RE: "IMMUNITY TO POLIOMYELITIS IN THE NETHERLANDS"

Subhash C. Arya

Centre for Logistical Research and Innovation New Delhi-110048, India

In a recent issue of the Journal, Conyn-van Spaendonck et al. (1Go) reported that during 1995–1996, many persons in the Netherlands lacked protective antibodies to polioviruses. The lowest prevalence of 59.0 percent for type 2 poliovirus antibody was found among religious groups that reject vaccinations. The concurrent highest antibody prevalence of 96.6 percent was for type 1 poliovirus among the general population who had received inactivated poliovirus vaccine. Surely, global eradication of poliomyelitis by the year 2005 would protect the Orthodox Reformed population in the Netherlands against future episodes of poliomyelitis. During the interim period, it would be desirable to carry out poliovirus antibody surveillance for declining poliomyelitis immunity in those susceptible to poliomyelitis in the general population, including persons receiving immunosuppressive therapy or abusing drugs.

A widespread lack of poliovirus antibody was found in young drug addicts in the San Patrignano rehabilitative community of Rimini, Italy; seronegativity (27 percent for type 1 poliovirus, 27 percent for type 2 poliovirus, 34 percent for type 3 poliovirus, and 11 percent for all three types) was highest among drug addicts positive for human immu-nodeficiency virus-1 (2Go). Furthermore, for 16 adult recipients of bone marrow transplants in Finland, a decline in antibody titers against poliovirus resulted in loss of protection against poliomyelitis (3Go). An identical scenario in the Netherlands in either the general or the Orthodox Reformed population could be disastrous and be associated with episodes of poliomyelitis.

Any episodes of poliomyelitis in the Netherlands should be diagnosed promptly by using magnetic resonance imaging (MRI). MRI of the cervical spine in a 27-year-old man who developed acute flaccid paralysis 3 months after his 2-month-old infant was immunized with live poliovirus vaccine showed smooth hyperintense bands (4Go). Both sagittal-spin proton-density weighted and T-2 weighted images revealed involvement of regions corresponding to the anatomic location of ventral horns. In the future in the Netherlands, performing MRI on those afflicted with poliomyelitis could assist clinicians in offering interferon-{alpha} that can halt the clinical progression of poliomyelitis within 24 hours (5Go).

Constant serosurveillance for poliomyelitis (1Go) and MRI-guided therapeutic intervention for episodes of acute flaccid paralysis is essential in the Netherlands and should include a sizable number of persons in the Orthodox Reformed population (1Go). An integrated prophylactic and therapeutic approach should even prevent long-term disability after viral damage to target neurons.

REFERENCES

  1. Conyn-van Spaendonck MAE, de Melker HE, Abbink F, et al. Immunity to poliomyelitis in the Netherlands. Am J Epidemiol 2001;153:207–14.[Abstract/Free Full Text]
  2. Pregliasco F, Minolfi V, Boschin A, et al. A seroepidemiological survey of immunity against poliomyelitis in a group of HIV positive and HIV drug addicts. Eur J Epidemiol 1995;11:693–5.[ISI][Medline]
  3. Parkkali T, Ruutu T, Stenvik M, et al. Loss of protective immunity to polio, diphtheria and Haemophilus influenzae type b after allogenic bone marrow transplantation. APMIS 1996;104:383–8.[ISI][Medline]
  4. Malzberg MS, Rogg JM, Tate CA, et al. Poliomyelitis: hyperintensity of the anterior horn cells on MR images of the spinal cord. Am J Roentegenol 1993;161:863–5.
  5. Levin S. Interferon treatment of poliomyelitis. J Infect Dis 1985;153:745–6.

 

THE AUTHORS REPLY

M. A. E. Conyn-van Spaendonck, H. E. de Melker, F. Abbink, N. Elzinga-Gholizadea, T. G. Kimman and T. van Loon

National Institute of Public Health and the Environment Bilthoven, the Netherlands
Department of Virology Eijkman Winkler Institute University Medical Center Utrecht Utrecht, the Netherlands

We thank Dr. Arya for his remarks (1Go) on our paper (2Go) concerning the lack of protective antibodies against polioviruses in the Netherlands. First, our study provides generally very reassuring data on immunity in the Dutch population. Antibodies persist for very long periods of time not only in naturally infected persons but also in those with immunity induced by inactivated polio vaccine available since 1957. Vaccine coverage is very high (97 percent).

Indeed, the prevalence of poliovirus antibodies is low among about 275,000 Orthodox Reformed persons who refuse vaccination on religious grounds and are sociogeographically clustered. However, this is a small proportion of our population (<2 percent). The remaining group of unvaccinated persons has not been vaccinated for various reasons but is protected by herd immunity. This herd immunity was confirmed in both the 1978 and 1992–1993 outbreaks, where cases occurred among only unvaccinated persons who belonged to Orthodox Reformed groups. Immunocompromised persons such as those infected with human immunodeficiency virus (HIV) will also be protected by herd immunity. Furthermore, a (small) study by Kroon et al. showed no lower polio antibody titers of HIV-infected persons when compared with controls (3Go).

Because of the known clusters of nonvaccinated Orthodox Reformed persons in the Netherlands, surveillance of acute flaccid paralysis, as recommended by the World Health Organization, is extended with virologic surveillance based on registration of any enterovirus isolation from stool followed by further typing and with environmental surveillance by sampling the sewage systems in areas with these nonvaccinated clusters. With these additional efforts, no indications were found for circulation of polioviruses in the Netherlands since the 1992–1993 outbreak. Moreover, serologic surveys are carried out to monitor the immunity of the population, which we intend to repeat regularly.

Use of magnetic resonance imaging and prescription of interferon-{alpha} in cases with acute poliomyelitis is beyond the scope of our study but will surely be applied by clinicians if there is professional consensus regarding this approach.

REFERENCES

  1. Arya SC. Re: "Immunity to poliomyelitis in the Netherlands." (Letter). Am J Epidemiol 2001;154:684.[Free Full Text]
  2. Conyn-van Spaendonck MAE, de Melker HE, Abbink F, et al. Immunity to poliomyelitis in the Netherlands. Am J Epidemiol 2001;153:207–14.[Abstract/Free Full Text]
  3. Kroon FP, van Dissel JT, Labadie J, et al. Antibody response to diphtheria, tetanus, and poliomyelitis vaccines in relation to the number of CD4+ T lymphocytes in adults infected with human immunodeficiency virus. Clin Infect Dis 1995;21:1197–203.[ISI][Medline]