Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia.
Matched MeSH terms: Disease Outbreaks/prevention & control
The control of dengue outbreak requires a multi-pronged effort by the various government agencies. It requires co-operation of the community in the control activities, strict adherence to existing control procedures and guidelines by health personnel, increased manpower where necessary and strengthening co-operation between various health agencies to prevent delay in instituting control measures.
Besides response and recovery, prevention and preparedness are the two critical components of any contingency plan. The author discusses the various elements which must be present in the prevention and preparedness plan of countries in Asia. As the continent has such diverse peoples and veterinary infrastructures, the actual plan may vary from one country to another, but must incorporate those elements which are crucial to ensure the success of the preparedness plan.
Matched MeSH terms: Disease Outbreaks/prevention & control
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.
The author presents reports of foot and mouth disease (FMD) submitted between 1996 and 2001 to the Office International des Epizooties (OIE: World organisation for animal health) Sub-Commission for FMD in South-East Asia. Of the ten countries in South-East Asia, FMD is endemic in seven (Cambodia, Laos, Malaysia, Myanmar, the Philippines, Thailand and Vietnam) and three are free of the disease (Brunei, Indonesia and Singapore). Part of the Philippines is also recognised internationally as being free of FMD. From 1996 to 2001, serotype O viruses caused outbreaks in all seven of the endemically infected countries. On the mainland, three different type O lineages have been recorded, namely: the South-East Asian (SEA) topotype, the pig-adapted or Cathay topotype and the pan-Asian topotype. Prior to 1999, one group of SEA topotype viruses occurred in the eastern part of the region and another group in the western part. However, in 1999, the pan-Asian lineage was introduced to the region and has become widespread. The Cathay topotype was reported from Vietnam in 1997 and is the only FMD virus currently endemic in the Philippines. Type Asia 1 has never been reported from the Philippines but was reported from all countries on the mainland except Vietnam between 1996 and 2001. Type A virus has not been reported from east of the Mekong River in the past six years and seems to be mainly confined to Thailand with occasional spillover into Malaysia. The distribution and movement of FMD viruses in the region is a reflection of the trade-driven movement of livestock. There is great disparity across the region in the strength and resources of the animal health services and this has a direct impact on FMD control. Regulatory environments are not well developed and enforcement of regulations can be ineffectual. The management of animal movement is quite variable across the region and much market-driven transboundary movement of livestock is unregulated. Formal quarantine approaches are generally not supported by traders or are not available. Vaccination is not used widely as a control tool because of the expense. However, it is applied by the Veterinary Services in Malaysia to control incursions of the disease and there is a mass vaccination programme for large ruminants in Thailand where the Government produces and distributes vaccine. Vaccination is also used by the commercial pig sector, particularly in the Philippines and Thailand.
Matched MeSH terms: Disease Outbreaks/prevention & control
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.
Matched MeSH terms: Disease Outbreaks/prevention & control
A Hepatitis A outbreak occurred in Mukim Hulu Langat, Hulu Langat district from April 2002 to October 2002. Of the 51 cases notified, most were among students and the ethnic groups involved were Malays and the Orang Asli (local indigenous community). Epidemiological investigations revealed that the cases were localized along rivers used for recreational activities in this area. River water analysis indicated human faecal contamination and it was believed that the contamination was due to the Orang Asli community living upstream. This occurred due to lack of toilet facilities, water at point of use and the existing traditional practices of the Orang Asli community. Control measures instituted were intense health education to the Orang Asli to avoid using the rivers for defecation, multi agency efforts to provide sanitary toilets and adequate water to the villages affected. Future measures include conducting a sero- prevalence survey to determine the feasibility of Hepatitis A immunization to the susceptible population in this area. The outbreak that began in April 2002 was controlled by October 2002.
