strongyloidiasis is a current major STH disease in Lao PDR. We also report the molecular-phylogenetic identification of S. stercoralis adult males collected from 40 representative human strongyliodiasis fecal samples. DNA was extracted, amplified, and sequenced from a portion of the mitochondrial cox1 gene and the nuclear 18S ribosomal DNA. Phylogenetic analyses indicated that all specimens sequenced belonged to S. stercoralis (Bavay, 1876) Stiles and Hassall, 1902. The cox1 sequences exhibited great diversity (24 haplotypes) in Lao PDR. This is the first molecular identification and report of genetic diversity of S. stercoralis in humans from Lao PDR. An effective parasite control program is needed to reduce the serious health impacts.

Single donor-derived strongyloidiasis in three solid organ transplant recipients: case series and review of the literature.

Donor-derived Strongyloides stercoralis infections in transplant recipients are a rare but recognized complication. In this case series, we report donor-derived allograft transmission of Strongyloides in three solid organ transplant recipients. Following detection of infection in heart and kidney-pancreas recipients at two different transplant centers, a third recipient from the same donor was identified and diagnosed. S. stercoralis larvae were detected in duodenal aspirates, bronchial washings, cerebrospinal fluid, urine and stool specimens. Treatment with ivermectin and albendazole was successful in two of the three patients identified. The Centers for Disease Control and Prevention was contacted and performed an epidemiologic investigation. Donor serology was strongly positive for S. stercoralis antibodies on retrospective testing while all pretransplant recipient serum was negative. There should be a high index of suspicion for parasitic infection in transplant recipients and donors from endemic regions of the world. This case series underscores the need for expanded transplant screening protocols for Strongyloides. Positive serologic or stool tests should prompt early treatment or prophylaxis in donors and recipients as well as timely notification of organ procurement organizations and transplant centers.

Strongyloides stercoralis transmission by kidney transplantation in two recipients from a common donor.

Strongyloides stercoralis hyperinfection in an immunocompromised host has a high mortality rate but may initially present with nonspecific pulmonary and gastrointestinal symptoms. Donor-derived S. stercoralis by kidney transplantation is an uncommon diagnosis and difficult to prove. We report two renal allograft recipients on different immunosuppressive maintenance regimens that developed strongyloidiasis after transplantation from the same donor. Recipient 1 presented with a small bowel obstruction. Larvae were demonstrated on a duodenal biopsy and isolated from gastric, pulmonary, and stool samples. Serologic testing for S. stercoralis was negative at a referral laboratory but positive at the Centers for Disease Control. The patient's hospital course was complicated by a hyperinfection syndrome requiring subcutaneous ivermectin due to malabsorption. Recipient 1 survived but the allograft failed. Recipient 2 had larvae detected in stool samples after complaints of diarrhea and was treated. On retrospective testing for S. stercoralis, pretransplant serum collected from the donor and Recipient 1 was positive and negative, respectively. Donor-derived strongyloidiasis by renal transplantation is a preventable disease that may be affected by the immunosuppressive maintenance regimen. Subcutaneous ivermectin is an option in the setting of malabsorption. Finally, routine screening for S. stercoralis infection in donors from endemic areas may prevent future complications.

Transmission of Strongyloides stercoralis through transplantation of solid organs--Pennsylvania, 2012.

Strongyloides stercoralis is an intestinal nematode endemic in the tropics and subtropics. Immunocompetent hosts typically are asymptomatic, despite chronic Strongyloides infection. In contrast, immunocompromised patients are at risk for hyperinfection syndrome and disseminated disease, with a fatality rate >50%. The infection source for immunocompromised patients, such as solid organ transplant recipients, is not always apparent and might result from reactivation of chronic infection after initiation of immunosuppressive therapy or transmission from the donor. In October 2012, the United Network for Organ Sharing (UNOS) notified CDC of a left kidney and pancreas recipient in Pennsylvania diagnosed with strongyloidiasis. This report summarizes the results of the investigation of the source of Strongyloides infection in three of four organ recipients. Testing of pretransplant donor and recipient sera confirmed that infection in the recipients was donor derived. This investigation underscores the importance of prompt communication between organ procurement organizations, transplant centers, and public health authorities to prevent adverse events in recipients when transmission is suspected. Additionally, it emphasizes the utility of stored pretransplant samples for investigation of suspected transplant-transmitted infections and the need to consider the risk for Strongyloides infection in organ donors.

Strongyloides stercoralis infection in an intestinal transplant recipient.

