Tropical fever

2019 Article - "Dengue virus transmission from live donor liver graft" (pdf, 1MB)

Summary: Arboviral transmission through transplanted organs is rare. We report a highly probable case of dengue viral transmission during live donor liver transplantation. Fever with severe thrombocytopenia was observed in the donor and recipient within 6 and 9 days after transplantation, respectively. Dengue diagnosis was confirmed by testing blood and explant tissue from donor and recipient using dengue specific NAT (nucleic acid testing) and serology. Serology indicated the donor to have secondary dengue infection that ran a mild course. However, the dengue illness in the recipient was severe and deteriorated rapidly, eventually proving fatal. The recipient’s explant liver tissue tested negative for viral RNA indicative of a pre-transplant naïve status. The prM-Envelope gene sequence analysis of the donor and recipient viral RNA identified similar serotype (DENV1) with almost 100% sequence identity in the envelope region. Molecular phylogenetic analysis of donor and recipient viral envelope sequences with regional and local dengue strains further confirmed their molecular similarity, suggesting a probable donor to recipient transmission via organ transplantation. Screening of living donors for dengue virus may be considered in endemic regions.

Kits used: FTD Tropical fever core, FTD Dengue differentiation

2018 Article - "Expression analysis of toll-like receptors of Dengue-infected cornea by real-time polymerase chain reaction" (limited access)

Background: Toll-like receptors (TLRs) play a significant role based on innate immune mechanism during viral infection. TLR signaling mechanism designates to protect the cells from invading viruses. The expression of TLRs during dengue virus (DENV) infection not yet well explained. This study evaluates the TLR gene expression from DENV-infected patient’s cornea.

Methods: Reverse transcriptase PCR was performed for the detection and genotyping of viral nucleic acid from corneal grafts and DENV-infected cell suspension. TLR expression studies were done on DENV-infected cornea by real-time RT2 Profiler PCR Array.

Results: The reverse transcriptase PCR and genotyping confirmed the presence of DENV-3. TLR expression studies revealed the upregulated expression of TLR4, TLR7, TLR9 and TLR10.

Conclusion: Molecular testing of DENV reveals that serological positivity induces transmission of the virus through cornea and stimulates the expression of TLR4, TLR7, TLR9 and TLR10, which may lead to up-regulation of innate pro-inflammatory response in the cornea.

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2017 Article - "Chikungunya, dengue and West Nile virus infections in Northern Tanzania" (pdf, 95KB)

Summary: The aim of the study was to determine the prevalence of Chikungunya virus (CHIKV), Dengue virus (DENV) and West Nile virus (WNV) in Bondo and Magugu wards in Handeni and Babati districts in Northern Tanzania, in a cross sectional analytical study.

This was cross sectional, community based study involving individuals aged 1-80 years of age. Reverse transcription Polymerase Chain Reaction (RT-PCR) was used to detect arboviruses in whole blood samples. Data was analyzed using SPSS 22.0. Chi square and logistic regression analyses were used to determine associations of explanatory factors and arbovirus infection.

Out of 128 participants recruited, 10 (7.8%) and 1 (0.8 %) were positive for CHIKV and DENV, respectively. None of the participants recruited was positive for WNV. Most cases of arboviruses were detected in Magugu with 8 (12.31%) and 1 (1.54%) individuals being positive for CHIKV and DENV respectively. Male sex was associated with CHIKV infection (χ2=9.126, p=0.003), with five times more odds of having CHIKV infection compared to females (OR: 5.30;(95%CI: 1.21-23.17), P=0.027). No WNV case was detected in any of the sites.

CHIKV is the most prevalent arbovirus in the Northern part of Tanzania. Magugu site has more arbovirus transmission than Bondo site. WNV could be a rare virus in the Northern part of Tanzania. Male sex is associated with higher CHIKV infection rates, with older children being more affected.

