Legionnaire’s Disease Outbreak at a Long Term Care Facility: Environmental Health Considerations

In summer of 2011, Columbus Public Health (CPH) began investigating an outbreak of legionnaire’s disease that was linked to a long-term care facility. This lecture will describe the environmental assessment performed by Columbus Public Health at the facility and the obstacles that were encountered during the investigation.

Legionnella spp. has been typically associated with stagnant water from point sources such as cooling towers, but can also be cultured from potable water systems. As part of the environmental assessment, all water systems in the facility were evaluated for possibility of contamination. The potable water distribution system consisted of two boilers, mixing valves at each boiler, and essentially two distinct and independent loops. The potable water system was assessed for chlorine, pH, and temperature, and sampling was performed at the distill ends, boiler, mixing valve and selected rooms based on exposure by affected individuals. One hundred (100) mL samples were taken based on guidance from the Environmental Legionella Isolation Techniques Evaluation (ELITE) approved lab that was closest in proximity to the site. The Centers for Disease Control (CDC) was contacted for assistance with epidemiologic case studies and a follow up assessment.

Lab samples of the potable water system were shown to culture legionella at several points in the potable water system, thus implicating the water supply as the outbreak vehicle. Remediation efforts that took place included heating of the water system (according to ASHRAE guidelines), soaking of shower heads in bleach solution and follow up testing of the water system.

In closing, the management of legionnaire’s outbreaks in these types of settings are can stretch the resources of local public health and the long-term care facilities and this presentation is designed to educate attendees as to a local health department’s perspective and lessons learned.

Food and Water borne Enteric Protozoa: Current considerations for Environmental Health

Enteric protozoa continue to contribute to the burden from preventable infectious diseases affecting humans and animal health in industrialized settings. Giardia, Cryptosporidium and Entamoeba sp., are the most commonly reported protozoa associated with enteric infections, and are mainly associated with food and waterborne outbreaks. Others such as Cyclospora, Dientamoeba fragilis, Balantidium coli, Cystoisospora belli, and Blastocystis hominis are emerging as important causes of illness, with serious implications for travellers to developing regions, immuno-compromised populations and young children. Although public health measures in most developed countries are more stringent than in developing settings, minority groups, institutionalized persons and the immuno-compromised remain at extremely high risk. In an era where environmental health interventions has reversed the burden from communicable diseases, globalization, explosion of urban populations and the
emerging effects of climate change, are predicted to have unprecedented effects on the risk and transmission of infectious intestinal illnesses, threatening previous gains. Furthermore, the challenges of protozoan diseases transmitted by food, water and animals are expected to increase as a result of complex interactions between the human and animal hosts, and the need to increase food production, international food trade and the demand for alternate water sources.

Enteric protozoa have been implicated in several large water-bone outbreaks in
the USA, Norway, and Australia. Giardia intestinalis was the most common cause of parasitic drinking water outbreaks and Cryptosporidium was responsible for the majority of individual cases, while Entamoeba histolytica and Cyclospora have caused fewer cases in the USA. Cryptosporidium, C. cayetanensis, Giardia and Toxoplasma gondii are the main protozoa associated with food-borne infections in developed countries. While the majority of laboratory confirmed cases of foodborne parasitic diseases are due to G. intestinalis, Toxoplasma is the major cause of reported illness, the fourth highest cause of hospitalization and the second leading cause of deaths from overall foodborne illnesses in the USA.  This paper discusses food and waterborne transmission of enteric protozoa, highlights emerging technologies for their diagnosis and molecular epidemiology, and emerging water and waste water quality issues and technologies, to aid in their surveillance, prevention and control.

PLASMODIUM VIVAX: The need for future research and development of appropriate diagnostic tools [POSTER]

Plasmodium vivax, one of the parasitic agents causing malaria, is prevalent in many regions of the world. P. vivax is known globally to increase morbidity, but not mortality as seen in other forms of malaria. Normally, organ dysfunction (i.e. lungs, kidneys, central nervous system disorders) is not normally seen in patients with P. vivax but is routinely seen in patients with Plasmodium falciparum infection. In recent years, multiple case presentations describing mixed P. vivax and P. falciparum infections have been published hypothesizing that mixed infection may be the etiology for organ system involvement. However, where P. vivax was traditionally thought of as a focal, benign form of malaria, a number of remote, solely P. vivax case presentations have described patients who exhibit increased cerebral malaria and increased incidence of severe thrombocytopenia. By literature review, this study examines multiple case presentations and articles relating to this phenomenon in order to assess if the global health community is on the cusps of a more pathogenic state of P. vivax.

Furthermore, this paper will analyze potential causes in the change of P. vivax epidemiology and whether diagnostic methods are appropriate in diagnosing malaria given the increase incidence of mixed infection.

The Worldwide Fusarium Keratitis Epidemic of 2004-2006: What Would the Reverend Henry Whitehead and Doctor John Snow Have Done?

Public health “experts” attributed several cholera outbreaks in London in the mid-1800’s to “miasma,” polluted gases arising from the products of filth and decay. Dr. John Snow, a physician, and The Reverend Henry Whitehead, a minister, later proved epidemiologically that cholera was transmitted by contaminated water.

Between 2004-2006, a worldwide epidemic of Fusarium fungal eye infections, involving approximately 2000 victims, occurred which was attributed by the manufacturer to a “perfect storm” of events related to the contents of a specific contact lens solution and to the microbiological characteristics of the Fusarium organism. During its investigation, the manufacturer was cited by the U.S. Food and Drug Administration for inadequacies in temperature control in the production, storage, and transport of their products at/from their Greenville, SC facility. A previously published study (J Glaucoma. 2001;10(5):401-405) reported temperatures of up to 75oC/167oF in enclosed spaces in the southern U.S. during the summer months. We previously reported that heating (to 56oC/133oF) this contact lens solution, containing the antimicrobial agent, alexidine 0.00045%, in its high density polyethylene (HDPE) plastic (but not glass) container caused it to lose its anti-Fusarium properties (Arch Ophthalmol. 2011;129(2):133-136). This suggests that, during the worldwide Fusarium keratitis epidemic of 2004-2006, an irreversible chemical interaction occurred between the heated HDPE plastic bottle and the antimicrobial agent, alexidine, inactivating it. This study may be the first proven instance of human ocular disease shown to be associated with plastic containers and suggests that some plastics may have negative effects on human health in ways not previously considered.

Multiple parallels will be drawn between the London cholera outbreaks of the mid-1800’s and the worldwide Fusarium keratitis epidemic of 2004-2006 showing that scientists, intellectual curiosity, human nature, politics, business interests, greed, incompetence, and ignorance have changed little in over 150 years.