Evaluation of rapid influenza diagnostic tests for influenza A and B in the tropics.

Rapid diagnosis of influenza is important for early treatment and institution of control measures. In developing tropical countries such as Malaysia, influenza occurs all year round, but molecular assays and conventional techniques (such as immunofluorescence and culture) for diagnosis are not widely available. Rapid influenza diagnostic tests (RIDTs) may be useful in this setting.

Detection of Respiratory Viruses from ARTI Patients by xTAG RVP Fast v2 Assay and Conventional Methods.

Introduction: Acute respiratory tract infections (ARTIs) are a major cause of morbidity and mortality in paediatric patients. Therefore, early detection of the viral aetiologies of ARTIs is essential for patient management and infection control. In this study, we evaluated the performance of a new multiplex polymerase chain reaction (PCR) assay (xTAG Respiratory Viral Panel [RVP] Fast v2) in the detection of respiratory viruses by comparing it with that of viral culture and direct immunofluorescence (IF) staining.

The Use of NS1 Rapid Diagnostic Test and qRT-PCR to Complement IgM ELISA for Improved Dengue Diagnosis from Single Specimen.

Timely and accurate dengue diagnosis is important for differential diagnosis and immediate implementation of appropriate disease control measures. In this study, we compared the usefulness and applicability of NS1 RDT (NS1 Ag Strip) and qRT-PCR tests in complementing the IgM ELISA for dengue diagnosis on single serum specimen (n = 375). The NS1 Ag Strip and qRT-PCR showed a fair concordance (κ = 0.

Evolution of Influenza B Virus in Kuala Lumpur, Malaysia, between 1995 and 2008.

Influenza B virus causes significant disease but remains understudied in tropical regions. We sequenced 72 influenza B viruses collected in Kuala Lumpur, Malaysia, from 1995 to 2008. The predominant circulating lineage (Victoria or Yamagata) changed every 1 to 3 years, and these shifts were associated with increased incidence of influenza B.

Early detection of dengue virus by use of reverse transcription-recombinase polymerase amplification.

A method for the rapid diagnosis of early dengue virus (DENV) infection is highly needed. Here, a prototype reverse transcription-recombinase polymerase amplification (RT-RPA) assay was developed. The assay detected DENV RNA in <20 min without the need for thermocycling amplification.

Outbreak of human infection with Sarcocystis nesbitti, Malaysia, 2012.

An outbreak of fever associated with myalgia and myositis occurred in 2012 among 89 of 92 college students and teachers who visited Pangkor Island, Malaysia. The Sarcocystis nesbitti 18S rRNA gene and sarcocysts were obtained from muscle tissues of 2 students. Our findings indicate emergence of S.

Detection of dengue viruses using reverse transcription-loop-mediated isothermal amplification.

Background: Early and rapid detection of dengue virus (DENV) infection during the febrile period is crucial for proper patient management and prevention of disease spread. An easy to perform and highly sensitive method is needed for routine implementation especially in the resource-limited rural healthcare settings where dengue is endemic.

Methods: A single-tube reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay with a set of nine primers was developed for the detection of all four DENV serotypes and their different genotypes.

Real-time polymerase chain reaction for diagnosis and quantitation of negative strand of chikungunya virus.

Quantitative real-time polymerase chain reaction (qRT-PCR) is useful for diagnosis and studying virus replication. We developed positive- and negative-strand qRT-PCR assays to detect nsP3 of chikungunya virus (CHIKV), a positive-strand RNA alphavirus that causes epidemic fever, rash, and arthritis. The positive- and negative-strand qRT-PCR assays had limits of quantification of 1 and 3 log10 RNA copies/reaction, respectively.

Seroprevalence of seasonal and pandemic influenza a in Kuala Lumpur, Malaysia in 2008-2010.

Relatively little is known about the burden of influenza in tropical countries. The seroprevalence of pandemic influenza A (H1N1) 2009, seasonal H1N1 and H3N2 was determined in Kuala Lumpur, Malaysia. Pre- and post-pandemic residual laboratory sera were tested by hemagglutination-inhibition.

Displacement of predominant respiratory syncytial virus genotypes in Malaysia between 1989 and 2011.

