Chapter 6: Neglected Global Epidemics: three growing threats
Road traffic hazards: hidden epidemics
More than 20 million people are severely injured or killed on the world's roads each year. The burden falls most heavily on developing countries, where it will grow heavier still because of the rapid increase in the number of vehicles.
In addition to the direct costs of road injuries and deaths, the increase in the number of vehicles and reliance on certain transport policies have other serious health implications as well as wider social, economic and environmental impacts (22). In some countries, air pollution from road transport causes even more deaths than those resulting from traffic accidents (23). Besides the direct impacts on respiratory and heart disease, motorized transport produces around a quarter of the anthropogenic emissions of gases leading to climate change (24). These "hidden epidemics" receive relatively little national or international attention compared with the focus on major communicable and noncommunicable diseases.
To a large extent, road injuries are preventable. There are many available and affordable interventions that can prevent injuries and save lives: to date, most of the evaluation of these interventions has been carried out in developed countries, and more research is needed on their effectiveness in developing countries. Renewed efforts are under way to increase worldwide awareness of the problem and its solutions and to encourage the introduction of road safety policies and practices. Several countries are using integrated strategies to deal with traffic risks and enhance the benefits of transport and land use policies to promote physical activity and cohesive projects for community development (25).
The epidemic of road traffic injuries in developing countries is still in its early stages, but it threatens to grow exponentially unless there is swift action to counter it (26). Low-income and middle-income countries already bear the brunt of 90% of the disability-adjusted life years (DALYs) lost to road traffic injuries and deaths. While fatality rates in high-income countries are declining, they are rapidly accelerating in the developing world, especially in Asia (27). The problem is so severe that, by 2020, road crash injuries are likely to represent the third leading cause worldwide of DALYs lost (28). By then, road traffic deaths are expected to increase by 92% in China and 147% in India, with an average increase of 80% in many other developing countries (29).
In addition to the unacceptable human toll, the global economic cost of road crashes has been estimated at about US$ 518 billion annually, of which the developing country share is about US$ 65 billion (27). Countries struggling for economic development clearly cannot afford such losses, which have a significant impact on national health care systems. Injuries account for approximately one-third of the acute patient load in many hospitals in low- income and middle-income countries, and between 30% and 86% of all trauma admissions (30); road traffic injuries constitute the majority of such admissions.
Although more than 3000 people are killed each day, full recognition of the scale of the problem is obscured because road crashes usually cause only a few deaths at a time and generate little press coverage, contributing to the hidden nature of the epidemic of road traffic injuries.
In contrast to some other epidemics, road traffic injuries are largely influenced by decisions and choices at both policy and individual levels, which means that the problem is amenable to control. Vehicles in developing countries are known to have a far more lethal impact than those in highly motorized countries -- by as much as 200-fold in some cases (27). As the number of cars increases rapidly in developing countries, the roads are becoming significantly more dangerous; in the same way that the increased vehicle usage can be forecast, so can the expected deaths and injuries for vulnerable road users. A global commitment to bring this epidemic under control can succeed, but it will need intersectoral collaboration, targeted policies and national action plans. With an estimated 1.3 million fatalities each year from road traffic injuries, the opportunity of saving so many lives must be grasped.
Sharing responsibility for safety
Evidence from developed countries shows that crashes are preventable and interventions have already saved hundreds of thousands of lives. The existing data highlight the need for an approach to road safety which recognizes that the driver, the vehicle, and the built environment make up three components of a dynamic system within which safety is a shared responsibility. This approach seeks to identify all sources of error or design weakness that contribute to road traffic injuries and then tries to mitigate the consequences (31).
In many developed countries, the past few decades have witnessed many improvements in safety measures for vehicles, roadways and drivers. Innovations in cars include impact- absorbing front ends, collapsible steering columns, seat belts, integral head-rests, airbags and child seats. Roadway designs have been improved to place barriers between traffic moving in opposite directions and to eliminate highway intersections. Pedestrians have been separated from vehicles by roadside barriers, street lighting has been improved, and speed bumps have been created to slow the traffic. The wearing of seat belts for drivers and passengers and helmets for motorcyclists has been made obligatory, and strict laws for speeding and drink-driving have been introduced and enforced. Hundreds of thousands of lives have been saved as a result of these measures. For example, death rates related to motor vehicles dropped in the United States by more than 40% between 1966 and 1997.
