Epidemic of Zika virus and maxillofacial surgery

Epidemic of Zika virus and maxillofacial surgery

YBJOM-4775; No. of Pages 3 ARTICLE IN PRESS Available online at www.sciencedirect.com British Journal of Oral and Maxillofacial Surgery xxx (2016) x...

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YBJOM-4775; No. of Pages 3

ARTICLE IN PRESS Available online at www.sciencedirect.com

British Journal of Oral and Maxillofacial Surgery xxx (2016) xxx–xxx

Editorial

Epidemic of Zika virus and maxillofacial surgery

Abstract Zika is a RNA virus spread by the ubiquitous Aedes mosquitoes. It was first discovered in Uganda in 1947, and arrived in south-east Asia by the middle of the 20th century. In 2014 the virus started to spread across the Pacific Islands to reach South America. Since then it has spread rapidly northwards, and reached Mexico and the Caribbean in November 2015. Clinically it presents as a self-limiting febrile illness. However, there is increasing evidence of a link between Zika virus and the Guillain-Barré syndrome, and maternal Zika virus infection and microcephaly of the fetus. © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Zika virus; Microcephaly; Guillain–Barré syndrome; Virus induced congenital malformation

Introduction There has been a sudden and unexpected rise in the fetal and neonatal diagnosis of microcephaly, and postfebrile Guillain–Barré syndrome. The exact aetiology of this outbreak has not yet been confirmed, but there is growing evidence of an association with the emergence of Zika virus disease.1–7 This review aims to increase awareness among oral and maxillofacial surgeons who are increasingly likely to manage affected patients. Zika is a single-stranded RNA virus, part of a viral family transmitted by mosquito ticks.2–8 The genus of this flavivirus includes yellow fever, dengue, West Nile, and Japanese encephalitis viruses. There are two main lineages of Zika virus: the African and the Asian,8 and it is spread by Aedes mosquitoes,1–9 the wide geographical distribution of which has resulted in the rapid formation of pandemics, and its spread is likely to continue.3,8 Zika virus was first discovered in Uganda in 1947 in rhesus monkeys, and later in humans in 1952, and it arrived in south-east Asia by the mid-20th century.3,5 In the 21st century it has spread across the Pacific Islands, and reached South America about 2014. Since then it has spread rapidly northwards through Brazil, reaching Mexico in November 2015 and the Caribbean in January 2016.5,8 Tourists have already introduced it to Europe, and as of 29 January 2016 there were

5 confirmed cases in the UK6 and 5 in Germany.4 The updates on areas with ongoing transmission are available on line.7 An estimated 80% of people who are infected with Zika virus have no symptoms.1,3,5 Symptomatic disease is generally a mild, dengue-like, febrile illness, including maculopapular rash, arthralgia, or non-purulent conjunctivitis. Symptoms usually last up to a week. Severe disease that requires admission to hospital is uncommon, and deaths are rare.1,3,5 There is no specific treatment or vaccine currently available.1,3,5 Laboratory diagnosis consists mainly of detection of the viral RNA genome through reverse transcriptase polymerase chain reaction (RT-PCR), isolation of the virus, or the detection of specific Zika virus IgM or IgG antibodies by serological tests.3 Diagnosis by serology can be difficult as the virus can cross-react with other flaviviruses.5 The laboratory tests are also time-consuming and there is a need for a cheap, commercially-available, diagnostic test.5 Transmission of Zika virus by transfusion of infected blood or blood products remains a possibility.3,5 During an outbreak in French Polynesia, 3% of symptom-free blood donors were found to have antibodies for Zika virus, but we know of no documented cases of infection by transfusion.3 It would be prudent to take similar precautions as are taken for dengue virus to avoid contamination of blood banks by Zika virus.3

http://dx.doi.org/10.1016/j.bjoms.2016.02.001 0266-4356/© 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Please cite this article in press as: Shakib K. Epidemic of Zika virus and maxillofacial surgery. Br J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.bjoms.2016.02.001

