The complete nucleotide sequences are reported of two strains of echovirus 7, the prototype Wallace strain (Eo7-Wallace) and a recent Malaysian strain isolated from the cerebrospinal fluid of a child with fatal encephalomyelitis (Eo7-UMMC strain). The molecular findings corroborate the serological placement of the UMMC strain as echovirus 7. Both Eo7-Wallace and Eo7-UMMC belong to the species human enterovirus B and are most closely related to echovirus 11. Eo7-UMMC has undergone significant genetic drift from the prototype strain in the 47 years that separate the isolation of the two viruses. Phylogenetic analysis revealed that Eo7-UMMC did not arise from recombination with another enterovirus serotype. The molecular basis for the severely neurovirulent phenotype of Eo7-UMMC remains unknown. However, it is shown that mutations in the nucleotide sequence of the 5' untranslated region (UTR) of Eo7-UMMC result in changes to the putative structure of the 5' UTR. It is possible that these changes contribute to the neurovirulence of Eo7-UMMC.
A specific and sensitive method based on RT-PCR was developed to detect enterovirus 71 (EV71) from patients with hand, foot and mouth disease, myocarditis, aseptic meningitis and acute flaccid paralysis. RT-PCR primers from conserved parts of the VP1 capsid gene were designed on the basis of good correlation with sequences of EV71 strains. These primers successfully amplified 44 strains of EV71 including 34 strains isolated from Singapore in 1997 and 1998, eight strains from Malaysia isolated in 1997 and 1998, one Japanese strain and the neurovirulent strain EV71/7423/MS/87. RT-PCR of 30 strains of other enteroviruses including coxsackievirus A and B, and echoviruses failed to give any positive amplicons. Hence, RT-PCR with these primers showed 100% correlation with serotyping. Direct sequencing of the RT-PCR products of 20 EV71 strains revealed a distinct cluster with two major subgroups, thus enabling genetic typing of the viruses. The genetic heterogeneity of these strains culminated in amino acid substitutions within the VP1, VP2 and VP3 regions. The sequencing of a 2.9 kb fragment comprising the capsid region and the major part of 5' UTR of two Singapore strains revealed that they belonged to a group distinct from the prototype EV71/BrCr strain and the EV71/7423/MS/87 strain. The dendrogram generated from 341 bp fragments within the VP1 region revealed that the strains of Singapore, Malaysia and Taiwan belong to two entirely different EV71 genogroups, distinct from the three genogroups identified in another recent study.
Stool samples from healthy children mainly of the low income group aged 0 to 7 years of age from five Maternal and Child Health Centres in Kuala Lumpur were obtained for isolation of enteroviruses. The specimens were collected before and after the mass vaccination given in the face of polio type 1 epidemic which started in October, 1971. The prevelance rate of enteroviruses was 11.9% (3.0% polioviruses, 8.9% non-polio enteroviruses) before the vaccination and essentially the same after. Coxsackie A viruses predominated over the other enteroviruses in the pre- and post-vaccination phases. The highest isolation rate of enteroviruses was observed in children 0 to 2 years age. No significant differences in distribution by sex, race and month were noted. A sharp fall in the prevalence rates of total enteroviruses and polioviruses was noted shortly after the mass vaccination campaign However, the rates reverted to the pre-vaccination state during the next successive years.
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. Another large outbreak of HFMD with 55 fatal cases and a similar clinical picture was reported in Taiwan in 1998. In 2000, an outbreak of HFMD resulted in the deaths of three children who had rapid cardio-respiratory decompensation and one child who survived a central nervous system infection.
Manisya Zauri Abdul Wahid, Tengku Rogayah T. Abd. Rashid, Hariyati Md. Ali, Hamadah Mohd Shafiff, Mohd. Shamsul Samsuddin, Syarifah Nur Aisyatun Syed Mohd Salleh, et al.
Introduction:Echoviruses are Enteroviruses (HEVs) that infect millions of people annually worldwide, primarily paediatrics. These viruses are frequently associated with outbreaks and sporadic cases of viral meningitis, enceph-alitis, paralysis, myocarditis, severe systemic infections; and hand-foot-mouth disease. This study is a retrospective study to identify Echovirus serotypes circulating in Malaysia from January 2014 to June 2019, and their roles in outbreak prediction. This study investigated the Echovirus serotypes circulating in Malaysia from January 2014 to June 2019. Methods: A total of 13,855 inpatient samples consisting respiratory secretion, stool, tissue and body fluid from around the country were received by the Virology Unit, Institute for Medical Research between January 2014 and June 2019. The presence of HEV’s RNA was detected by qPCR. The identified positive sample was further isolated by cell culture and identified by Immunofluorescence Assay (IFA). The IFA positive samples were subjected to amplification of partial VP4 gene by RT-PCR, and proceeded to Sanger sequencing for phylogenetic analysis by using ChromasPro and MEGA Software. The sequence generated were analysed by BLAST to confirm the sequence serotypes generated. Results: Echovirus genome was detected in 0.35% (37/10,681) of the patients. The circulating Echovirus subtypes in Malaysia between January 2014 and June 2019 were Echo-11 (43.2%; 16/37), followed by Echo-6 (16.2%; 6/37); 8.1% (3/37) of Echo-7 and Echo-13, respectively. Meanwhile, other types of Echoviruses (24.3%; 9/37) such as Echo 3-5, Echo-14, Echo-16, Echo-18, Echo-25 and Echo-30 were also detected in this study. Conclusion: In this study, it has been found that Echovirus 11 serotype is the most predominant Echovirus serotype circulating in Malaysia between January 2014 and June 2019. It has been reported to cause severe diseases, such as aseptic meningitis. Therefore, the identification of circulating serotypes of Echovirus is critical to predict the Echovi-rus outbreak and to reduce the risk of developing severe disease in Malaysia.
The hand, foot, and mouth disease (HFMD) outbreak occurred in the state of Johor, Malaysia in the months 0f October and November 2000 aber the HFMD outbreak started in Singapore in September 2000. The HFMD notification and investigation forms sent to the Epidemiology Unit of the Johor Health Department from district health offices and hospitals during the outbreak were analysed. Patients’ specimens were sent to the Institute for Medical Research, Kuala Lumpur and the Universiti Malaya Medical Centre, Kuala Lumpur for viral isolation. A total of 1,122 HFMD cases were notified during the outbreak period with 2 deaths giving 0.2% casefatality rate. From all the cases, 544 (48.5%) patients were admitted to the hospital while the rest were treated as outpatients. Majority (81.7%) of children with HFMD were aged below 5 years old with the commonest age group (46.9%) being between 1 to 2 years old. Sixty-eight patients had positive specimens for viral isolation belonging to enteroviruses namely Enterovirus 71 (43 cases), Coxsackievirus Type A16 (11), Echovirus 7 (3), and Coxsackievirus Type B (2); and non-enteroviruses namely Herpes Simplex Virus Type 1
(5), and Adenovirus (4). Fever and mouth ulcer were the two most common symptoms among HFMD children but vesicles on palms and soles were more common than rashes in children with positive enteroviral isolation.
Study site: University Malaya Medical Centre (UMMC)
Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50