Control Of Disease Outbreaks Research Articles

Aileen Joy Plant (née Parnell)

An Australian infectious disease epidemiologist widely admired for her global work controlling disease outbreaks and for her capacity for friendship

SARS: how a global epidemic was stopped

SARS: how a global epidemic was stopped

Review of Rapid Molecular Diagnostic Tools for Avian Influenza Virus

Molecular diagnostic tests are commonly used to diagnose avian influenza virus because they are sensitive and can be performed rapidly, with high throughput, and at a moderate cost. Molecular diagnostic tests recently have proven themselves to be invaluable in controlling disease outbreaks around the world. Several different methods, including traditional reverse transcription-polymerase chain reaction (PCR), real-time reverse transcription-polymerase chain reaction, and nucleic acid sequence-based amplification among others, have been described for the diagnosis of avian influenza in poultry with many different variations of primers, probes, enzymes, etc. Few of these tests have been validated, with the understanding that validation should be described as a level of comparison testing to show "fitness for purpose." None of the molecular diagnostic tests are validated for all species or specimen types that might be presented to a diagnostic laboratory. The sensitivity and specificity for all the molecular tests are governed by three critical control points, including RNA extraction, enzymes used for amplification, and the sequence of primers and probes. The RNA extraction step is of particular concern, since high-quality RNA is needed for any of the molecular tests. Some sample types, including cloacal (fecal) swabs and tissues, are difficult to process, with issues of poor RNA extraction or PCR inhibitors being common. The development of internal controls, robotics, and bead reagents are providing improved performance of existing tests, and new technologies will likely provide better tests for the future. With any molecular test, assay assurance must be performed on an ongoing basis, which includes the use of proficiency panels to measure test performance.

Report of the equine herpesvirus-1 Havermeyer Workshop, San Gimignano, Tuscany, June 2004

Amongst the infectious diseases that threaten equine health, herpesviral infections remain a world wide cause of serious morbidity and mortality. Equine herpesvirus-1 infection is the most important pathogen, causing an array of disorders including epidemic respiratory disease abortion, neonatal foal death, myeloencephalopathy and chorioretinopathy. Despite intense scientific investigation, extensive use of vaccination, and established codes of practice for control of disease outbreaks, infection and disease remain common. While equine herpesvirus-1 infection remains a daunting challenge for immunoprophylaxis, many critical advances in equine immunology have resulted in studies of this virus, particularly related to MHC-restricted cytotoxicity in the horse. A workshop was convened in San Gimignano, Tuscany, Italy in June 2004, to bring together clinical and basic researchers in the field of equine herpesvirus-1 study to discuss the latest advances and future prospects for improving our understanding of these diseases, and equine immunity to herpesviral infection. This report highlights the new information that was the focus of this workshop, and is intended to summarize this material and identify the critical questions in the field.

Animal disease outbreak control : the use of crisis management tools

In this era of globalisation the effective control of animal disease outbreaks requires powerful crisis management tools. In the 1990s software packages for different sectors of the government and agricultural industry began to be developed. In 2004, as a special application for tracking the movement of animals and animal products, the European Union developed the Trade Control and Expert System (TRACES) on the basis of its predecessor, the ANImal MOvement (ANIMO) project. The nationwide use of the ANIMO system by the veterinary authorities in Germany marked the beginning of the development in 1993 of a computerised national animal disease reporting system--the TierSeuchenNachrichten (TSN)--using the ANIMO hardware and software components. In addition to TRACES and TSN the third pillar for the management of animal disease outbreaks and crises in Germany is the national cattle and swine database--called Herkunftssicherungs- und Informationssystem für Tiere. A high degree of standardisation is necessary when integrating the different solutions at all levels of government and with the private sector. In this paper, the authors describe the use of these tools on the basis of their experience and in relation to what we can do now and what we should opt for in the future.

Preventing and controlling disease outbreaks in a complex emergency situation: discussion of the tsunami aftermath

The effects of the tsunami tidal wave which hit countries in south Asia and east Africa on 26 December 2004, presented a potential communicable disease threat immediately after the initial physical devastation

BIOLOGICAL WEAPONS CONTROL AND DISEASE SURVEILLANCE

In a workshop of the Biological Weapons Prevention Project (BWPP) held at the South African Centre for Conflict Resolution in Cape Town on 12 October 2004, a presentation was made by ILIAAD (International Lookout for Infectious Animal & Anthropo-zoonotic Disease) entitled ‘Animal disease outbreaks as a metaphor for managing biological weapons attacks on human populations’. The presentation explored the crucial role of strict quarantine in the successful containment of the outbreak of an exotic type of foot and mouth disease (FMD) in KwaZulu-Natal province of South Africa in 2000, and argued that strict quarantine could be similarly effective in controlling disease outbreaks caused by the intentional use of pathogens. Thus emerging disease outbreaks were linked with the threat of biological weapons. This commentary will review the origin of that linkage, how it evolved, and what lessons the media and information strategies of that evolution may have for current efforts in preventing the development, production and use of biological weapons.

