Allegra is a PhD candidate working with Prof. Menachem Elimelech looking at water and sanitation as it impacts public health. Allegra’s research project examines the survival of viruses in sewage treatment, and explores the mechanisms that may contribute to their elimination in drinking and wastewater treatment.
After graduating from Rensselaer Polytechnic Institute in 1998 with a B.S. in Chemical Engineering, Allegra joined Jesuit Volunteers International and taught Physics and Information Technology in Dangriga, Belize for two years. She then joined Woodstock Theological Center at Georgetown University where she worked on the Global Economy and Cultures project. The project explored how local cultures can offer "bottom-up" development opportunities and partnerships.
Allegra is interested in wastewater treatment in lesser-developed countries. Her current research involves the fate and transport of viral human pathogens in aquatic systems. She spent the summer of 2004 in Cali, Colombia, learning about waste stabilization pond systems for treatment of sewage as well as the status of sanitation in both villages and large cities in Colombia. In 2006 she conducted field work in Nantes, France on norovirus removal in several types of sewage treatment (waste stabilization pond, activated sludge, and submerged membrane bioreactor).
Allegra was a 2006 Associate World Fellow as part of the Yale World Fellows Program, which is an effort to build a global network of emerging leaders and broaden international understanding at Yale.
Allegra’s research is funded through a National Science Foundation Graduate Research Fellowship.
Allegra’s research investigates:
- the extent of removal of norovirus in sample wastewater treatment systems
- the effect of physicochemical characteristics of norovirus in their adsorption in aquatic systems
Why study norovirus?
- Worldwide, diarrheal disease remains one of the top five causes of childhood mortality, responsible for millions of deaths annually in lesser-developed countries.1
- Viruses are responsible for 75% of acute gastroenteritis cases across all age groups.1
- While childhood diarrhea is usually attributed to rotavirus, recent studies using broadly reactive reverse-transcription polymerase chain reaction (RT-PCR) found noroviruses in 7 – 22% of stool samples from children with acute gastroenteritis, and new diagnostic techniques showed antibodies to norovirus present in 50 – 90% of children studied.2
- The US Centers for Disease Control (CDC) found that 96% of adult gastroenteritis epidemics were attributed to noroviruses.2
- Researchers in England estimate that healthcare-associated outbreaks of gastroenteritis in England cost the English National Health Service US$184 million in 2002-2003, most of which were due to norovirus (63%).3
Why study sewage treatment?
- While the epidemiology of how gastroenteritis outbreaks spread has been well characterized, understanding where the initial cases come from is more difficult to attribute. Transmission of norovirus in outbreaks has been attributed to contaminated oysters (10%), other contaminated food (37%), person-to-person contact (20%), contaminated water (6%), and undetermined sources (27%).2
- Since water transmission is one of the common denominators that may be responsible for transporting viruses from their source (an infected human) to the more easily identifiable culprits listed above, it is important to understand how noroviruses are removed in municipal sewage treatment, and then transported in aquatic environments.
- While a well-designed sewage treatment system can remove bacterial and protozoan pathogens to extremely satisfactory levels, there is a paucity of information regarding the fate of viral pathogens in sewage treatment.
Why study the physicochemical characteristics of norovirus?
- The survival of norovirus in aquatic environments depends on the robustness of the virus as well as their tendency to adsorb to particles that settle out of solution. For the latter aspect, the non-biological physicochemical characteristics of noroviruses as particles will govern their behavior. Investigation of these characteristics of particles is one of the strengths of the Elimelech group.
2Goodgame, R.W., Viral causes of diarrhea. Gastroenterology Clinics, 2001. 30(3).
3Lopman, B.A., et al, Epidemiology and cost of nosocomial gastroenteritis, Avon, England, 2002-2003. Emerging Infectious Diseases, 2004. 10(10): p. 1827-1834.
Sewage sampling at a waste stabilization pond (WSP) in Maine, USA |
|||
|
| Sewage Sampling at a WSP in Brittany, France | ||
|
| Spending time with friends in Belize |
 |
