LIVE POLIO IRUS VACCINES

-Y
554 Efficacy-Field Evidence
TABLE 6. REPORTED CASES OF PARALYTIC POLIOMYELITIS IN NICARAGUA AMONG VACCINEES: BY
VIRUS TYPE RECEIVED AND INTERVALS BETWEEN VACCINE ADMINISTRATION AND
PROBABLE DATE OF ONSET OF SYMPTOMS
NUMBER OF PARALYTIC CASES
ORAL VACCINE
VIRUS TYPE
TOTAL
1-9
DAYS
10-30
DAYS
1-4
MONTHS
5-20
MONTHS*
UN-
SPECIFIED
TOTAL 27 4 1 3 12 7
2, 3, and 1 8 1 7
2 and 3 3 - - - 2 1
2 4 -- - 1 3
Trivalent 12 4 1 2 2 3
* Up to 14 May.
cured; in other cases the information obtained
was incomplete.
Before February 1960, blood and fecal material
(stool samples or rectal swabs) were obtained
from suspected cases admitted to the
poliomyelitis unit of the general hospital in
Managua and sent to Pearl River. Type 3 poliovirus
was isolated from three of these cases.
Beginning in February and up to 14 May 1960,
duplicates of 96 stool specimens were sent both
to Pearl River and to Panama. Fecal material
was collected from 55 per cent of all cases
notified in the country up to 14 May, and from
70 per cent of those reported from Managua.
The majority of fecal material samples were obtained
soon after onset of paralysis. From three
patients, swabs were obtained three, six, and
eight weeks after onset, respectively. Up to
20 May 90 specimens were examined in one or
both laboratories. All of the samples collected
were obtained from cases which occurred in
1960, with the exception of one which had ons'et
in 1959, and was seen six months after the
appearance of symptoms. Poliovirus Type 1
was isolated from 47 cases and Type 3 virus
from two patients. No poliovirus was isolated
from four specimens and retests of these samples
are currently in progress. Nine specimens
were negative for cytopathogenic agents. From
four specimens, cytopathogenic agents were isolated
that were not neutralized by Types 1 and/
or 2, and/or 3 poliovirus antisera. The examination
of 16 recently received specimens is incomplete.
From the 27 cases with a history of vaccine
administration, specimens for virus study were
obtained from 20 of them: blood and fecal material
from three cases, blood from only four
cases, and fecal material from only 13 patients.
Up to 31 May results were available for 11 of
these cases: Type 1 poliovirus was isolated from
six of the cases, from one case Type 3 poliovirus
was recovered, from two cases non-poliovirus
was isolated, and from two cases no agents
were recovered. The isolation of poliovirus Type
1, even in absence of serologic confirmation,
probably indicates, under the present circum-
.tances, that the paralytic disease observed was
due to the isolated type of virus.
POLIOMYELITIS SURVEILLANCE IN
NICARAGUA
For 15 of the 27 cases reported as having
been fed the live poliovirus vaccine, their vaccination
history was documented. Records for
the remaining 12 were either incomplete or absent,
and as a consequence, it cannot be established
whether or not these individuals received
all three types of poliovirus vaccine. Since Type
1 virus was the last strain fed in the 1958 campaign
and approximately 17 per cent of those
who started the monovalent feedings did not
receive Type 1 vaccine, a corresponding proportion
would not have been vaccinated against the
epidemic type of 1959-1960 although they had
a history of vaccination.
Table 7 summarizes the information available
for the 15 paralytic cases whose vaccination his-