1.Hypopituitarism in a Dengue Shock Syndrome Survivor without known Pituitary Adenoma
Lim, L.L. ; Ibrahim, L. ; Paramasivam, S.S. ; Ratnasingam, J. ; Chan, S.P. ; Tan, A.T.B. ; Vethakkan, S.R.
Tropical Biomedicine 2016;33(4):746-752
Dengue infection is endemic in South East Asia and parts of the Americas. Dengue
hemorrhagic fever is characterized by vascular permeability, coagulation-disorders and
thrombocytopenia, which can culminate in hypotension i.e. dengue shock syndrome.
Hypopituitarism arising as a complication of dengue is extremely rare. Hemorrhagic pituitary
apoplexy of pre-existing pituitary adenomas has been rarely reported in dengue. We describe
an uncommon case of hypopituitarism in a dengue shock syndrome survivor without known
pituitary adenoma. A 49 years old nulliparous lady (from Kuala Lumpur, Malaysia) presented
with typical symptoms of hypocortisolism. Postural hypotension was evident with normal
secondary sexual characteristics. Further history revealed that she survived an episode of
dengue shock syndrome 6 years ago where premature menopause developed immediately
after discharge, and subsequently insidious onset of multiple hormonal deficiencies indicative
of panhypopituitarism. There were no neuro-ophthalmological symptoms suggestive of pituitary
apoplexy during hospitalization for severe dengue. Magnetic resonance imaging of the pituitary
6 years later revealed an empty sella. Autoimmune screen and anti-thyroid peroxidase
antibodies were negative. We describe a rare possible causative association of severe dengue
with panhypopituitarism without known pituitary adenoma, postulating pituitary infarction
secondary to hypotension (mimicking Sheehan’s syndrome), or a direct viral cytopathic effect.
Subclinical pituitary apoplexy secondary to asymptomatic pituitary hemorrhage however
cannot be excluded. Future research is required to determine the need for and timing of
pituitary axis assessment among dengue shock syndrome survivors.
2.Prevalence of Toxoplasma gondii in pet and stray cats in Klang Valley, Malaysia
Tan, L.P. ; Megat Abd. Rani, P.A. ; Sharma, R.S.K. ; Syed Hussain, S.S. ; Watanabe, M.
Tropical Biomedicine 2020;37(No.3):542-550
Toxoplasma gondii, a zoonotic protozoan that has a worldwide distribution, is known to infect many warm-blooded vertebrates. The feline species including domestic cats are the definitive hosts for Toxoplama gondii and shed the infective oocyst. There is lack of information on the prevalence of Toxoplasma gondii in cats in Malaysia. The objective of this study was to determine both the seroprevalence of T. gondii and the prevalence of T. gondii DNA in cats’ feces in Klang Valley, Malaysia. 198 blood and 201 fecal samples were collected from pet and stray cats from the local council, Dewan Bandaraya Kuala Lumpur (DBKL) and University Veterinary Hospital, Universiti Putra Malaysia respectively. The overall seroprevalence of Toxoplasma gondii in cats in the Klang Valley was found to be 5.5%. There was a high prevalence (10.5%) of T. gondii DNA detected in the cat fecal samples in both pet and stray cats suggestive of T. gondii oocyst shedding. Stray cats showed a higher seroprevalence and molecular prevalence of T. gondii than the pet cats. However, comparative analysis using Chi-square test showed no significant difference between both groups (P>0.05). Higher prevalence (10.5%) of cats shedding T. gondii DNA as compared to the seroprevalence (5.5%) was found in the cat population in the Klang Valley. The high prevalence of cats shedding T. gondii DNA is alarming as this may directly reflect the number of oocysts excreted into the environment posing a significant public health hazard.
3.First molecular detection of Tritrichomonas foetus in domestic cats in Klang Valley, Malaysia
Tan, L.P. ; Megat Abd. Rani, P.A. ; Sharma, R.S.K. ; Syed Hussain, S.S. ; Watanabe, M.
