By Neena Bhandari

Professor Tania C Sorrell, Director, Sydney Institute for Emerging Infectious Diseases and Biosecurity and Centre for Infectious Diseases and Microbiology, Sydney Medical School, University of Sydney; and Senior Physician in Infectious Diseases at Sydney West Area Health Service.

What are the new and emerging infectious diseases threatening the world in the coming decade?

In the context of emerging infectious diseases in what might happen in the next 10 years, we are really thinking in terms of two major problems – outbreaks which might develop into pandemics and the continuing increase in anti-microbial resistance and hence the dual problems of preventing and managing outbreaks and treating infections which are not responsive to the drugs we have available.

Recent experiences and information over the last few decades reveals that most of the new emerging infectious diseases have related to animal-human contact. More than 60 percent of emerging infectious diseases in the past decade have resulted from animal-human contact and of these, 70 percent are due to contact between humans and wildlife. In developing countries, these issues are even more important with increasing land clearing, intensive farming of poultry, and infections passing from wild birds into domestic birds.

For the next 10 years a significant number of new infections will be related to animal-human contact and that is an area that needs to be carefully surveyed. We have experience from the 2009 influenza pandemic that we have to keep up surveillance for a number of these pathogens and the developed countries need to enable developing countries to build this capacity in this area so that we can form a global community or network that is capable of identifying and managing these infections.

The new diseases of the future will be a continuation of resistance development unless we can contain the use of anti-microbial agents appropriately and other infection control issues that lead to the spread of these pathogens.

What are the major challenges in combating infectious diseases of the future?

In terms of the challenges facing the world to combat emerging infectious diseases of the future, First, we must develop global capabilities i.e. the ability globally to rapidly identify and communicate problems and to try and contain outbreaks or episodes of resistant infections through an integrated approach. We not only have to engage the public health, medical, nursing and clinical communities, but also the public in general in understanding how this happens so we can actually contain the problems.

Which of the common infections have become antibiotic resistant, especially in Asia?

There has been an increase in potentially untreatable diseases caused by bacteria and other organisms that are highly resistant to antibiotics, including Tuberculosis. TB is one of the diseases that had become multi-drug resistant. In many Asian and African countries there is no laboratory facility to determine resistance or susceptibility to anti-TB drugs so it is extremely important to develop the capacity in developing countries to identify this so we can institute appropriate isolation and management procedures for treatment.

There is growing resistance to drugs in a number of common infections like typhoid fever, Methicillin-resistant Staphylococcus aureus (MRSA) increasing problem in hospitals and communities, ecoli, sexually transmitted diseases like gonorrhoea and malaria, HIV and its ability to evolve very quickly and the importance of keeping up new drug developments in that area and monitoring the susceptibility of the human immunodeficiency virus.

New fungi are causing invasive diseases because of immuno compromise and they are often resistant to our best of fungal agents.

How important is Internet as a tool in clinical medicine and disease outbreak investigation and pandemics such as swine flu and SARS?

Internet is being used as a “syndromic surveillance” tool. We have an extensive global network if there is a blip in certain diseases. Internet is important for rapid public health responses and for researchers to share information on genetic constitution of the organisms that might be picked up so they can share rapid diagnostic development. Video conferencing can be used to educate people, data management on outbreaks following on space and time so notification can occur worldwide to formulate and facilitate management strategies.

Australia’s position as one of the few developed nations in the Asia-Pacific region provides us with a unique opportunity to lead in interdisciplinary research and capacity building and to collaborate with our neighbours in prevention, containment and eradication of emerging infectious diseases at home and abroad.

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Professor Kevin Marsh, Director of the Kenya Medical Research Institute (KEMRI) Wellcome Trust programme in Kilifi, Kenya.

What are the most important challenges in the field of infectious diseases facing the world in the coming decade?

The three major infectious diseases problems worldwide have been Tuberculosis, HIV and Malaria. We can add three more massive global issues: Pneumonia, which is always ignored. It is a major killer of children throughout most of the world and still there isn’t the same degree of emphasis on it. Secondly, the general issue of drug resistance and antibiotic resistance in particular, which is going to be a major issue all over the world. As it gets worse, it removes cheap effective drugs and pushes us towards more expensive drugs and that in the end, in case of sudden infections, will make it very difficult to treat if resistance keeps developing in the same sort of way as it has been in the last couple of years.

