The global and local context of emerging and re-emerging infections

Emerging and re-emerging infections pose a national and global threat to health to susceptible populations.

Detection and control of some infectious diseases are important not because they represent a consistently high burden, but because of the risk they pose to susceptible populations. Such diseases include emerging infections transmitted from animals to humans but also resurgent infectious diseases previously eliminated or effectively controlled.

History records the devastating impact of emerging infections and drug-resistant infectious agents. The emphasis now is on early detection and control, to prevent the spread of emerging infections or the risk they become established. With routine intercontinental travel, the cross-border dissemination of novel infectious diseases can be alarmingly rapid.

Emerging threats to health include both zoonotically transmitted viruses (such as dengue virus, novel avian influenza viruses, Middle East respiratory syndrome coronavirus, MERS-CoV, Chikungunya virus and Nipah virus) and antibiotic-resistant strains of bacteria.

The situation in Bangladesh

Bangladesh provides opportunities to study emerging infections and their transmission within animal populations, from animals to humans and from person to person. As well as helping
to control infections locally, such work has a vital role to play in identifying and containing emerging and re-emerging infections, including drug-resistant agents that pose a regional and global public health threat.

Dengue is common in Dhaka and an emerging risk in rural areas. Nipah virus causes yearly outbreaks of encephalitis in Bangladesh, with more than 75% case fatality. Avian influenza 
is endemic in Bangladeshi poultry, but has thus far caused only mild illness in humans.
Yearly outbreaks of anthrax occur in ruminants such as cattle, with some human infections. Behavioural change interventions to prevent cross-species transmission are often hampered by local poverty and food insecurity.

Multidrug-resistant tuberculosis (MDR-TB) is common in Bangladesh, and the infrastructure to treat MDR-TB is limited. Global spread of antibiotic-resistant bacteria and malaria, some originating from South Asia, has caused international concern and Bangladesh is seen as one of the crossroads between Asia and Africa for their spread.