1.Soil-Transmitted Helminths in Malaysia landscape: an aborigines study
Brandon-Mong, G.J. ; Abdullah, N.A. ; Shukor, N. ; Jaturas, N. ; Richard, R.L. ; Choo, J.C. ; Majid, M.A.A. ; Mahboob, T. ; Tan, T.C. ; Nissapatorn, V.
Tropical Biomedicine 2017;34(2):363-374
Soil-transmitted helminths (STH) is a group of parasitic nematodes, including
Trichuris trichiura, Ascaris lumbricoides, Ancylostoma duodenale and Necator americanus,
which can cause gastrointestinal disorders in humans. STH is prevalent among neglected
communities in both developing and developed countries. This present study aims to determine
the current prevalence of STH infections in Aboriginal population after mass delivering of
antihelminthic drugs was proposed by WHO in 2005 and a health education learning package
(HELP) was initiated in Malaysia in 2012. A total of 235 human fecal samples were collected
and a pre-tested questionnaire was given to gather information about the socio-demographic
of the Aborigine communities living in Kedah and Selangor, Malaysia. The samples were
screened by a direct-fecal smear and confirmed by formalin-ether sedimentation methods.
From human faeces, 81.7% was found to be infected with one or more STH species. T.
trichiura was the most commonly detected (76.6%), followed by hookworms (26.4%) and A.
lumbricoides (19.1%). Triple infections were found in 6.4% of the studied population. Univariate
analysis showed that individuals with age group, male, presence of indoor toilet, family size
with <7 members and bad living habits (i.e., without antihelminthic drugs) were significantly
associated with STH infections. The analysis further showed that walking barefoot was the
significant contributing factor to hookworm infections. The high prevalence of human STH
infections is alarming. Thus, the urgency in implementing health education related behavioral
practice and hygiene to reduce disease burden in these rural communities are a crucial need.
2.DNA barcoding relates Trichuris species from a human and a man’s best friend to non-human primate sources
Brandon-Mong, G.J. ; Ketzis, J.K. ; Choy, J.S. ; Boonroumkaew, P. ; Tooba, M. ; Sawangjaroen, N. ; Yasiri, A ; Janwan, P. ; Tan, T.C. ; Nissapatorn, V.
Tropical Biomedicine 2018;35(4):1131-1139
Trichuris trichiura, the whipworm of humans, is one of the most prevalent soiltransmitted
helminths (STH) reported worldwide. According to a recent study, out of 289
STH studies in Southeast Asia, only three studies used molecular methods. Hence, the
genetic assemblages of Trichuris in Southeast Asia are poorly understood. In this study,
we used partial mitochondrial DNA (cytochrome c oxidase subunit 1 or COI) sequences for
analysis. Trichuris grouped in a same clade with different hosts indicate the potential of
cross infection between hosts. Based on COI, the adult Trichuris isolated from a Malaysian
patient was most closely related to Trichuris isolated from Papio anubis (olive baboons)
from the USA. The Trichuris isolated from the dog from Malaysia was genetically similar
to a Trichuris species isolated from Macaca silenus (lion-tailed macaque) from Czech
Republic. Both the human and dog isolated Trichuris grouped in clades with different
hosts indicating the potential of cross infection between hosts. Specific PCR primers
based on the partial COI of T. trichiura isolated from African green monkey and T. serrata
were designed and successfully amplified using multiplex PCR of the pooled DNA samples.
Our results suggest a complex parasite-host relationship, and support the theory of cross
infection of Trichuris between humans and non-human primates as suggested in previous
publications.