Seroprevalence of anti-rubella and anti-measles antibodies in women at the verge of marriage in Iran.

BACKGROUND: Measles and rubella as two highly contagious eruptive diseases are on the agenda to be eliminated in Iran by 2020. To evaluate the seroimmunity of the future mothers against rubella and measles, a nationwide serosurvey was implemented in 10 provinces, selected at random from 31 provinces in the country. METHODS: using a multistage sampling method, 1600 participants were interviewed and blood sampled in 40 'Pre-marriage Consultation Centers' across 40 districts. Using ELISA method, the sera were tested for anti-rubella and anti-measles IgG antibodies in the National Reference Laboratory for Measles and Rubella, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. RESULTS: Of the 1600 initial participants, the sera of 1573 participants were tested for rubella and 1569 for measles. The total seroprevalence of anti-rubella and anti-measles antibodies were 90.6% (95%CI: 89.1 to 92.0%) and 80.7% (95%CI: 78.7 to 82.6%) respectively. After 14 years, the effect of the immunization campaign of 2003 against rubella and measles on the age group of 5 to 25 years, was still apparent, i.e., there was a sharp difference between the seroprevalence of antibody (against both measles and rubella) of those who at the time of the present study were above 18 years with the younger age cohorts. For both diseases, higher seroprevalence of antibodies was detected in women above 18 years old. CONCLUSION: Implementation of a Supplemental Immunization activity or revision of the national immunization schedule to add a third dose of measles and rubella containing vaccine during adolescence are/might be considered as possible options for bridging the gap in the seroimmunity of the younger age groups.

The spatial analysis of annual measles incidence and transition threat assessment in Iran in 2016.

Background: During the past years, due to the increase in immunization coverage and promotion of surveillance data, the incidence of measles decreased. This study aimed to determine the measles incidence risk, to conduct spatial mapping of annual measles incidence, and to assess the transition threat in different districts of Iran. Methods: A historical cohort study with retrospective data was conducted. The measles surveillance data containing 14 294 cases suspected of having measles in Iran were analyzed during 2014-2016. WHO Measles Programmatic Risk Assessment Tool was applied to calculate and map the incidence of measles in each district, to determine the annual incidence rate, and to conduct spatial threat assessment risk. Threat assessment was measured based on factors influencing the exposure and transmission of measles virus in the population. The annual measles incidence rate and spatial mapping of incidence in each Iranian district was conducted by Measles Programmatic Risk Assessment Tool. Data were analyzed by descriptive statistics in Excel 2013 and Arc GIS 10.3. Results: Of 14 294 suspected cases, 0.6% (CI 95%: 0.599-0.619) were identified as clinically compatible measles, 0.280 (CI 95%: 0.275-0.284) as confirmed rubella, 0.52% (CI 95%: 0.516-0.533) as epi-linked measles, 4.6% (CI 95%: 0.450-0.464) as lab-confirmed measles, and 94% (CI 95%: 93.93-94.11) were discarded. The annual incidence rate in cases per 100 000 populations increased from 0.0726, (CI 95%; 0.0714-0.0738) in 2014 to 0.1154 (CI 95%; 0.1135-0.1173) in 2016, and the 3-year incidence rate during the study period was 1.032 (CI 95%; 1.017-1.047) and the annual average was 0.3442 (CI 95%; 0.3387-0.3496). Conclusion: The average annual incidence rate of measles in Iran was low, but after a 11-fold increase in the number of measles cases in 2015, the number of measles cases decreased to more than 7-times in 2016. However, maintaning a high immunization coverage of measles and timely vaccination can be effective in reaching the goal of measles elimination.

Sero-epidemiological evaluation of rubella immunity among pre-marriage women in Iran.

Few studies have addressed the seroepidemiological profile of rubella among a representative population of young adult women. This study aims to determine the immunity and susceptibility rate against rubella in a representative population of women in reproductive age in Iran through serological evaluation. This cross-sectional study was conducted in 2012 on 804 pre-marriage women in Iran. Multi-stage random sampling was used for choosing study sample. Serologic test were used to assess subjects' immunity to rubella and their titers of IgG antibody against rubella with ELISA method was measured. In total, 98.4% (95% CI: 97.5% -99.2%) of study participants were immune against rubella. Five women (0.6%) were in borderline category and 1% (8 women) was susceptible to rubella. The proportion of immune people in low and high incidence regions was 99.3% (95% CI: 97.8-99.9%), and 97.5% (95% CI: 96.4-98.5%), respectively (P = 0.05). Our data indicated that level of immunity to rubella in women of reproductive age in Iran is satisfactory. This finding indicates the achievement of Iran to the goal of high level of serum immunity against rubella among young women.

