1.Morphological and molecular detection of Blastocystis in wildlife from Tioman Island, Malaysia
Mohd Zain, S.N. ; Farah Haziqah, M.T. ; Woh, P.Y.
Tropical Biomedicine 2017;34(1):249-255
Blastocystis infection is widely reported in wildlife, livestocks and in non-human
primates however, occurrence in Malaysian wildlife is scarce
2.Post-era mass drug administration: an update on intestinal parasitic infections in urban poor communities in Peninsular Malaysia
Sahimin, N. ; Abd Khalil, N.S. ; Lewis, J.W. ; Mohd Zain, S.N.
Tropical Biomedicine 2020;37(No.2):363-371
The health impact of a Malaysian national helminth control program which provided school-based anthelmintic chemotherapy from 1974 to 1983 was re-visited after three decades post MDA and associated risk factors amongst urban poor communities identified. Stool samples collected were screened using the formalin ethyl-acetate concentration technique recovered at least one species of helminth and/or protozoan. Despite a steady decline observed between 1974-1983 however, post MDA infections continue to persist in pockets of communities moderately (18.9%; n=39/206) with higher infection recorded amongst PPR flat residents (22.5%, n=16/71). Among risk factors identified, waste management method was the primary factor for Ascaris lumbricoides infections (n=33; 16.0%), whereas age, education, employment and source of drinking water were significant risk factors for cryptosporidiosis. Despite the government’s efforts to improve health through the provision of basic amenities to the general public, higher prevalence values amongst PPR flat dwellers suggests the need to implement targeted chemotherapeutic treatment of, once a year deworming as recommended by World Health Organization when the baseline prevalence of soil-transmitted helminth infections in the community is over 20%, in addition to preventive measures though improvements in health awareness programs and improved waste management methods.
3.Molecular characterisation and genetic affinities of Cyclophyllidean cestodes infecting wild rats in Peninsular Malaysia
Mohd-Saad, N. ; Mohd Zain, S.N. ; Sharma, R.S.K. ; Omar, H.
Tropical Biomedicine 2022;39(No.2):170-178
Cestode infections is widely reported in rodents, however species identification remains problematic due
to the genetic or interspecies variation. Therefore, this study was aimed to verify the Cyclophyllidean
parasites recovered from wild rats captured from different forest types using molecular based methods.
Maximum-likelihood (ML) and neighbour-joining (NJ) trees were constructed inferred from 18 small
subunit nuclear ribosomal RNA gene (18SrDNA) and mitochondrial cytochrome c oxidase subunit
one gene (COX1) sequences of cestode worms recovered from 124 individuals from four rat species.
Sequences obtained from both Hymenolepis diminuta and Hydatigera parva represents the first
records in Malaysia. All the sequences were successfully amplified with product with total length of
205 and 1202 base pairs (bp), respectively. Three cestode species from the Family Hymenolepididae
(Hymenolepis diminuta) and Family Taeniidae (Hydatigera parva; Hydatigera taeniaeformis) were
successfully characterized using phylogenetic analyses and haplotype networking. Phylogenetic
analysis showed that H. diminuta, Hydatigera parva (Hy. parva) and Hydatigera taeniaeformis (Hy.
taeniaeformis) formed its own monophyletic clade in 18SrDNA analyses. Results also showed that
Hy. taeniaeformis shared the same haplotype group with Hy. taeniaeformis from China (COX1) and
linked with Hy. taeniaeformis from Japan (18SrDNA) while the Malaysian H. diminuta clearly formed
a separate haplotype and networked with other regions. The Malaysian Hy. parva isolation, on the
other hand, appeared to be genetically distinct from the European Hy. parva (Spain) strain, but closely
linked to the local isolates. Molecular methods employed successfully improved in the detection of
complex species in this group. The findings showed that molecular data can be useful to deeply study
intra-specific variation in other cestode worms.
4.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.
5.Current status of infectious diseases among migrants and non-citizens in Malaysia
Mohd Putera, N.W.S. ; Azman, A.S. ; Mohd Zain, S.N. ; Yahaya, H. ; Lewis, J.W. ; Sahimin, N.
