A study implementing real-time PCR to identify Strongyloides species of third-stage larvae in human stool samples from Southern Vietnam.

Background: Strongyloidiasis, a neglected disease caused by intestinal nematodes of the genus, is endemic to tropical and subtropical areas such as Vietnam. Morphological methods only identify the genus, while DNA-molecular techniques are susceptible in Strongyloides spp. detection. The study aims to determine the prevalence of dominant Strongyloides species among the population in Duc Hoa district, Long An, Vietnam. Methods: A cross-sectional study used 1190 stool specimens collected from July 2017 to November 2018. All samples were transported within 2 h, stored at 2-8°C, and processed within 48 h for microscopy smear and culture at the Laboratory of Medical Parasitology, Pham Ngoc Thach University of Medicine (PNT). Then all positive samples with the above 2 methods were verified by real-time PCR technique. Real-time PCR amplification was conducted at the Laboratory of Molecular Biology, PNT. Results: Direct microscopy and modified Harada-Mori culture detected Strongyloides spp. larvae in 79/1190 samples (6.6%). About 94.2% of the DNA samples were Strongyloides stercoralis, 2.9% were co-infections with Strongyloides ratti and S. stercoralis, and 2.9% were patients with S. ratti. The identity of 12/14 sequences was confirmed as S. stercoralis with a high level of similarity (91.3%-100%) and over 98% for S. ratti. Conclusion: DNA-molecular techniques and sequence analysis are highly suitable for identifying Strongyloides species isolated from stool samples. It is remarkable evidence of the presence of zoonosis S. ratti disease in human, not just the known S. stercoralis. It is likely to result in a certain proportion of people being infected by this animal-borne infectious pathogen.

The kinetic profile of clinical and laboratory findings and treatment outcome of patients with toxocariasis.

OBJECTIVES: Human toxocariasis is a widespread zoonosis for which a chemotherapy decision and therapy effectiveness are difficult to determine. We aimed to investigate the kinetic profile of clinical and laboratory findings and treatment outcome of patients with toxocariasis in Vietnam. METHODS: The prospective study was conducted between October 2017 and June 2019. The diagnosis of toxocariasis was established based on clinical, laboratory (eosinophilia, raised IgE concentration) and serological (positive Toxocara IgG ELISA) evaluation as well as the exclusion of another helminthic co-infection. The patients were followed up after seven days, then one, three and six months after chemotherapy by thiabendazole. RESULTS: The study involved 80 patients with a mean age of 41.6 ± 15.2 years of whom 58.8% were female. At three and six months after chemotherapy, most patients demonstrated resolution of clinical signs and symptoms, eosinophil count and IgE concentration but not in the proportion of IgG seropositivity. Skin lesions and eosinophilia resolved earlier than the other symptoms (one month after treatment). About four-fifths of the patients were "cured" after three and six months of follow-up; 33.8% showed side effects to thiabendazole therapy but no severe events were reported. The most common adverse reaction was neurologic symptoms followed by gastrointestinal or skin manifestations which lasted as long as 4 days. CONCLUSIONS: In toxocariasis patients, cutaneous manifestations and eosinophilia resolve more rapidly than other clinical and laboratory findings while IgG titre has a very slow kinetic after therapy. Thiabendazole seems to be a potential alternative for the treatment of human toxocariasis.

Clinical and Laboratory Findings among Patients with Toxocariasis in Medic Medical Center, Ho Chi Minh City, Vietnam in 2017-2019.

BACKGROUND: Human toxocariasis is prevalent in many countries but this disease has been rarely reported from Vietnam. We aimed to investigate the clinical and laboratory findings and assess possible association between these findings in patients with toxocariasis in Vietnam. METHODS: A prospectively study, between October 2017 and June 2019 was performed involving 120 toxocariasis patients at Medic Medical Center, Ho Chi Minh City, Vietnam. The diagnosis of toxocariasis was established based on clinical, laboratory (eosinophilia, raised IgE concentration) and serological (positive Toxocara IgG ELISA test) evaluation as well as the exclusion of other helminthic coinfection. RESULTS: The most frequently reported manifestation was of skin (n = 93, 77.5%), including urticarial (n= 69, 57.5%) followed by neurologic, gastrointestinal and pulmonary signs/symptoms. Hepatic involvement occurred in 8.3% of the patients. No significant relationship between clinical findings and laboratory parameters was found except the higher values of eosinophil count and IgE concentration among patients with liver involvement. There was a significant relationship between eosinophil count and IgE concentration (r=0.389, P<0.001). Serological findings did not show a correlation with clinical and other laboratory findings. CONCLUSION: Our data revealed a wide range of clinical symptoms/signs and a high incidence of skin manifestations in patients with toxocariasis. Eosinophil count and IgE concentration are valuable markers for the evaluation of the disease.

Clinical features of three patients with paradoxical immune reconstitution inflammatory syndrome associated with Talaromyces marneffei infection.

Talaromyces marneffei infection is a major cause of death in HIV-infected individuals in South and Southeast Asia. Talaromycosis immune reconstitution inflammatory syndrome has not been well described. Here we report the clinical features, management, and outcomes of three HIV-infected patients with talaromycosis-associated paradoxical immune reconstitution inflammatory syndrome in Ho Chi Minh City, Vietnam.