Susceptible and Protective HLA Class 1 Alleles against Dengue Fever and Dengue Hemorrhagic Fever Patients in a Malaysian Population

BACKGROUND: The human leukocyte antigen alleles have been implicated as probable genetic markers in predicting the susceptibility and/or protection to severe manifestations of dengue virus (DENV) infection. In this present study, we aimed to investigate for the first time, the genotype variants of HLA Class 1(-A and -B) of DENV infected patients against healthy individuals in Malaysia. METHODOLOGY/PRINCIPAL FINDINGS: This study was carried out with 92 dengue disease patients and 95 healthy controls from three different ethnic groups (Malay, Chinese and Indian) in Malaysia. All patients with clinical and laboratory confirmation of DENV infection were typed for the HLA-A and B loci, using polymerase chain reaction-sequence specific primer techniques. In our total population, a significant increase for HLA-B*53 (P = 0.042, Pc = 1.008) allele and a significant decrease for A*03 (P = 0.015, Pc = 0.18, OR = 5.23, 95% CI = 1.19-23.02) and B*18 (P = 0.017, Pc = 0.408) alleles were noted in DHF patients as compared to healthy donors. We also observed that in the Malay DHF patients, allele B*13 (P = 0.049, Pc = 1.176, OR = 0.18, 95% CI = 0.03-0.90) was present at a significantly higher frequency in this population while allele HLA-B*18 (P = 0.024, Pc = 0.576) was seen to be negatively associated with DHF. CONCLUSIONS/SIGNIFICANCE: These are the first findings on genetic polymorphisms in our population and we conclude that: (1) In our total population, HLA-B*53 probably involve in disease susceptibility, while the HLA-A*03 and HLA-B*18 may confer protection from progression to severe disease; (2) In the Malay population, HLA-B*13 and B*18 are probably associated in disease susceptibility and protection, respectively. These results could furnish as a valuable predictive tool to identify ethnically different individuals at risk and/or protection from severe forms of DENV infection and would provide valuable informations for the design of future dengue vaccine

Cytokine expression profile of dengue patients at different phases of illness

Background: Dengue is an important medical problem, with symptoms ranging from mild dengue fever to severe forms of the disease, where vascular leakage leads to hypovolemic shock. Cytokines have been implicated to play a role in the progression of severe dengue disease; however, their profile in dengue patients and the synergy that leads to continued plasma leakage is not clearly understood. Herein, we investigated the cytokine kinetics and profiles of dengue patients at different phases of illness to further understand the role of cytokines in dengue disease. Methods and Findings: Circulating levels of 29 different types of cytokines were assessed by bead-based ELISA method in dengue patients at the 3 different phases of illness. The association between significant changes in the levels of cytokines and clinical parameters were analyzed. At the febrile phase, IP-10 was significant in dengue patients with and without warning signs. However, MIP-1 beta was found to be significant in only patients with warning signs at this phase. IP-10 was also significant in both with and without warning signs patients during defervescence. At this phase, MIP-1b beta and G-CSF were significant in patients without warning signs, whereas MCP-1 was noted to be elevated significantly in patients with warning signs. Significant correlations between the levels of VEGF, RANTES, IL-7, IL-12, PDGF and IL-5 with platelets; VEGF with lymphocytes and neutrophils; G-CSF and IP-10 with atypical lymphocytes and various other cytokines with the liver enzymes were observed in this study. Conclusions: The cytokine profile patterns discovered between the different phases of illness indicate an essential role in dengue pathogenesis and with further studies may serve as predictive markers for progression to dengue with warning signs

Результаты внедрения новой формы управляемой самостоятельной работы студентов в учебный процесс на кафедре патофизиологии

МЕДИЦИНСКИЕ ИНСТИТУТЫОБУЧЕНИ

Evaluation of the dried blood spot (DBS) collection method as a tool for detection of HIV Ag/Ab, HBsAg, anti-HBs and anti-HCV in a Malaysian tertiary referral hospital

INTRODUCTION: Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter. MATERIALS AND METHODS: A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard. RESULTS: For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs. CONCLUSION: DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres

The role of hospital environment in transmissions of multidrug-resistant gram-negative organisms

10.1186/s13756-020-0685-1Antimicrobial Resistance and Infection Control912

Strategies to reduce hospital-associated bloodstream infections in a limited resource setting: Preventing Infections in Neonates (PIN) collaborative

Abstract Background: Hospitalized neonates are at high risk for hospital-associated bloodstream infections (HA-BSI) and require locally contextualized interventions to prevent HA-BSI. Methods: The Preventing Infections in Neonates (PIN) collaborative aimed to reach a 50% decrease in neonatal HA-BSI rates for a 27-bed Level IV neonatal intensive care unit (NICU). Using quality improvement (QI) methodologies, a multidisciplinary cross-cultural collaborative implemented phased and bundled interventions from July 2017 to September 2019. Descriptive statistics and statistical process control charts were used to analyze infection rates. Results: There were 916 admissions, 19,812 patient-days, and 4264 central line days in the NICU during the project period. Monthly baseline preintervention HA-BSI median rate was 3.95/1000 patient-days and decreased to 1.73/1000 patient-days (56% change) during the bundled interventions. Quarterly HA-BSI rates also decreased from the preintervention median of 4.5/1000 patient-days to 3.3/1000 patient-days during the intervention period (IRR 0.73; 95%CI 0.39, 1.36). Staff were highly compliant with hand hygiene and environmental cleaning. Through project efforts, compliance with bundle elements increased from 25% at baseline to a peak of 97% for central line (CL) insertion checklists and from 13% to a peak of 56% for CL maintenance checklists. Conclusions: Unit-based bundled interventions can reduce neonatal HA-BSI in limited resource settings. Future studies can assess similar practices in other units and the impact of the pandemic on interventions to reduce HA-BSIs

