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. nesbitti infections in humans in Malaysia.
A Monte Carlo simulation based on the population structure of a small-scale human population, the Semai Senoi of Malaysia, has been developed to study the combined effects of group, kin, and individual selection. The population structure resembles D.S. Wilson's structured deme model in that local breeding populations (Semai settlements) are subdivided into trait groups (hamlets) that may be kin-structured and are not themselves demes. Additionally, settlement breeding populations are connected by two-dimensional stepping-stone migration approaching 30% per generation. Group and kin-structured group selection occur among hamlets the survivors of which then disperse to breed within the settlement population. Genetic drift is modeled by the process of hamlet formation; individual selection as a deterministic process, and stepping-stone migration as either random or kin-structured migrant groups. The mechanism for group selection is epidemics of infectious disease that can wipe out small hamlets particularly if most adults become sick and social life collapses. Genetic resistance to a disease is an individual attribute; however, hamlet groups with several resistant adults are less likely to disintegrate and experience high social mortality. A specific human gene, hemoglobin E, which confers resistance to malaria, is studied as an example of the process. The results of the simulations show that high genetic variance among hamlet groups may be generated by moderate degrees of kin-structuring. This strong microdifferentiation provides the potential for group selection. The effect of group selection in this case is rapid increase in gene frequencies among the total set of populations. In fact, group selection in concert with individual selection produced a faster rate of gene frequency increase among a set of 25 populations than the rate within a single unstructured population subject to deterministic individual selection. Such rapid evolution with plausible rates of extinction, individual selection, and migration and a population structure realistic in its general form, has implications for specific human polymorphisms such as hemoglobin variants and for the more general problem of the tempo of evolution as well.
Numerous human diseases, including those caused by viruses like Nipah virus and SARS-CoV, can be traced back to bats as their origin. Malaysia, notably Sabah and Sarawak in Borneo Island, is home to a rich diversity of bats that serve as hosts for various viruses. This comprehensive review represents the inaugural exploration of viruses found in Malaysian bats, as documented in scientific journals. It also encompasses documented instances of bat virus-related disease outbreaks in Malaysia up to the present day, along with an analysis of the risk factors associated with virus spillover events. Furthermore, this review offers insights into prospective research areas of significance and suggests potential mitigation strategies.
Global public health policies span national borders and affect multitudes of people. The spread of infectious disease has neither political nor economic boundaries, and when elevated to a status of pandemic proportions, immediate action is required. In federal systems of government, the national level leads the policy formation and implementation process, but also collaborates with supranational organisations as part of the global health network. Likewise, the national level of government cooperates with sub-national governments located in both urban and rural areas. Rural areas, particularly in less developed countries, tend to have higher poverty rates and lack the benefits of proper medical facilities, communication modes and technology to prevent the spread of disease. From the perspective of epidemiological surveillance and intervention, this article will examine federal health policies in three federal systems: Australia, Malaysia and the USA. Using the theoretical foundations of collaborative federalism, this article specifically examines how collaborative arrangements and interactions among governmental and non-governmental actors help to address the inherent discrepancies that exist between policy implementation and reactions to outbreaks in urban and rural areas. This is considered in the context of the recent H1N1 influenza pandemic, which spread significantly across the globe in 2009 and is now in what has been termed the 'post-pandemic era'.
Avian influenza viruses are highly infectious micro-organisms that primarily affect birds. Nevertheless, they have also been isolated from a number of mammals, including humans. Avian influenza virus can cause large economic losses to the poultry industry because of its high mortality. Although there are pathogenic variants with a low virulence and which generally cause only mild, if any, clinical symptoms, the subtypes H5 and H7 can mutate from a low to a highly virulent (pathogenic) virus and should be taken into consideration in eradication strategies. The primary source of infection for commercial poultry is direct and indirect contact with wild birds, with waterfowl forming a natural reservoir of the virus. Live-poultry markets, exotic birds, and ostriches also play a significant role in the epidemiology of avian influenza. The secondary transmission (i.e., between poultry farms) of avian influenza virus is attributed primarily to fomites and people. Airborne transmission is also important, and the virus can be spread by aerosol in humans. Diagnostic tests detect viral proteins and genes. Virus-specific antibodies can be traced by serological tests, with virus isolation and identification being complementary procedures. The number of outbreaks of avian influenza seems to be increasing - over the last 5 years outbreaks have been reported in Italy, Hong Kong, Chile, the Netherlands, South Korea, Vietnam, Japan, Thailand, Cambodia, Indonesia, Laos, China, Pakistan, United States of America, Canada, South Africa, and Malaysia. Moreover, a growing number of human cases of avian influenza, in some cases fatal, have paralleled the outbreaks in commercial poultry. There is great concern about the possibility that a new virus subtype with pandemic potential could emerge from these outbreaks. From the perspective of human health, it is essential to eradicate the virus from poultry; however, the large number of small-holdings with poultry, the lack of control experience and resources, and the international scale of transmission and infection make rapid control and long-term prevention of recurrence extremely difficult. In the Western world, the renewed interest in free-range housing carries a threat for future outbreaks. The growing ethical objections to the largescale culling of birds require a different approach to the eradication of avian influenza.
