Organic Waste Recycling

Characteristics of organic wastes 69

Table 2.25 Partial list of parasitic zoonoses (continued)

Disease in humans Causative organism Vertebrate animals
principally involved
Mammomonogamiasis Mammomonogamum
laryngeus

Ruminants

Strongyloidiasis Strongyloides stercoralis Dogs, monkeys

Strongyloides fuelleborni Dogs, monkeys

Thelaziasis Thelazia species Dogs, ruminants

Trichinellosisa Trichinella spiralis and other

Trichinella species

Swine, rodents, wild

carnivores, marine

mammals

Trichostrongyliasis Trichostrongylus

colubriformus and other

Trichostrongylus species

Ruminants

From WHO (1970); reproduced by permission of the World Health Organization, Geneva. This list
is not comprehensive and is confined to those diseases in which the animal link in the chain of
infection to humans is considered to be important, although not alwaus essential.
a Diseases or causative organisms of particular importance over large areas

The detection and identification of pathogenic microorganisms are generally
difficult, time-consuming and expensive. For routine analyses or monitoring,
fecal indicator microorganisms are the preferred microbes analyzed. An ideal
indicator should be non-pathogenic, easily detected and counted, present where
fecal pathogens are present but in higher numbers, and a member of the normal
flora of the intestinal tract of healthy persons.
Some of the common fecal indicators for bacteria are fecal coliforms, fecal
streptococci, Clostridium perfringens, and Pseudomonas aeroginosa.
Bacteriophages or coliphages which use bacteria as their host cells have been
employed as indicators for enteric viruses. It should be noted that at present,
definite relationships between the die-offs of the indicator microorganisms and
those of the pathogenic microorganisms are not well established. For example, in a
sludge composting unit, the absence of fecal coliforms does not necessarily mean
that other enteric bacteria will be dead. Therefore, appropriate indicator
microorganisms should be selected for a specific case or a treatment/reuse method
being employed. Because they are the most hardy and resistant of all helminth
pathogens, viable Ascaris ova have been recommended to be the best pathogen
indicator for non-effluent wastes (such as nightsoil, the contents of pit latrines, and
septage Feachem et al. 1983). Liquid or effluent wastes are normally treated by
waste stabilization ponds and/or other conventional waste treatment processes
including sedimentation. Under satisfactory operation most helminth ova would be
removed by sedimentation, while bacteria and viruses are still carried over with the
effluents. In this case the use of indicators for either fecal bacteria or viruses would
be appropriate. Methods to enumerate common fecal indicators for bacteria and