Successful results of a program combining live and inactivated poliovirus vaccines to control poliomyelitis in Gaza.

Trivalent oral poliovirus vaccine ( TOPV ) has been used in Gaza since 1967. After an initial decrease of 33% in the incidence of the paralytic disease, no further decrease could be noted. The mean annual incidence until 1977 was 10 per 100,000 inhabitants. Two outbreaks caused by poliovirus type 1 were registered in 1974 and 1976 with an incidence of 18 per 100,000 inhabitants. In these outbreaks, 34% and 50% of the affected children, respectively, had received three to four doses of TOPV . A new vaccination schedule was introduced in 1978, combining live and inactivated poliovirus vaccines. In the years 1978-1980, the incidence decreased to 2.6 per 100,000 inhabitants; and during 1981-1982, only three cases were recorded. These results indicate that a schedule like the one used in Gaza could serve as a model to control poliomyelitis in developing countries where TOPV alone is not successful.

Cell mediated immunity to polio antigens in the early stage of acute poliomyelitis.

Specific cell-mediated immunity to polio antigens in 22 children suffering from acute paralytic poliomyelitis was investigated by the macrophage migration inhibition factor (MIF) technique. A positive response was observed in 9 of the 11 patients tested 1-4 days after the onset of the paralysis, and in 6 of the 8 patients tested between 15-90 days. In one case, the response was positive before paralysis became evident. In the 8 patients tested 90-360 days after paralysis, only three gave positive results. No response was observed in 34 of 39 healthy children tested 1-3 months after having received oral polio vaccine, or in 30 healthy adults.

Study of the HLA antigen in Arab children with paralytic poliomyelitis.

In 1974 and 1976, two outbreaks of paralytic poliomyelitis occurred in a vaccine-protected infant population in the Gaza Strip. To test the possibility of an increased susceptibility to the disease, the frequency of HLA antigens was studied in 58 of the affected children and compared with 113 control subjects. HLA-AW19 and -B7 were found more frequently in the affected children. These differences were not statistically significant but are consistent with the possibility that patients with the paralytic disease may have an HLA genetic makeup different from that of the rest of the population.

HLA antigens in the Arab population of the Gaza Strip.

The HLA antigen system was studied in the Arab population of the Gaza Strip. The lymphocytes of 113 individuals were typed for 13 and 16 antigens at loci A and B, respectively. The distribution of the HLA antigens was found to be similar to that of an average Caucasoid Middle Eastern population. This was more marked when the tested population was compared with Arab populations living in northern Israel or originating from Lebanon, suggesting that they probably all share a common gene pool. The only noteworthy variation in the Gaza population was the high frequency of BW21, previously found only in Eritreans and Turks.

A new variant of mannosidosis with increased residual enzymatic activity and mild clinical manifestation.

A partial deficiency of alpha-mannosidase was found in cultured skin fibroblasts, serum, and extracts of leukoytes in two siblings with mild mental retardation, delayed speech, a suggestion of coarse or full facies, and limited mobility of the large joints. All other lysosomal enzymes tested were within the normal range. Their father demonstrated intermediate alpha-mannosidase activity. The addition of 2 mM Zn++ caused a 40% increase of the alpha-mannosidase activity in cell extracts of both patients and control subjects. pH profiles and Cellogel electrophoresis of the patients' cells indicated 20% residual activity of the acidic alpha-mannosidase isoenzyme (pH optimum at 4.0), whereas the activity of the isozyme with pH optimum of 6.0 was normal. Increasing substrate concentration (1--10 mM) demonstrated a 4 to 5-fold increase in the apparent Km of the acidic alpha-mannosidase in the patients' fibroblasts. This residual activity, however, was apparently not sufficient for the normal catabolism of mannose-containing molecules, since electron microscopic examination of the cultured fibroblasts demonstrated numerous lysosomal storage bodies.

Paralytic poliomyelitis in the Gaza Strip and West Bank during recent years.

Numerous cases of paralytic poliomyelitis occurred during epidemic years and in interepidemic periods in recent years in the Gaza Strip and the West Bank. During the epidemics of 1974 and 1976, more than 100 paralytic cases were recorded each year. The dominant poliovirus was type 1. In interepidemic years, especially in the Gaza Strip, type 3 poliovirus was the prevalent type. The age group affected were infants and children up to 3 years and 50% of cases occurred during the first 12 months of life. Since 1968, oral poliovirus vaccine has been administered extensively to infants, 2 to 13 months of age. Though vaccine coverage was far from being complete, 3 doses of trivalent oral vaccine were given to the great majority of infants of this age group. Many of the paralytic cases occurred in unvaccinated or incompletely vaccinated (1-2 doses) children. However, numerous cases were recovered in children given three and four feedings. Serologic studies carried out on many of the paralyzed children indicated that "vaccine failures" had occurred. It seems that many of the vaccine failures were due to the massive and widespread circulation of various types of interfering enteroviruses. Laboratory tests of vaccine samples returned from the field prove that the vaccines used were undoubtedly of adequate potency. For these reasons we are planning a program of combined use of oral and inactivated vaccine in order to bypass the interference phenomenon.

The cell mediated immune response in acute poliomyelitis and its use in early diagnosis.

Specific cell mediated immunity to polio antigens was investigated in 22 children suffering from acute paralytic poliomyelitis by the macrophage migration inhibition (MIF) technique. A positive response was observed in 9 out of the 11 patients tested 1-14 days after the onset of the paralysis and in 6 out of the 8 patients tested between 15-90 days. In one case, the response was positive even before paralysis became evident. Out of the 8 patients tested 90-360 days after paralysis, only 3 gave positive results. No response whatsoever could, on the other hand, be observed in the great majority of children tested 1-3 months after having received oral polio vaccine or in healthy adults. These findings demonstrate that in poliomyelitis the specific C.M.I. response can be detected before the circulating antibodies and suggest that possibility of the use of this technique in the early diagnosis of poliomyelitis as well as in the differentiation between this disease and other neurological disorders.