Viruses have become more mobile alongside with increasing human mobility and speed of travel. At the same time we get access to information on viral outbreaks and epidemics from large parts of the world faster than ever before. Two recent epidemics will be presented to explore the value and the consequences of communicating epidemiological information through the Internet. The epidemiology, clinical features, diagnostic procedures and prophylaxis of imported viral infections are presented. Risk factors for the emergence and resurgence of viral diseases are being discussed.
Background On August 24, 2011, 31 US-bound refugees from Kuala Lumpur, Malaysia (KL) arrived in Los Angeles. One of them was diagnosed with measles post-arrival. He exposed others during a flight, and persons in the community while disembarking and seeking medical care. As a result, 9 cases of measles were identified. Methods We estimated costs of response to this outbreak and conducted a comparative cost analysis examining what might have happened had all US-bound refugees been vaccinated before leaving Malaysia. Results State-by-state costs differed and variously included vaccination, hospitalization, medical visits, and contact tracing with costs ranging from $621 to $35,115. The total of domestic and IOM Malaysia reported costs for US-bound refugees were $137,505 [range: $134,531 - $142,777 from a sensitivity analysis]. Had all US-bound refugees been vaccinated while in Malaysia, it would have cost approximately $19,646 and could have prevented 8 measles cases. Conclusion A vaccination program for US-bound refugees, supporting a complete vaccination for US-bound refugees, could improve refugees' health, reduce importations of vaccine-preventable diseases in the United States, and avert measles response activities and costs.
Matched MeSH terms: Disease Outbreaks/economics; Disease Outbreaks/prevention & control
Dengue is a rapidly spreading mosquito-borne disease caused by the dengue virus (DENV) and has emerged as a severe public health problem around the world. Guangdong, one of the southern Chinese provinces, experienced a serious outbreak of dengue in 2014, which was believed to be the worst dengue epidemic in China over the last 20 years. To better understand the epidemic, we collected the epidemiological data of the outbreak and analyzed 14,594 clinically suspected dengue patients from 25 hospitals in Guangdong. Dengue cases were then laboratory-confirmed by the detection of DENV non-structural protein 1 (NS1) antigen and/or DENV RNA. Afterwards, clinical manifestations of dengue patients were analyzed and 93 laboratory-positive serum specimens were chosen for the DENV serotyping and molecular analysis. Our data showed that the 2014 dengue outbreak in Guangdong had spread to 20 cities and more than 45 thousand people suffered from dengue fever. Of 14,594 participants, 11,387 were definitively diagnosed. Most manifested with a typical non-severe clinical course, and 1.96 % developed to severe dengue. The strains isolated successfully from the serum samples were identified as DENV-1. Genetic analyses revealed that the strains were classified into genotypes I and V of DENV-1, and the dengue epidemic of Guangdong in 2014 was caused by indigenous cases and imported cases from the neighboring Southeast Asian countries of Malaysia and Singapore. Overall, our study is informative and significant to the 2014 dengue outbreak in Guangdong and will provide crucial implications for dengue prevention and control in China and elsewhere.
Since its isolation in Tanzania in 1953, chikungunya virus has caused periodic outbreaks in both tropical Africa and Asia. In the last decade, the virus has shown not only increased activity but has expanded its geographical locations, thus classical delineation of various genotypes of chikungunya virus to specific geographic locales no longer holds true. Rapid mass movement of people and the constant presence of the right vectors in this region could have contributed to the change in virus ecology. This paper documents the first detection of chikungunya virus of Central/East genotype in Malaysia from a patient who was most likely infected with the virus during her visit to India. Without good Aedes vector measures, only time will tell whether this genotype rather than the existing endemic genotype will subsequently cause the next chikungunya outbreak in Malaysia.
