Browsing by Subject "Malaysia"

Background: Torque Teno Virus (TTV) is ubiquitous, possibly zoonotic, and has potential for clinical and global health research application. The goals of the current study were to determine prevalence of TTV among pneumonia patients in two Malaysian hospitals, compare results from qPCR and conventional PCR detection methods, and to compare TTV infection against self-reported exposure to bushmeat products.

Methods: Medical officers obtained plasma, PBMC, and NP swab samples, along with bushmeat exposure information from 34 pneumonia patients in Sibu and Kapit hospitals. Samples were tested for TTV using qPCR. Results were corroborated using conventional PCR. Cornfield’s and McNemar’s exact methods were used to analyze infection by exposure, and agreement between PCR results respectively. Diagnostic abilities of the qPCR test were analyzed using conventional PCR as the gold standard.

Results: Conventional PCR reported 17.65% TTV prevalence, while qPCR reported 91.18%. Household size (OR=0.00, 95% CI=0.00, 0.96) and gender (OR=infinity, 95% CI=1.39, infinity) had statistically significant impacts on odds of infection. The qPCR method showed 100% sensitivity, but 7.69% specificity.

Conclusions: Results suggest low prevalence of TTV within the study population, and reaffirm findings by other researchers that smaller household size and being female are associated with decreased odds of TTV infection. Though statistically insignificant, indications that exposure to bushmeat in general increases odds of TTV infection should be investigated further. Researchers must be aware of differences in diagnostic capabilities between PCR methods for TTV detection when designing their own diagnostic studies or conducting TTV related literature reviews.

Background

Melioidosis is a neglected tropical disease that is highly prevalent in Southeast Asia. Misdiagnoses are common as the presenting symptoms are similar to other diseases including upper respiratory infections. When not treated with antibiotics, the disease can lead to severe morbidity or death. Current diagnostics in low- and middle-income countries are often not sensitive nor rapid. Point-of-care rapid diagnostic tests (POC-RDTs) are a potential solution. Few studies have compared the accuracy of POC-RDTs and molecular assays against blood culture. The goal of this study was to conduct such comparisons in detecting Burkholderia pseudomallei infections among infection-suspected patients in Kapit, Sarawak, Malaysia.

Methods

We used an informed consent process as approved by two institutional review boards. In this cross-sectional study, we engaged patients meeting a melioidosis-like case definition that included classical symptoms such as prolonged fever with joint pain and/or abscess. We studied the patients routinely collected clinical specimens with a POC-RDT (Active Melioidosis DetectTM) and a molecular assay compared with the B. pseudomallei bacterial culture for isolation of the bacterial organism.

Results

One hundred patients aged 6 months - 79 years from Kapit Hospital were enrolled in the study from June 12, 2018 to January 8, 2019. Of the 100 sera, 97 urine, and 16 bodily fluid samples (total n= 213) tested with the RDT, 23 samples gave positive results (7 sera, 15 urine, and 1 bodily fluids). Compared to the molecular assay, the POC-RDT had a sensitivity of 40% (95% CI, 5%- 85%), specificity of 94% (95% CI, 87% - 98%), and an accuracy of 90% (95 CI, 82% - 95%) for sera; and a sensitivity of 80% (95% CI, 28%- 99%),a specificity of 65% (95% CI, 55% - 75%), and an accuracy of 87% (95 CI, 77% - 94%) for urine; and a sensitivity of 80% (95% CI, 28%- 99%), a specificity of 65% (95% CI, 55% - 75%), and an accuracy of 81% (95 CI, 54% - 96%) for other bodily fluids. Additionally, when compared to the bacterial culture results, the POC-RDT showed a sensitivity of 38% (95% CI, 9%- 76%), specificity of 95% (95% CI, 88% - 99%), and an accuracy of 90% (95 CI, 82% - 95%) for sera; a sensitivity of 88% (95% CI, 47%- 100%), a specificity of 88% (95% CI, 77% - 95%), and an accuracy of 94% (95 CI, 84% - 98%) for urine; and a sensitivity of 25% (95% CI, 1%- 81%), a specificity of 100% (95% CI, 74% - 100%), and an accuracy of 81% (95 CI, 54% - 96%) for other bodily fluids.

