Recovery from chikungunya is previously considered universal and mortality due to the virus is rare and unusual. Findings from recent chikungunya outbreaks occurred in Reunion Island and India have since challenged the conventional view on the benign nature of the illness. Malaysia has experienced at least of 4 outbreaks of chikungunya since 1998. In the present on-going large outbreak due to chikungunya virus of Central/East African genotype, a previous healthy sixty six years gentleman without co-morbidity was noted to have severe systemic infection by the virus and involvement of his liver. He subsequently passed away due to cardiovascular collapse after 5 days of illness.
In the last four years, Malaysia has had three outbreaks of chikungunya virus infection. The first two occurred in Perak in 2006.The third began in Johor in early 2008. The genome of the viruses suggests that on each occasion a different virus was introduced into the population. The first outbreak in Bagan Panchor was due to an Asian genotype virus. The second in the Kinta district of Perak in late 2006 was due to a Central/East African genotype virus. Contact tracing was even able to discover the patient who was the source of the virus from the Indian subcontinent. The third outbreak in Johor was also of a Central/East African strain of virus, but introduced independently. The epidemiology of that outbreak is described in this issue of the MJM.
Many countries neighboring Malaysia have reported human infections by chikungunya virus, a mosquito-borne togavirus belonging to the genus Alphavirus. However, although there is serological evidence of its presence in Malaysia, chikungunya virus has not been known to be associated with clinical illness in the country. An outbreak of chikungunya virus occurred in Klang, Malaysia, between December 1998 and February 1999. The majority of the cases were in adults and the clinical presentation was similar to classical chikungunya infections. Malaysia is heavily dependent on migrant workers from countries where chikungunya is endemic. It is speculated that the virus has been re-introduced into the country through the movement of these workers.
Chikungunya infections were detected in Singapore among returning travelers who had visited friends and relatives (VFR) in India and Malaysia. These sporadic imported cases occurred over a year before the 2008 chikungunya outbreaks in Singapore, demonstrating the potential for introducing this emerging viral infection into new areas via VFR travel.
Chikungunya is a re-emerging mosquito-borne viral infection that has spread from East Africa to Indian Ocean islands and re-emerged in India since 2004. In Malaysia, chikungunya re-emerged after a hiatus of seven years, causing a localised outbreak in a north-western coastal town in 2006 and subsequently widespread outbreaks in 2008. Since the first local outbreak of chikungunya in Singapore in January 2008, chikungunya infections have been increasingly reported in Singapore. In this case series, five patients aged 37-62 years, with chikungunya infection confirmed in August 2008, were reported. Three of the five were male, and only one had medical comorbidities. Two had a travel history to Johor, Malaysia, where local outbreaks of chikungunya had been reported. Fever, arthralgia and rash were the most common symptoms. Fever lasted four to five days while viraemia lasted four to 11 days, persisting two to three days after defervescence in three patients. A biphasic pattern of fever was observed in two patients. Leucopenia was noted in all patients, while mild thrombocytopenia and transaminitis occurred in three of five patients. Two patients had persistent polyarthralgia at two to three weeks after the onset of symptoms. Fever, arthralgia and rash should prompt consideration of acute chikungunya in Singapore. While taking the travel history, doctors should be mindful that indigenous chikungunya cases can occur.
An adult Malaysian woman returned to Japan from Kuala Lumpur and had onset of dengue fever-like symptoms including high fever, malaise and arthritis in early January 2009. Serum obtained on the following day was tested at the National Institute of Infectious Diseases in Tokyo, where it was determined to be positive for chikungunya virus (CHIKV) RNA. IgM antibody against CHIKV was negative on January 6 and sero-converted to be positive on January 14, confirming a recent CHIKV infection. Except for arthralgia, all her symptoms resolved uneventfully within 10 days.
In the last few years, chikungunya has become a major problem in Southeast Asia, with large numbers of cases being reported in Singapore, Malaysia, and Thailand. Much of the current epidemic of chikungunya in Southeast Asia is being driven by the emergence of a strain of chikungunya virus that originated in Africa and spread to islands in the Indian Ocean, as well as to India and Sri Lanka, and then onwards to Southeast Asia. There is currently no specific treatment for chikungunya and no vaccine is available for this disease. This review seeks to provide a short update on the reemergence of chikungunya in Southeast Asia and the prospects for control of this disease.