Kit used: FTD Tropical fever core

2017 Article - "The prevalence of dengue virus serotypes in asymptomatic blood donors reveals the emergence of serotype 4 in Saudi Arabia" (pdf, 1MB)

Summary: Transmission of dengue virus (DENV) through blood transfusion has been documented and hence screening for DENV during blood donation has been recently recommended by the American Association of Blood Banks and Centres of Disease Control and Prevention. DENV is endemic in the Western province of the Kingdom of Saudi Arabia (KSA) and serotypes 1, 2 and 3, but not 4, have been detected. However, little is known regarding the rates of DENV during blood donation in the kingdom. The aim of this study was therefore to measure the prevalence of dengue virus and its serotypes in eligible Saudi blood donors in the endemic Western region of KSA.

This was a cross-sectional study and serum samples were collected from 910 eligible Saudi male blood donors. DENV IgM and IgG antibodies were measured serologically by ELISA while viral serotypes were detected by a single step IVD CE certified multiplex RT-PCR kit (FTD Dengue differentiation). The overall prevalence was 39 and 5.5% for IgG+ and IgM+, respectively. There were 12 (1.3%) with exclusively IgM+, 317 (34.8%) exclusively IgG+ and 38 (4.2%) with dual IgM+/IgG+ donors. The overall prevalence was 3.2% (n = 29) and 2.3% (n = 21) for primary and secondary infections. PCR was positive in 5.5% (n = 50) and, DENV-2 (n = 24; 48%) was the most frequent serotype and was significantly higher than DENV-1 (20%; P = 0.02) and DENV-3 (2%; P = 0.1 × 10−5) but not DENV-4 (30%; P = 0.2). There was no significant difference between both DENV-4 and DENV-1 (P = 0.4). The combination of the PCR and serology findings showed that 22 (2.4%) and 28 (3.1%) donors had primary and secondary viremic infections, respectively.

Kit used: FTD Dengue differentiation

2017 Article - "An intricate case of multidrug resistant Plasmodium falciparum isolate imported from Cambodia" (pdf, 843KB)

Summary: Imported cases of multidrug resistant Plasmodium falciparum and treatment failure with artemisinin based regimens, although rare, have been described also in Western countries and their management is often challenging. This is also due to an inadequate knowledge and implementation of health prevention measures. A complex case of imported malaria caused by Plasmodium vivax/P. falciparum isolates in a patient who was not taking chemoprophylaxis while he was travelling in Cambodia is reported in this article. After failures of artemisinin-based and both oral and intravenous quinine-based regimens, a multidrug resistant P. falciparum was detected. The patient was successfully treated with atovaquone–proguanil. This experience highlights the importance of a careful management that should be based not only on the most up-to-date guidelines, but also on the awareness of a rapidly evolving scenario. .

Kit used: FTD Malaria differentiation

2016 Article - "Immune Response to Dengue Virus Infection in Pediatric Patients in New Delhi, India— Association of Viremia, Inflammatory Mediators and Monocytes with Disease Severity" (pdf, 2MB)

Dengue virus is a human pathogen that causes dengue fever, which can either resolve after mild fever or lead to severe dengue hemorrhagic fever/dengue shock syndrome. The role of dengue virus levels in the blood and the kinetics of infection and immune response that results in severe dengue disease in humans is not well characterized. In this study, we analyzed 97 children with varying degrees of dengue disease, and we show that the dengue virus quantity in blood does not show any significant association with severe disease. However, most severe dengue patients had lower levels of interferons and Th1 cytokines and increased levels of secreted factors such as IL-6, IL-8 and IL-10 that could potentially cause leakage in blood capillaries. Our results indicate that monocytes, which are infected with dengue virus in patients, could possibly play a major role in dengue pathogenesis. Furthermore, using computational analysis we identified association of some of the secreted factors with severe disease and also predicted the markers that could serve as indicators of recovery from severe dengue.

Kit used: FTD Dengue/Chik and FTD Dengue differentiation

2016 Article - "Ebola virus disease diagnosis by real-time RT-PCR A comparativestudy of 11 different procedures" (pdf, 874KB)

Summary: The aim of this study was to compare technical performances and practical aspects of 11 Ebola virus real-time reverse-transcription PCR procedures. The most promising assays have been tested using serial dilutions of culture-derived Ebola virus RNA. Their analytical sensitivity and potential range of quantification using quantified in vitro transcribed RNA have been determined; viral load values in the serum of an Ebola virus disease patient obtained with these assays were reported. Finally, ease of use and turnaround times of these kits were evaluated.

Kits used: FTD Ebola