Impact and Effectiveness of Monovalent Rotavirus Vaccine in Armenian Children.

BACKGROUND: The Republic of Armenia was 1 of the 2 earliest countries in the Newly Independent States to introduce rotavirus vaccine into its national immunization program to reduce the burden of rotavirus disease (documented to cause 38% of acute gastroenteritis hospitalizations [AGE] among children aged <5 years). In November 2012, RV1 (Rotarix) was introduced for Armenian infants at ages 6 and 12 weeks. METHODS: The established active surveillance system at 2 hospitals in the capital, Yerevan, whereby children aged <5 years hospitalized for AGE have stool sample tested for rotavirus antigen, was used to assess trends in rotavirus hospitalizations. Immunization records on children enrolled after vaccine introduction were obtained from clinics, and vaccine effectiveness (VE) was estimated using children with AGE who test negative for rotavirus as controls for the rotavirus-positive cases. RESULTS: Among infants, rotavirus hospitalizations were reduced by 48% within the first year after introduction, and by ≥75% in years 2 and 3 following introduction. Reductions of ≥30% in other young children too old to have been vaccinated suggest additional benefit through indirect protection; overall in year 3, rotavirus hospitalizations were reduced by 69% among children aged <5 years. The overall VE of 2 RV1 doses in protecting against rotavirus hospitalization (any severity) was 62% (95% confidence interval [CI], 36%-77%) among children aged 6-23 months; 68% (95% CI, 24%-86%) among those aged 6-11 months, and 60% (95% CI, 20%-80%) in children aged 12-23 months. Against more severe rotavirus disease, VE was 79% (95% CI, 55%-90%) and similarly high in both age groups. CONCLUSIONS: RV1 is effective in young Armenian children and substantially reduced rotavirus hospitalizations shortly after introduction.

Novel Methicillin-Resistant Staphylococcus aureus CC8 Clone Identified in a Hospital Setting in Armenia.

Whole-genome sequencing (WGS) of methicillin-resistant Staphylococcus aureus (MRSA) has been sparse in low- and middle-income countries, therefore, its population structure is unknown for many regions. We conducted a pilot surveillance of MRSA in the maternity ward of a teaching hospital in Armenia, to characterize the genotypes of circulating MRSA clones. In total, 10 MRSA isolates from a hospital environment (n = 4) and patients (n = 6) were recovered between March and May 2015 and April and May 2016, respectively. WGS analysis showed that the isolates belonged to two clonal complexes (CCs): CC8 (n = 8) and CC30 (n = 2). MRSA CC30 isolates carried staphylococcal cassette chromosome mec (SCCmec) type IVa, whereas MRSA CC8 revealed a type-VT-related SCCmec, which contained a CRISPR/Cas array and showed a high similarity to SCCmec found in coagulase-negative staphylococci. All but one MRSA CC8 isolates carried a plasmid identical to the pSK67 and four also carried a pathogenicity island similar to SaPI5. Phylogenetic analysis showed that the MRSA CC8 isolates formed a monophyletic cluster, which emerged around 1995 and was distinct from representatives of globally-distributed MRSA CC8 lineages. WGS characterization of MRSA in countries with no previous S. aureus genomic surveillance can therefore reveal an unrecognized diversity of MRSA lineages.