MyMedR

Displaying publications 21 - 27 of 27 in total

Abstract:

Sort:

Exotic and emerging viral encephalitides

Solomon T

Curr. Opin. Neurol., 2003 Jun;16(3):411-8.
PMID: 12858080

The exotic and emerging viral encephalitides are caused by animal or human viruses and characterised by sudden unexpected outbreaks of neurological disease, usually in tropical and sub-tropical regions, but sometimes spreading to temperate areas. Although a wide range of viruses come within this label, as this review highlights, there are common research questions as to the origin and spread of the viruses, the contribution of viral and host factors to the clinical presentations and outcome, and the possibilities for treatment and vaccination.

Matched MeSH terms: West Nile Fever/virology
A descriptive analysis of clinical characteristics of COVID-19 among healthcare workers in a district specialist hospital

Tan-Loh J, Cheong BMK

Med J Malaysia, 2021 01;76(1):24-28.
PMID: 33510104

INTRODUCTION: COVID-19 is a highly transmissible respiratory virus that has affected millions of people worldwide in the span of months. The burden of disease among healthcare workers (HCW) has not been well studied despite reports of infectivity and transmission around the world. Two HCW in Hospital Teluk Intan (HTI) contracted COVID-19 while attending a social event. They were in close proximity with colleagues upon returning to work, resulting in the spread of infection among other HCW in HTI.
OBJECTIVE: The objectives of this paper are to gain a better understanding of the key presenting symptoms of COVID-19 in HCWs in a district specialist hospital, to establish the proportion of symptomatic COVID-19 cases among HCWs and its severity and to determine the time taken from onset of symptoms or perceived exposure to diagnostic testing.
METHODOLOGY: This is a retrospective descriptive analysis of clinical characteristics of subjects infected with COVID-19 among HCW in HTI. Their demography and clinical characteristics were recorded.
RESULTS: There were 47 HCW in HTI who tested positive for COVID-19. The mean age of the patients was 37.5 years old. 7 patients (15.2%) had at least more than one comorbidity. Average duration of time from perceived close contact to onset of symptom was 4.5 days, while the mean duration of time from symptoms to first positive RT-PCR result was 3.4 days. Six patients (13.0%) were asymptomatic throughout, whereas 40 (87.0%) had at least one symptom prior to hospitalization. The most commonly reported symptoms were fever (65.2%), sore throat (39.1%) and cough (37.0%). In terms of severity of symptoms, the majority of patients experienced mild symptoms (Group 2, 52.2%). Two patients (4.3%) with multiple comorbidities had severe disease requiring ICU admission and mechanical ventilation. There were no mortalities, and the longest staying patient was hospitalized for 18 days. The high rates of infectivity among HCW in HTI can be attributed to working in close proximity while in the asymptomatic incubation phase, while no HCW directly involved in the care of COVID-19 positive patients were tested positive.
CONCLUSION: We report that HCW share similar clinical characteristics of COVID-19 infection as those of non HCW patients in earlier studies. The infection can spread rapidly within healthcare settings via close contacts among infected HCWs. As such, we advocate distancing when working and usage of personal protective equipment when treating patients with respiratory illness to reduce transmission of COVID-19.

Matched MeSH terms: Fever/virology
Differential Diagnosis of Flavivirus Infections in Horses Using Viral Envelope Protein Domain III Antigens in Enzyme-Linked Immunosorbent Assay

Piyasena TBH, Setoh YX, Hobson-Peters J, Prow NA, Bielefeldt-Ohmann H, Khromykh AA, et al.

Vector Borne Zoonotic Dis, 2017 12;17(12):825-835.
PMID: 29083957 DOI: 10.1089/vbz.2017.2172

In Australia, infection of horses with the West Nile virus (WNV) or Murray Valley encephalitis virus (MVEV) occasionally results in severe neurological disease that cannot be clinically differentiated. Confirmatory serological tests to detect antibody specific for MVEV or WNV in horses are often hampered by cross-reactive antibodies induced to conserved epitopes on the envelope (E) protein. This study utilized bacterially expressed recombinant antigens derived from domain III of the E protein (rE-DIII) of MVEV and WNV, respectively, to determine whether these subunit antigens provided specific diagnostic markers of infection with these two viruses. When a panel of 130 serum samples, from horses with known flavivirus infection status, was tested in enzyme-linked immunosorbent assay (ELISA) using rE-DIII antigens, a differential diagnosis of MVEV or WNV was achieved for most samples. Time-point samples from horses exposed to flavivirus infection during the 2011 outbreak of equine encephalitis in south-eastern Australia also indicated that the rE-DIII antigens were capable of detecting and differentiating MVEV and WNV infection in convalescent sera with similar sensitivity and specificity to virus neutralization tests and blocking ELISAs. Overall, these results indicate that the rE-DIII is a suitable antigen for use in rapid immunoassays for confirming MVEV and WNV infections in horses in the Australian context and warrant further assessment on sensitive, high-throughput serological platforms such as multiplex immune assays.

