Environmental Engineering Reference
In-Depth Information
At Manteno State Hospital in Illinois, 453 cases of typhoid fever were reported,
resulting in 60 deaths in 1939.
59
It was demonstrated by dye and salt tests that
sewage from the leaking vitrified clay tile hospital sewer line passing within
a few feet of the drilled well-water supply seeped into the well. The hospital
water supply consisted of four wells drilled in creviced limestone. The state
sanitary engineer had previously called the hospital administrator's attention
to the dangerously close location of the well to the sewer and made several
very strong recommendations over a period of eight years, but his warning went
unheeded until after the outbreak. Indictment was brought against three officials,
but only the director of the Department of Public Welfare was brought to trial.
Although the county court found the director guilty of omission of duty, the
Illinois Supreme Court later reversed the decision.
An explosive epidemic of infectious hepatitis in Delhi, India, started during
the first week of December 1955 and lasted about six weeks. About 29,300
cases of jaundice had developed in a total population of 1,700,000 people. (The
authorities estimated the total number of infections at 1,000,000.) No undue
incidence of typhoid or dysentery occurred. Water was treated in a conventional
rapid sand filtration plant; however, raw water may have contained as much
as 50 percent sewage. Inadequate chlorination (combined chlorine), apathetic
operation control, and poor administration apparently contributed to the cause of
the outbreak, although the treated water was reported to be well clarified and
bacteriologically satisfactory.
60
Waterborne salmonellosis in the United States is usually confined to small
water systems and private wells.
61
However, an outbreak of gastroenteritis in
Riverside, California, in 1965 affected an estimated 18,000 persons in a popu-
lation of 130,000. Epidemiologic investigation showed that all cases harbored
Salmonella typhimurium
, serological type B and phage type II, which was iso-
lated from the deep-well groundwater supply. There was no evidence of coliform
bacteria in the distribution system, although 5 of 75 water samples were found
positive for
S. typhimurium
, type B, phage II. The cause was not found in spite
of an extensive investigation.
62
Of potential for causing protozoal infections in humans are the species
Enta-
moeba histolytica, Giardia lamblia, Cryptosporidium parvum
and
C. hominis,
Cyclospora cayetanensis, Enterocytozoon bieneusi, Isopora belli
and
I. hominis
,
and
Balantidium coli
.
63
E. histolytica, G. lamblia, C. parvum
and
C. hominis
,
and
C. cayetanensis
have all been implicated in diseases of the water route. The
remaining organisms stated above are intestinal parasites so there is potential
for their transmission by contaminated water. Nonetheless, present-day concerns
center on three genera, namely
Giardia, Cryptosporidium
,and
Cyclospora
.Also
of interest are the free-living amoebae,
Naegleria
spp., especially
,N.fowleri
,the
etiologic agent of an explosive disease of the central nervous system termed pri-
mary
amebic meningoencephalitis (PAM)
and
Acanthamoeba
spp., which are also
free-living amoebae and causative agents of
granulomatous amebic encephalitis
(GAE)
and
acanthamoeba keratitis
(see Table 1.4).
