Can Skin Infection With Group A Streptococcus Cause Acute Rheumatic Fever?
Funder
National Health and Medical Research Council
Funding Amount
$459,450.00
Summary
It is traditionally taught that the cause of acute rheumatic fever (ARF) is always infection of the throat with the bacterium group A streptococcus (GAS). However, in Aboriginal communities of the Top End of the Northern Territory the incidence of ARF is the highest reported in the world, yet GAS is uncommonly isolated from the throat. There is further information to suggest that GAS skin sores may underlie many cases of ARF. If this were proven, it would completely alter the traditional view of ....It is traditionally taught that the cause of acute rheumatic fever (ARF) is always infection of the throat with the bacterium group A streptococcus (GAS). However, in Aboriginal communities of the Top End of the Northern Territory the incidence of ARF is the highest reported in the world, yet GAS is uncommonly isolated from the throat. There is further information to suggest that GAS skin sores may underlie many cases of ARF. If this were proven, it would completely alter the traditional view of the cause of ARF, and have important implications for prevention of ARF around the world. Presently, these approaches focus on diagnosing and treating sore throat, but no country has proven that such a program can be successful in substantially reducing new cases of ARF. If it was known that skin infection could lead to ARF, then countries (including Australia) could emphasise the importance of skin health programs. A further benefit of this knowledge would be to influence GAS vaccine development, which presently is largely focused on the prevention of sore throat. A different possibility has recently been raised - that the cause of ARF may not always be GAS, but instead that the related bacteria GCS and GGS may have the potential to cause this disease. Proof of this hypothesis would even more dramatically alter our understanding of disease causation, prevention, and vaccine development. We propose to determine the cause of ARF in Aboriginal communities by regularly swabbing families of people with a history of ARF, and using genetic fingerprinting of the bacteria from the skin and throat swabs. When cases of ARF occur, we will be able to determine the site and type of infection that precipitated the attack. We will conduct a related study in more communities, in which we will swab family members of people with ARF and of control families (without ARF) to determine the bacteria most commonly isolated from ARF families.Read moreRead less
Improving Delivery Of Secondary Prophylaxis For Rheumatic Heart Disease: A Stepped-wedge, Community-randomised Trial
Funder
National Health and Medical Research Council
Funding Amount
$1,913,074.00
Summary
Rheumatic heart disease (RHD) is a major health problem in Indigenous communities. Continued progress in controlling RHD requires an understanding of how to improve delivery of regular injections of penicillin - secondary prophylaxis (SP). We will evaluate a systems-based approach to improving delivery of SP, using a stepped-wedge trial in 12 communities in NT and Qld. If successful, this model will provide a practical and transferable model.
A New Model For The Pathogenesis Of Rheumatic Fever: Superantigen Priming Of The Immune Response To Group A Streptococci
Funder
National Health and Medical Research Council
Funding Amount
$248,820.00
Summary
Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, c ....Acute rheumatic fever (ARF) is now rare in developed countries. However, it remains a major problem in Aboriginal Australians in the NT where the rate of ARF is the highest in the world. This leads to high rates of rheumatic heart disease (up to 3% of individuals in some communities) and a premature mortality of over four times that for developing countries. Immunisation and improved living conditions offer a long-term solution but these remain a distant prospect. In the short and medium term, control of this ARF will partly depend on new and better treatment and prevention strategies. To achieve these goals a deeper understanding of the immune mechanisms underlying this disease is urgently needed. It is known that ARF is caused by an abnormal immune response following streptococcal infection. This leads to the production of cells called T cells that attack the body s own tissues rather than the bacteria itself. This autoimmune disease is responsible for the heart damage that underlies ARF. It is believed that this proces only occurs when susceptible individuals are infected with specific rheumatogenic strains of streptococci. However there are a number of deficiencies in this model and it is proposed that there is an additional factor responsible for the abnormal immune response in ARF. This project will explore the possibility that bacterial toxins called superantigens are the critical missing factor , by studying the immune response in ARF. Superantigens are produced by certain streptococci and staphylococci, and are potent in minute quantities causing widespread activation of the immune system. They have been found to play an important role in a number of autoimmune diseases and the type of immune response found in ARF fits well with that expected if superantigens were involved. If superantigens play an important role in causing the abnormal immune response in ARF then a number of new avenues would open for the treatment and prevention of this disease.Read moreRead less
Roles Of Impaired Apoptosis And Differentiation In Tumourigenesis And Therapy
Funder
National Health and Medical Research Council
Funding Amount
$21,656,910.00
Summary
The ten scientific laboratories in this program have joined forces to investigate two ways in which tumours develop. Both are of particular interest, because they suggest new ways in which cancer might be overcome. Most of our tissues are continually renewed throughout life by production of new cells. Therefore many of the old cells in each tissue must die off to maintain the proper cell numbers. To eliminate cells that are no longer needed or have become damaged, the body has developed a remark ....The ten scientific laboratories in this program have joined forces to investigate two ways in which tumours develop. Both are of particular interest, because they suggest new ways in which cancer might be overcome. Most of our tissues are continually renewed throughout life by production of new cells. Therefore many of the old cells in each tissue must die off to maintain the proper cell numbers. To eliminate cells that are no longer needed or have become damaged, the body has developed a remarkable cell suicide process termed apoptosis. Unfortunately, however, occasionally a random accident to the genes in one of our cells prevents the machinery for apoptosis from being turned on. In that case, the cell will not die when it should and, by continually dividing, it may eventually give rise to a cancer. Since most cancer cells still retain most of the machinery for apoptosis, however, a drug that could switch on this natural cell death machinery would provide a promising new approach to cancer therapy. Identifying and developing such drugs is one major long-term goal of this program. The other focus of our program concerns stem cells. These are rare cells with the remarkable ability to generate an entire tissue. For example, one of our laboratories has identified stem cells that can generate all the cells in the breast. The almost unlimited regenerative capacity of stem cells has a built-in danger. If a stem cell acquires the ability to proliferate excessively, it can go on to form a tumour. Indeed, many cancer researchers now suspect that rare stem cells within a tumour cause its inexorable growth. If tumour growth is maintained by stem cells, it will be essential to develop new forms of therapy that target these rare cancer stem cells rather than merely the bulk of the tumour cells. This is another key long-term goal of our program.Read moreRead less
