1.Current status of parasitic infections among Pangkor Island community in Peninsular Malaysia
Ahmad, A.F. ; Ngui, R. ; Muhammad Aidil ; R., Lim, Y.A.L. ; Rohela, M.
Tropical Biomedicine 2014;31(4):836-843
Limited data is available on the prevalence of parasitic infections among the
island communities in Malaysia with most studies performed between 1960s-1980s. This
study was conducted to determine the current prevalence status of parasitic infections
among communities living in Pangkor Island Peninsular Malaysia. A total of 131 stool and 298
serum samples were collected and subjected to microscopic examination for intestinal protozoa
and helminths and detection of Toxoplasma gondii antibodies using commercial ELISA kits
respectively. In addition, thin and thick peripheral blood films were microscopically screened
for the presence of Plasmodium spp. and microfilariae respectively. The overall prevalence
of intestinal parasitic infections among Pangkor Island community was 9.9% (13/131) with T.
trichiura (5.3%) being the most common intestinal parasite detected. Toxoplasmosis was
reported in almost 60% of the community with the seroprevalence being significantly high
among females (64.7%) compared to males (52.8%) (p=0.038). None of those examined samples
were infected with intestinal sarcocystosis, malaria and filariasis. This study revealed that
the prevalence of intestinal parasitic infections among Pangkor Island community has been
greatly reduced compared to that reported 35 years ago. Massive improvements in the
socioeconomic status, personal hygiene, water facilities and sanitation may have contributed
to the low prevalence of parasitic infections in this community. Nevertheless, further studies
still need to be performed to determine the possible risk factors for the high prevalence of
toxoplasmosis in this community.
2.A preliminary screening of potentially antimalarial plants against Plasmodium falciparum in vitro
Khaw, L.T. ; Leerach ; N., Yap ; N.J. ; Jaturas ; N. ; Mahboob T. ; Tan, T.C. ; Lim, Y.A.L.
Tropical Biomedicine 2015;32(4):676-683
Plasmodium is a blood protozoan parasite that is responsible for malaria. To date,
Plasmodium falciparum has shown multi-drug resistance, particularly in Thailand, Myanmar
and Malaysia. The aim of the study is to screen the plant extracts that can effectively inhibit
P. falciparum 3D7, a common lab strain malaria parasite. Nine plants were collected and
processed through maceration using hexane, chloroform and ethanol, resulting in 24 crude
plant extracts. Of these, extracts from Artabotrys crassifolius, Pericampylus glacus and
Leuconotis eugeniifolia showed promising antiplasmodial activities at IC50 of 15.32 to 39.75
μg/mL in a modified schizont maturation assay. Further studies are warranted to explore its
efficacies and lead compounds of these three plant extracts for the development of
antiplasmodial drugs.
3.Titiwangsa Lake a source of urban parasitic contamination
Azlan, A. Majid. ; Rasid, M.N. ; Richard, R.L. ; Mahboob, T. ; Jaturas, N. ; Tan, T.C. ; Lim, Y.A.L. ; Nissapatorn, V.
Tropical Biomedicine 2016;33(3):594-598
Urban recreational lake acts as a source of waterborne parasites contamination,
as reported in 2013 in Petaling Jaya, Selangor, Malaysia. This scenario will lead to the
transmission of waterborne diseases due to exposure of water-related activities by humans.
This study was conducted to reveal the occurrence of common waterborne parasites in a
urban lake (i.e. Titiwangsa Lake). The lake is situated in the city of Kuala Lumpur and is
known to be overcrowded with vast activities participated by both local and tourist. Results
of study showed the presence of Cryptosporidium, Giardia, free-living amoeba, and helminthlike
ova from the lake.
4.First molecular genotyping of A302S mutation in the gamma aminobutyric acid (GABA) receptor in Aedes albopictus from Malaysia
Tropical Biomedicine 2015;32(3):554-556
Given the lack of molecular evidence in altered target-site insecticide resistance
mechanism in Aedes albopictus (Skuse) worldwide, the present study aims to detect the
presence of A302S mutation in the gene encoding the gamma aminobutyric acid receptor
resistant to dieldrin (Rdl) in Ae. albopictus for the first time from its native range of South East
Asia, namely Malaysia. World Health Organization (WHO) adult susceptibility bioassay indicated
a relatively low level of dieldrin resistance (two-fold) in Ae. albopictus from Petaling Jaya,
Selangor. However, PCR-RFLP and direct sequencing methods revealed the presence of the
A302S mutation with the predomination of heterozygous genotype (40 out of 82 individuals),
followed by the resistant genotype with 11 individuals. This study represents the first fieldevolved
instance of A302S mutation in Malaysian insect species.