Tropical Biomedicine 2020;37(No.3):756-762
Tritrichomonas foetus is known to cause chronic diarrhea in the feline species in many different regions of the world. However, there is a paucity of information on T. foetus among cats in Malaysia. This study was conducted to determine the prevalence of Tritrichomonas foetus in the pet and stray cat population in Klang Valley, Malaysia. A total of 201 pet and stray cats’ fecal samples were collected in Klang Valley. 24 samples were cultured in the InPouch® TF Feline to observe for motile trophozoites. A nested PCR protocol was used to screen for T. foetus in the collected samples. The prevalence of T. foetus in the cat population in Klang Valley was 33%. There was no association between Tritrichomonas infection and age, sex, breed or management of the cats. However, statistical analysis revealed that stray cats were more likely to be infected with T. foetus compared to pet cats. This study confirmed for the first time the presence of T. foetus among the cat population in Klang Valley, Malaysia.
4.Human leukocyte antigen (HLA) class II association in chronic hepatitis B patients with hepatocellular carcinoma in a Malay population: A pilot study
Krishnan, P.B ; Abdullah, M. ; Hudu, S.A ; Sekawi, Z. ; Tan, S.S. ; Amin-Nordin, S.
Tropical Biomedicine 2019;36(3):703-708
Asian countries account for almost three quarter of hepatocellular carcinoma
(HCC) reported globally and chronic hepatitis B infection is one of the main contributors.
Clinical observations show that Malay patients with chronic hepatitis B and HCC tend to have
a worse outcome, when compared to other two major races in Malaysia. The objectives of
this study was to determine the frequency of human leukocyte antigen (HLA) class II alleles
in chronic hepatitis B patients with HCC among Malays compared to the general population
to identify potential associations of HLA alleles with this disease. HLA class II typing was
performed in chronic hepatitis B patients with hepatocellular carcinoma (n=12) by -polymerase
chain reaction, sequence specific primer (PCR-SSP) method. There were higher allelic
frequencies of certain HLA-DQB1 and HLA-DRB1 alleles; HLA-DQB1*03 (07) (41.7%), and
HLA-DRB1*12 (41.7% vs 28.6%) and compared to controls (41.7% vs 29.7%). However, there
was no significant statistical correlation found when compared with the normal healthy
general population. This study provides an insight into the HLA Class II association with
chronic hepatitis B and hepatocellular carcinoma in Malays. However, findings from this
study should be validated with a larger number of samples using a high resolution HLA typing.
5.Development of a TaqMan minor groove binding probe-based quantitative reverse transcription polymerase chain reaction for the detection and quantification of Zika virus
Chin, K.L. ; Teoh, B.T. ; Sam, S.S. ; Loong, S.K. ; Tan, K.K. ; Azizan, N.S. ; Lim, Y.K. ; Khor, C.S. ; Nor&rsquo ; e, S.S. ; Abd-Jamil, J. ; AbuBakar, S.
Tropical Biomedicine 2022;39(No.4):518-523
6.Presence of SARS-CoV-2-like coronaviruses in bats from east coast Malaysia
Gilbert, M. ; Mohamed, M. ; Choong, S.S. ; Baqi, A. ; Kumaran, J.V. ; Sani, I. ; Noralidin, A ; Manaf, A. ; Reduan, F.H. ; Tan, L.P. ; Jusoh, M.
Tropical Biomedicine 2023;40(No.3):273-280
Most of the public health importance coronaviruses, such as Severe acute respiratory syndrome
coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-2
are likely originated from bats and spread to humans through intermediate hosts; civet cats, dromedary
camel and Malayan pangolin, respectively. SARS-CoV-2-like coronaviruses were detected in Thailand,
which is neighbouring with Kelantan in East Coast Malaysia. To date, there is no report on the presence
of public health concerns (SARS-CoV, SARS-CoV-2 and MERS-CoV) coronaviruses in bats from Malaysia.
This study was aimed to elucidate the presence of these coronaviruses in bat samples from East Coast,
Malaysia. A total of hundred seventy oropharyngeal swab samples were collected from three states
of East Coast Malaysia. Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was conducted
based on partial 3’ Untranslated region (3’UTR) or ORF10 gene and the products were sequenced. The
sequences were compared with all coronavirus sequences from the National Center for Biotechnology
Information-GenBank (NCBI-GenBank) using NCBI-Basic Local Alignment Search Tool (NCBI-BLAST)
software. A phylogenetic tree was constructed to determine the genetic relationship among the detected
coronaviruses with the reference coronaviruses from the NCBI-GenBank. Our results showed that SARSCoV-2-like viruses were present in 3% (5/170) of the bats from East Coast Malaysia that have 98-99%
sequence identities and are genetically related to SARS-CoV-2 from humans. This finding indicates the
presence of SARS-CoV-2-like viruses in bats from East Coast Malaysia that may become a public health
concern in the future.