Monitoring of Surveillance Quality Indicators of Measles in Iranian Districts: Analysis of Measles Surveillance System 2014-2016.

BACKGROUND: The elimination target for measles as an acute and contagious disease in Eastern Mediterranean Region (EMR) and Iran is planned by high-quality surveillance. We aimed to monitor the surveillance quality indicators of measles by in all districts of Iran during 2014-16. STUDY DESIGN: A cross-sectional study. METHODS: Four quality surveillance indicators of measles including non measles discarded rate, percent of suspected cases with adequate investigation, percent of adequate blood specimen collection and percent with timely availability of laboratory results were assessed in Iran. Surveillance data of measles were extracted from the measles surveillance system and the risk point score for each district was calculated based on WHO Risk Assessment Tool by a function of four indicators. RESULTS: Overall, 14312 suspected cases and 322 districts were assessed and the risk points of measles' quality surveillance showed that 92.8% of Iranian districts were categorized as low risk, 2.8% medium risk, 0.62% high risk and 3.73% very high-risk category. The appropriate non measles discarded rate indicator was 87.3%. The percent of suspected cases with adequate investigation (more than 2 per 100000 people) was 87.9%. Moreover, the average of percent adequate blood specimen collection and percent with timely availability of laboratory results was 85.16% and 85.71%, respectively in all Iranian districts. CONCLUSIONS: The surveillance quality indicators in Iran were good and higher than the WHO plans. Increasing the percentage of non-measles discarded rate could improve the poor quality in high risk and very high-risk districts.

Documentation of Measles Elimination in Iran: Evidences from 2012 to 2014.

BACKGROUND: Documentation of achieving the goal of measles elimination to justify to international organizations including the WHO is a priority for public health authorities. This study aimed to address the status of Iran in the achievement of the measles elimination goal from 2012-2014. STUDY DESIGN: A descriptive study METHODS: Data on the measles outbreaks were extracted from the national notifiable measles surveillance system in Iran from 2012 to 2014. The required documents regarding the achievement of measles elimination, including Effective Reproduction Number (R) and the distribution of outbreak size, was addressed. The R was calculated using the proportion of imported cases as 1 - P, where P is equal to the proportion of cases that were imported. The distribution of the measles outbreaks size was described using descriptive statistics to show their magnitudes. The proportion of large outbreaks with more than 10 cases was considered as a proxy of the R value. RESULTS: The total number of measles cases was 232 cases (including 186 outbreak related cases) in 2012 and 142 cases in 2014, including108 outbreak related cases. The distribution of the measles outbreak size of occurred outbreaks from that period indicated that there were 37 outbreaks with three or more than three cases. The R value in 2012 was 0.87 and the corresponding value for 2014 was 0.76. CONCLUSIONS: According to the magnitude of effective reproduction number and distribution of outbreaks' size, measles has been eliminated in Iran. However, it is necessary to consider the potential endemic activity of measles because of no authorized immigration.

Successful control and impending elimination of measles in the Islamic Republic of Iran.

Measles is still one of the most common infectious killers of children in the world, especially in developing countries. In Iran, during the prevaccine era, 150,000-500,000 cases of measles were reported annually, with a death rate of 10%-15%. After the establishment of Expanded Program on Immunization program in 1984, vaccination rates for the first and second doses of measles vaccine increased to >90% by the mid-1990s, and the number of measles cases decreased to 2652 in 1996. In response to increased numbers of cases in older age groups during 1996-2002, a nationwide measles-rubella vaccination campaign was conducted in 2003, and 33,100,000 persons (99%) aged 5-25 years were vaccinated. During 2004-2009, 221 laboratory-confirmed measles cases (<1 case per million population) were detected, primarily in rural areas and among migrant groups who traveled to or came from high-incidence countries. High routine immunization coverage, low disease incidence, and surveillance system data suggest that interruption of endemic virus transmission might have already been achieved in Iran, but challenges remain and continued efforts are needed to sustain this accomplishment.