Matched MeSH terms: West Nile Fever/virology
Fulltext Knowledge, attitudes and practices towards antibiotic use in upper respiratory tract infections among patients seeking primary health care in Singapore

Pan DS, Huang JH, Lee MH, Yu Y, Chen MI, Goh EH, et al.

BMC Fam Pract, 2016 11 03;17(1):148.
PMID: 27809770 DOI: 10.1186/s12875-016-0547-3

BACKGROUND: Patients' expectations can influence antibiotic prescription by primary healthcare physicians. We assessed knowledge, attitude and practices towards antibiotic use for upper respiratory tract infections (URTIs), and whether knowledge is associated with increased expectations for antibiotics among patients visiting primary healthcare services in Singapore.

METHODS: Data was collected through a cross-sectional interviewer-assisted survey of patients aged ≥21 years waiting to see primary healthcare practitioners for one or more symptoms suggestive of URTI (cough, sore throat, runny nose or blocked nose) for 7 days or less, covering the demographics, presenting symptoms, knowledge, attitudes, beliefs and practices of URTI and associated antibiotic use. Univariate and multivariate logistic regression was used to assess independent factors associated with patients' expectations for antibiotics.

RESULTS: Nine hundred fourteen out of 987 eligible patients consulting 35 doctors were recruited from 24 private sector primary care clinics in Singapore. A third (307/907) expected antibiotics, of which a substantial proportion would ask the doctor for antibiotics (121/304, 40 %) and/or see another doctor (31/304, 10 %) if antibiotics were not prescribed. The majority agreed "antibiotics are effective against viruses" (715/914, 78 %) and that "antibiotics cure URTI faster" (594/912, 65 %). Inappropriate antibiotic practices include "keeping antibiotics stock at home" (125/913, 12 %), "taking leftover antibiotics" (114/913, 14 %) and giving antibiotics to family members (62/913, 7 %). On multivariate regression, the following factors were independently associated with wanting antibiotics (odds ratio; 95 % confidence interval): Malay ethnicity (1.67; 1.00-2.79), living in private housing (1.69; 1.13-2.51), presence of sore throat (1.50; 1.07-2.10) or fever (1.46; 1.01-2.12), perception that illness is serious (1.70; 1.27-2.27), belief that antibiotics cure URTI faster (5.35; 3.76-7.62) and not knowing URTI resolves on its own (2.18; 1.08-2.06), while post-secondary education (0.67; 0.48-0.94) was inversely associated. Those with lower educational levels were significantly more likely to have multiple misconceptions about antibiotics.

CONCLUSION: Majority of patients seeking primary health care in Singapore are misinformed about the role of antibiotics in URTI. Agreeing with the statement that antibiotics cure URTI faster was most strongly associated with wanting antibiotics. Those with higher educational levels were less likely to want antibiotics, while those with lower educational levels more likely to have incorrect knowledge.

Matched MeSH terms: Fever/virology
Deciphering the potential of baicalin as an antiviral agent for Chikungunya virus infection

Oo A, Rausalu K, Merits A, Higgs S, Vanlandingham D, Bakar SA, et al.

Antiviral Res, 2018 02;150:101-111.
PMID: 29269135 DOI: 10.1016/j.antiviral.2017.12.012

