Memórias do Instituto Oswaldo Cruz Fundação Oswaldo Cruz, Fiocruz ISSN: 1678-8060 EISSN: 1678-8060 Vol. 106, Num. 4, 2011, pp. 390-393

Memórias do Instituto Oswaldo Cruz, Vol. 106, No. 3, 2011, pp. 390-393

SHORT COMMUNICATIONS

Monitoring the circulation of rotavirus among children after the introduction of the Rotarix^TM vaccine in Goiânia, Brazil

Ana Maria Tavares Borges⁺; Menira Dias e Souza; Fabíola Souza Fiaccadori; Divina das Dores de Paula Cardoso

Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil
+ Corresponding author: amtborges@hotmail.com

Financial support: CNPq

Received 17 September 2010
Accepted 8 April 2011

Code Number: oc11084

Abstract

The epidemiological features of rotavirus A (RVA) infection differ between children from developing and developed countries which could result in differences in vaccine efficacy around the world. To evaluate the impact of Rotarix^TM on RVA prevalence, we monitored RVA genotypes circulating in Goiânia by monitoring virus in faecal samples from children that had or had not been previously vaccinated. From February-November of 2008, 220 faecal samples were collected from children in seven day-care centres. RVA detection was performed by two methodologies and the results were confirmed by polyacrylamide gel electrophoresis. From the 220 samples, eight were RVA-positive (3.6%) and five were from children that had received either one or two doses of the vaccine. All positive samples were collected from children with diarrhoea during August and September. Genotyping of the RVA characterised five of the viral samples as genotype G2P[4] and one as G8P[4], suggesting that G2P[4] was the predominant circulating genotype in Goiânia during the study. The fact that vaccinated children were also infected by RVA suggests that the vaccine does not fully protect against infection by the G2[P4] RVA genotype.

Key words: rotavirus - rotavirus infections - rotavirus vaccine - epidemiology

Gastroenteritis is a prevalent cause of childhood morbidity and mortality (Boschi-Pinto et al. 2008). Various agents are implicated in the aetiology of acute gastroenteritis, including rotavirus A (RVA), which is one of the most important aetiological agents of this syndrome, especially among children. Other studies have shown that more than 90% of children less than five years of age have been infected at least once by RVA and that most fatal cases associated with RVA infection occur in developing countries (Glass et al. 2006).

The epidemiological characteristics of RVA infection, such as seasonality, mortality, mean age of infection, circulating genotypes, transmission route and minimum infectious dose differ among studies conducted in developed and developing countries, which could have an impact on the efficacy of the vaccine against RVA in different parts of the world (Parashar & Glass 2009).

Different approaches have been used in the development of vaccines against RVA (Vesikari et al. 1984, Midthun & Kapikian 1996, Bresee et al. 1999, WHO 2009). In the last two decades, more vaccines against RVA have been developed and tested in clinical trials. Two vaccines, Rotarix^TM (GlaxoSmithKline) and Rotateq (Merck), have been licensed and are currently available in different parts of the world (Vesikari et al. 2006, WHO 2009). Rotarix^TM, an oral attenuated monovalent vaccine formulated with strain RIX4414 genotype G1P[8] (Gentsch et al. 2009), was first included in the Brazilian immunisation program in March of 2006.

This study was performed to evaluate the impact of Rotarix^TM on RVA occurrence in Goiânia, state of Goiás (GO), Brazil, through detection and molecular characterisation of the virus in samples from vaccinated and unvaccinated children.

For this study, 220 faecal samples were collected from an equal number of children in seven day-care centres [Municipal Centers for Early Childhood Education (CMEIs)] from February-November of 2008 in Goiânia.

