Congenital Rubella syndrome cases (based on WHO criteria) one decade after Measle and Rubella vaccination campaign in Tehran, Iran.
Abstract
Mohammad Vafaee-Shahi, Samileh Noorbakhsh, Leila Tahernia, Sarvenaz Ashouri, Aina Riahi
Background: Active CRS surveillance is recommended strongly even in country with full rubella vaccination.
Objective: Searching the CRS based on WHO criteria one decade after MR vaccination campaign (2003)
Methods: a prospective case control study carried out in a third referral educational hospital (Rasoul Akram hospital) in Tehran, IRAN during five years (2013 -2018). From 89 CRS suspected infants (according to WHO criteria); serum samples were tested for rubella-specific IgG and IgM by ELISA method. Selected samples (positive Rubella IgM) were tested for rubella RNA by reverse transcriptase–polymerase chain reaction (RT–PCR).
Findings: “Confirmed CRS” based on positive IgM was found in 5.6% (5/89) all were < 4 months old. Positive RT–PCR detected in 1.2 % (1/89) of “CRS suspected” infants.Except a good correlation between abnormal neurologic findings and positive IgM in “Confirmed CRS “cases, other clinical findings were not related to serologic tests. The “Compatible CRS” cases in the 31 patients who had primary negative IgM serology and did not have sufficient laboratory evidence to confirm CRS, but clinical symptoms favoured CRS.
Conclusion: Despite MR vaccination in Iran, after one decade “confirmed CRS” and “compatible CRS” were diagnosed in 5 and 31 from 89 CRS suspected cases. The incidence of “confirmed CRS” in every 100 CRS suspected infants (after campaign) is 5.6 %; and 31 CRS Compatible cases are so important. Without active CRS surveillance; mild infection such as IUGR, hearing loss,heart abnormalities, impaired vision, and mental retardation even in developed country might be missed.Fetal infection is persistent which impose additional costs on the country. Another mass vaccination in women and girls is needed. Also, the antirubella IgG testing before pregnancy in women who were not vaccinated; vaccination of women before marriage /preganacy should be obligatory in order to prevent the CRS.