Proven cost-effective interventions in developed countries can be effective for low-income countries too. For maximum impact, all prevention strategies should be used in conjunction with effective law enforcement (32).
While the data on safety interventions are compelling, existing knowledge needs to be adapted so as to underpin successful interventions in developing countries. The unique road safety circumstances of each country and region are important subjects for research. Lifestyle and other factors behind the contrasting patterns in road casualties between poor and rich countries also need to be better understood. For example, in wealthier countries, most people injured in a crash are inside the vehicle. In poorer countries, however, the majority of victims are the most vulnerable road users: pedestrians, cyclists, and passengers on public transport (33).
In many countries, bicycles and motorcycles are the cheapest and most dangerous form of transport (34), sharing the road with cars, buses and trucks. Cyclists, motorcyclists and their passengers are very vulnerable to speed and poor visibility, and those without safety helmets or other protection are particularly at risk. Brain injuries are a common cause of death in road crashes involving two-wheeled vehicles. The use of lights during the daytime shows promising results, as they make the cyclists and motorcylists more conspicuous.
Mobilizing action
Many political leaders are not fully aware of the magnitude and severity of road traffic injuries. Long-term awareness and advocacy campaigns are required to generate immediate and sustained action to promote global and national road safety. WHO has been increasingly involved in road traffic injury prevention in recent years. In 2001 it developed a five-year strategy for road traffic injury prevention to provide guidance to researchers, practitioners and policy-makers and to raise public awareness of road traffic injury prevention (35). This strategy, which emphasizes epidemiology, prevention and advocacy, is currently being implemented with active WHO participation in a number of countries, including Cambodia, Ethiopia, Mexico, Poland and Viet Nam.
World Health Day, which is celebrated around the world on 7 April each year, will focus in 2004 on road safety and will be marked by the launch of the World Report on Road Traffic Injury Prevention, to be published by WHO in collaboration with the World Bank. This report will document comprehensively the determinants and magnitude of road traffic injuries and will propose science-based evidence and solutions. In May 2003, the United Nations General Assembly recognized road injuries as a global epidemic, and a special session of the United Nations General Assembly in April 2004 is planned in conjunction with World Health Day to promote road safety and encourage countries to develop national plans. UNICEF, the United Nations Development Programme, the United Nations Department for Economic and Social Affairs, and other organizations, are also helping to raise awareness.
Country leaders and civil society should be encouraged to recognize the burden of deaths and injuries on their roads and to commit themselves to reducing it. National programmes to improve road safety will require not just participation of the public health and transport sectors, but also support from decision-makers in justice, law enforcement, health care, education and urban design sectors. In addition, governmental efforts will need support from nongovernmental organizations and professional societies.
A comprehensive assessment of each country's road safety system will identify the details of the current burden (who is injured or killed; where, when, and how the incident took place), the options for reducing that burden, the spectrum of players from different sectors that can be involved and trained, and the unique challenges within the country. The types of trained people needed to prevent and treat road traffic injuries will depend on the country's current capacity and its success in attracting additional resources.
Public health has traditionally been strong in disease surveillance: gathering and using information about the patterns, risk factors and effectiveness of interventions to prevent and mitigate a disease. Surveillance and research skills can be applied to road traffic injuries, and traditional public health assessments can be expanded to include other critical parts of the country's systems. After completing and analysing the assessment, all sectors can collaborate to develop and implement a plan to change roads, laws, vehicle designs and behaviour that will save lives. Poor countries will need outside support to build the capacity to implement road safety measures.
Injury prevention, safety and treatment
Prevention, safety and treatment are the three primary aspects of a national plan to reduce road injuries. All three components need both short-term and long-term planning and surveillance to track progress and successes. Legislation and enforcement will be essential.
The first and most important objective is to prevent a crash from happening. Some countries have already made progress in prevention by separating pedestrians from cars and trucks, creating barriers and fences, building guard-rails, widening shoulders, and eliminating "black spots" where road crashes are most likely to happen. Additional successful efforts include speed control measures such as installing rumble strips and speed bumps (see Box 6.4), enforcing speed limits and severe laws on drinking and driving (32).