Conclusion

While study enrollment will continue, data from the first 100 participants, suggests the POC-RDT had poor sensitivity, good accuracy, and high specificity in detecting B. pseudomallei infection. Thus far, the POC-RDT assay seems to work better on urine specimens. Due to low sensitivity, the study data do not support recommending POC-RDT strips as a single diagnostic method. However, as the POC-RDT had high specificity when the test is positive it seems appropriate for clinicians to assume the patient is infected and to prescribe specific antimicrobial therapy. While more participant data are needed, it seems likely that the POC-RDT could be useful in helping physicians to begin treatment early with the high specificity that the POC-RDT has exhibited. If paired with an RDT with high sensitivity, this POC-RDT would add a great value to infection management.

Background: Recent epidemiological studies demonstrate that the prevalence of the fifth major human malaria parasite, Plasmodium knowlesi (monkey malaria), is often underestimated and misdiagnosed with standard microscopy blood film. We sought to adapt and compare a new simple molecular diagnostic method for P. knowlesi with the gold standard nested molecular assay and microscopy blood film in P. knowlesi hotspot areas in Sarawak, Malaysia. In addition, we analyzed the statistical association between P. knowlesi positive test results and demographic and behavioral/occupational risk factors.

Methods: The study was conducted at Sibu, Kapit and Sarikei Hospitals in Sarawak, Malaysia. 115 blood samples were collected from malaria suspected patients seeking treatment at these hospitals. Samples were analyzed by microscopy, Nested polymerase chain reaction (PCR) and single-step PCR. Sensitivity, specificity, and practical value of the new single-step PCR assay was calculated. Bivariate and multivariate regression was conducted to test the possible risk factors for the detection of P. knowlesi.

Results: Single-step PCR showed low sensitivity (51.92%, 95%CI 37.63 - 65.99%) compared to nested PCR and 46.03% (95%CI 33.39 - 59.06%) compared to microscopy. When compared to nested PCR, microscopy had a false positive rate of 20.6%. However, it only missed 2 cases of P. knowlesi. The mean age in the study population was 40.35. Patients enrolled at Kapit hospital had higher odds ratio for positive P. knowlesi PCR results (adjusted OR = 4.46, 95%CI 1.16 – 11.51). Age above 21 years (adjusted OR = 6.28, 95%CI 1.53 – 25.64), male gender (adjusted OR = 2.46, 95%CI 0.91 – 6.65) and living near a vegetation (Plantation, forest, fruit trees or wet rice paddy) (adjusted OR = 5.96, 95%CI 1.11 – 31.83) were associated with increased risk for P. knowlesi infection.

Conclusions: Data from this study showed that single-step PCR has a low sensitivity and thus, it is not a suitable alternative for accurate detection of P. knowlesi. Further studies are required for assessment and development of other diagnostic assays or new primer sets. Multivariate analysis revealed that adult men over the age of 21 who live near agricultural areas have the highest risk for P. knowlesi malaria infection. Large- scale descriptive studies of both non-human hosts and vectors would greatly influence prevention and control strategies of this zoonotic disease.

Introduction: According to the World Health Organization (WHO), 500 million arbovirus cases are diagnosed around the world annually, with 2.7 million associated deaths [1]. The burden of disease caused by dengue, chikungunya, and Zika viruses is likely to be underestimated due to a lack of accurate diagnostic tools and knowledge gaps regarding their epidemiology [2, 3]. This thesis uses a subset of data from an on-going 24-month study to evaluate the potential etiology of dengue-like symptoms of patients recruited from medical facilities in Sarawak, Malaysia. A secondary aim is to assess the diagnostic clinical effectiveness of a new detection method, the novel T-Cor 8 Multiplexing Platform (Tetracore, Inc., USA), using qRT-PCR assays as the gold standard method for comparison. The prevalence of arboviral infections as determined by gold-standard qRT-PCR assays and potential risk factors in the study population were also analysed.