RVA was detected using two commercial kits with different detection methods: immunochromatography (Rotavirus adenovirus latex strip-Operon Biotechnologies, Germany) and the immunoenzymatic assay (Ridascreen® Rotavirus/r-biopharm). The positive results were confirmed by polyacrylamide gel electrophoresis, as previously described by Pereira et al. (1983), using a 20% faecal suspension in phosphate buffered saline (pH 7.4). The positive RVA samples were genotyped by reverse transcription-polymerase chain reaction (PCR) followed by Multiplex nested-PCR using the primers described by Gentsch et al. (1992), Gouvea et al. (1994) and Das et al. (1994).

This study has been approved by the Committee in Ethics and Research from the Hospital Materno Infantil (protocol 22/08).

Statistical analysis was performed using either the Chi-squared test or the Fisher's exact test. Statistical significance was accessed at p < 0.05.

From the 220 collected samples, 139 were obtained from children that had been previously vaccinated with Rotarix^TM (1 or 2 doses) and 81 from unvaccinated children. Seventy-seven samples were considered diarrhoeic and 143 were not. Of the total samples, 3.6% were positive for RVA. If we only consider the samples collected from children with diarrhoea, 10.4% (p < 0.001) were positive for RVA, which confirms the relevance of diarrhoeal symptoms during RVA infection (Costa et al. 2004). Previous studies conducted in children from the same region found that 14.4-37.2% of the samples were positive for RVA (Cardoso et al. 2003, Costa et al. 2004), which was higher than the rate observed in the present study. Even if we consider the small sample size, which is a limitation of this study, our data still suggests that there was a decrease in RVA prevalence after the introduction of the vaccine by the Brazilian National Immunization Program. Recent studies conducted in both developed and developing countries have also reported a decrease in RVA circulation after the introduction of Rotarix^TM (De Vos et al. 2006, Leite et al. 2008, Correia et al. 2010, Lanzieri et al. 2010, Zeller et al. 2010).

Among the positive samples, five were obtained from children that had completed the vaccination scheme, which includes two doses of Rotarix^TM (p > 0.05), and one had received only one dose (Table I). Regarding the gender of the children, five of the eight RVA-positive children were male and three were female. The RVA-positive samples were obtained from children at CMEIs in five districts. Therefore, it is unlikely that the virus spread from child to child inside the CMEIs; instead, the samples reflect the viral circulation in Goiânia during 2008.

RVA infection was only detected during August and September of 2008, which is statistically significant (p < 0.001) (Table II). Previous studies conducted in the Central West Region have reported a clear RVA season (dry season April-August) (Cardoso et al. 2003, Andreasi et al. 2007). However, 2008 was somewhat atypical in that the dry season lasted until September (data from National Institute of Meteorology of Goiânia). Therefore, our results also indicate that the circulation of RVA in the Central West Region occurs predominantly during the dry season of the year (Cardoso et al. 2003).

Viral genotyping showed that two of the eight RVA-positive samples could not be P-typed, whereas all positive samples could be G-typed; seven samples were characterised as G2 and one was characterised as G8. Five of the samples were genotype G2P[4] and one was G8P[4]. We acknowledge the small number of RVA-positive samples; however, a predominance of RVA genotype G2P[4] was observed as compared to the other genotypes, which suggests that the vaccine may not induce a protective response against this genotype. A predominance of the G2P[4] genotype has also been observed in different parts of Brazil, such as Aracajú (Gurgel et al. 2007), Recife (Nakagomi et al. 2008), Uberaba (Domingues et al. 2008), Rio de Janeiro (Carvalho-Costa et al. 2009), São Paulo (Sáfadi et al. 2010), Salvador and Goiânia (Munford et al. 2009). Nevertheless, the changing circulation pattern of RVA throughout the year should not be disregarded. Many countries where the vaccine was not implemented, such as El Salvador, Guatemala and Honduras (Patel et al. 2008), have also reported the emergence of the G2P[4] genotype.