Chikungunya virus, a mosquito-borne alphavirus, is endemic in Africa and Southeast Asia but is rarely reported in Taiwan. We report the case of a Taiwanese woman who developed Chikungunya fever, which was first diagnosed by a clinician rather than by fever screening at an airport. The woman presented with fever, maculopapular rash, and arthralgia, the triad for the disease, on the day she returned home after a trip to Malaysia. These symptoms are very similar to those of dengue fever, which is endemic in Southern Taiwan. Chikungunya infection was confirmed by reverse transcriptase-polymerase chain reaction and seroconversion on paired serum specimens. For approximately 40 years until 2006, no cases of Chikungunya fever had been found in Taiwan. Clinicians in Taiwan should consider Chikungunya fever as a possible diagnosis for a febrile patient with arthralgia, rash, and a history of travel to an endemic area, such as Africa or Southeast Asia.
In 2008, an outbreak of chikungunya infection occurred in Johor. We performed a retrospective review of all laboratory confirmed adult chikungunya cases admitted to Hospital Sultanah Aminah, Johor Bahru from April to August 2008, looking into clinical and laboratory features. A total of 18 laboratory confirmed cases of chikungunya were identified with patients presenting with fever, joint pain, rash and vomiting. Haemorrhagic signs were not seen. Lymphopenia, neutropenia, thrombocytopenia, raised liver enzymes and deranged coagulation profile were the prominent laboratory findings. We hope this study can help guide physician making a diagnosis of chikungunya against other arborviruses infection.
Chikungunya virus (CHIKV) is an emerging mosquito-borne alphavirus that has caused multiple unprecedented and re-emerging outbreaks in both tropical and temperate countries. Despite ongoing research efforts, the underlying factors involved in facilitating CHIKV replication during early infection remains ill-characterized. The present study serves to identify host proteins modulated in response to early CHIKV infection using a proteomics approach.
During an outbreak of chikungunya in a dengue hyperendemic area within the Kinta district of Perak, two patients with acute febrile illness were laboratory confirmed to have co-infection of both dengue and chikungunya viruses in their blood. The concomitant presence of two types of viruses transmitted by the same vector in a susceptible population contributed to the resultant event. A good understanding of virus vector ecology in association with population dynamics and wider application of improved laboratory techniques by using different cell-lines suited for optimal replication of each type of virus and the correct utilization of powerful molecular techniques will enhance accurate diagnosis of these infectious diseases.
This is a retrospective cross-sectional study based on the database of clusters of patients with clinical diagnosis of chikungunya (CHIK) that were referred to the National Public Health Laboratory for diagnostic investigations from January 2006 to December 2009. Of the 13,759 referred patients, a total of 6314 (45.9%) patients were laboratory confirmed to have CHIK and 7445 (54.1) patients were considered as clinical cases of CHIK by epidemiological link. Epidemic curves plotted using date of onset of illness for all referred clusters of cases showed that there were three unrelated outbreaks of CHIK in Malaysia from 2006 to 2009. There were two small outbreaks that occurred within the state of Perak in 2006. The cluster of cases in 2008 and 2009 were of related outbreak which started in Johor state and subsequently spread to various parts of Malaysia. The mean age of the patients was 37.0 years old and those patients in the laboratory confirmed group were significantly younger than those in the epidemiological linked group. The main presenting clinical features recorded in this study were fever, arthralgia, myalgia and rashes. Those patients in the laboratory confirmed group had a significant higher incidence of fever, arthralgia and rash than those in the epidemiological linked group.
Many triggering factors for onset of emerging infectious diseases are now recognised, such as: globalisation, demographic increase, population movements, international trade, urbanisation, forest destruction, climate changes, loss in biodiversity, and extreme life conditions such as poverty, famine and war. Epidemic burden is often leading to disasters, in terms of human losses, as well as economic, political or social consequences. These outbreaks may jeopardize within a few weeks or months, industry, trade, or tourism. While dengue and its most severe forms (hemorrhagic and shock syndrome) is spreading all over the tropical world, another arbovirosis, chikungunya disease dramatically spread in Indian Ocean islands where 30 to 75% of population were infected in 2005 and 2006, and then extended its progression towards India, Sri Lanka, Indonesia, Malaysia, Maldives islands with more than a million people infected with the East-African strain, replacing the former Asian strain which was known to prevail more than 30 years ago in India. Patients experience sequelae with disability, work loss, and rarely severe outcome recently identified in La Réunion and Mayotte (French overseas territories). No country, no part of the world may consider itself as protected against such events. However, consequences of emerging or re-emerging diseases are more and more unacceptable when they impact the poorest countries of the world. Viruses, bacteria, as well as wild animals, birds, or arthropods are not stopped by borders. It is time now to promote barriers against infectious diseases, including prevention, anticipation, disease surveillance and research. This is not only for humanitarian reasons, but also for contributing to a sustainable development with equity for worldwide population. This report presents comprehensive actions taken in 2006 for tracing the epidemic and mobilise research, as requested to the task force set up by the Prime Minister by March 20, 2006.
