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Volume 18, Number 12—December 2012

Conference Summary

Workshop on Research Priorities for Management and Treatment of Angiostrongyliasis1

Robert H. CowieComments to Author , James R. Hollyer, Alexandre J. da Silva, Robert G. Hollingsworth, Marlena C. Dixon, Praphathip Eamsobhana, LeAnne M. Fox, William L. Gosnell, Kathleen Howe, Stuart Johnson, Jaynee R. Kim, Kenton J. Kramer, Phaik Eem Lim, John F. Lindo, Zhao-Rong Lun, Arnaldo Maldonado, Alessandra L. Morassutti, Gerald S. Murphy, Sarah Y. Park, Yvonne Qvarnstrom, Ralph D. Robinson, Kittisak Sawanyawisuth, John Teem, Silvana C. Thiengo, Cheridah D. Todd, Hung-Chin Tsai, Gordon D. Wallace, Cecelia A. Waugh, A. Christian Whelen, Patricia P. Wilkins, Ting-Bao Yang, and Hoi-Sen Yong
Author affiliations: University of Hawaii at Manoa, Honolulu, Hawaii, USA (R.H. Cowie, J.R. Hollyer, J.R. Kim); Centers for Disease Control and Prevention, Atlanta, Georgia, USA (A.J. da Silva, Y. Qvarnstrom, L.M. Fox., P.P. Wilkins),; Hawaii Department of Health, Honolulu (M.C. Dixon, S.Y. Park, A.C. Whelen); John A. Burns School of Medicine, Honolulu (W.L. Gosnell, K.J. Kramer, G.D. Wallace); Mahidol University, Bangkok, Thailand (P. Eamsobhana); US Department of Agriculture, Hilo, Hawaii, USA (R. G. Hollingsworth); Hilo, Hawaii, USA (K. Howe); Loyola University Medical Center and Hines VA Hospital, Hines, Illinois, USA (S. Johnson); University of Malaya, Kuala Lumpur, Malaysia (P.E. Lim, H.-S. Yong); Sun Yat-Sen University, Guangzhou, People’s Republic of China (Z.-R. Lun, T.-B. Yang); Instituto Oswaldo Cruz/Fiocruz, Rio de Janeiro, Brazil (A. Maldonado, Jr, S.C. Thiengo); Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil (A.L. Morassutti); Tripler Army Medical Center, Honolulu (G.S. Murphy); University of the West Indies, Mona, Kingston, Jamaica (J.F. Lindo, R.D. Robinson, C.D. Todd, C. A. Waugh); Khon Kaen University, Khon Kaen, Thailand (K. Sawanyawisuth); Florida Department of Agriculture and Consumer Services, Tallahassee, Florida, USA (J. Teem); and Kaohsiung Veterans General Hospital, Kaosiung City, and National Yang-Ming University, Taipei, Taiwan (H.-C. Tsai).

Main Article

Table

Research and outreach needs for management and treatment of angiostrongyliasis

Detection of Angiostrongylus cantonensis rat lungworms in hosts
• Genomics/proteomics: sequence genome/develop proteomics for fast detection
• Obtain comparative data on sensitivity and specificity of available techniques
• Develop methods of parasite detection in fresh human food, mainly vegetables
and fruits
• Sample other potential hosts, notably flatworms and freshwater crustaceans, to
assess their potential as hosts and their parasite load
• Develop low-technology detection methods
• Gain a better understanding of the biology of the hosts as it relates to parasite
transmission
Control of hosts in the field (rats, slugs/snails, paratenic hosts)
• Identify paratenic hosts, their relevance, and their importance
• Gain a better understanding of the basic biology of snails and slugs, including
genetics, which could be useful in developing interventions
• Undertake surveys of rats in areas where A. cantonensis lungworms have been
reported (e.g., south Florida, Rota)
• Develop cultural methods of snail/slug control, such as natural barriers (e.g., sand)
• Gain a better understanding of the environmental variables that affect slug and
snail host survival and reproduction, e.g., humidity, temperature, etc., and the
potential effects of climate change/global warming
Public education to minimize chance of infection
• Involve children (ages 7–14) in educational efforts and build education about
angiostrongyliasis into science/math curriculum (in the United States, there may
be a National Science Foundation GK-12 grant opportunity)
• Require continuing education for health care practitioners
• Better define risk factors so that these can be the focus of education
• Increase outreach to farmers and farmers’ markets. Focus on potential impact
on profits
• Use social media networks, e.g., Facebook, Twitter, etc., and contribute regularly
• Define public health messages clearly and consistently
• Create an angiostrongyliasis listserve
Control of hosts/larvae on produce (e.g., washing/rinsing)
• Evaluate different rinse ingredients
• In the United States, obtain Environmental Protection Agency and/or Food and
Drug Administration approval of methods for washing produce; similarly, in Hawaii,
obtain approval from the Departments of Agriculture and Health, as well as other
regulatory agencies
• Undertake surveys to ascertain the distribution of larvae and hosts, including
slugs/snails on different kinds of fresh produce
• Develop a hand-held loop-mediated isothermal amplification device or other
simple methods for detection of A. cantonensis lungworms in the field
• Investigate irradiation of produce as a sanitizing method
Diagnosis
• Improve and standardize serology
• Develop rapid tests for detection, e.g., PCR, antigen detection, chromatography,
dipsticks
• Standardize clinical criteria for diagnosis
• Validate PCR or other molecular methods for detection of A. cantonensis
lungworms in patients
• Develop a cooperative network for sharing specimens, antigens and DNA
sequences
Treatment
• Undertake well-thought-out clinical trials
• Assess the value of early use of anthelmintics
• Standardize the protocol for lumbar puncture (e.g., are serial/repeat tests
beneficial; how often should they be done?)
• Develop guidelines for the use of steroid therapy, e.g., when to start, dosage, rate
of tapering off
• Determine standard of care
Pathophysiology
• Determine the actual mechanism of neurologic injury in humans: (i) increased
intracranial pressure, (ii) the inflammatory reaction, and if so which cytokines are
involved, (iii) mechanical damage from worm migration, or (iv) a combination
of these
• Develop the best animal model for human disease
• Assess the influence of parasite inoculum on incubation period and severity of the
illness, in particular how the number of parasites in the inoculum correlates with
the number of parasites reaching the brain
• Determine how the parasites invade the central nervous system (CNS)
• Determine at which larval stage intervention (anthelmintics) will prevent symptoms
• Investigate pathophysiology in infected hosts (slugs/snails, rats, paratenic hosts)
• Investigate the mechanism by which steroid treatment alleviates symptoms:
inflammation reduction or reduction of intracranial pressure
Epidemiology
• Refine understanding of risk factors
• Develop better tools for molecular epidemiology
• Standardize the methodology of environmental assessments in terms of location
characteristics and the geographic distribution of the parasite and the disease in
a region
• Develop centralized reporting of epidemiologic findings
• Determine the relationship between infection and disease: what triggers the
disease, how the level of exposure is related to incidence of the disease

Main Article

1This workshop was organized and conducted under a grant to the University of Hawaii, where the work was done.

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