Study of Genetic Diversity of Strongyloides stercoralis for Confirmation of Parasite Origins and Correlation with Patients Data

Abstract

Strongyloidiasis, which is caused by Strongyloides stercora/is, affects 100-300 million people worldwide. Correlations of phylogenetic tree of S.stercora/is and patient data, including residential area,  physician diagnosis  and laboratory results are  useful for epidemiological study. However,  there is presently  no report  on such study  in Thailand. In this research, sixteen  stool samples  were  collected  from  Vajira  Hospital  and  Ratchaburi Hospital.  Then,  ITS1 region  of rDNA gene as target DNA was amplified by polymerase chain reaction (PCR). Phylogenetic tree was constructed. Patient history, diagnosis and laboratory results (complete  blood count  testing) were   collected  for   analyzing  correlations  with   phylogenetic tree   groups.  According to  the  phylogenetic tree   S. stercora/is could   be  divided  into  12  clusters   (clusters I-XII). The percentage of Bangkok patients, patients from  other provinces and patients from  Ratchaburi province were 43.7, 25.0 and 31.3, respectively. Cluster X was found  in more than one sources with  most patients  (75.0%)  in the age range60  years old and  usually found  associated  with unstable  angina,  gastrointestinal symptoms,  pulmonary symptoms  and  immunocompromised conditions. Clusters  V, IX, X and XI were found in the patients> 60 years of age. Symptoms of diseases  of60  years  patients  and  over age groups  had no statistically  significant  difference

(p-value  = 0.59;  p > 0.05). Cluster  X and XI caused  leukocytosis. Cluster  IV, VI, IX, X and XI caused  neutrophilia (5 cases). Cluster  III, V, VII and XII caused eosinophilia  (4 cases). Cluster VII  was  obtained   from  HIV  patients  with  bacteremia infections. Other   laboratory  results

correlated with  the diseases found  in HIV patients  infected  with  S. stercoralis. In conclusion, the  phylogenetic tree  can  be used  to divide  S. stercoralis into  12  clusters.  This  research is useful  in  epidemiology  for  cluster  classification  of S. stercora/is, confirming the  source  of infection  and correlation of patient data and clusters.