From 1989 to 2011 in Kuala Lumpur, Malaysia, multiple genotypes from both respiratory syncytial virus (RSV) subgroups were found co-circulating each year. RSV-A subgroup predominated in 12 out of 17years with the remaining years predominated by RSV-B subgroup. Local RSV strains exhibited temporal clustering with RSV strains reported in previous epidemiological studies.

Epidemiology and seasonality of respiratory viral infections in hospitalized children in Kuala Lumpur, Malaysia: a retrospective study of 27 years.

Background: Viral respiratory tract infections (RTI) are relatively understudied in Southeast Asian tropical countries. In temperate countries, seasonal activity of respiratory viruses has been reported, particularly in association with temperature, while inconsistent correlation of respiratory viral activity with humidity and rain is found in tropical countries. A retrospective study was performed from 1982-2008 to investigate the viral etiology of children (≤ 5 years old) admitted with RTI in a tertiary hospital in Kuala Lumpur, Malaysia.

Chikungunya virus of Asian and Central/East African genotypes in Malaysia.

Background: Chikungunya virus (CHIKV) of the Central/East African genotype has caused large outbreaks worldwide in recent years. In Malaysia, limited CHIKV outbreaks of the endemic Asian and imported Central/East African genotypes were reported in 1998 and 2006. Since April 2008, an unprecedented nationwide outbreak has affected Malaysia.

Enterovirus 71 outbreak, Brunei.

Enterovirus 71 (EV71) outbreaks occur periodically in the Asia-Pacific region. In 2006, Brunei reported its first major outbreak of EV71 infections, associated with fatalities from neurologic complications. Isolated EV71 strains formed a distinct lineage with low diversity within subgenogroup B5, suggesting recent introduction and rapid spread within Brunei.

Reemergence of endemic Chikungunya, Malaysia.

Chikungunya virus infection recently reemerged in Malaysia after 7 years of nondetection. Genomic sequences of recovered isolates were highly similar to those of Malaysian isolates from the 1998 outbreak. The reemergence of the infection is not part of the epidemics in other Indian Ocean countries but raises the possibility that chikungunya virus is endemic in Malaysia.

Negative cross-reactivity of rabbit anti-Malassezia furfur antibodies with other yeasts.

Anti-Malassezia furfur monospecific polyclonal antibodies was produced by repeated immunization of rabbit with Malassezia furfur yeast cells mixed with Freud adjuvant. The antibody titres of respective rabbit's serum samples prior to and after each immunization against M. furfur were assayed by indirect immunofluorescence technique using the M.

Seroprevalence of Malassezia furfur in an urban population in Malaysia.

An in-house prepared M. furfur antigen was used to carry out a seroprevalence study in an urban population in Malaysia by indirect immunofluorescence assay. Of the 800 serum samples from all ages screened, 738 samples were positive for M.

Isolation of Waddlia malaysiensis, a novel intracellular bacterium, from fruit bat (Eonycteris spelaea).

An obligate intracellular bacterium was isolated from urine samples from 7 (3.5%) of 202 fruit bats (Eonycteris spelaea) in peninsular Malaysia. The bacterium produced large membrane-bound inclusions in human, simian, and rodent cell lines, including epithelial, fibroblastlike, and lymphoid cells.

Isolation of Nipah virus from Malaysian Island flying-foxes.

In late 1998, Nipah virus emerged in peninsular Malaysia and caused fatal disease in domestic pigs and humans and substantial economic loss to the local pig industry. Surveillance of wildlife species during the outbreak showed neutralizing antibodies to Nipah virus mainly in Island flying-foxes (Pteropus hypomelanus) and Malayan flying-foxes (Pteropus vampyrus) but no virus reactive with anti-Nipah virus antibodies was isolated. We adopted a novel approach of collecting urine from these Island flying-foxes and swabs of their partially eaten fruits.

Echovirus 7 associated encephalomyelitis.

Background: Hand, foot, and mouth disease (HFMD) is endemic in Malaysia. In 1997, a large outbreak of enterovirus 71 (EV-71) associated HFMD resulted in 41 deaths due to severe left ventricular dysfunction and central nervous system infection with extensive damage to the medulla and pons. The clinical presentation in all these patients were rapid cardio-respiratory decompensation leading to cardiac arrest.