5.Higher efficacy of a single dosage albendazole and different soil-transmitted helminths re-infection profiles amongst indigenous Negritos from inland jungle versus those in resettlement at town peripheries
Tropical Biomedicine 2022;39(No.3):402-411
Demarginalization through initiation of resettlement program since 1978 is an inevitable progress
faced by the indigenous Orang Asli (OA) population in Peninsular Malaysia. As Malaysian huntergatherers, the Negrito has been exposed to various environmental-cultural variations. These changes may
influence the pattern of soil-transmitted helminth (STH) infections, the common malady amongst OA.
This study evaluated the deworming effects of single-dosage albendazole (400 mg) and STH-reinfection
rate between Negritos who are still living in the inland jungle versus those living in resettlements at town
peripheries (RPS). Stool samples from the consented participants were first examined using the direct
faecal smear, formalin-ether sedimentation and Kato Katz techniques. Subsequently, stool collections
were carried out in three time points following treatment (i.e., 21 days, 3 months and 6 months).
In brief, a total number of 54 Negritos (inland: 24; RPS: 30) with a complete set of stool collection
was included in this longitudinal study. This study revealed 72.2% cure rate against T. trichiura
in the inland but only 15.0% in the RPS. Although the efficacy of albendazole against T. trichiura
was ultimately low in the RPS, 62.6% egg reduction rate (ERR) (arithmetic mean) was noted (p
= 0.001). For A. lumbricoides and hookworm, high cure rates were found in both communities
(85.7–100.0%). Reinfection for T. trichiura was seen in less than 1 month with higher rate in the
RPS (90.0%) as opposed to the inland (44.4%) at 21 days following treatment. This study found that
the inland OA had better tolerability to single-dosage albendazole and experienced slower STH
reinfection rates versus the RPS. Hence, the selection of albendazole dosage should be targeted
and the use of single- dosage albendazole (biannually) would be more suitable for the inland OA.
Conversely, we propose the use of 3-days albendazole regimens in the resettled RPS population.
6.Serological survey of canine vector-borne diseases in two animal shelters in central Peninsular Malaysia
Vinnie-Siow, W.Y. ; Low, V.L. ; Tan, T.K. ; Teoh, Y.B. ; Prakash, B.K. ; Lim, Y.A.L.
Tropical Biomedicine 2021;38(No.1):145-149
Canine vector-borne diseases (CVBDs) are increasingly becoming a cause for global concern
because of their high morbidity and mortality rates in dogs. However, information on their
occurrence in Malaysia is still scanty. In this study, a total of 103 dog blood samples were
collected from two animal shelters in central Peninsular Malaysia and tested for the
antibodies against Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi, and the antigen of
Dirofilaria immitis. Of the 103 tested dogs, 44.7% (46) were found to be seropositive for Ehrlichia
spp., 30.1% (31) for Anaplasma spp. and 13.6% (14) for D. immitis. Co-infections of Anaplasma
spp. + Ehrlichia spp. (18.5%, 19) were most prevalent, followed by Anaplasma spp. + D. immitis
(1.9%; two) and D. immitis + Ehrlichia spp. (1.0%; one). Furthermore, three dogs (2.9%) were
also found to have triple infection, testing seropositive for Ehrlichia spp., Anaplasma spp. and
D. immitis. The dogs which were found to be seropositive with at least one pathogen were
66.7% (32/51) at shelter A, and 55.8% (29/52) at shelter B. Serological evidence showed that
the exposure of major vector-borne diseases in dogs in shelters was relatively high in the
surveyed areas. Routine detection and control of vector-borne diseases are of paramount
importance for reducing the risk of CVBDs transmission in dogs and humans.
7.Imported case of Leishmania tropica cutaneous leishmaniasis in a 10-year-old child in Malaysia
Tan, T.K. ; Yap, N.J. ; Leong, K.F. ; Teh, C.S. ; Tay, S.T. ; Lim, Y.A.L.
