1.Decrease in RT-PCR Ct values among SARS-CoV-2 positive samples during the emergence of B.1.617.2 (Delta) variant in Malaysia
Che-Kamaruddin N. ; Teoh B.T. ; Tan K.K. ; Tan J.Y. ; Wong J.E. ; Tiong V. ; Abd-Jamil J. ; Nor&rsquo ; e S.S. ; Khor C.S. ; Johari J. ; Yaacob C.N. ; Zulkifli M.M.S. ; CheMatSeri A. ; Mahfodz N.H. ; Azizan N.S. ; AbuBakar S.
Tropical Biomedicine 2025;42(No. 1):1-9
Reverse transcription-polymerase chain reaction (RT-PCR) cycle threshold (Ct) value in detecting the
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is inversely proportionate to
the virus load in the patient’s specimen. These values could be beneficial in the epidemic trajectory
at the population level. The SARS-CoV-2 B.1.617.2 (Delta) variant which emerged in late 2020, caused
an unprecedented exponential increase in SARS-CoV-2 infection cases worldwide. In Malaysia, the
surge in coronavirus disease 2019 (COVID-19) cases and the inclining positivity rate contributed to the
epidemic waves in late May 2021. Sudden surge in cases was suggested to be associated with increased
transmission caused by the emergence of the B.1.617.2 variant. In the present study, Ct value distribution
of the positive COVID-19 samples from 2020 and 2021 was tabulated against SARS-CoV-2 genomic
variants determined from genomic sequencing. A significant decreasing pattern of median Ct values
from overall 2020 and 2021 samples was evident (p<0.01). However, notable variability was observed
in the Ct values between 2020 and 2021, which samples showing lower median Ct values in 2021. The
percentages of SARS-CoV-2 genomic variants B.1.36 and B.1.524 were 31.6% and 68.4%, respectively,
for samples obtained in October and December 2020. Whereas samples obtained in June and July 2021
were 100% of the B.1.617.2 variant. The population neutralizing antibody against SARS-CoV-2 during
the initial peak of B.1.617.2 was low, however, increased during the B.1.617.2 wave. A decreasing trend
in the Ct value distribution from samples tested in our laboratory correlated well with the increasing
weekly COVID-19 cases reported by the Malaysia national data, which was subsequently attributed to
the emergence of B.1.617.2 variant. This study proposes that analyzing Ct value distribution in screened
SARS-CoV-2 samples could reveal population-level transmission dynamics and emerging variants.
Coupled with genomic sequencing, it supports early control strategies against new SARS-CoV-2 strains.
2.Assessment of Fasciola and Paramphistomes co-infection in large ruminants through faecal egg counts around Taiping, Malaysia
Che-Kamaruddin, N. ; Isa, N.M.M.
Tropical Biomedicine 2023;40(No.3):344-350
Emerging cases of Fasciola and Paramphistomes co-infection have been reported, especially in tropical
regions. Thisis due to Fasciola and Paramphistomes sharing biological factors which influence the pattern
of transmission, especially in faecal egg shedding due to interaction and competition in the definitive
host. Most reports surveyed the occurrence of fasciolosis in ruminants with a lack of observation of
faecal egg distribution. Therefore, present study is aimed to assess the distribution of Fasciola and
Paramphistomes faecal egg count (fec) in co-infected large ruminants in Larut, Matang, and Selama areas
(Taiping). A total of 371 faecal samples were collected at random from 23 ruminant herds. Flukefinder®
sedimentation was used to quantify the Fasciola and Paramphistomes eggs. Descriptive analyses were
performed to determine the prevalence of co-infections, and Spearman correlation analysis was used
to correlate the fec. Overall, the prevalence of Fasciola and Paramphistomes co-infection was 23.7%
(n=89/371) in Taiping. Prevalence of paramphistomosis was always higher than fasciolosis in overall
and single infection, with 46.9% (n=174/371) and 22.9% (n=85/371) compared to 36.9% (n=137/371)
and 12.9% (n=48/371) respectively. Egg per gram (epg) of both parasites were positively skewed with
a median of 1.5 epg in fasciolosis and 10.5 epg in paramphistomosis. Spearman correlation analysis
of the epg in co-infected bovine was found to have a moderately positive correlation with rs=0.39
(p-value<0.01). The recent study observed a moderate prevalence of Fasciola and Paramphistomes coinfection in a large ruminant population from Taiping, with the prevalence of paramphistomosis being
higher than fasciolosis. Hence, this suggests that infection with one of these parasites increases the
chance of infection with another. There is a need to integrate fec in parasite surveillance to monitor the
trend of parasite transmission. Findings in the present study could tailor control strategies, especially
for fasciolosis to limit the economic loss and prevent zoonotic transmission.


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