This is the first study conducted in Goiânia to evaluate the occurrence of gastroenteric virus among children in day-care. It is also the first study on RVA prevalence in children of this region after the introduction of Rotarix^TM by the National Immunization Program in 2006. Despite the small sample number, our findings suggest a decrease in RVA circulation among children under five years of age and the predominance of G2P[4] genotype, which could be associated with the introduction of the Rotarix^TM vaccine in children in Brazil.

Further studies on RVA circulation are being conducted to better evaluate the possible impact of vaccination on viral prevalence and the emergence of genotypes in the region.

References

1. Andreasi MSA, Batista SMF, Tozetti IA, Ozaki CO, Nogueira MM, Fiaccadori FS, Borges AMT, Santos RAT, Cardoso DDP 2007. Rotavírus A em crianças de até três anos de idade, hospitalizadas com gastroenterite aguda em Campo Grande, estado do Mato Grosso do Sul. Rev Soc Bras Med Trop 40: 411-414.
2. Boschi-Pinto C, Velebit L, Shibuya K 2008. Estimating child mortality due to diarrhoea in developing countries. Bull World Health Organ 86: 710-717.
3. Bresee JS, Glass RI, Ivanoff BN, Gentsch JR 1999. Current status and future priorities for rotavirus vaccine development, evaluation and implementation in developing countries. Vaccine 17: 2207-2222.
4. Cardoso DDP, Soares CMA, Souza MB, Azevedo MS, Martins RMB, Queiróz DA, Brito WM, Munford V, Rácz ML 2003. Epidemiological features of rotavirus infection in Goiânia, Goiás, Brazil, from 1986 to 2000. Mem Inst Oswaldo Cruz 98: 25-29.
5. Carvalho-Costa FA, Araújo IT, Santos de Assis RM, Fialho AM, de Assis Martins CM, Bóia MN, Leite JP 2009. Rotavirus genotype distribution after vaccine introduction, Rio de Janeiro, Brazil. Emerg Infect Dis 15: 95-97.
6. Correia JB, Patel MM, Nakagomi O, Montenegro FM, Germano EM, Correia NB, Cuevas LE, Parashar UD, Cunliffe NA, Nakagomi T 2010. Effectiveness of monovalent rotavirus vaccine (Rotarix) against severe diarrhea caused by serotypically unrelated G2P[4] strains in Brazil. J Infect Dis 201: 363-369.
7. Costa PSS, Grisi SJFE, Cardoso DDP, Fiaccadori FS, Souza MBLD, Santos RAT 2004. Manifestações clínicas e epidemiológicas das infecções por rotavírus A. Pediatria (Sao Paulo) 26: 151-154.
8. Das BK, Gentsch JR, Cicirello HG, Woods PA, Gupta A, Ramachandran M, Kumar R, Bhan MK, Glass RI 1994. Characterization of rotavirus strains from newborns in New Delhi, India. J Clin Microbiol 32: 1820-1822.
9. De Vos B, Delem A, Hardt K, Bock HL, Meurice F, Innis B 2006. A short report on clinical evaluation of RIX4414: highlights of world-wide development. Vaccine 24: 3777-3778.
10. Domingues AL, Morais AT, Cruz RL, Moreira LP, Gouvêa VS 2008. Rotavirus-associated infantile diarrhea in Uberaba, Minas Gerais, on the wake of the Brazilian vaccination program. J Clin Virol 43: 298-301.
11. Gentsch JR, Glass RI, Woods P, Gouvea V, Gorziglia M, Flores J, Das BK, Bhan MK 1992. Identification of group A rotavirus gene 4 types by polymerase chain reaction. J Clin Microbiol 30: 1365-1373.
12. Gentsch JR, Parashar UD, Glass RI 2009. Impact of rotavirus vaccination: the importance of monitoring strains. Future Microbiol 4: 1231-1234.