7.First molecular detection of porcine circovirus type 4 (PCV4) in Malaysia
Tan, C.Y. ; Thanawongnuwech, R. ; Arshad, S.S. ; Hassan, L. ; Lee, C.Y. ; Low, S.E. ; Fong, W.C.M. ; Ooi, P.T.
Tropical Biomedicine 2023;40(No.3):301-306
Porcine circovirus type 4 (PCV4) is the newest member in the porcine circovirus family, first reported in
2020. To date, the presence of PCV4 has only been reported in China, South Korea and most recently
in Thailand. Detection of PCV4 have been reported in various production stages of pigs from piglets,
finishers to sows; associated with a myriad of clinical manifestations including porcine dermatitis and
nephropathy syndrome (PDNS), postweaning multisystemic wasting syndrome (PMWS), respiratory,
enteric and neurological diseases. While successful virus isolation and culture has yet to be reported,
pathogenicity of PCV4 has been demonstrated through infectious clone studies. The objective of this
study is to investigate the presence of PCV4 in Malaysian porcine population to update the epidemiology
of porcine circoviruses in Malaysia. A total of 49 samples from commercial intensive pig farms,
abattoir and wild boar population were subjected to conventional polymerase chain reaction assay to
detect PCV4 capsid (cap) genome. Resulting cap nucleotide sequences were analyzed for maximum
likelihood phylogeny relationship. Results revealed that PCV4 is present in Peninsular Malaysia at a
molecular prevalence of 4.08% (2 / 49 samples). Both PCV4 positive samples originated from clinically
healthy finishers. Malaysian PCV4 strains were classified as genotype PCV4b, and were found to be
phylogenetically distinct from the China, South Korea and Thailand strains. With this latest update of
the novel PCV4 in Malaysia, it is clear that more attention needs to be given to the investigation of
novel porcine circoviruses (PCV) and management of PCV diseases.
8.Multiplex sequencing of SARS-Cov-2 genome directly from clinical samples using the Ion Personal Genome Machine (PGM)
Tan, K.K. ; Tiong, V. ; Tan, J.Y. ; Wong, J.E. ; Teoh, B.T. ; Abd-Jamil, J. ; Johari, J. ; Nor&rsquo ; e, S.S. ; Khor, C.S. ; Yaacob, C.N. ; Zulkifli, M.M.S. ; CheMatSeri, A. ; Mahfodz, N.H. ; Azizan, N.S. ; AbuBakar, S.
Tropical Biomedicine 2021;38(No.3):283-288
Various methods have been developed for rapid and high throughput full genome sequencing of SARS-CoV-2. Here, we described a protocol for targeted multiplex full genome sequencing of SARS-CoV-2 genomic RNA directly extracted from human nasopharyngeal swabs using the Ion Personal Genome Machine (PGM). This protocol involves concomitant amplification of 237 gene fragments encompassing the SARS-CoV-2 genome to increase the abundance and yield of viral specific sequencing reads. Five complete and one near-complete genome sequences of SARS-CoV-2 were generated with a single Ion PGM sequencing run. The sequence coverage analysis revealed two amplicons (positions 13 751-13 965 and 23 941-24 106), which consistently gave low sequencing read coverage in all isolates except 4Apr20-64Hu. We analyzed the potential primer binding sites within these low covered regions and noted that the 4Apr20-64-Hu possess C at positions 13 730 and 23 929, whereas the other isolates possess T at these positions. The genome nucleotide variations observed suggest that the naturally occurring variations present in the actively circulating SARS-CoV-2 strains affected the performance of the target enrichment panel of the Ion AmpliSeq™ SARS CoV 2 Research Panel. The possible impact of other genome nucleotide variations warrants further investigation, and an improved version of the Ion AmpliSeq™ SARS CoV 2 Research Panel, hence, should be considered.