Disease Notification Among Physicians in a Nigerian Tertiary Health Institution

The objective of this study was to assess the physicians' knowledge, attitudes, and practice as related to disease notification. A random sample of 125 physicians was initially recruited for the study but only 120 returned the questionnaires completed, giving a response rate of 96%. Knowledge about disease notification was generally low (14.2%) and among physicians with good knowledge, those in public health specialty had the highest percentage (52.3%) while those in pathology specialty had no knowledge at all (0%). A positive attitude was reported by a large majority (94.2%), who believed that disease notification is beneficial to Nigeria's health care delivery system because it aids-prevention and control of disease outbreak. This attitude was significantly more common in those with few years of professional activity. Even though most of the diseases for routine and immediate notification were diagnosed and treated almost on daily basis by the physicians, yet only 5.8% of them had reported these diseases to the appropriate health authority in the last six months. This study showed that there is a great need for efforts to improve physicians' knowledge on disease notification. Nigerian Medical Practitioner Vol. 45 No 6, 2004 (111-115)

Suppressive subtraction libraries to identify interferon-inducible genes in fish.

Previous attempts to identify genes in fish that respond to virus infection or interferon induction have not been particularly productive. Since these genes are very important in developing strategies to control disease outbreaks in aquaculture, we began a study of interferon-inducible genes in fish using suppressive subtraction hybridization to construct cDNA libraries enriched for interferon-inducible genes. Subtraction hybridization libraries were constructed with cDNA obtained from the kidney, spleen, and liver of Chinook salmon (Oncorhynchus tshawytscha) and staghorn sculpin (Hemilepidotus spinosus) before and after injection with poly IC, a potent interferon inducer. The "identified" genes in both cDNA libraries corresponded to previously identified genes of the fish complement system, the interferon-inducible proteins observed in mammalian cells, and the Vig-1 gene, identified in fish cells after infection with fish rhabdoviruses.

Persistence of herpesvirus of eel Herpesvirus anguillae in farmed European eel Anguilla anguilla.

Herpesvirus of eel Herpesvirus anguillae (HVA) was isolated repeatedly from farmed eel of an outwardly healthy stock, but virus isolation was much greater in an experimental group of fish that were injected with dexamethasone. The results suggest that HVA can establish a latent infection in eel. Previous exposure of these eels to HVA virus was shown by detection of HVA-specific antibodies. These eels did not show clinical signs after a secondary infection with HVA. Tracing of seropositive eel stocks, which had previous contact with HVA, and of HVA carrier fish can be useful to control disease outbreaks due to HVA infection.

Mitigation of bioterrorist threats in the 21st century.

There is a raising level of awareness and concern that agriculture and food supplies might serve as targets for bioterrorists. To minimize such threats a number of new initiates are urgently needed: 1. Greater levels of financial commitment from federal, state, and international organizations for research on highly infectious diseases and for emergency response infrastructure; 2. Wellorchestrated emergency response plans based on inter-agency, inter-departmental and stakeholder working groups; 3. Teams prepared for risk assessment and risk communication; 4. Modern systems of animal identification and accurate trace-back for animal movement; 5. Increased biosecurity in intensive production operations; 6. Accurate intelligence as to what pathogens pose the highest risks for economic and social impact; 7. Establishment of new international animal and plant disease research networks and partnerships; 8. Strengthen international disease surveillance networks for early detection and intervention; 9. New generations of rapid diagnostic tests for pathogen detection that are practical for field and diagnostic laboratories; 10. Increased level of commitment to pathogen genomics research for molecular epidemiology and vaccine development; 11. New chemical and immunological intervention strategies to prevent or control disease outbreaks; 12. Increased level of training on exotic and emerging animal diseases in basic veterinary education and through continuing education for veterinarians, state and federal field personnel and laboratory diagnosticians.

Guidelines for the epidemiologic assessment of occupational asthma: Report of the Subcommittee on the Epidemiologic Assessment of Occupational Asthma, Occupational Lung Disease Committee

Physician reporting of cases of communicable disease has played an important role in detection and control of disease outbreaks.’ A similar expectation exists for physician reporting of occupational diseases, including occupational asthma. The diagnosis of a single case of occupational asthma may be a sentinel event that reveals the need to search for other cases, as well as remediable underlying causes.’ As stated by Rutstein et al.,3 such an occurrence may: “(1) provide the impetus for epidemiologic or industrial hygiene studies, or (2) serve as a warning signal that materials substitution, engineering control, personal protection, or medical care may be required.” Also, other purposes may be served by consequent epidemiologic and industrial hygiene studies. An epidemiologic survey may be needed to convince responsible parties that a health problem exists that is in some measure attributable to workplace exposures. An epidemiologic survey will be needed to quantitate the magnitude of a work-related health problem, whether the magnitude is expressed as disease prevalence, incidence, or some other measure. An epidemiologic study may identify personal risk factors that explain why certain persons have manifested a disease as a consequence of their occupational exposure(s). Resultant recommendations for control of exposures in the workplace may facilitate management of the index case and affected co-workers, and help prevent the occurrence of additional cases.