Estimating The Burden Of Group A Streptococcal Diseases In Victoria
Funder
National Health and Medical Research Council
Funding Amount
$386,760.00
Summary
Despite the considerable advances in the diagnosis and treatment of group A streptococcal (GAS) diseases made during the last century, the impressive spectrum of infections caused by this organism continues to have a significant impact in developed countries. This spectrum includes diseases that are mild but common (e.g. sore throat, skin sores), rare but very severe (e.g. bloodstream infections, flesh-eating bacteria) and those that are more common in developing countries and the Aboriginal pop ....Despite the considerable advances in the diagnosis and treatment of group A streptococcal (GAS) diseases made during the last century, the impressive spectrum of infections caused by this organism continues to have a significant impact in developed countries. This spectrum includes diseases that are mild but common (e.g. sore throat, skin sores), rare but very severe (e.g. bloodstream infections, flesh-eating bacteria) and those that are more common in developing countries and the Aboriginal population (e.g. rheumatic fever, kidney disease). Streptococcal sore throat remains one of the most common childhood infections, and severe group A streptococcal diseases are thought to be increasing in incidence in Australia. Yet, there are no accurate data on the incidence and costs of these or other GAS diseases in non-Aboriginal Australians, or in most other populations around the world. It is becoming more urgent to collect this data as numerous vaccine candidates are entering human trials, new approaches to the treatment of sore throat are emerging, and new strategies to treat and control the spread of severe disease are being developed. We propose a comprehensive strategy to measure the incidence, prevalence and costs of each group of GAS diseases. We will follow a group of families for 12 months to detect cases of GAS sore throat and skin sores and measure the impact on the family. We will survey children in schools to estimate the prevalence of skin sores. We will check hospital records to calculate the number of cases of rheumatic fever and kidney disease. And we will maintain surveillance for severe diseases by checking hospital and laboratory records. We will also check to see if family members of people with severe disease have the GAS bacterium in their throats. We will then compile these data into a comprehensive estimate of the burden of disease in Victoria, and estimate the cost-effectiveness of different treatment and prevention strategies.Read moreRead less
In cancer cells the normal process of cell death (called apoptosis) is defective, helping abnormal cells to grow and multiply unchecked. The Bak protein is a member of the Bcl-2 family of apoptosis regulators, and plays a pivotal role in mediating cell death. By defining each step in Bak-mediated apoptosis, we aim to better understand how cancer cells accumulate, and how targeting the Bcl-2 family may lead to effective anti-cancer therapeutics.
Role Of Bak And Bax Membrane Anchors In Targeting And Apoptotic Pore Formation.
Funder
National Health and Medical Research Council
Funding Amount
$352,319.00
Summary
In cancer cells the normal process of cell death (called apoptosis) is defective, helping abnormal cells to grow and multiply unchecked. The Bak and Bax proteins are members of the Bcl-2 family of apoptosis regulators, and play a pivotal role in mediating cell death. By defining how these proteins form a pore in mitochondria, the point of no return in cell death, will help the development of novel anti-cancer agents that target the Bcl-2 family in general, and Bak and Bax in particular.
Immunising Aboriginal Mothers With Pneumococcal Polysaccharide Vaccine To Prevent Infant Ear Disease And Carriage
Funder
National Health and Medical Research Council
Funding Amount
$1,131,530.00
Summary
Aboriginal children experience the highest rates of acute and chronic ear infections in the world, with resultant permanent ear damage, hearing loss and educational disadvantage. These infections are mainly bacterial, and Streptococcus pneumoniae (pneumococcus) is the predominant pathogen. Pneumococcal colonisation and infection begins within days of birth, many months before any potential immunological protection from infant pneumococcal conjugate vaccine may be expected. New strategies are nee ....Aboriginal children experience the highest rates of acute and chronic ear infections in the world, with resultant permanent ear damage, hearing loss and educational disadvantage. These infections are mainly bacterial, and Streptococcus pneumoniae (pneumococcus) is the predominant pathogen. Pneumococcal colonisation and infection begins within days of birth, many months before any potential immunological protection from infant pneumococcal conjugate vaccine may be expected. New strategies are needed to eliminate, or at least delay, this early-onset pneumococcal colonisation. One such strategy is the administration to the mother of pneumococcal vaccine, which may protect the newborn infant by leading to higher titres of transplacental or breast milk pneumococcal antibodies and-or by reducing carriage (and transmission to the infant) of maternal pneumococci. Previous small studies using this strategy have been encouraging, but there have been no studies properly evaluating carriage or disease endpoints in infants. The polysaccharide pneumococcal vaccine is currently recommended for all Aboriginal and Torres Islander persons aged 15 years or more in the Northern Territory but uptake of the vaccine has been poor. We propose to conduct a pilot study to determine if maternal immunisation with this vaccine, either in the third trimester of pregancy of immediately following delivery, can reduce pneumococcal carriage and the prevalence of middle ear disease among Aboriginal infants at seven months of age. We aim to recruit 210 Aboriginal women who have uncomplicated pregnancies from Darwin and remote communities in the Top End of the Northern Territory. Each subject and their infant offspring will be followed-up after vaccination and at birth, one , two and seven months after birth.Read moreRead less