Strongyloides stercoralis is a helminth in tropical and subtropical areas. It may cause latent infection and progress to Strongyloides hyperinfection syndrome, which is associated with a high mortality rate. Transplant recipients under the treatment of immunosuppressant agents are at risk of severe S. stercoralis infection. According to related literature, most cases of S. stercoralis infection after solid organ transplantation are caused by reactivation of latent infections in the recipients, whereas only a few are acquired from the donors. We report on an intestinal transplant recipient who had S. stercoralis infection diagnosed by a larva of this parasite found in the stool from the ileostomy stoma 1 month after transplantation. The donor was considered the source of the infection because the donor was from an endemic area and had marked eosinophilia, and the recipient had no contact history or clinical manifestations related to the S. stercoralis infection before transplantation. The patient was treated with ivermectin and exhibited no evidence of infection after 7 months.

Synergistic effects of seasonal rainfall, parasites and demography on fluctuations in springbok body condition.

1. Seasonality of rainfall can exert a strong influence on animal condition and on host-parasite interactions. The body condition of ruminants fluctuates seasonally in response to changes in energy requirements, foraging patterns and resource availability, and seasonal variation in parasite infections may further alter ruminant body condition. 2. This study disentangles the effects of rainfall and gastrointestinal parasite infections on springbok (Antidorcas marsupialis) body condition and determines how these factors vary among demographic groups. 3. Using data from four years and three study areas, we investigated (i) the influence of rainfall variation, demographic factors and parasite interactions on parasite prevalence or infection intensity, (ii) whether parasitism or rainfall is a more important predictor of springbok body condition and (iii) how parasitism and condition vary among study areas along a rainfall gradient. 4. We found that increased parasite intensity is associated with reduced body condition only for adult females. For all other demographic groups, body condition was significantly related to prior rainfall and not to parasitism. Rainfall lagged by two months had a positive effect on body condition. 5. Adult females showed evidence of a 'periparturient rise' in parasite intensity and had higher parasite intensity and lower body condition than adult males after parturition and during early lactation. After juveniles were weaned, adult females had lower parasite intensity than adult males. Sex differences in parasitism and condition may be due to differences between adult females and males in the seasonal timing of reproductive effort and its effects on host immunity, as well as documented sex differences in vulnerability to predation. 6. Our results highlight that parasites and the environment can synergistically affect host populations, but that these interactions might be masked by their interwoven relationships, their differential impacts on demographic groups, and the different time-scales at which they operate.

The effect of maternal Strongyloides venezuelensis infection on mice offspring susceptibility and immune response.

Species of Strongyloides infect a wide range of hosts worldwide. Due to their complex life cycle, it is hard to control the transmission of these parasites. Several species show evidence of vertical transmission; however, the impact of this transmission route on the susceptibility of the offspring has been poorly investigated. Herein, we used Strongyloides venezuelensis infected mice to evaluate transplacental and transmammary parasite transmission and their effect on the susceptibility of offspring. Swiss female mice were infected at the end of the gestation or during the breastfeeding period, and their offspring were examined for the presence of the parasite one week after infection of the mother. Our data showed that female mice infected with S. venezuelensis during gestation did not transmit the parasite to their offspring. On the other hand, all newborn mice breastfeeding in S. venezuelensis infected females got infected. To evaluate the effect of early exposure to the parasite on susceptibility and immune response of the hosts, the offspring of each experimental group (non-infected, gestation-infected, and breastfeeding-infected mothers) received anti-helminth treatment after parasite evaluation and were subcutaneously infected with S. venezuelensis upon reaching adulthood. Mice from the group of breastfeeding-infected mothers showed lower susceptibility to S. venezuelensis in adulthood in comparison with mice from non-infected mothers. The low parasite burden was accompanied by earlier eosinophil and neutrophil activation in the gut and higher serum levels of IgE. In contrast, S. venezuelensis infection in adult mice born from gestation-infected mothers presented with more worms in the intestine and lower levels of parasite-reactive IgM in serum in comparison with mice born from non-infected mothers, thus suggesting that early exposure to parasite antigens may modulate the protective immune response. Altogether, our data confirmed transmammary, but not transplacental, transmission of S. venezuelensis in mice and demonstrated that early exposure to the parasite and/or their antigens has an important effect on host susceptibility to a later infection.

The Strongyloides stercoralis-hookworms association as a path to the estimation of the global burden of strongyloidiasis: A systematic review.

TRIAL REGISTRATION: PROSPERO (registration code CRD42019131127).

Possible transmission of Strongyloides fuelleborni between working Southern pig-tailed macaques (Macaca nemestrina) and their owners in Southern Thailand: Molecular identification and diversity.

