MOLECULAR EPIDEMIOLOGY OF A MEASLES VIRUS IN SAO PAULO, BRAZIL: AN IMPORTED CASE

Sao Paulo, March 27, 2013

Brazil follows the recommendations of the World Health Organization concerning the use of several strategies of measles vaccination programs and has succeeded in reducing transmission of the wild-type viruses. Sao Paulo State follows the same pattern; however, there was circulation of an imported case of virus in 2001 and 2005, which was shown to belong to the D5 group and in 2011 to the D4 group³. In 2012 there were no reports of confirmed measles cases.

In Sao Paulo on 12.23.2012, Epidemiological Surveillance Center notified a suspected case of measles virus of a 20-year-old male, living in the city of Bauru/SP, with a history of international travel to Florida, USA. The patient had previously received two doses of measles vaccine. When returning to SP/Brazil he presented the first symptoms on 12.25.2012, with fever followed by rash, cough, coryza, conjunctivitis, diarrhea and prostration. Samples were collected on 01.02.2013. The Adolfo Lutz Institute (SP) processed samples by using ELISA assay measles-specific immunoglobulin (IgM/IgG) and Real Time PCR assays, which confirmed the presence of measles virus.

Phylogenetic analysis of measles virus wild type strain has been used to trace the routes of transmission and circulation. We used the region encoding the nucleoprotein (N), that presents variability from 7% to 12% among wild-type viruses. For molecular epidemiology, genotype designations are considered the operational taxonomic unit, while related genotypes are grouped by eight clades designated A, B, C, D, E, F, G and H. Within these clades, there are 23 recognized genotypes⁶.

Our result indicated that the virus was a member of genotype D8. This patient had contact with two persons, a 20-year-old female and a 13-year-old male who had previously received two doses of measles vaccine, and who received a third dose on 01.02.2013, developing measles symptoms on 01.08.2013. Samples were collected on 01.11.2013. Results showed IgM no reagent and IgG reagent for the two patients' contacts. Real Time PCR assay confirmed measles virus and sequencing was processed showing Genotype D8. This genotype has circulated in England and has been detected in other countries including the USA, Canada and China²,⁴,⁷.

Although patients had received two doses of vaccine, several obstacles to eradicate measles should be considered such as the persistent infection with transmissible measles virus which poses a biological barrier to its eradication⁵. However, such cases should always be monitored to assure that contacts remain uninfected¹. The air travelling passengers were also contacted to initiate preventive measures against the virus.

To maintain good measles control, children should be vaccinated against measles at the right time through routine childhood immunization; likewise, all young adults who travel internationally should be vaccinated as well. Clinician awareness remains important for the early identification and control of measles to avoid further transmission during outbreaks and to enable the timely implementation of public health measures.

We thank Paul A. Rota, Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA, by protocol for the test-Real Time PCR.

REFERENCES

• ¹
  Bellini WJ, Rota PA. Biological feasibility of measles eradication. Virus Res. 2011;162: 72-9.
• ²
  Duraisamy R, Rota PA, Palani G, Elango V, Sambasivam M, Lowe L, et al. Molecular characterization of wild-type measles viruses in Tamil Nadu, India, during 2005-2006: relationship of genotype D8 strains from Tamil Nadu to global strains. J Med Virol. 2012;84:348-57.
• ³
  Oliveira MI, Figueiredo CA, Afonso AMS, Santos FC, Lemos XR, Yu ALF, et al. Resurgence of measles virus in São Paulo, Brazil. Rev Inst Med Trop Sao Paulo. 2012;54:113-4.
• ⁴
  Roggendorf H, Santibanez S, Mankertz A, van Treeck U, Roggendorf M. Two consecutive measles outbreaks with genotypes D8 and D4 in two mainly unvaccinated communities in Germany. Med Microbiol Immunol. 2012;201:349-55.
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  Rosewell A, Reinten-Reynolds T, Spokes PJ. EpiReview: measles in NSW, 2002-2011. N S W Public Health Bull. 2012;23:201-7.
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  Rota PA, Brown K, Mankertz A, Santibanez S, Shulga S, Muller CP, et al. Global distribution of measles genotypes and measles molecular epidemiology. J Infect Dis. 2011;204(Suppl 1):S514-23.
• ⁷
  Vainio K, Steen TW, Arnesen TM, Rønning K, ånestad G, Dudman S. Measles virus genotyping an important tool in measles outbreak investigation in Norway, 2011. Euro Surveill. 2012;17:1-10.

Publication Dates

• Publication in this collection
  Jul-Aug 2013