Methods: In this cross-sectional study, patients more than seven years of age with dengue-like symptoms were enrolled at medical facilities in the towns of Sibu and Kapit in Sarawak, Malaysia. Blood, urine, and gingival crevicular fluid samples, as well as risk factor data, were collected from participants at the time of enrolment. These samples were studied by qRT-PCR assays and the novel T-Cor 8 Multiplexing Platform.

Results: Seven (14%) of 51 participants’ serum RNA samples tested positive for arbovirus infection by gold-standard qRT-PCR assays. Two participants (4%) were positive for dengue subtype-1, four participants (8%) were positive for dengue subtype-2, and one participant (2%) was positive for dengue subtype-4. No patient samples had molecular evidence of chikungunya or Zika viruses. The T-Cor 8 multiplexing platform demonstrated a 71% sensitivity (95% confidence interval 29-96%), 93% specificity (95% confidence interval 81-99%), and 90% accuracy (95% confidence interval 78-97%) compared to the gold-standard assays on serum RNA samples. From this subset of data, we failed to identify important risk factors for arboviral infection.

Conclusion: From this limited subset of data, we conclude that the T-Cor 8 platform’s simplicity and accuracy in detecting at least dengue virus infections has considerable potential for clinical usefulness in low-resource settings.

Introduction: Pneumonia, despite its stereotype as a routine disease, remains the leading cause of morbidity and mortality among children under five worldwide, responsible for nearly 16% of all childhood deaths(1). With an imprecise definition and multiple etiologies, diagnosis and treatment of the disease is difficult when based solely on clinical and symptomatic manifestations(2). This study was conducted as a subset of an ongoing year-long study aimed to determine the viral etiology of and risk factors for pneumonia among 600 patients admitted to Sibu and Kapit Hospitals in Sarawak, Malaysia. Specifically, this sub-study examined molecular diagnostics for two common respiratory pathogens, which often infect children seen at these hospitals and which lacked any such diagnostic capability. We sought to determine the prevalence of respiratory syncytial virus (RSV) subtypes A and B and parainfluenza virus (PIV) types 1- 4. The study describes demographic, viral and behavioral risk factors for these admissions. Additionally, the study aimed to assess viral transmission in the air in hospital wards.

Methods: To determine the viral etiology of pneumonia cases, this cross-sectional study enrolled 129 patients over the age of one month, who had been diagnosed and hospitalized with pneumonia at Sibu or Kapit Hospital in Sarawak, Malaysia between June 15 and July 27, 2017. Nasopharyngeal (NP) swabs were collected and analyzed using real-time reverse transcription polymerase chain reaction (qRT-PCR) at Sibu Hospital’s Clinical Research Centre laboratory. A multivariable model was used to assess risk factors for the presence of different respiratory viruses.

Results: Of 129 specimens collected, 40 samples tested positive for RSV-A (31.01%), two were positive for RSV B (01.55%), one was positive for PIV-3 (0.78%) and one was positive for PIV-4 (0.78%). No samples were positive for PIV-1 or PIV-2. The prevalence of RSV-A was 46% (23/50) at Kapit Hospital and 21.52% at Sibu Hospital (17/79). In Sibu Hospital’s pediatric wards, one bioaerosol tested positive for adenovirus and two tested as suspect-positives for adenovirus. One (1) bioaerosol sample from an adult ward at Sibu Hospital tested as a suspect-positive for RSV-A. A multivariable analysis found risk factors of age (>1 year and 1-5 years vs > 5 years) and location of hospitalization (Kapit vs Sibu) potentially important predictors of RSV-A molecular detection.

Conclusions: During this brief demonstration study, we found a high prevalence of RSV-A among pneumonia patients admitted to the two hospitals. Having routine diagnostic capability for these viruses, particularly RSV, could help clinicians prescribe antiviral therapies which could reduce RSV morbidity and mortality.