Larry Wymer

Mr. Larry Wymer

orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 October 2010 in Environmental Health
Verified
Journal Article
Open access
PDF file
Tim WadeTim Wade
Tim Wade
ESElizabeth Sams
Elizabeth Sams
KBKristen P Brenner
Kristen P Brenner
RHRichard Haugland
Richard Haugland
ECEunice Chern
Eunice Chern
ADAlfred dufour
Alfred dufour
In the United States and elsewhere, recreational water quality is monitored for fecal indicator bacteria to help prevent swimming-associated illnesses. Standard methods to measure these bacteria take at least 24 hours to obtain results. Molecular approaches such as quantitative polymerase chain reaction (qPCR) can estimate these bacteria faster, in under 3 hours. Previously, we demonstrated that measurements of the fecal indicator bacteria Enterococcus using qPCR were associated with gastrointestinal (GI) illness among swimmers at freshwater beaches. In this paper, we report on results from three marine beach sites.

1 December 2016 in Annals of the American Thoracic Society
Verified
Journal Article
Closed access
MDMaura Donohuue
Maura Donohuue
LWLarry Wymer
Larry Wymer
Rationale: Many nontuberculous mycobacteria (NTM) are clinically significant pathogens that cause disease in a variety of different human organs and tissues. Objectives: A population-based study was undertaken to investigate the prevalence of patients with a positive specimen for NTM within five states of the United States. Methods: We determined the case and age distribution of patients with at least one specimen positive for NTM, using data submitted to the disease surveillance systems of five states (Maryland, Mississippi, Missouri, Ohio, and Wisconsin) between 2008 and 2013. Crude, age-specific, and age-adjusted prevalence rates per 100,000 persons were calculated for each state. Measurements and Main Results: From 2008 to 2013, a total of 24,226 NTM cases were reported to the disease surveillance systems of the five states. The overall average annual age-adjusted prevalence rate rose from 8.7 to 13.9 per 100,000 persons between the beginning and end of the surveillance period. The number of cases and case rate in the 50–80+-year age group was higher than in the 0–49-year age group. Prevalence by age category differed among the five states. The highest number of NTM cases was observed in Mississippi for the 80+-year age group, whereas Wisconsin observed the highest number of NTM cases in the 60- to 69-year age group. Conclusions: From 2008 to 2013, the number of patients with positive specimens for NTM rose. This trend is likely to continue in the coming decade as the U.S. population ages. To reduce the prevalence of NTM infections, medical guidance for susceptible populations is needed regarding actions that can be taken to avoid sources and routes of exposure to NTMs if the disease burden is to be reduced.

10 May 2013 in BMC Public Health
Verified
Journal Article
Open access
PDF file
LWLarry Wymer
Larry Wymer
Tim WadeTim Wade
Tim Wade
ADAlfred dufour
Alfred dufour
The United States Environmental Protection Agency (USEPA) and its predecessors have conducted three distinct series of epidemiological studies beginning in 1948 on the relationship between bathing water quality and swimmers’ illnesses. Keeping pace with advances in microbial technologies, these studies differed in their respective microbial indicators of water quality. Another difference, however, has been their specific health endpoints. The latest round of studies, the National Epidemiological Assessment of Recreational (NEEAR) Water studies initiated in 2002, used a case definition, termed “NEEAR GI illness” (NGI), for gastrointestinal illness corresponding closely to classifications employed by contemporary researchers, and to that proposed by the World Health Organization. NGI differed from the previous definition of “highly credible gastrointestinal illness” (HCGI) upon which the USEPA’s 1986 bathing water criteria had been based, primarily by excluding fever as a prerequisite.

1 August 2016 in Science of The Total Environment
Verified
Journal Article
Closed access
SVStephen Vesper
Stephen Vesper
LWLarry Wymer
Larry Wymer
DCDavid Cox
David Cox
GDGary Dewalt
Gary Dewalt

16 December 2021 in Journal of Water and Health
Verified
Journal Article
Open access
PDF file
ECEunice C. Chern
Eunice C. Chern
LWLarry Wymer
Larry Wymer
KBKristen Brenner
Kristen Brenner
KOKevin Oshima
Kevin Oshima
RHRichard A. Haugland
Richard A. Haugland
Limited information exists on the environmental persistence of genetic markers for fecal indicator bacteria (FIB) in treated wastewaters. Here, the decay rate constants of culturable cells and genetic markers for four diverse groups of FIBs, such as enterococci, Clostridium, Escherichia coli, and Bacteroides, were investigated in freshwater microcosms seeded with disinfected and non-disinfected secondary-treated wastewaters. Decay rate constants of genetic markers and culturable cells varied significantly among the different FIB groups. Water temperatures (winter vs. fall/spring/summer) significantly affected the decay of all genetic marker and cell types; however, genetic marker decay were not found to be significantly different in disinfected (chlorination/ultraviolet) and non-disinfected wastewater-seeded microcosms or, for example, lake- and river-receiving waters. No evidence was seen that decay rate constants of FIB genetic markers from treated wastewater were substantially different from those observed in similar, previously reported microcosm studies using raw sewage. Unexpected relationships between decay rate constants of genetic markers and culturable cells of Bacteroides were observed. Results suggest that decay rate constants of FIB genetic markers determined from other studies may be applicable to treated wastewaters. Results of this study should be informative for ongoing efforts to determine the persistence of FIB genetic markers relative to surviving pathogens after wastewater treatment.

1 August 2002 in Environmetrics
Verified
Journal Article
Closed access
PDF file
LWLarry Wymer
Larry Wymer
ADAlfred P. Dufour
Alfred P. Dufour