Arnold Mukaratirwa1, Chipo Berejena2, Pasipanodya Nziramasanga2, Ismail Ticklay3, Archebald Gonah4, Kusum Nathoo3, Portia Manangazira5, Douglas Mangwanya6, Joan Marembo7, Jason M Mwenda8, Goitom Weldegebriel9, Mapaseka Seheri10, Jacqueline E Tate11, Catherine Yen11, Umesh Parashar11, Hilda Mujuru3. 1. Department of Medical Microbiology (University of Zimbabwe-College of Health Sciences), Zimbabwe; National Virology Reference Laboratory, Ministry of Health and Child Care, Zimbabwe. Electronic address: amukaratirwa@yahoo.com. 2. Department of Medical Microbiology (University of Zimbabwe-College of Health Sciences), Zimbabwe; National Virology Reference Laboratory, Ministry of Health and Child Care, Zimbabwe. 3. Department of Paediatrics and Child Health (University of Zimbabwe-College of Health Sciences), Zimbabwe. 4. Paediatric Ward, Chitungwiza Central Hospital, Zimbabwe. 5. Epidemiology and Disease Control Directorate, Ministry of Health and Child Care, Zimbabwe. 6. National Health Laboratory Services Directorate, Ministry of Health and Child Care, Zimbabwe. 7. Expanded programme on Immunization Unit, Ministry of Health and Child Care, Zimbabwe. 8. World Health Organization, Regional Office for Africa, Brazzaville, Congo. 9. World Health Organization, Inter-Country Support Team Office, Harare, Zimbabwe. 10. SAMRC Diarrhoeal Pathogens Research Unit, Department of Virology, Sefako Makgatho Health Sciences University, Pretoria, South Africa. 11. Centers for Disease Control and Prevention, Atlanta, GA, USA.
Abstract
BACKGROUND: Sentinel surveillance for diarrhoea is important to monitor changes in rotavirus epidemiological trends and circulating genotypes among children under 5 years before and after vaccine introduction. The Zimbabwe Ministry of Health and Child Care introduced rotavirus vaccine in national immunization program in May 2014. METHODS: Active hospital-based surveillance for diarrhoea was conducted at 3 sentinel sites from 2008 to 2016. Children aged less than 5 years, who presented with acute gastroenteritis as a primary illness and who were admitted to a hospital ward or treated at the emergency unit, were enrolled and had a stool specimen collected and tested for rotavirus by enzyme immunoassay (EIA). Genotyping of positive stools was performed using reverse-transcription polymerase chain reaction and genotyping assays. Pre-vaccine introduction, 10% of all positive stool specimens were genotyped and all adequate positive stools were genotyped post-vaccine introduction. RESULTS: During the pre-vaccine period, a total of 6491 acute gastroenteritis stools were collected, of which 3016 (46%) tested positive for rotavirus and 312 (10%) of the rotavirus positive stools were genotyped. During the post-vaccine period, a total of 3750 acute gastroenteritis stools were collected, of which 937 (25%) tested positive for rotavirus and 784 (84%) were genotyped. During the pre-vaccine introduction the most frequent genotype was G9P[8] (21%) followed by G2P[4] (12%), G1P[8] (6%), G2P[6] (5%), G12P[6] (4%), G9P[6] (3%) and G8P[4] (3%). G1P[8] (30%) was most dominant two years after vaccine introduction followed by G9P[6] (20%), G2P[4] (15%), G9P[8] (11%) and G1P[6] (4%). CONCLUSION: The decline in positivity rate is an indication of early vaccine impact. Diversity of circulating strains underscores the importance of continued monitoring and strain surveillance after vaccine introduction.
BACKGROUND: Sentinel surveillance for diarrhoea is important to monitor changes in rotavirus epidemiological trends and circulating genotypes among children under 5 years before and after vaccine introduction. The Zimbabwe Ministry of Health and Child Care introduced rotavirus vaccine in national immunization program in May 2014. METHODS: Active hospital-based surveillance for diarrhoea was conducted at 3 sentinel sites from 2008 to 2016. Children aged less than 5 years, who presented with acute gastroenteritis as a primary illness and who were admitted to a hospital ward or treated at the emergency unit, were enrolled and had a stool specimen collected and tested for rotavirus by enzyme immunoassay (EIA). Genotyping of positive stools was performed using reverse-transcription polymerase chain reaction and genotyping assays. Pre-vaccine introduction, 10% of all positive stool specimens were genotyped and all adequate positive stools were genotyped post-vaccine introduction. RESULTS: During the pre-vaccine period, a total of 6491 acute gastroenteritis stools were collected, of which 3016 (46%) tested positive for rotavirus and 312 (10%) of the rotavirus positive stools were genotyped. During the post-vaccine period, a total of 3750 acute gastroenteritis stools were collected, of which 937 (25%) tested positive for rotavirus and 784 (84%) were genotyped. During the pre-vaccine introduction the most frequent genotype was G9P[8] (21%) followed by G2P[4] (12%), G1P[8] (6%), G2P[6] (5%), G12P[6] (4%), G9P[6] (3%) and G8P[4] (3%). G1P[8] (30%) was most dominant two years after vaccine introduction followed by G9P[6] (20%), G2P[4] (15%), G9P[8] (11%) and G1P[6] (4%). CONCLUSION: The decline in positivity rate is an indication of early vaccine impact. Diversity of circulating strains underscores the importance of continued monitoring and strain surveillance after vaccine introduction.
Authors: Mike J Mwanga; Betty E Owor; John B Ochieng; Mwanajuma H Ngama; Billy Ogwel; Clayton Onyango; Jane Juma; Regina Njeru; Elijah Gicheru; Grieven P Otieno; Sammy Khagayi; Charles N Agoti; Godfrey M Bigogo; Richard Omore; O Yaw Addo; Seheri Mapaseka; Jacqueline E Tate; Umesh D Parashar; Elizabeth Hunsperger; Jennifer R Verani; Robert F Breiman; D James Nokes Journal: BMC Infect Dis Date: 2020-07-13 Impact factor: 3.090
Authors: Julia Simwaka; Mapaseka Seheri; Gina Mulundu; Patrick Kaonga; Jason M Mwenda; Roma Chilengi; Evans Mpabalwani; Sody Munsaka Journal: PLoS One Date: 2021-02-04 Impact factor: 3.240