Ruchi Joshi

Ruchi Joshi is a Master of Science (M.S.) student in Environmental and Conservation Sciences program at North Dakota State University (NDSU). She holds a Bachelor of Science degree in Biotechnology with Minors in Microbiology and Chemistry from NDSU (2011). Her present research is on understanding the survival of Cryptosporidium oocysts in the winter season of North Dakota.


Phone: 701-541-9340

Understanding the Survival of Cryptosporidium oocysts in North Dakota under Winter Conditions

Fellow: Ruchi Joshi

Advisor: Eakalak Khan, Ph.D., Professor and Chair, Department of Civil Engineering, North Dakota State University
Co-Advisor: John M. McEvoy, Ph.D., Associate Professor, Department of Veterinary and Microbiological Sciences, North Dakota State University

Degree Progress: M.S. in Environmental and Conservation Sciences graduation April 2014


Cryptosporidium is an infective protozoan which is one of the most important contaminants found in drinking water and is associated with high risk of waterborne illness. Cryptosporidium causes a parasitic gastrointestinal disease called cryptosporidiosis in mammals. Cryptosporidiosis is potentially lethal for mammals which have suppressed immune systems. An infected mammal can shed up to 107 oocysts per ml of its fecal matter which can contaminate soil and water. Severity of the public health concerns can be estimated by the fact that ingestion of contaminated water containing as few as 10 oocysts can lead to cryptosporidiosis. The mechanism of Cryptosporidium transport in the environment remains poorly understood. Cattle and other livestock are reservoirs of human pathogenic Cryptosporidium species. Application of liquid manure to the fields is a common practice in many North American farm operations. Fertilizing agricultural lands with manure contaminated with Cryptosporidium can result in cryptosporidiosis outbreaks.

Considering both, the climate conditions in North Dakota and survival conditions of Cryptosporidium, it is apparent that Cryptosporidium oocysts can survive in North Dakota. Besides these conditions, data has been provided by the Centre for Disease Control & Prevention (CDC) reflecting a gradual increment in the number of Cryptosporidiosis cases within North Dakota. Therefore, taking in account the capability of Cryptosporidium of causing a public health outbreak, it is very important to understand the effect of low temperature on Cryptosporidium.

Project Objectives:

The main objective of this study is to investigate the excystation of Cryptosporidium parvum.The specific objectives include:

  1. To investigate the survival of Cryptosporidium parvum oocysts by subjecting them to different temperatures and determining their viability.
  2. To determine the infectivity of the Cryptosporidium parvum oocysts by an in vivo method.
  3. To study the morphological changes in the Cryptosporidium parvum oocysts before and after exposing to different temperatures.


Joshi, R., Wadhawan, T., Khan, E. 2012. Cryptosporidium: A stubborn drinking water contaminant. 84th Annual North Dakota Water Pollution Control Conference for Young Professionals (NDWPCC), Minot, North Dakota, USA. (3rd Position awarded)

Joshi, R., Wadhawan, T., McEvoy, J., Khan, E. 2012. Cryptosporidium: An Unusual Apicomplexan. 72nd Annual Meeting North Central Branch of the American Society for Microbiology (ASM), Fargo, ND, USA.

Ruchi Joshi

Eakalak Khan


Advisor: Dr. Eakalak Khan
Professor and Chair,
Civil Engineering Department
North Dakota State University
Phone: (701) 231-7717


John McEvoy


Co-Advisor: Dr. John M. McEvoy
Associate Professor,
Veterinary and Microbiological Sciences Department North Dakota State University
Phone: (701) 231-8530