Almost all individuals tested were over 15
years of age. Fluorescent immunoassays were
performed by the Parasitic Diseases Branch of
the Centers for Disease Control, Atlanta, Georgia. The overall prevalence of positive titers was
93.6%, a finding to be expected on the basis of
comparison groups (p <0.05). The MLTsof the
four groups were similar, however, whentiters
<4 were excluded, suggesting that if infection
did occur there waslittle, if any, difference in
ability to mount an antibody response. Table 3b
shows that individuals living on Rongelap had
including Oceania.”* A greater numberofpersons with insignificant titers (<4) was found in
the Rongelap and Ailingnae groups (Table 3a).
Furthermore, the mean log titer (MLT) of the
combined Rongelap and Ailingnae groups was
significantly lower than those of the Utirik and
sons from Rongelap and Ailingnae were
included, although the differenceis not statistically significant. It is possible, therefore, that
the lower mean toxoplasma antibodytiter of the
Rongelap-Ailingnae exposure group wasdue to
a decreased opportunity for exposure to the
investigations by others in tropical regions,
the lowest MLTs whether or not exposed per-
Table 3
Serum toxoplasmatiters and chorioretinal scars.
a)
Rongelap and Ailingnae
Utinik
Comparison
6.6643.72
8.29+2.49
7.8142.49
(61)**
(97)
(100)
18.0%
3.1%
4.0%
8.12+2.19
8.55+2.03
8.14+1.95
MLT*
<4
MLT minus <4
b)
MLT
MLT minus
Rongelap and
- Ailingnae
Exposed
Exposure Group
Island of Residence
Ebeye
Majuro
Rongelap
Utirik
7,.69+2.51
(103)
8.11243.34
(62
7.22+3.23
(87)
8.48+2.56
(172)
7.844+2.44
(69)
8.57+2.64
(53)
7,624+2.84
(71)
8.49+2.36
(172)
c)
Age Distribution
<10 yr
10-19 yr
>19 yr
Rongelap and
Ailingnae
5.89+3.55
(28)
8.2743.58
(11)
6.82+3.88
(22)
Utirik
8.36+3.00
(50)
7,86+1.83
(14)
8.3641 .82
(33)
Comparison
7.49+2.56
(39)
7.76+2.80
(21)
8.15+2.26
(40)
me
t
2
3
3
J
Jo
o«
au