Chikungunya virus (CHIKV) and dengue virus (DENV) co-circulate in areas endemic with the Aedes mosquito vectors. Both viruses cause similar illnesses which may be difficult to distinguish clinically. CHIKV is also associated with persistent arthralgia.
Chikungunya is an acute febrile illness caused by an alphavirus which is transmitted by infective Aedes mosquitoes. Two previous outbreaks of chikungunya in Malaysia were due to chikungunya virus of Asian genotype. The present outbreak involved two adjoining areas in the suburb of Ipoh city within the Kinta district of Perak, a state in the northern part of Peninsular Malaysia. Thirty seven residents in the main outbreak area and two patients in the secondary area were laboratory confirmed to be infected with the virus. The index case was a 44-year Indian man who visited Paramakudi, Tamil Naidu, India on 21st November 2006 and returned home on 30th of November 2006, and subsequently developed high fever and joint pain on the 3rd of December 2006. A number of chikungunya virus isolates were isolated from both patients and Aedes albopictus mosquitoes in the affected areas. Molecular study showed that the chikungunya virus causing the Kinta outbreak was of the Central/East African genotype which occurred for the first time in Malaysia.
An outbreak of Chikugunya (CHIK) fever occurred among the fishing community in Bagan Pancor, Perak. The outbreak was laboratory confirmed within 48 hours after the receipt of the specimens. Fifty-three patients' serum samples were submitted for laboratory investigation and 47 (88.7%) were confirmed to be positive for CHIK infection by RT-PCR, and/or virus isolation, and/or in-house immunoflourescent test. RT-PCR and virus isolation were the tests of choice for patients with illness of four days or less and detection of CHIK specific IgM for those with more than four days of fever. The nucleic acid sequence based on the 354- and 294-bp of the nsP1 and E1 genes of the CHIK virus detected from pools of adults Aedes aegypti mosquitoes were identical to those CHIKV virus isolated from humans in the same locality. Phylogenetic analysis of the CHIK virus based on the 257 nts partial E1 gene indicates that Bagan Panchor's strain was closely related to the first CHIK virus isolated during the outbreak in Klang in 1998.
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.
Malaysia experienced its first outbreak of chikungunya virus (CHIKV) infection in late 1998 in Klang District in Selangor; six years later the virus re-emerged in the state of Perak. All the CHIKV isolates in 1988 and 2006 shared high sequence similarities and belonged to the Asian genotype. In 2007 and 2008 CHIKV infection again reemerged but the genotype was the Central/East African genotype. This strain was found to be similar to the strains causing outbreaks in the India Ocean. In 2009, the strains circulating in Malaysia, including the state of Kelantan, based on the partial E1 gene, also belong to the Central/East African genotype.
Chikungunya infection has become a public health threat in Malaysia since the 2008 nationwide outbreaks. Aedes albopictus Skuse has been identified as the chikungunya vector in Johor State during the outbreaks. In 2009, several outbreaks had been reported in the State of Kelantan. Entomological studies were conducted in Kelantan in four districts, namely Jeli, Tumpat, Pasir Mas and Tanah Merah to identify the vector responsible for the virus transmission.
The resurgence of Chikungunya virus (CHIKV) in the southern, northeastern and northern parts of Thailand, inflicting approximately 46,000 reported cases since October 2008 until December 2009, has raised public health concerns. In the present study, we characterized nearly complete genome sequences of four CHIKV isolates obtained from 2008 to 2009 outbreaks in Thailand. Phylogenetic analysis was performed to determine the relationships of the study viruses with previously reported isolates. Results showed that 2008-2009 Thailand isolates belonged to the East, Central and South African genotype and were most closely related to isolates detected in Malaysia and Singapore in 2008. This was in contrast to isolates from all previous outbreaks in Thailand which were caused by an Asian genotype. We describe several novel mutations in Thailand isolates that warrants further investigation on characterization of CHIKV from different parts of the country to better understand the molecular epidemiology of Chikungunya fever outbreaks in Thailand.