The past decade has seen the re-emergence of Chikungunya virus (CHIKV) as a major global health threat, affecting millions around the world. Although fatal infections are rare among infected patients, the occurrence of long-lasting polyarthralgia has a significant impact on patients' quality of lives and ability to work. These issues were the stimuli for this study to determine the potential of baicalin, a bioflavonoid, as the novel antiviral compound against CHIKV. It was found that baicalin was well tolerated by Vero, BHK-21 and HEK 293T cells with maximal nontoxic doses >600 μM, ≈ 350 μM and ≈110 μM, respectively. Antiviral assays indicated that baicalin was the most effective inhibitor when tested for its direct virucidal activity with EC50 ≈ 7 μM, followed by inhibition of virus entry into the host cell, attachment of virus particle to cellular receptors and finally intracellular replication of viral RNA genome. In silico analysis using molecular docking demonstrated close interactions between baicalin and CHIKV envelope protein with considerably strong binding affinity of -9.7 kcal/mol. qRT-PCR analysis revealed that baicalin had the greatest effect on the synthesis of viral negative stand RNA with EC50 ≈ 0.4 μM followed by the inhibition of synthesis of positive-strand genomic (EC50 ≈ 13 μM) and subgenomic RNAs (EC50 ≈ 14 μM). These readings indicate that the compound efficiently inhibits replicase complexes formation but is a less potent inhibitor of existing replicase complexes. Coherent with this hypothesis, the use of recombinant CHIKV replicons harboring Renilla luciferase marker showed that replication of corresponding replicon RNAs was only slightly downregulated at higher doses of baicalin, with EC50 > 100 μM. Immunofluorescence and western blotting experiments demonstrated dose-dependent inhibition of expression of different viral proteins. It was also observed that levels of important protein markers for cellular autophagy (LC3) and apoptosis (Bax) were reduced in baicalin treatment groups as compared with untreated virus infected controls. In summary, given its low toxicity and high efficacy against CHIKV, baicalin has great potential to be developed as the novel antiviral compound for CHIKV. In vivo studies to evaluate its activity in a more complexed system represent a necessary step for future analysis.

Matched MeSH terms: Chikungunya Fever/virology*
Fulltext Serological Evidence of Zika Virus Infection in Febrile Patients and Healthy Blood Donors in Sabah, Malaysian Borneo, 2017-2018

Ngwe Tun MM, Mori D, Sabri SB, Kugan O, Shaharom SB, John J, et al.

Am J Trop Med Hyg, 2021 Nov 22;106(2):601-606.
PMID: 34814105 DOI: 10.4269/ajtmh.21-0802

Several Zika virus (ZIKV) seroprevalence studies have been conducted in Africa, Asia, Oceania, the Americas, and the Caribbean. However, studies on ZIKV seroprevalence are limited in Malaysia though several studies have shown that the disease is endemic in the Malaysian state of Sabah. To evaluate the seroprevalence of ZIKV infection, 818 serum samples were collected from febrile patients and healthy blood donors from the Kudat and Kota Kinabalu districts in Sabah from 2017 to 2018. They were screened for ZIKV infection by IgM and IgG ELISA, and positive ZIKV IgM samples were subjected to a 90% neutralization test for confirmation. Twenty-four (6% [95% CI 4 to 8]) confirmed and two (0.5% [95% CI 0.13 to 1.8]) probable ZIKV infections were detected among 400 febrile illness patients. Of 418 healthy blood donor samples, six (1.4% [95% CI 0.65 to 3]) were determined as confirmed ZIKV infections and six (1.4% [95% CI 0.65 to 3]) indicated probable ZIKV infection. This is the first study on the seroprevalence of ZIKV infections among patients and healthy blood donors in Sabah. Compared with previous studies in Malaysia, this study shows that the incidence of ZIKV infection has increased. It also suggests that a sero-surveillance system is essential to determine the circulation of ZIKV in Sabah, Malaysia.

Matched MeSH terms: Fever/virology*
The relationships between West Nile and Kunjin viruses

Scherret JH, Poidinger M, Mackenzie JS, Broom AK, Deubel V, Lipkin WI, et al.

Emerg Infect Dis, 2001 Jul-Aug;7(4):697-705.
PMID: 11585535

Until recently, West Nile (WN) and Kunjin (KUN) viruses were classified as distinct types in the Flavivirus genus. However, genetic and antigenic studies on isolates of these two viruses indicate that the relationship between them is more complex. To better define this relationship, we performed sequence analyses on 32 isolates of KUN virus and 28 isolates of WN virus from different geographic areas, including a WN isolate from the recent outbreak in New York. Sequence comparisons showed that the KUN virus isolates from Australia were tightly grouped but that the WN virus isolates exhibited substantial divergence and could be differentiated into four distinct groups. KUN virus isolates from Australia were antigenically homologous and distinct from the WN isolates and a Malaysian KUN virus. Our results suggest that KUN and WN viruses comprise a group of closely related viruses that can be differentiated into subgroups on the basis of genetic and antigenic analyses.

Matched MeSH terms: West Nile Fever/virology*