Diarrheal Diseases Hospitalization in Yemen before and after Rotavirus Vaccination

Abstract

The study aims to assess the impact of rotavirus vaccine introduction on diarrheal diseases hospitalization and to identify the rotavirus genotypes most prevalent before and after vaccine introduction among children ≤ 5 years of age. Rotarix™ ® rotavirus vaccine is currently licensed for infants in Yemen and was introduced in 2012. The vaccination course consists of two doses. The first dose is administrated at 6 weeks of age and the second dose is completed by 10 weeks. Based on a longitudinal observational study, we assessed the impact of vaccination on rotavirus hospitalization before and after vaccination among children ≤ 5 years of age at the Yemeni-Swedish Hospital (YSH) in Taiz, Yemen. Prevaccination covered January 2009–July 2012 during which 2335 fecal samples were collected from children ≤ 5 years old. Postvaccination covered January 2013–December 2014 during which 1114 fecal samples were collected. Rotavirus was detected by Enzyme Linkage Immunosorbent Assay (ELISA). The incidence of rotavirus hospitalization decreased from 43.79% in 2009 to 10.54% in 2014. Hospitalization due to rotavirus diarrhea was reduced by 75.93%. Vaccine coverage increased from 23% in 2012 to 72% in 2014. Also, the results showed that the most predominant genotypes in prevaccination period were G2P[4] (55.0%), followed by G1P[8] (15.0%), while in postvaccination period G1P[8] (31%) was the predominant genotype, followed by G9P[8] (27.5%). In conclusion, rotavirus vaccination in Yemen resulted in sharp reduction in diarrheal hospitalization. A successful rotavirus vaccination program in Yemen will rely upon efficient vaccine delivery systems and sustained vaccine efficacy against diverse and evolving rotavirus strains.

Systematic review of the rotavirus infection burden in the WHO-EMRO region

“…96 In Yemen there was a steady decline in RV detection following vaccine introduction; the detection rates during the pre-vaccination period was 43.8% and 37.4% in 2009 and 2010, respectively, but declined during the post-vaccination period to 17.9% in 2013 and to 10.5% in 2014. 174 In the same study, a 75.9% reduction in hospitalization due to RV diarrhea was reported over five years (2009: 43.8%; 2014: 10.5%).…”

“…The results of these studies reflect that vaccination can markedly reduce RVGE disease burden, especially hospitalization due to diarrhea. 99,141,173,174 The WHO recommends sentinel surveillance before and after the introduction of vaccines to monitor vaccine impact. As financial resources may be limited in this region, regional governments should consider sharing their data with local laboratories or existing surveillance networks to help achieve this goal.…”

“…173 In another study in Yemen, the G1P [8] detection rate increased from 15% in the pre-vaccination period to 31% in the post-vaccination period and became the predominant genotype, followed by G9P [8] (27.5%). 174 In Iran, there was also an emergence of new RV genotypes over time, with G12P [8] being detected for the first time in 2016. 57 In Egypt, genotype G6P [14] was first reported in 2011.…”

Circulating rotavirus G and P strains post rotavirus vaccination in Eastern Mediterranean Region

“…Post-vaccination studies included one in Saudi Arabia, 18 2 in Yemen, 19,20 and 2 in Morocco. 21,22 Three of these 5 studies investigated the rotavirus strains as pre-and post-vaccination, 2 in Yemen 19,20 and one in Morocco.…”

“…21,22 Three of these 5 studies investigated the rotavirus strains as pre-and post-vaccination, 2 in Yemen 19,20 and one in Morocco. 21 The studies that investigated the pre-vaccination rotavirus strain prevalence in other EMR countries are from Bahrain, 8 Egypt, 23 Kuwait, 10 Iran, 7,[24][25][26][27] Iraq, 28,29 Jordan, 30 Saudi Arabia, 31,32 Libya, 33 Morocco, 21,34,35 Oman, 36,37 Yemen, 19,20,38,39 Tunisia, [40][41][42][43][44] and Pakistan. [45][46][47][48][49] We excluded other 8 countries of the EMR from this review )Sudan, Somalia, Afghanistan, Qatar, United Arab Emirates, Djibouti, Syria, and Lebanon( because there were no reports on circulating rotavirus strains among children under 5 years of age.…”