13. Glass RI, Parashar UD, Bresee JS, Turcios R, Fischer TK, Widdowson MA, Jiang B, Gentsch JR 2006. Rotavirus vaccines: current prospects and future challenges. Lancet 368: 323-332.
14. Gouvea V, Santos N, Timenetsky MCST 1994. Identification of bovine and porcine rotavirus G types by PCR. J Clin Microbiol 32: 1338-1340.
15. Gurgel RQ, Cuevas LE, Vieira SC, Barros VC 2007. Predominance of rotavirus P[4]G2 in a vaccinated population, Brazil. Emerg Infect Dis 13: 1571-1573.
16. Lanzieri TM, Costa I, Shafi FA, Cunha MH, Ortega-Barria E, Linhares A, Colindres RE 2010. Trends in hospitalizations from all-cause gastroenteritis in children younger than 5 years of age in Brazil before and after human rotavirus vaccine introduction, 1998-2007. Pediatr Infect Dis J 29: 673-675.
17. Leite JPG, Carvalho-Costa FA, Linhares AC 2008. Group A rotavirus genotypes and the ongoing Brazilian experience - A Review. Mem Inst Oswaldo Cruz 103: 745-753.
18. Midthun K, Kapikian AZ 1996. Rotavirus vaccines: an overview. Clin Microbiol Rev 9: 423-434.
19. Munford V, Gilio AE, de Souza EC, Cardoso DM, Cardoso DDP, Borges AMT, Costa PSS, Melgaço IAM, Rosa H, Carvalho PRA, Goldani MZ, Moreira Jr ED, Santana C, El Khoury, Ikedo F, Rácz ML 2009. Rotavirus gastroenteritis in children in 4 Regions in Brazil: a hospital-based surveillance study. J Infect Dis 200: S106-113.
20. Nakagomi T, Correia JB, Nakagomi O, Montenegro FM, Cuevas LE, Cunliffe NA, Hart CA 2008. Norovirus infection among children with acute gastroenteritis in Recife, Brazil: disease severity is comparable to rotavirus gastroenteritis. Arch Virol 153: 957-960.
21. Parashar UD, Glass R 2009. Rotavirus vaccines - early success, remaining questions. N Engl J Med 360: 1063-1065.
22. Patel MM, De Oliveira LH, Bispo AM, Gentsch J, Parashar UD 2008. Rotavirus P[4]G2 in a vaccinated population, Brazil. Emerg Infect Dis 14: 863-865.
23. Pereira HG, Leite JP, Azeredo RS, Farias V, Sutmoller F 1983. An atypical rotavirus detected in a child with gastroenteritis in Rio de Janeiro, Brasil. Mem Inst Oswaldo Cruz 78: 245-250.
24. Sáfadi MAP, Berezin EN, Munford V, Almeida FJ, Moraes JC, Pinheiro CF, Racz ML 2010. Hospital-based surveillance to evaluate the impact of rotavirus vaccination in São Paulo, Brazil. Pediatr Infect Dis J 29: 1019-1022.
25. Vesikari T, Isolauri E, d'Hondt E, Delen A, Andre FE, Zissis G 1984. Protection of infants against rotavirus diarrhoea by RIT 4237 attenuated bovine rotavirus strain vaccine. Lancet 1: 977-981.
26. Vesikari T, Kavonen A, Pauustinen L, Szakal ED, Zeng SQ, Delen A, DeVos B 2006. A short report on highlights of world-wide development of RIX4414: an European experience. Vaccine 24: 3779.
27. WHO - World Health Organization [Media Centre] 2009. Global use of rotavirus vaccines recommended [cited 5 June 2009]. Available from: www.who.int/mediacentre/news/releases/2009/rotavirus_vaccines_20090605/en/.
28. Zeller M, Rahman M, Heylen E, Coster SD, De Vos S, Arijs I, Novo L, Verstappen N, Ranst MV, Matthijnssens J 2010. Rotavirus incidence and genotype distribution before and after national rotavirus vaccine introduction in Belgium. Vaccine 28: 7507-7513.

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