West Nile Virus and Polio-like Syndromes: An Emerging Threat

Posted on the 21 June 2014 by Pranab @Scepticemia


While the whole nation has been gripped by a media-induced frenzy about the fatal effects of the so-called “litchi virus” (do not get me started on this! This issue deserves a whole post of its own!), another virus-related news has quietly slipped beneath the radars of the cumulative hysteria. This article in the Times of India has implicated the West Nile Virus as the causative agent of acute flaccid paralysis which has historically been associated with the polio virus. India has earned the polio-eradicated status a couple months ago and now is under a new threat from another virus that causes similar issues.

Notably, the three patients who have been diagnosed to have been afflicted with WNV-associated poliomyelitis-like syndrome are all adults, aged between 42 and 55 years. In India, polio coverage was targeted at children only, and surveillance included adolescents aged up to 15 years. In this connection, if I can recollect correctly, Namibia is the only country that has previously faced the threat of adult poliomyelitis with patients in their 50s being struck down by the polio virus. Anyways. Coming back to this issue. If the newspaper article is to be believed, then the leading neurologists seem to have been flummoxed by this change in pathological behavior of the WNV. While this is a rare presentation, it is not entirely unheard of. In 2002, there were letters published in the NEJM (1,2) that clearly spoke of a poliomyelitis-like condition arising from a WNV infection.

In another correspondence published in the NEJM (3), there is histopathological study of the spinal cord of an 81 year old male who succumbed following a West Nile Virus infection.

Lumbar Spinal Cord Specimen from a Man with a Poliomyelitis-like Syndrome Associated with West Nile Virus. The sample is marked by loss of anterior-horn neurons, infiltrating macrophages, perivascular lymphocytes, and gliosis (hematoxylin and eosin, ×200). (3)

The Indian series of cases has also been published (4) and is receiving quite a bit of attention from the small niche of researchers and academics who are interested in the current status of neurological diseases, while the major media attention has been grabbed by the Litchi Virus. While this does not disrupt India’s status as a nation that has successfully eradicated polio, it certainly does raise a lot of uncomfortable and worrisome questions about the future of public health management of emerging infectious diseases in India.

In conclusion, while it is a very few cases to hit the panic button yet, still, it would not be hyperbole to state that there is a lot of reason to be concerned about the way things are shaping up, and especially in the fact that we do not have a horizontal public health program that can speak to the multiple vertical preventive programs running in the nation and tie them up together to combat the challenge of such emerging diseases.

References:

1. John TJ. Spinal cord disease in West Nile virus infection. N Engl J Med. 2003  Feb 6;348(6):564-6; author reply 564-6. PubMed PMID: 12575663.

2. Leis AA, Stokic DS, Polk JL, Dostrow V, Winkelmann M. A poliomyelitis-like syndrome from West Nile virus infection. N Engl J Med. 2002 Oct 17;347(16):1279-80. Epub 2002 Sep 23. PubMed PMID: 12270971.

3. John TJ. Spinal cord disease in West Nile virus infection. N Engl J Med. 2003  Feb 6;348(6):564-6; author reply 564-6. PubMed PMID: 12575663.

4.Maramattom BV, Philips G, Sudheesh N, & Arunkumar G (2014). Acute flaccid paralysis due to West nile virus infection in adults: A paradigm shift entity. Annals of Indian Academy of Neurology, 17 (1), 85-8 PMID: 24753667