Tuberculosis (TB)-associated immune reconstitution inflammatory syndrome in TB-HIV co-infected patients in Malaysia: prevalence, risk factors, and treatment outcomes

Background: Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is an important early complication of antiretroviral therapy (ART) in countries with high rates of endemic TB, but data from South-East Asia are incomplete. Identification of prevalence, risk factors and treatment outcomes of TB-IRIS in Malaysia was sought. Methods: A 3-year retrospective study was conducted among TB-HIV co-infected patients treated at the University of Malaya Medical Centre. Simple and adjusted logistic regressions were used to identify the predictors for TB-IRIS while Cox regression was used to assess the influence of TB-IRIS on long-term CD4 T-cell recovery. Results: One hundred and fifty-three TB-HIV patients were enrolled, of whom 106 had received both anti-TB treatment (ATT) and ART. The median (IQR) baseline CD4 T-cell count was 52 cells µL–1 (13–130 cells µL–1). Nine of 96 patients (9.4%) developed paradoxical TB-IRIS and eight developed unmasking TB-IRIS, at a median (IQR) time of 27 (12–64) and 19 (14–65) days, respectively. In adjusted logistic regression analysis, only disseminated TB was predictive of TB-IRIS [OR: 10.7 (95% CI: 1.2–94.3), P = 0.032]. Mortality rates were similar for TB-IRIS (n = 1, 5.9%) and non-TB-IRIS (n = 5, 5.7%) patients and CD4 T-cell recovery post-ART was not different between the two groups (P = 0.363). Conclusion: Disseminated TB was a strong independent predictor of TB-IRIS in Malaysian HIV-TB patients after commencing ART. This finding underscores the role of a high pathogen load in the pathogenesis of TB-IRIS; so interventions that reduce pathogen load before ART may benefit HIV patients with disseminated TB

A reproducible method for extraction of Plasmodium falciparum DNA by microwave irradiation and its potential for rapid molecular diagnosis

Malaria remains one of the most important communicable diseases. A rapid, simple and accurate method is a crucial part of malaria diagnosis. The aim of this study was to re-evaluate the microwave irradiation method to extract DNA from Plasmodium falciparum and compare with six other existing DNA extraction methods such as QIAamp DNA mini kit (Qiagen), FTA elute card, phenol-chloroform, Chelex, Chelex without proteinase-K and Rapid boiling. Two different P. falciparum isolates were used: (i) Laboratory strains with 0.3% parasitemia and (ii) clinical isolate with 0.6% parasitemia. Each DNA extraction method was validated for the presence of P. falciparum by a routine nested and real time PCR. In order to evaluate the sensitivity of the DNA extraction by microwave, double serial dilution of P. falciparum from in vitro culture at parasitemia that ranged from 0.0001 to 0.17% were used to extract the DNA by microwave and the P. falciparum DNA was then detected by nested and real-time PCR. The nested and real-time PCR were able to detect. P. falciparum DNA at the parasitemia level as low as 0.0003% and 0.0001%, respectively. Our results can reproduce the results from earlier studies and reveal microwave as a rapid and simple tool to extract P. falciparum DNA and subsequent molecular diagnosis of malaria

A large exposure to brucella melitensis in a diagnostic laboratory

Background: Brucella species are easily transmitted by aerosols and can be acquired in the laboratory. Aim: To report the management of a large exposure to Brucella melitensis that occurred over six days in a hospital diagnostic laboratory. Methods: Fifty-one exposed staff were managed according to Centers for Disease Control and Prevention guidelines. A further 96 non-exposed laboratory staff were tested for seroprevalence. Testing was carried out using the Brucella sp. serum agglutination test. Findings: Twenty-seven people had high-risk exposure and 24 had low-risk exposure. High-risk staff were offered post-exposure prophylaxis. Twelve (44.4) agreed to this, of whom eight (66.7) completed the course. Overall compliance with serological follow-up at baseline, 2, 4, 6 weeks and 8 months was 45.9. Despite this poor compliance there were no clinical brucellosis cases and no seroconversion in the 47.1 of staff tested at 8 months. Brucella sp. seroprevalence among all staff tested was 3/147 (2.0). Conclusion: Lack of experience with Brucella spp. and lack of policies for handling potentially hazardous organisms contributed to this prolonged exposure. As compliance with current recommendations may be poor, the optimum frequency of serological follow-up and target groups for prophylaxis should be reassessed. Laboratories in low- or non-endemic areas must prepare for potential isolation of Brucella spp. The impact of human brucellosis in Malaysia requires further study. (C) 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved