Comparison of Molecular and Parasitological Methods for Diagnosis of Human Trichostrongylosis

Abstract

Human trichostrongyliasis is a zoonotic disease that is prevalent among rural populations in some countries. This study was performed to evaluate various parasitological methods and polymerase chain reaction (PCR) for the diagnosis of human trichostrongyliasis. A total of 206 fresh stool samples were collected from residents of endemic villages of Northern Iran. All samples were examined using conventional parasitological methods, including wet mount, formalin ethyl acetate concentration (FEAC), agar plate culture (APC), Harada–Mori culture (HMC), and Willis, along with the PCR technique. Among the total of 206 individuals examined, 72 people (35%) were found infected with Trichostrongylus species using combined parasitological methods. By considering the combined results of parasitological methods as the diagnostic gold standard, the Willis technique had a sensitivity of 91.7% compared with 52.8% for the APC, 40.3% for the HMC, 37.5% for FEAC, and 5.6% for the wet mount technique. The diagnostic specificity of all the parasitological methods was 100%. Furthermore, the PCR method detected Trichostrongylus spp. DNA in 79 fecal samples (38.3%) with a sensitivity of 97.2% and a specificity of 93.3%. According to the current findings, the Willis method was more sensitive than are the other parasitological methods in the diagnosis of human trichostrongyliasis. However, the PCR assay was more sensitive and more reliable in the detection of human trichostrongyliasis in comparison with the parasitological methods.

Trichostrongylosis: a zoonotic disease of small ruminants

“…Saraei et al (2019) showed a higher sensitivity of FEAC (95.8%) than the agar plate culture method (90.1%) in diagnosis of trichostrongylosis. However, a recent study showed that among conventional parasitological stool examination techniques, Willi's method is more sensitive (91.7%) followed by the agar plate culture method (52.8%), Harada–Mori culture (40.3%), FEAC (37.5%) and 5.6% for the wet mount technique (Pandi et al , 2021). The same study showed the polymerase chain reaction (PCR) assay to be highly sensitive (97.2%) and specific in diagnosing human trichostrongylosis.…”

Investigating intestinal parasitic infections with emphasis on molecular identification of Strongyloides stercoralis and Trichostrongylus colubriformis in north of Iran

“…( Sharifdini et al, 2017a ). It is found 30 species of Trichostrongylus in ruminants and 11 species in humans all over the world, of which 9 species have been identified in people living in Iran ( Gholami et al, 2015 ; Pandi et al, 2021 ). Human infections mainly occur by eating water and vegetables contaminated with third-stage larvae (filariform) or occasionally through skin penetration by the larvae ( Gholami et al, 2015 ; Mizani et al, 2017 ; Sharifdini et al, 2017a ).…”

Diagnóstico de parasitoses intestinais e teciduais

“…Este fenômeno decorre das diferentes densidades dos ovos e cistos em relação à solução (CARVALHO; MOREIRA; PENA;MARINHO et al, 2012).Para executar a técnica de Willis, é fundamental a utilização de uma solução saturada de cloreto de sódio (NaCl), constituída por aproximadamente 40 gramas de NaCl dissolvidos em 10 ml de água, uma vez que a densidade desta solução contrasta com a dos ovos leves e cistos, permitindo, assim, que eles flutuem. Os materiais essenciais incluem amostras fecais, a solução salina saturada, um bastão de madeira ou de vidro, uma lâmina, uma lamínula e o reagente Lugol (PANDI; SHARIFDINI; ASHRAFI; ATRKARROUSHAN et al, 2021).…”