Tropical Biomedicine 2022;39(No.1):86-88
The present paper reported a first imported case of cutaneous leishmaniasis in a 10-yearold child who returned from Saudi Arabia to Malaysia. Six weeks after his travel to Malaysia,
two erythematous dermal nodules were developed over his right cheek and chin. Occurrence
of intracellular amastigote of Leishmania was observed through examination of skin biopsy
with hematoxylin and eosin stain. Furthermore, molecular analysis of ribosomal internal
transcribed spacer 1 (ITS1) of Leishmania spp. confirmed the child was infected with Leishmania
tropica. The child was given oral fluconazole and he had a 80% recovery before he went back
to Saudi Arabia.
8.Epidemiological study of human intestinal parasites in Sarawak, East Malaysia: A review
Tahar, A.S. ; Bilung, L.M. ; Apun, K. ; Richard, R.L. ; Lim, Y.A.L.
Tropical Biomedicine 2021;38(No.3):377-386
Intestinal parasitic infections are endemic in rural settings and may account for asymptomatic infections to various health complications. These infections are a cause of concern for communities of lower economic status, especially in developing countries. In Sarawak, indigenous populations residing in geographically inaccessible areas are socially and economically disadvantaged. Through close association with nature, these populations are prone to intestinal parasitism. Currently, scattered information has led to a continual state of neglect at each level of parasitic infection control. This urges for a review of their distribution and transmission based on previous reports to understand the pattern of the diseases in the state which can further address the improvement of mass controlling programs. A literature search was conducted to collect previous reports on human intestinal parasites in Sarawak, East Malaysia from PubMed (Medline), SCOPUS, ScienceDirect and Web of Science from January 2019 to March 2021. Extrapolating the current data in Sarawak which is still considered limited, further interdisciplinary strategies are demanded to give insights in the epidemiology and true prevalence of intestinal parasites in Sarawak. This review addresses for redirection of attitude towards intestinal parasitic infections where it should be given with ample attention by rural populations. In tandem to that, improvement of rural livelihood such as standard of living and sanitation in Sarawak should be accredited as part of the efforts to reduce the number of intestinal parasitic infections in the state. As a control measure, mass deworming should be reconsidered especially to the rural populations.
9.Poverty related diseases amongst Malaysia’s low-income community: a review
Abu Bakar, N. ; Sahimin, N. ; Lim, Y.A.L. ; Ibrahim, K. ; Mohd Zain, S.N.
Tropical Biomedicine 2023;40(No.1):65-75
Poverty, as proven by several studies, is a driving force behind poor health and hygiene practices.
This review attempts to outline common communicable and non-communicable diseases that
disproportionately affect Malaysia’s 2.91 million low-income households. The current study also looks
into the government’s housing and healthcare programmes for this demographic to improve their
health and well-being. The initial examination yielded incredibly little research on this marginalised
community, with event reporting typically generalised to the Malaysian community as a whole rather
than analysing disease incidences based on household income, which would better reflect povertydriven diseases. As a result, there is an acute need for more accurate information on the epidemiology
of diseases among the poor in order to address this public health issue and provide conclusions that
can drive policy designs.
10.Nematode control failure due to anthelmintic resistance in a sheep farm in Malaysia: First identification of the F200Y mutation in the isotype 1 β-tubulin gene
Khadijah, S. ; Wahaf, A.N.S. ; Syahmi, M.I. ; Tan, T.K. ; Low, V.L. ; Azrul, L.M. ; Chong, J.L ; Lim, Y.A.L ; Abdullah, C.I.
Tropical Biomedicine 2018;35(4):999-1006
This paper reports total nematode anthelmintic resistance towards albendazole,
fenbendazole, levamisole and ivermectin in a commercial sheep farm located in Terengganu,
Malaysia. Faecal Egg Count Reduction Test (FECRT) was conducted on 25 sheep, where
five sheep in each group were treated with the respective four anthelmintics based on live
bodyweight. The balance of five sheep placed in the control group were not treated with
any anthelmintics. At day 13 post-treatment, faecal egg count was conducted and nematode
worm egg count reduction percentage was calculated to determine the resistance status
towards the respective anthelmintics tested. Results showed that nematodes were resistant
to all the anthelmintics tested, namely albendazole, fenbendazole, levamisole and ivermectin
with reduction percentage of 87%, 46%, 94% and 68%, respectively. Subsequently, the third
stage larvae of Haemonchus contortus and Trichostrongylus colubriformis recovered
from post-treatment faecal cultures were subjected to allele-specific polymerase chain
reaction (AS-PCR) assay to determine the presence of the benzimidazole resistance gene.
This study reports the occurrence of the classical F200Y mutation in the isotype 1 β-
tubulin gene, for the first time in Malaysia.