Human strongyloidiasis is caused by Strongyloides stercoralis, S. fuelleborni fuelleborni and Strongyloides f. kellyi. Strongyloides fuelleborni is a soil-transmitted nematode parasite typically infecting non-human primates. The southern pig-tailed macaque (Macaca nemestrina) is distributed throughout the southern part of Thailand and could be a source of zoonotic transmission of this nematode. Here, we extracted DNA from Strongyloides speciescultured from the feces of southern pig-tailed macaques and their owners. Using PCR and sequencing of the extracted DNA, we compared the nucleotide sequences of these worms using portions of the 18S rDNA hypervariable region IV (HVR-IV) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Sequences from the 18S rRNA gene were obtained from worms from 23 southern pig-tailed macaques and from one owner. These sequences were identical with each other and with all East and Southeast Asian S. fuelleborni sequences (from Japan, Thailand, and Lao PDR) in the GenBank database. A median-joining network of published cox1 sequences (n = 123), in combination with the present 24 new sequences, represented 107 haplotypes distributed among six clusters, which corresponded to geographical localities but did not relate to host species. The S. fuelleborni cox1 sequences from some southern pig-tailed macaques and the one infected owner shared the same cox1 haplotype. This is the first evidence of likely zoonotic transmission of S. fuelleborni from a reservoir host, M. nemestrina.

Update on the major imported helminth infections in travelers and migrants.

Helminth infections cause considerable morbidity worldwide and may be frequently underdiagnosed especially in areas of lower endemicity. Patients may harbor latent infections that may become symptomatic years or decades after the initial exposure and timely diagnosis may be critical to prevent complications and improve outcomes. In this context, disease in special populations, such as immunosuppressed patients, may be of particular concern. Heightened awareness and recent diagnostic developments may contribute to the correct management of helminth infections in nonendemic regions. A review of the main helminth infections in travelers and migrants (strongyloidiasis, taeniasis-neurocysticercosis and schistosomiasis) is presented, focusing on epidemiology, developments in diagnosis, treatment and prevention.

Strongyloides stercoralis hyperinfection transmitted by liver allograft in a transplant recipient.

We describe a case of Strongyloides stercoralis hyperinfection in a liver allograft recipient 2.5 months after transplantation. The patient lives in Spain, which is not considered an endemic country for strongyloidiasis, and denied prior residence or travel to any known endemic area. The initial symptoms were fever and vomiting, and he subsequently developed a severe respiratory disease. An endoscopic biopsy of ulcerative lesions of the duodenum revealed massive mucosa infiltration by larvae and adult worms, which were also found in respiratory samples. The patient was successfully treated with combined therapy with albendazole and ivermectin. The strongyloides infection was transmitted by the liver allograft. The donor was from Ecuador and, retrospectively, his serum tested positive for S. stercoralis IgG antibodies. Additionally, the pancreas-left kidney allograft recipient from the same donor later developed an intestinal strongyloidiasis without hyperinfection syndrome. To our knowledge, this is the first confirmed case of S. stercoralis infection transmission from the same donor to two solid allograft recipients.

Assessment of the global paradigms of genetic variability in Strongyloides stercoralis infrapopulations determined by mitochondrial DNA sequences.

Microevolutionary data of Strongyloides stercoralis infrapopulations are regarded as a requirement for determining the global genetic structure and transmission paradigms of this neglected tropical nematode among the neighboring countries of the world. English databases were searched from 2010 to 2019, analyzing a total of 10 publications. The cytochrome c oxidase subunit 1 sequences of S. stercoralis isolated from Asian and African continents were subjected to calculate the diversity indices and genetic differentiation. A parsimonious haplotype network indicated a star-like trait a total of 106 (Homo sapiens) and 48 haplotypes (Canid) being grouped into four distinct geographical haplogroups. A significant genetic diversity was identified in human-derived S. stercoralis (Haplotype diversity: 0.78) and those with dog (Hd: 0.86) origins. Cladistic phylogenetic tree indicated the Japanese, Thailandish, and Myanmarese clades have a sister relationship with the Laotian clade. The statistically significant Fst values indicated that human S. stercoralis populations of Japanese-Thailandish, Japanese-Myanmarese, and Japanese-Laotian origins were genetically differentiated (Fst: 0.48430 to 0.54903). We conclude that a high gene migration of human strongyloidiasis is being unequivocally shared between the Laotion-Myanmarese and Laotion-Thailandish population pairs. The current findings enhance our knowledge to assess the transmission dynamics and the evolutionary patterns of S. stercoralis in various geographical regions of the globe; also it will serve as a basis for public health policy to control human strongyloidiasis particularly in immunocompromised individuals. Besides, the infected canids and other environmental reservoirs for zoonotic transmission of S. stercoralis to humans should be de-wormed along with their owners.