Helminth Eggs

Helminths, or parasitic worms, are transmitted through their eggs, which are the infective stage of their life cycle, and are among the most important biological contaminants in environmental engineering. Helminth eggs are relevant in the public health and environmental fields due to their:

a) Low infectious dose

b) Persistence in the environment (up to several years)

c) High resistance to conventional disinfection processes

Even though helminths are pluricellular animals, their eggs are microscopic (20 to 90 µm for those relevant in the environmental engineering field) and contained in variable amounts in wastewater, sludge, and excreta samples.

Helminth eggs infect humans through:

1. The ingestion of food crops polluted with wastewater, sludge, or excreta.

2. Direct contact with polluted sludge or fecal material.

3. The ingestion of polluted meat or fish.

The eggs of different helminth species vary in terms of shape, size and resistance. Due to different health conditions in different countries, the type of helminth eggs and their content in wastewater and sludge also varies. Ascaris eggs are the most common and ascariasis is the most common helminthiasis worldwide. The content of other helminth eggs in wastewater determines the local patterns of disease.

Helminth eggs are among the most important biological contaminants in environmental engineering. They are relevant in the public health and environmental fields due to their very low infectious dose, their persistence in the environment (up to several years), and their high resistance to conventional disinfection processes.

Helminthiasis are endemic in Africa, Latin America, and East Asia where poverty and poor sanitation conditions prevail. It is estimated that 2.5 billion people are affected by helminthiasis, leading to serious collateral effects on quality of life that result in diarrhea, severe problems of undernourishment, anemia, and physical and mental underdevelopment, mostly in children between 5 and 15 years of age.