Related Experiment Video
Updated: Jun 28, 2026
07:23
Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay
Published on: June 9, 2011
Emerging and re-emerging viruses in Malaysia, 1997-2007
Kok Keng Tee1, Yutaka Takebe, Adeeba Kamarulzaman
1Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. k2tee@yahoo.com
Summary
Malaysia has faced numerous emerging zoonotic and non-zoonotic viruses, including Nipah virus and enterovirus 71, causing significant public health challenges and mortality. Ongoing surveillance is crucial for managing viral threats and their economic impact.
Area of Science:
- Virology
- Epidemiology
- Public Health
Background:
- Malaysia has experienced a rise in novel zoonotic and non-zoonotic viral emergences over the last decade.
- These outbreaks, including Nipah virus encephalitis and enterovirus 71, have caused substantial morbidity, mortality, and economic burden.
- New bat-borne viruses (Tioman, Pulau, Melaka) and H5N1 avian influenza have been identified, alongside the spread of HIV-1 recombinant form (CRF33_01B).
Purpose of the Study:
- To document and analyze the emergence of novel and re-emerging viral pathogens in Malaysia.
- To highlight the public health impact and economic burden of these viral outbreaks.
- To underscore the importance of ongoing viral surveillance and control strategies.
Main Methods:
- Review of epidemiological data and outbreak reports.
- Identification and characterization of novel viruses.
- Monitoring of viral spread and genetic diversity, including HIV-1 recombinant forms.
Main Results:
- Significant outbreaks of Nipah virus (1998) and enterovirus 71 (1999, 2000, 2003) caused high mortality and neurological complications.
- Discovery of new bat-associated viruses: Tioman virus (1999), Pulau virus (1999), and Melaka virus (2006).
- Detection of H5N1 avian influenza in poultry (2004, 2006, 2007) without human infections, and emergence of HIV-1 CRF33_01B.
Conclusions:
- Malaysia is a hotspot for diverse viral emergences, necessitating robust public health responses.
- Effective control measures, like culling pigs during the Nipah outbreak, are vital.
- Continuous surveillance and research are essential to mitigate the impact of emerging infectious diseases.
Related Concept Videos
00:36Viral Mutations
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material for adaptive...
01:28Infectious Diseases and Their Occurrence
Infectious diseases appear in populations through various transmission patterns, influenced by pathogen characteristics, population immunity, environmental conditions, and social behavior. Understanding these patterns is essential for effective public health surveillance and intervention. These categories—sporadic, outbreak, epidemic, pandemic, and endemic—help frame the nature and scope of disease events.Sporadic diseases occur irregularly and infrequently, without a predictable temporal or...
00:57Viral Recombination
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
01:17Poliomyelitis
Poliomyelitis is caused by poliovirus, a small, non-enveloped, positive-sense RNA virus of the Picornaviridae family and Enterovirus genus. Transmission occurs primarily via the fecal-oral route, often through ingestion of contaminated water or food. The virus initially replicates in the oropharynx and intestinal mucosa, particularly in lymphoid tissues such as the tonsils, Peyer’s patches, and regional lymph nodes. Primary viremia follows, allowing dissemination throughout the body.In most...
02:33Retroviruses
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
01:29Coronavirus
Coronaviruses, including the severe acute respiratory syndrome coronavirus (SARS-CoV), are enveloped viruses characterized by their single-stranded, positive-sense RNA genome and helical nucleocapsid structure. The hallmark of these viruses is their club-shaped spike (S) glycoproteins that protrude from the viral envelope, facilitating attachment to host cells. Typically, coronaviruses infect the upper respiratory tract, often causing mild or asymptomatic disease. However, certain strains like...