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Possible cases of sexual transmission of Zika virus have been reported,3–6 and viable Zika virus has been detected in semen more than two weeks after the patient’s recovery.3 Microcephaly induced by Zika virus Intrauterine infections that affect the brain are relatively rare, and include cytomegalovirus, toxoplasmosis, herpes, syphilis, and rubella.1,2 Among the flaviviruses there have been only isolated reports that linked West Nile encephalitis virus to fetal brain damage.1 In October 2015 the Brazilian Ministry of Health reported an unusual increase in cases of microcephaly in areas of Zika virus infection. The report showed a rapid increase in newborn babies with microcephaly, from an annual number of about 175, to 1248 cases in 2015 (by 28 November). It was particularly alarming that 509 cases were reported from 21-28 November 2015.3,7 On 17 November 2015 the Brazilian Ministry of Health reported the presence of Zika virus RNA in amniotic fluid samples collected from two pregnant women who had had symptoms compatible with Zika virus disease at 18 and 19 weeks’ gestation. Fetal Zika virus infection was confirmed through detection of its genome by RT-PCR in amniotic fluid from the two children, both born with microcephaly. Samples of urine and serum from the mothers did not stain for the Zika virus genome at 28 weeks’ gestation, but amniocenteses showed a viral load 10 000 times higher than is normally found in blood from adults with acute infection and exanthema. Ultrasonography done at 20 weeks’ gestation showed calcifications in the fetal brains, and repeat scans at 28 weeks’ gestation confirmed the diagnosis of microcephaly.3,7 In November 2015, the health authorities in French Polynesia reported an unusual increase of at least 17 cases of microcephaly during the Zika virus outbreaks in their islands. On 28 November 2015, the Brazilian Ministry of Health reported the presence of Zika virus genome in the blood and tissue samples of a baby with microcephaly who had presented with microcephaly and other congenital anomalies and died within five minutes of birth.3 There are also case reports of cerebral calcification and macular atrophy in children born with microcephaly in Brazil.2,7 The previous lack of reports of fetal infection with Zika virus is notable. It may be because of the previous rarity of the disease, possible early acquisition of immunity in endemic areas, or genomic changes in the virus. A new, more virulent, strain of Zika virus is a possibility. Several national health care organisations in the affected areas have taken the unprecedented step of advising women against becoming pregnant,4 and Public Health England has joined authorities across the world in advising pregnant women against going to any of the 23 countries where the virus has been confirmed.6,7

Zika virus-induced Guillain–Barré syndrome During its ongoing epidemic of Zika virus, El Salvador has notified PAHO/WHO of a coincidental increase in the number of cases of Guillain-Barré syndrome. Their usual annual number is about169; however, from 1 December 2015 to 6 January 2016, 46 were recorded, including two deaths.10 During the outbreak in French Polynesia, 74 of 8750 suspected cases of Zika virus infection presented with neurological or autoimmune syndromes. Of these, 42 were diagnosed as Guillain-Barré syndrome.3 In Brazil, 121 cases of neurological signs and GuillainBarré syndrome have been notified, all of which had a history of illness with a rash and were notified in endemic states between January-July 2015.3 Investigations are in progress to find a causal association between Zika virus infection and Guillain-Barré syndrome. Based on the temporal correlations, a causal link between them is plausible. In conclusion, the spread of Zika virus infections to South, Central, and North America is an important development in the epidemiology of this emerging vector-borne disease, the full impact of which is not yet clear. There is limited but increasing knowledge about the infection in humans. Important uncertainties remain about the disease, complications, and degrees of risk for pregnant women.

Conflicts of Interest We have no conflicts of interest.

Ethics Statement/confirmation of patients’ permission Not applicable as this is a review article.

References 1. Oliveira Melo AS, Malinger G, Ximenes R, et al. Zika virus intrauterine infection causes fetal brain abnormality and microcephaly: tip of the iceberg? Ultrasound Obstet Gynecol 2016;47:6–7. 2. Ventura CV, Maia M, Bravo-Filho V, et al. Zika virus in Brazil and macular atrophy in a child with microcephaly. Lancet 2016 Jan 7 (Epub ahead of print). 3. European Centre for Disease Prevention and Control. Rapid risk assessment. Zika virus epidemic in the Americas: potential association with microcephaly and Guillain-Barré syndrome. Stockholm, Sweden: European Centre for Disease Prevention and Control; 2015. Available from URL: http://ecdc.europa.eu/en/publications/Publications/ zika-virus-americas-association-with-microcephaly-rapid-riskassessment.pdf. 4. BBC News. Zika virus: up to four million Zika cases predicted. Available from URL: http://www.bbc.com/news/health-35427493.

Please cite this article in press as: Shakib K. Epidemic of Zika virus and maxillofacial surgery. Br J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.bjoms.2016.02.001

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5. World Health Organization. Zika virus factsheet (updated 2016). Available from URL: http://www.who.int/mediacentre/factsheets/zika/en/. 6. Public Health England. Zika virus: travel advice for pregnant women. Available from URL: https://www.gov.uk/government/news/ zika-virus-travel-advice-for-pregnant-women. 7. Petersen EE, Staples JE, Meaney-Delman D, et al. Interim guidelines for pregnant women during a zika virus outbreak - United States, 2016. MMWR Morb Mortal Wkly Rep 2016;65:30–3. 8. Hayes EB. Zika virus outside Africa. Emerg Infect Dis 2009;15:1347–50. 9. Gatherer D, Kohl A. Zika virus: a previously slow pandemic spreads rapidly through the Americas. J Gen Virol 2015 (Epub ahead of print).

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10. World Health Organization. Guillain-Barré syndrome: El Salvador. Available from URL: http://www.who.int/csr/don/21-january2016-gbs-el-salvador/en/.

Kaveh Shakib ∗ Department of Oral & Maxillofacial Surgery, Royal Free Hospital London ∗ Tel.: +0202164271. E-mail address: [email protected]

Please cite this article in press as: Shakib K. Epidemic of Zika virus and maxillofacial surgery. Br J Oral Maxillofac Surg (2016), http://dx.doi.org/10.1016/j.bjoms.2016.02.001