Molecular epidemiology and transmission of Schistosoma japonicum in China Prof' Joanne P' Webster

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Molecular epidemiology and transmission of
Schistosoma japonicum in ChinaProf. Joanne P.
Webster
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Introduction
The helminth Schistosoma japonicum is the
causative agent of one of the most important
human parasitic diseases in the Far East (China,
Philippines, Indonesia, and Taiwan), where an
estimated two million people are infected.
Schistosome life-cycle
Mammalian definitive host
miracidia
cercariae
Molluscan intermediate host
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Reasons for schistosomiasis japonicums
persistance
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To gain an insight into the transmission and
epidemiological processes of the disease, a
detailed understanding of schistosome population
genetic structure is important.
In Collaboration/Association with Anhui
Institute of Parasitic Diseases Anhui, P.R.
China. Zhejiang Academy of Medical Sciences,
Zhejiang, P.R. China Asian schistosome Network
(Danish Bilharzia Laboratories) Excellent
training Shared Phd Students between our
Institutes (currently 2 Chinese Nationals 1
European) and visiting fellowships. Funded by
(currently (too) small scale, each 10-20K UK
max) The Royal Society DBL/TDR Wellcome Trust
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e.g. Study I Variability between geographic
isolates across mainland China?
Developed new and refined, Ethically and
Biologically superior diagnostics tools,
including both simple, rapid field-applicable
tests and sophisticated molecular epidemiological
toolswhich strengthen surveillance capacity.
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e.g. Study II Variability between definitive
host species?
Multiple host species Multiple parasite
genotypes and hence polymorphism in nature
Segregation into two main clusters Humans and
bovines versus domestic animals.
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Implications
- Chemotherapy of humans may be inefficient if
rapid reinfection from animal reservoir hosts
occurs bovines differentially responsible -
cost-effective targeting of restricted control
programmes.
- Different circulating strains/genotypes can
lead to potentially increased host morbidity and
mortality, since intra-host competition may
result in increased virulence.
- Multiple genotypes should be incorporated into
vaccine design.
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Priority themes for future European-Chinese
programmes? One example Increasing support
for quantitative epidemiology studies,
particularly those addressing the
wildlife-livestock-human interfaces. Except
for the diseases of political importance, such as
bird flu, mouth-foot-disease and etc., other
diseases in animals have been paid scant
attention by government, public and
researchers. We need to increase our
understanding of the expanding drivers of
pathogen emergence (including, potentially,
climate change), harnessing genomics and modern
molecular techniques, and take into account both
pathogen and host diversity and the complexities
of the pathogen-host-environment, including
evolving pathogen variants and host immune
resistance.   Mechanisms to facilitate data
sharing (e.g. translation of current research in
Chinese-only journals?) research, training and
infrastructure facilitation of interdisciplinary
networks involving European-Chinese
collaborations.