world health report 2007 xvi global public health security in the 21st century Threats to public health security chapter by IHR(2005), Which result from human actions or causes, from human interaction with the environment, and from sudden chemical and radioactive events, including industrial accidents and natural phenomena. it begins by illustrating how inadequate investment in public health, resulting from a false sense of security in the absence of infectious disease outbreaks, has led to reduced vigilance and a relaxing of adherence to effective prevention programmes. For example, following the widespread use of insecticides in large-scale, systematic control programmes, by the late 1960s most of the important vector-borne diseases were no longer considered major public health problems outside of sub-Saharan Africa Control programmes then lapsed as resources dwindled. The result was that within the next 20 years, many important vector-borne diseases including African trypanosomia- sis, dengue and dengue haemorrhagic fever, and malaria emerged in new areas or re-emerged in areas previously affected. Urbanization and increasing intemational trade and travel have contributed to rapid spread of dengue viruses and their vectors. Dengue caused an unprecedented pandemic in 1998, with 1.2 million cases reported to WHO from 56 countries. Since then, dengue epidemics have continued, affecting millions of people from Latin America to South-East Asia. Globally, the average annual number of cases reported to WHO has nearly doubled in each of the last four decades Inadequate surveillance results from a lack of commitment to build effective health ystems capable of monitoring a country 's health status. The rapid global emergence and spread of HIV/AIDS in the 1970s illustrates this. The presence of this new healt threat was not detected by what were invariably weak health systems in many develop ing countries. It only belatedly became a matter of international concern with the first cases in the United States. In addition to limited disease surveillance capacity and data early efforts to control the AldS epidemic were also hampered by a lack of solid data on sexual behaviour in african countries the United states and other industrialized countries. Behavioural data were practically non-existent in the developing world. The understanding of HIV/AIDS in the context of sexuality, gender relations and migration in the developing world took years to develop and is still poorly understood ven with reliable operations in place, other influences on public health programmes can have lethal and costly repercussions. Such was the case in August 2003, when unsubstantiated claims originating in northern Nigeria that the oral poliomyelitis vac- cine(OPV)was unsafe and could sterilize young children led to the suspension immunization in two northern states and substantial reductions in polio immun coverage in a number of others. The result was a large outbreak of polio across Nigeria and the reinfection of previously polio-free areas in the south of the country This outbreak eventually paralysed thousands of children in Nigeria and spread from northern Nigeria to 19 polio-free countriesThreats to public health security Chapter 2 explores a range of threats to global public health security, as defined by IHR (2005), which result from human actions or causes, from human interaction with the environment, and from sudden chemical and radioactive events, including industrial accidents and natural phenomena. It begins by illustrating how inadequate investment in public health, resulting from a false sense of security in the absence of infectious disease outbreaks, has led to reduced vigilance and a relaxing of adherence to effective prevention programmes. For example, following the widespread use of insecticides in large-scale, systematic control programmes, by the late 1960s most of the important vector-borne diseases were no longer considered major public health problems outside of sub-Saharan Africa. Control programmes then lapsed as resources dwindled. The result was that within the next 20 years, many important vector-borne diseases including African trypanosomia￾sis, dengue and dengue haemorrhagic fever, and malaria emerged in new areas or re-emerged in areas previously affected. Urbanization and increasing international trade and travel have contributed to rapid spread of dengue viruses and their vectors. Dengue caused an unprecedented pandemic in 1998, with 1.2 million cases reported to WHO from 56 countries. Since then, dengue epidemics have continued, affecting millions of people from Latin America to South-East Asia. Globally, the average annual number of cases reported to WHO has nearly doubled in each of the last four decades. Inadequate surveillance results from a lack of commitment to build effective health systems capable of monitoring a country’s health status. The rapid global emergence and spread of HIV/AIDS in the 1970s illustrates this. The presence of this new health threat was not detected by what were invariably weak health systems in many develop￾ing countries. It only belatedly became a matter of international concern with the first cases in the United States. In addition to limited disease surveillance capacity and data, early efforts to control the AIDS epidemic were also hampered by a lack of solid data on sexual behaviour in African countries, the United States and other industrialized countries. Behavioural data were practically non-existent in the developing world. The understanding of HIV/AIDS in the context of sexuality, gender relations and migration in the developing world took years to develop and is still poorly understood. Even with reliable operations in place, other influences on public health programmes can have lethal and costly repercussions. Such was the case in August 2003, when unsubstantiated claims originating in northern Nigeria that the oral poliomyelitis vac￾cine (OPV) was unsafe and could sterilize young children led to the suspension of polio immunization in two northern states and substantial reductions in polio immunization coverage in a number of others. The result was a large outbreak of polio across northern Nigeria and the reinfection of previously polio-free areas in the south of the country. This outbreak eventually paralysed thousands of children in Nigeria and spread from northern Nigeria to 19 polio-free countries. 2 chapter xvi global public health security world health report 2007 in the 21st century