The OIE Southeast Asia Foot-and-Mouth Disease Campaign (SEAFMD) involves the coordinated control of foot-and-mouth disease by eight of the ASEAN countries. A long term vision for SEAFMD has been developed and the core element is a progressive zoning approach to the control and eradication of FMD in the region. This paper describes the current status of FMD in Southeast Asia and progress towards achievement of OIE free zone status for FMD in parts of the Philippines and Malaysia and the initiation of the Malaysia-Thailand-Myanmar (MTM) Peninsular Campaign for FMD Freedom. In mainland Southeast Asia, the progressive zoning approach involves several sub-regional groups working in parallel to oversee the epidemiological and economic studies required to determine the feasibility of the approach. Areas involved include the Lower Mekong Basin, Upper Mekong Basin, parts of Myanmar and the Red River Delta of Vietnam. The paper describes the current usage of vaccines for FMD in Southeast Asia and provides recommendations for their supply and use in the new regional initiatives.
Matched MeSH terms: Disease Outbreaks/prevention & control
Challenges arising from epidemic infectious disease outbreaks can be more effectively met if traditional public health is enhanced by sociology. The focus is normally on biomedical aspects, the surveillance and sentinel systems for infectious diseases, and what needs to be done to bring outbreaks under control quickly. Social factors associated with infectious disease outbreaks are often neglected and the aftermath is ignored. These factors can affect outbreak severity, its rate and extent of spread, influencing the welfare of victims, their families, and their communities. We propose an agenda for research to meet the challenges of infectious disease outbreaks. What social factors led to the outbreak? What social factors affected its severity and rate and extent of spread? How did individuals, social groups, and the state react to it? What are the short- and long-term effects on individuals, social groups, and the larger society? What programs can be put in place to help victims, their families, and affected communities to cope with the consequences--impaired mental and physical health, economic losses, and disrupted communities? Although current research on infectious disease outbreaks pays attention to social factors related to causation, severity, rate and extent of spread, those dealing with the "social chaos" arising from outbreaks are usually neglected. Inclusion, by combining traditional public health with sociological analysis, will enrich public health theory and understanding of infectious disease outbreaks. Our approach will help develop better programs to combat outbreaks and equally important, to help survivors, their families, and their communities cope better with the aftermath.
The microbes that cause infectious diseases are complex, dynamic, and constantly evolving. They reproduce rapidly, mutate frequently, breach species barriers, adapt with relative ease to new hosts and new environments, and develop resistance to the drugs used to treat them. In their article "Meeting the challenge of epidemic infectious diseases outbreaks: an agenda for research", Kai-Lit Phua and Lai Kah Lee clearly demonstrate how social, behavioural and environmental factors, linked to a host of human activities, have accelerated and amplified these natural phenomena. By reviewing published and non-published information about outbreaks of Nipah virus in Malaysia, severe acute respiratory syndrome (SARS) and avian influenza in Asia, and the HIV pandemic, they provide a series of examples that demonstrate the various social, behavioural and environmental factors of these recent infectious disease outbreaks. They then analyse some of these same determinants in important historical epidemics and pandemics such as plague in medieval Europe, and conclude that it is important to better understand the social conditions that facilitate the appearance of diseases outbreaks in order to determine why and how societies react to outbreaks and their impact on different population groups.
This study evaluates and discusses the impact of the rural health improvement scheme in reducing the incidence of dysentery, enteric fever, cholera and viral hepatitis in Sarawak, Malaysia, using data compiled from state and federal health department reports. This study suggests that from 1963 to 2002, water supply intervention contributed to a more than 200-fold decrease in dysentery and a 60-fold decrease in enteric fever. Variations in reporting of viral hepatitis during that period make it difficult to detect a trend. Cholera was still endemic in 2002. Cholera and dysentery outbreaks, occurring when rural populations relied on contaminated rivers for their water supply, suggested that sanitation intervention was not as effective in reducing waterborne diseases. Recommendations are made for successive one-component interventions focusing on catchment management to ensure protection of current and alternative water supplies.