Thirdly, the unknowns i.e. something completely out of the blue like the SARS outbreak a few years ago. The problem is knowing how to prepare for it and even if you do prepare for it then getting it right. If you under prepare, you will be criticised for allowing a disaster, and if you over prepare, you will be criticised for wasting money. So the problem of how to deal with global new emerging infections is always there in the background.

Are there sufficient global resources for fighting Malaria, AIDS, and Tuberculosis? The challenges of malaria in Africa and how is it different to Asia?

There has been a real increase in international and national investment and the amount spent on malaria control has gone up 10 times in the last 10 years. It is now about US$ 2 billion while a decade ago it used to be US$ 200 million so in that sense things are improving a lot. But it is still not yet enough because we need about US$ 5 billion a year. There has been a significant increase in money for controlling these diseases from the Global Fund and governments.

The number of people exposed to Malaria in Asia is more than in Africa so in one sense we have underestimated the problem in Asia, but it is still true that 90 per cent of all deaths due to malaria happen in Africa. Malaria in Africa is much more concentrated and intense so even though the number of people exposed to the disease is less, the impact in terms of health is greater.

There are five species of malaria that commonly infect humans and two are most important in terms of numbers and they are Plasmodium falciparum and Plasmodium vivax. Plasmodium falciparum is a problem all over the world and also in Africa. On the other hand, Asia has both species and they are often in the same places. It has been assumed in Asia that vivax isn’t so important, but now people are beginning to realise that for cause of ill-health, it is really more important than people thought and it is also more difficult to deal with in terms of control than Plasmodium falciparum.

So Asia has this additional problem of dealing with a species that is more difficult to control. There is a third emerging species of Plasmodium knowlesi, which is a malaria transmitted in monkeys. In the last few years across Asia and particularly in parts of Malaysia, this species is causing severe disease in humans. This is a new disease in humans, but in terms of numbers it affects less people than the other two species.

Is global warming having an impact on the spread of malaria and dengue in some of the most populous tropical and equatorial countries?

While global warming is not having an impact on the spread of malaria as yet, it is predicted that global warming will spread the range of dengue and the disease may begin to surface in areas where it wasn’t previously a problem.

Are governments meeting their commitments to health aid and the Millennium Development Goals when it comes to immunisation?

Immunisation has been one of the most successful international efforts. In the 1960s, less than five percent of the world’s children were immunised and now 80 percent or more are immunised. There are individual countries, where there have been lapses and they haven’t met their commitment, especially countries where there has been political conflict or war and in others like Nigeria, where there has been a problem with polio vaccine because of religious concerns.

People are worried that the Millennium Development Goals won’t be met, but although there are clearly lots of problems, they can be met in many places, they will be met in some places and they could be met in other places. There isn’t that hopelessness, which many think there is when it comes to health issues in Africa. There are quite large areas of Africa where things are happening fast and they could be accelerated elsewhere with the right kind of inputs.

Two things will be really critical to meeting the MDGs in Africa – controlling malaria as now we know that malaria causes lots of secondary deaths, and controlling pneumonia. Malaria makes it more likely to get other serious illnesses. In Bioko, Equatorial Guinea, malaria was controlled in one sweep in a year and their childhood mortality was reduced by two-thirds in one go. If you control malaria aggressively, you can prevent an enormous number of deaths due to not just malaria but other diseases. In Africa, if you control malaria, you can reduce childhood mortality down to the levels to achieve MDGs.

In coastal Kenya, malaria has dropped by 90 percent in the last five years. Infant childhood deaths have dropped by 40-50 percent in the last few years. It used to be 115 deaths per 1000 children under 5 years old, last year’s survey put it at 74/1000. It is one of the countries closer than others in meeting the MDGs. In some countries of Africa, there has been a major drop in mortality like Ethiopia, Malawi and Niger.

Is there a renewed commitment for research on vaccines for the Third World such as Malaria, HIV, acute respiratory disease, diarrhoeal disease, meningitis?

There have been vaccine initiatives for malaria which is in its Phase 3 Trials and may go for registration in the next few years.

Pneumococcal vaccination standardly used in the US, Europe and Australia, has now been introduced in Africa. It is likely to significantly reduce deaths due to pneumonia and that will help achieve the MDGs in Africa by bringing down childhood mortality.

The issue in the long term is affording the vaccines in routine use. The Global Alliance for Vaccines and Immunisation (GAVI) funds governments but in the long run governments would have to develop mechanisms to fund it themselves to maintain vaccine coverage.

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