TY - JOUR
T1 - Diversity of rotavirus strains circulating in children under five years of age who presented with acute gastroenteritis before and after rotavirus vaccine introduction, University Teaching Hospital, Lusaka, Zambia, 2008–2015
AU - Simwaka, J. C.
AU - Mpabalwani, Evans M.
AU - Seheri, Mapaseka
AU - Peenze, Ina
AU - Monze, Mwaka
AU - Matapo, Belem
AU - Parashar, Umesh D.
AU - Mufunda, Jacob
AU - Mphahlele, Jeffrey M.
AU - Tate, Jacqueline E.
AU - Mwenda, Jason M.
N1 - Funding Information:
We would like to thank the enabling environment and guidance provided by the Ministry of Health, the University Teaching Hospital management for conducting rotavirus surveillance. We also thank the parents of the patients for allowing us to stool samples and collect data, Further we thank WHO and CDC for continued financial and technical support during the surveillance. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention or the World Health Organization (WHO).
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/11/12
Y1 - 2018/11/12
N2 - Background: Following the introduction of rotavirus vaccine into the routine immunization schedule, the burden of rotavirus disease has significantly reduced in Zambia. Although rotavirus vaccines appear to confer good cross-protection against both vaccine and non-vaccine strains, concerns about strain replacement following vaccine implementation remain. We describe the diversity of the circulating rotavirus strains before and after the Rotarix® vaccine was introduced in Lusaka from January 2012. Methods: Under five children were enrolled through active surveillance at University Teaching Hospital using a standardized WHO case investigation form. Stool samples were collected from children who presented with ≥3 loose stool in 24 h and were admitted to the hospital for acute gastroenteritis as a primary illness. Samples were tested for group A rotavirus antigen enzyme-linked immunosorbent assay. Randomly selected rotavirus positive samples were analysed by reverse transcription polymerase chain reaction for G and P genotyping and and Nucleotide sequencing was used to confirm some mixed infections. Results: A total of 4150 cases were enrolled and stool samples were collected from 4066 (98%) children between 2008 and 2011, before the vaccine was introduced. Rotavirus antigen was detected in 1561/4066 (38%). After vaccine introduction (2012 to 2015), 3168 cases were enrolled, 3092 (98%) samples were collected, and 977/3092 (32%) were positive for rotavirus. The most common G and P genotype combinations before vaccine introduction were G1P[8] (49%) in 2008; G12P[6] (24%) and G9P[8] (22%) in 2009; mixed rotavirus infections (32%) and G9P[8] (20%) in 2010, and G1P[6] (46%), G9P[6] (16%) and mixed infections (20%) in 2011. The predominant strains after vaccine introduction were G1P[8] (25%), G2P[4] (28%) and G2P[6] (23%) in 2012; G2P[4] (36%) and G2P[6] (44%) in 2013; G1P[8] (43%), G2P[4] (9%), and G2P[6] (24%) in 2014, while G2P[4] (54%) and G2P[6] (20%) continued to circulate in 2015. Conclusion: These continual changes in the predominant strains suggest natural secular variation in circulating rotavirus strains post-vaccine introduction. These findings highlight the need for ongoing surveillance to continue monitoring how vaccine use affects strain evolution over a longer period of time and assess any normal seasonal fluctuations of the rotavirus strains.
AB - Background: Following the introduction of rotavirus vaccine into the routine immunization schedule, the burden of rotavirus disease has significantly reduced in Zambia. Although rotavirus vaccines appear to confer good cross-protection against both vaccine and non-vaccine strains, concerns about strain replacement following vaccine implementation remain. We describe the diversity of the circulating rotavirus strains before and after the Rotarix® vaccine was introduced in Lusaka from January 2012. Methods: Under five children were enrolled through active surveillance at University Teaching Hospital using a standardized WHO case investigation form. Stool samples were collected from children who presented with ≥3 loose stool in 24 h and were admitted to the hospital for acute gastroenteritis as a primary illness. Samples were tested for group A rotavirus antigen enzyme-linked immunosorbent assay. Randomly selected rotavirus positive samples were analysed by reverse transcription polymerase chain reaction for G and P genotyping and and Nucleotide sequencing was used to confirm some mixed infections. Results: A total of 4150 cases were enrolled and stool samples were collected from 4066 (98%) children between 2008 and 2011, before the vaccine was introduced. Rotavirus antigen was detected in 1561/4066 (38%). After vaccine introduction (2012 to 2015), 3168 cases were enrolled, 3092 (98%) samples were collected, and 977/3092 (32%) were positive for rotavirus. The most common G and P genotype combinations before vaccine introduction were G1P[8] (49%) in 2008; G12P[6] (24%) and G9P[8] (22%) in 2009; mixed rotavirus infections (32%) and G9P[8] (20%) in 2010, and G1P[6] (46%), G9P[6] (16%) and mixed infections (20%) in 2011. The predominant strains after vaccine introduction were G1P[8] (25%), G2P[4] (28%) and G2P[6] (23%) in 2012; G2P[4] (36%) and G2P[6] (44%) in 2013; G1P[8] (43%), G2P[4] (9%), and G2P[6] (24%) in 2014, while G2P[4] (54%) and G2P[6] (20%) continued to circulate in 2015. Conclusion: These continual changes in the predominant strains suggest natural secular variation in circulating rotavirus strains post-vaccine introduction. These findings highlight the need for ongoing surveillance to continue monitoring how vaccine use affects strain evolution over a longer period of time and assess any normal seasonal fluctuations of the rotavirus strains.
UR - http://www.scopus.com/inward/record.url?scp=85048350276&partnerID=8YFLogxK
U2 - 10.1016/j.vaccine.2018.03.035
DO - 10.1016/j.vaccine.2018.03.035
M3 - Article
C2 - 29907481
AN - SCOPUS:85048350276
SN - 0264-410X
VL - 36
SP - 7243
EP - 7247
JO - Vaccine
JF - Vaccine
IS - 47
ER -