Matched MeSH terms: Disease Outbreaks/prevention & control
The first sign of influenza activity in the Netherlands during the 2005-2006 influenza season was the isolation of influenza viruses in the last week of 2005. From Week 1 of 2006 onwards, an increase in clinical influenza activity was also observed that did not return to baseline levels until Week 15. Two waves of influenza activity were observed with peak incidences of 13.8 and 9.8 influenza-like illnesses per 10,000 inhabitants on Weeks 7 and 12, respectively. The first wave of influenza was caused primarily by influenza B viruses, whereas the second wave was caused predominantly by influenza A/H3N2 viruses. The influenza B viruses appeared to belong to two different phylogenetic lineages and were antigenically distinguishable from the vaccine strain. The isolated influenza A/H3N2 viruses were closely related to the vaccine strain for this subtype and only minor antigenic differences with the vaccine strain were observed for a limited number of isolates. Only a small number of influenza A/H1N1 viruses were isolated, which all closely resembled the H1N1 vaccine strain. For the 2006-2007 influenza season, the World Health Organization has recommended the following vaccine composition: A/Wisconsin/67/05 (H3N2), A/New Caledonia/20/99 (H1N1) and B/Malaysia/2506/05.
The gram-negative bacillus Burkholderia pseudomallei is a saprophyte and the cause of melioidosis. Natural infection is most commonly reported in northeast Thailand and northern Australia but also occurs in other parts of Asia, South America, and the Caribbean. Melioidosis develops after bacterial inoculation or inhalation, often in relation to occupational exposure in areas where the disease is endemic. Clinical infection has a peak incidence between the fourth and fifth decades; with diabetes mellitus, excess alcohol consumption, chronic renal failure, and chronic lung disease acting as independent risk factors. Most affected adults ( approximately 80%) in northeast Thailand, northern Australia, and Malaysia have >/=1 underlying diseases. Symptoms of melioidosis may be exhibited many years after exposure, commonly in association with an alteration in immune status. Manifestations of disease are extremely broad ranging and form a spectrum from rapidly life-threatening sepsis to chronic low-grade infection. A common clinical picture is that of sepsis associated with bacterial dissemination to distant sites, frequently causing concomitant pneumonia and liver and splenic abscesses. Infection may also occur in bone, joints, skin, soft tissue, or the prostate. The clinical symptoms of melioidosis mimic those of many other diseases; thus, differentiating between melioidosis and other acute and chronic bacterial infections, including tuberculosis, is often impossible. Confirmation of the diagnosis relies on good practices for specimen collection, laboratory culture, and isolation of B. pseudomallei. The overall mortality rate of infected persons is 50% in northeast Thailand (35% in children) and 19% in Australia.
Since the first H5N1 highly pathogenic avian influenza virus (HPAIV) infection in the region in August 2003, Cambodia, Laos, Malaysia, Myanmar, Indonesia, Thailand and Vietnam have all recorded outbreaks of the disease. The HPAIV continues to occur in some countries in Southeast Asia despite control programmes encompassing surveillance, vaccination and stamping out strategies. A number of strains have been circulating in the region since the first outbreaks in 2003, and although the source of the initial outbreaks in domestic poultry is not known, the continuing propagation of disease in the region is primarily the result of the movement of domestic poultry and poultry products, and people. A comprehensive approach using all the strategies available to break the chain of transmission of the virus in poultry will be needed to achieve lasting disease control.
Matched MeSH terms: Disease Outbreaks/prevention & control
Although drugs are haram and therefore prohibited in Islam, illicit drug use is widespread in many Islamic countries throughout the world. In the last several years increased prevalence of this problem has been observed in many of these countries which has in turn led to increasing injecting drug use driven HIV/AIDS epidemic across the Islamic world. Whilst some countries have recently responded to the threat through the implementation of harm reduction programmes, many others have been slow to respond. In Islam, The Quran and the Prophetic traditions or the Sunnah are the central sources of references for the laws and principles that guide the Muslims' way of life and by which policies and guidelines for responses including that of contemporary social and health problems can be derived. The preservation and protection of the dignity of man, and steering mankind away from harm and destruction are central to the teachings of Islam. When viewed through the Islamic principles of the preservation and protection of the faith, life, intellect, progeny and wealth, harm reduction programmes are permissible and in fact provide a practical solution to a problem that could result in far greater damage to the society at large if left unaddressed.