Box 6.4 A low-cost road safety strategy: speed bumps in Ghana
Road traffic crashes are a serious problem in Ghana, where the fatality rate per 10 000 vehicles is about 30--40 times higher than that in high-income countries. As excessive speed on interurban highways and in built-up areas has been identified as one of the key factors contributing to crashes, speed bumps have been installed at some crash-prone locations on the highways, in order to lower the speed of vehicles and improve the traffic environment for other road users such as pedestrians and cyclists. Low-cost rumble strips have been installed on the main Accra-Kumasi highway at a collision hot spot. Lower vehicle speeds reduce kinetic energy (which causes injuries and deaths on impact) as well as increasing the time to collision, thereby preventing crashes.
The use of speed bumps and rumble strips has been effective on Ghanaian roads. During the 16-month period between January 2000 and April 2001, traffic crashes were reduced by 35%, fatalities by 55% and serious injuries by 76%. These speed-reducing measures also succeeded in eliminating certain kinds of crashes and improving pedestrian safety.
Second, in the event of a crash, injuries can be minimized if drivers have taken safety precautions such as wearing helmets and seat belts. Crash-resistant vehicles can be built or imported with improved safety features such as rollover protection. Third, countries need effective trauma response systems in order to transport and treat victims without delay and to rehabilitate them. Rapid, efficient, emergency response systems can reduce morbidity and mortality. Quality rehabilitation care should be incorporated as part of a comprehensive plan to care for the injured (36).
Improving road safety requires strong commitment by governments to establish, finance and sustain road safety programmes. Collaboration with other stakeholders -- global, national and local -- will accelerate progress and contribute to the development of more sustainable forms of public and private transport. Countries can begin with a commitment to gather more assessment data and build a comprehensive database to monitor and evaluate national plans. As the knowledge base on road traffic injuries expands, there is greater scope for collaboration between countries and across disciplines and agencies. This collaboration will be a key element in shaping a rapid response to the epidemic, especially in poorer countries, and in ensuring a reduced impact on the global environment.
Because the burden of such injuries and deaths falls disproportionately on poor countries, it is important to pursue the goal of global safety equity, in which all persons have equal access to the means of assuring safety. To achieve this, these countries will need to build infrastructure and human resource capacity, and will look to developed countries for assistance. Governments can be encouraged to view road safety and protection from injury as an important contributor to sustainable economic, social and environmental development and to mobilize the necessary forces for effective prevention of an epidemic that, while largely hidden today, will become increasingly visible unless action is taken to control it.
Integrating road safety with broader policies
In most countries, the most insidious impact of road transport is air pollution, which causes public concern in both rich and poor countries. Estimates of the impact of air pollution on health indicate that this concern is justified. In Austria, France and Switzerland the number of deaths related to air pollution from traffic is twice the number of deaths from traffic accidents (23). In addition, gases that cause climate change -- a quarter of which come from transport (24) -- are expected to contribute to extreme weather events including floods and droughts, and changes in the habitat of disease vectors such as mosquitoes, with major health consequences (37).
Current transport patterns have many other consequences to health (22), including pervasive annoyance induced by traffic noise; adverse effects on rates of cardiovascular disease, diabetes, obesity and some cancers by discouraging the use of safe cycling and walking for transport (38); and constraints on the development of neighbourhood support networks. These consequences have a disproportionally adverse effect on the urban poor, because urban areas have higher levels of pollution and often provide fewer options for physical activity (39).
Traffic injuries are also higher among the urban poor, as they tend to live in areas of higher traffic volume -- with a greater proportion of vehicles exceeding speed limits (40,41). In addition, there is a clear relationship between degree of social and economic deprivation and risk of injury in children (42,43) Reasons for these differences include the need for children of families without a car to cross a greater number of roads than children whose families own a car (44). These intra-urban inequalities provide a focus for policy action: reducing health risks among the poor is a powerful tool for poverty reduction (45).
Policies adopted to reduce traffic-related air pollution do not usually consider the other health impacts of traffic such as traffic crashes and injuries, and vice versa (46). Health systems have an important role to play in the development of integrated transport strategies that take account of all relevant health impacts (25). Health impact assessment tools1 can be used to help visualize the expected health implications of transport policies and make suggestions on how they can be modified to maximize overall health benefits and minimize health inequalities (47).
All of the subjects of the previous chapters in this report have one point in common: they represent major issues that cannot be successfully resolved without the benefit of a strong health system. The fate of the child with malaria in Africa, the middle-aged man with diabetes in Latin America, and the mother infected with HIV in Asia may all depend on the strength of their national health system. Chapter 7 finds that many such systems are sadly inadequate to cope with the challenges they face, and suggests initiatives to make them fit for the future.