Tropical Biomedicine 2023;40(No.2):138-151
The mass movement of migrants to Malaysia for employment is one of the factors contributing to
the emergence and re-emergence of infectious diseases in this country. Despite mandatory health
screening for migrants seeking employment, prevalence records of infectious diseases amongst migrant
populations in Malaysia are still within negligible proportions. Therefore, the present review highlights
the incidence, mortality and overall status of infectious diseases amongst migrants’ populations in
Malaysia, which maybe be useful for impeding exacerbation of inequalities among them and improving
our national health system thru robust and effective emergency responses in controlling the prevalent
diseases found among these populations and maybe, Malaysian citizens too. Peer-reviewed articles from
January 2016 to December 2020 were searched through online platform including SCOPUS, PubMed,
Science Direct, and Google Scholar. Non-peer-reviewed reports and publications from ministry and
government websites including data from related agencies were also scoured from in order to ensure
that there are no cases being overlooked, as most published articles did not have migrants as the
research subjects. A total of 29 studies had been selected in the final analysis. Migrants in Malaysia
were at higher risk for tuberculosis, malaria, lymphatic filariasis, cholera, leprosy and leptospirosis.
Lymphatic filariasis was still endemic among this population while thousand cases of TB and cholera
had been reported among them due to cramp living conditions and poor sanitation in their settlements
respectively. While malaria had gradually decreased and become sporadic, the influx of migrant workers
had led to the rising of imported malaria cases. Low cases of leprosy had been recorded in Malaysia but
a significant proportion of it was contributed by migrant workers. As for leptospirosis, studies found
that there are prominent cases among migrant workers, which particularly highest within workers with
lower educational attainment. Infectious diseases are still prevalent among migrants in Malaysia due
to various interplay factors including their working sectors, country of origin, immunization status,
type of settlement, impoverished living conditions, and language and cultural barriers that impeding
access to health facilities.
6.Public health status of Myanmar refugees in South East Asia: A Malaysian case study
Mohd Hanapi, I.R. ; Sahimin, N. ; Lewis, J.W. ; Lau, Y.L. ; Othman, J. ; Tedong, P.A. ; Mohd Zain, S.N.
Tropical Biomedicine 2021;38(No.4):594-604
The United Nations High Commissioner for Refugees (UNHCR) reports over 80 million people
are displaced worldwide with approximately 26.3 million categorized as refugees and over
a million residing temporarily in South East Asia. Despite the lack of national legislative
framework in place for refugees and asylum seekers (RAS), Malaysia hosts approximately
178,140 as registered with UNHCR and the majority originate from Myanmar. In this review,
we examine refugees from South East Asia, particularly from Myanmar that have contributed
to the largest influx of refugees to this region with a focus on their health status. The
present study traces barriers to the health care of refugees in the country of asylum and also
the challenges faced by these communities in accessing health services.
7.Entamoeba infections and associated risk factors among migrant workers in Peninsular Malaysia
Sahimin, N. ; Yunus, M.H. ; Douadi, B. ; Yvonne Lim, A.L. ; Noordin, R. ; Behnke, J.M. ; Mohd Zain, S.N.
Tropical Biomedicine 2019;36(4):1014-1026
The influx of low skilled migrant workers to Malaysia from low socio-economic
countries where gastrointestinal parasitic infections are prevalent has raised concerns about
transmission to the local population. Three methods for detection (serology, microscopy and
molecular techniques) were utilized to identify Entamoeba infections amongst the targeted
cohort and determine risk factors associated with infection. Serological screening of 484
migrant workers from five working sectors in Peninsular Malaysia using IgG4 ELISA based on
the rPPDK antigen showed an overall seroprevalence of 7.4% (n = 36; CL95 = 5.3–10.1%) with
only one factor statistically associated with seropositivity of anti-amoebic antibodies, i.e.
years of residence in Malaysia (χ2
1 = 4.007, p = 0.045). Microscopic examination of 388 faecal
samples for protozoan cysts and trophozoites showed a slightly higher prevalence (11.6%;
n=45; CL95: 8.4–14.8%). Meanwhile, amplification of the 16S rDNA gene detected two species
i.e. Entamoeba dispar (23/388; 5.9%; CL95: 3.6–8.3%) and E. histolytica (11/388; 2.8%; CL95:
1.2–4.5%) and mixed infections with both parasites in only three samples (3/388; 0.8%; CL95:
0.2–2.2%). Entamoeba dispar infection was significantly associated with those employed in
food and domestic services (χ2
4 = 12.879, p = 0.012). However, none of the factors affected
the prevalence of E. histolytica infection. Despite the low prevalence of E. histolytica in
faecal samples of the study cohort, the presence of this pathogenic parasite still poses
potential public health risks and calls for tighter control strategies based on better availability
of chemotherapeutic treatment and accessibility to appropriate health education.