An outbreak of rubella occurred amongst 303 newly recruited residential Form IV students in a military vocational training school in Malaysia. Of the 303 Form IV students, 77 gave a history of acute illness. Rubella specific IgM was detected in the sera of 46.5% (141/303) whereas rubella specific IgG was detected in 100% of all Form IV students. Sixty five students with no clinical history of acute illness during the outbreak period had detectable rubella IgM in their sera and rubella specific IgM was detected in the sera of all symptomatic students except one. Maculopapular rash was the commonest presenting clinical feature among students with acute rubella infection in this outbreak (97.4%) followed by fever (88.2%). The duration of rash ranged from one to nine days with a mean of 4.6 days. Of the 65 students that had both fever and rash, 56 (85.2%) students had maculopapular skin eruption on the same day as the date of onset of fever, six (9.2%) developed the rash a day after the onset of fever and three (4.6%) had the rash after two days of fever. The duration of fever ranged from one to eight days with a mean of 3.5 days. The duration of conjunctivitis ranged from one to four days with a mean of 2.3 days, and all those who developed conjunctivitis had mild eye-discharge without photophobia. The duration of arthralgia ranged from one to three days with a mean of 2.1 days. The commonest type of joints affected was knee joints (66.7%, 12/18), followed by elbow and shoulder joints (27.8%, 5/18) and wrist joints (5.6%, 1/18). A good clinical history of the temporal relationship between the occurrence of rash and fever during the outbreak could easily differentiate rubella illness from that of measles.
Dengue fever is major public health problem especially among the highly urbanized states of Malaysia, such as, Selangor and Kuala Lumpur Federal Territory. We report an epidemiological cluster pattern of dengue outbreak in the district of Gombak, Selangor that may mimic other acute febrile illnesses in which the transmission mode is via close contact. This dengue outbreak consisted of two waves; an initial cluster of three cases (including the first deceased, JI) which occurred between 20th and 21st of July, followed by a later larger cluster of 11 cases that occurred between 1st and 8th of August 2005. This epidemiological clustering pattern of acute dengue virus infection among close contacts suggests an intense rate of dengue virus transmission within the vicinity of the first deceased's house.
At this moment, public health authorities, physicians and scientists around the world are struggling to cope with a severe and rapidly spreading new disease in humans called severe acute respiratory syndrome, or SARS. According to World Health Organisation (WHO) this appears to be the first severe and easily transmissible new disease to emerge in the 21st century. Though much about the disease remains poorly understood, including the details of the causative virus, we do know that it has features that allow it to spread rapidly along international air travel routes. As of 10 May 2003, a cumulative 7296 probable SARS cases with 526 deaths have been reported from 30 countries on three continents (WHO, ProMED). In the past week, more than 1000 new probable cases and 96 deaths were reported globally. This represents an increase of 119 new cases and 8 new deaths compared with 9 May 2003 (China (85), Taiwan (23), and Hong Kong (7) represented the overwhelming majority, with one additional case each reported from France, Malaysia, Singapore, and the United States). Only in China, as of 10 May 2003 (WHO) total of 4884 with 235 deaths have been reported. Some outbreaks have reassuring features.
Foodborne diseases are common in the developing countries due to the predominant poor food handling and sanitation practices, particularly as a result of inadequate food safety laws, weak regulatory structures, and inadequate funding as well as a lack of appropriate education for food-handlers. The most frequently involved foods in disease outbreaks are of animal origin. However, in spite of the adequate legislation and laws governing the abattoir operation in Malaysia, compliance with food safety requirements during meat processing and waste disposal is inadequate. Therefore, the present study was designed to assess the food safety knowledge, attitude, and practice toward compliance with abattoir laws among the workers in Terengganu, Malaysia.
Two outbreaks of mushrooms poisoning involving 3 and 9 soldiers respectively with one death on 9 March 1980 in Perak are described. The symptoms were compatible with muscarine [a neurotoxin] poisoning which was detected in the stomach contents of the dead soldier and the mushrooms consumed by one group.
An epidemio-meteorotropic analytical study of Selangor, in the Southwest coast of Peninsular Malaysia, examines the monthly incidence of dengue for the period 1973-1982 to assess possible quantitative association with the monthly rainfall. The relationships between rainfall, abundance of A. aegypti and dengue infection during 1982 in Jinjang, a dengue-prone area in Selangor, were also examined. A quantitative association between rainfall and the number of dengue cases was found during the first wet period. The lag time between the onset of heavy rain and dengue outbreak was about two to three months. A 120% increase in the number of dengue cases was observed when the monthly rainfall was 300 mm or more. Positive associations were seen between the incidence of dengue and the Aedes house index and the Breteau index in Jinjang. The relationships between these three variables and rainfall suggest that the latter might have exerted its effect on dengue infection partly through the creation of more breeding sites for A. aegypti. Assessment of the importance of A. aegypti in the transmission of dengue in this locality was not possible because of the lack of adjustment for A. albopictus, the other known vector of dengue in the state, and for social and other environmental factors influencing infection rates. In spite of this and the interpretational problems common in aggregate studies, the present analyses have provided relatively strong statistical evidence of an association between rainfall and dengue outbreaks in Selangor, thereby indicating that it is a factor worthy of careful surveillance and monitoring.