Professor Fiona Hunter, Brock University
Mosquitoes and Zika virus in the Americas
Historically there have been a relatively small number of mosquito-borne diseases in Canada including a brief, but unsustained, malaria outbreak during the construction of the Rideau Canal in the 19th century. Since 2001, however, there have been several outbreaks of West Nile virus encephalitis in humans. The students in my lab study mosquito systematics, geographic distributions, and arbovirus transmission dynamics. We have been able to model the effects of shorter winters and warmer summers on West Nike virus transmission in Canada and predict that more mosquito-borne viruses will become endemic over time.
To date there are ~500 human cases of travel-related Zika virus (ZIKV) infection in Canada. Understanding which local mosquito species might serve as competent vectors for this emerging disease is the current research focus in my lab. Based on the phylogenetic placement of ZIKV among the flaviviruses, we challenge the current paradigm that it is only Aedes aegypti and possibly Aedes albopictus that are of concern as vectors of ZIKV. Our lab has shown that under certain conditions local Canadian mosquito species can also become infected with ZIKV, develop disseminated infections, and spit out ZIKV in their saliva.
Transmission risks are complicated by the northward range expansions of at least 10 mosquito species over the past 15 years. Most importantly, in September and October of 2016 we discovered breeding populations of the Asian tiger mosquito (Aedes albopictus) and the yellow fever mosquito (Aedes aegypti) in southern Ontario for the first time ever.
With 15 years of intensive mosquito surveillance and viral testing for West Nile virus behind us, we are now setting up mosquito arbovirus surveillance programs in places like Dominican Republic. We would welcome collaborations in Commonwealth countries around the globe to more fully understand the transmission dynamics of emerging mosquito-borne diseases.
Professor Oyewale Tomori, Nigerian Academy of Science
Emerging Infectious diseases: Strengthening research collaboration among Commonwealth countries
Emerging infectious diseases continue to expose national and global unpreparedness for prevention and control of disease outbreaks. The widespread transmission of Ebola Virus Diseases (EVD) in Guinea, Liberia and Sierra Leone, and subsequent exportation to 7 other countries, highlight the significant threat of emerging diseases to global health security. Three of the ten countries which recorded at least on EVD case are members of the Commonwealth group of nations. During the period between 1940 and 1960, Britain, through the Medical Research Councils, spearheaded intense research collaboration in medicine and agriculture among countries that now make up the Commonwealth of Nations. During this period, as an example, workers in the Ugandan research center isolated several new viruses – Chikungunya, West Nile and Zika - that are now emerging and causing public health emergencies of global concern. However, soon after 1960, research collaboration activities waned, between Britain and independent African countries, except for the Gambia, where there was an active Medical Research Council Unit in Fajara. On the other hand, French speaking African countries and France have maintained active research collaboration through the network of the Institut Pasteur laboratories. The Commonwealth of Nations will benefit tremendously from a renewed and intensified research collaboration, especially on emerging infectious diseases. However, such collaboration must be based on equity contribution of human and financial resources by participating countries, so as to engender mutual respect and benefit.
Dr Hsu Li Yang, National University of Singapore
Antimicrobial Resistance in Singapore and the Region
Antimicrobial resistance is an escalating global health threat. In the local and regional setting, methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (CRAB) and Enterobacteriaceae (CRE) are increasingly common causes of difficult-to-treat infections, raising the spectre of a return to the pre-antibiotic era. In this discourse, we trace the links between acute, intermediate, and long-term care facilities in terms of MRSA transmission in a regional healthcare system in Singapore. We also review the epidemiology and prevalence of CRAB and CRE in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world’s population and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors – including inappropriate prescription of antibiotics, overstretched health systems and international travel - including the phenomenon of medical tourism – probably led to the rapid rise and spread of these drug-resistant bacteria in hospitals in South and Southeast Asia. Considerable political will and effort, including from countries outside these regions, is vital in order to reduce the prevalence of such bacteria in South and Southeast Asia, and preventing their global spread.