Environmental Surveillance of Poliovirus and Non-polio Enteroviruses in Iran, 2017-2023: First Report of Imported Wild Poliovirus Type 1 Since 2000.

In Iran, which is at high risk of the Wild Poliovirus (WPV) and Vaccine-Derived Poliovirus (VDPV) importation due to its neighborhood with two polio endemic countries, Pakistan and Afghanistan, Environmental Surveillance (ES) was established in November 2017. Sistan-Balouchestan province was chosen for the ES due to its vicinity with Pakistan and Afghanistan. Five sewage collection sites in 4 cities (Zahedan, Zabol, Chabahar and Konarak) were selected in the high-risk areas. Since the establishment of ES in November 2017 till the end of 2023, 364 sewage specimens were collected and analyzed. The ES detected polioviruses which have the highest significance for polio eradication program, that is, Wild Poliovirus type 1 (WPV1) and Poliovirus type 2 (PV2). In April and May 2019, three of 364 (0.8%) sewage specimens from Konarak were positive for imported WPV1. According to phylogenetic analysis, they were highly related to WPV1 circulating in Karachi (Sindh province) in Pakistan. PV2 was also detected in 5.7% (21/364) of the sewage specimens, most of which proved to be imported from the neighboring countries. Of 21 isolated PV2s, 7 were VDPV2, of which 5 proved to be imported from the neighboring countries as there was VDPV2 circulating in Pakistan at the time of sampling, and 2 were ambiguous VDPVs (aVDPV) with unknown source. According to the findings of this study, as long as WPV1 and VDPV2 outbreaks are detected in Iran's neighboring countries, there is a definite need for continuation and expansion of the environmental surveillance.

COVID-19 Vaccine Intention Among Iranian Health Workers: Application of the HBM Model.

The study aimed to determine the application of the health belief model (HBM) in the acceptance of COVID-19 vaccination among health workers in 2021. The cross-sectional study was conducted on 3600 health workers from February to March 2021. Data was collected using a researcher-made questionnaire that included the intention to receive vaccines based on the health belief model constructs. Data were analyzed using descriptive statistics indicators, Chi-square, ANOVA test, and logistic regression model at a 95% confidence level. More than 62% of the participants intended to receive the vaccine. The odds of intention to receive the vaccine among people who worked in the health center and did not have a history of hospitalization due to COVID-19 disease were 1.50 and 2.10 units more than the others. Intention to receive the vaccine in individuals with high perceived sensitivity was 1.10 units. Furthermore, in terms of perceived benefits, self-efficacy, and cue-to-action constructs were 1.15, 1.34, and 1.65 units respectively. The rate of vaccine acceptance among Iranian health care workers was relatively good and the constructs of HBM in predicting the rate of intention to receive the vaccine had good applicability.

Multicenter Study of Rotavirus Infection, Diversity of Circulating Genotypes and Clinical Outcomes in Children ≤5 Years Old in Iran.

BACKGROUND: To determine the epidemiology of rotavirus group A (RVA) infection in symptomatic children, and analyze genotype diversity in association with clinical characteristics, geographical and seasonal changes. METHODS: The stool samples of symptomatic children 5≥ years old were collected from 5 different hospitals during December 2020 and March 2022. Rotavirus stool antigen test was done and G and P genotypes of the positive samples were determined. Associations of the infection and genotype diversity with demographical and clinical data were assessed by statistical methods. RESULTS: RVA infection was detected in 32.1% (300/934) of the patients (Ranges between 28.4% and 47.4%). An inverse association with age was detected, where the highest frequency was measured in children ≤12 months of age (175/482, 36.3%). The infection was more frequent during winter (124/284, 43.7%) and spring (64/187, 34.2%). Children who were exclusively fed with breast milk showed a lower rate of infection (72/251, 28.6%). Among the 46 characterized genotypes (17 single- and 29 mixed-genotype infections), G1P[8] and G9P[4] were more frequently detected in children <36 (67/234, 28.63%) and 36-60 (7/24, 29.16%) months of age children, respectively. A seasonal diversity in the circulating genotypes was detected in different cities. Children with G1P[8], G1P[6], and mixed-genotype infection experienced a shorter duration of hospitalization, and a higher frequency of nausea and severe diarrhea, respectively. CONCLUSIONS: In this study high frequency of RVA infection was detected in symptomatic children in Iran. Moreover, genotype diversity according to geographic area, seasons, age groups, and clinical features of disease was detected.

The Psychometric Properties of Intention to Receive the COVID-19 Vaccine Scale Based on the Health Belief Model.

Acceptance of the SARS-CoV-2) COVID-19( vaccine is a very important factor to keep health workers safe. The study aimed to evaluate the psychometric properties of intention to receive the COVID-19 vaccine using a health belief model among health workers in Iran The study was a tools design study that was conducted in the period from February to March 2020, Iran Questionnaire items were designed using text review. The sampling method was multi-stage. Data were analyzed using descriptive statistics, confirmatory and exploratory factor analysis at a 95% confidence level using SPSS software version 16. The designed questionnaire had an appropriate content validity and internal consistency. Also, the exploratory factor analysis showed that a 5-factor structure was extracted and confirmatory factor analyses revealed that the conceptual five-factor structure of the measure had good fit indices. Reliability was evaluated using internal consistency. Cronbach Alpha coefficient was .82 and the intra-class correlation coefficient (ICC) was .9. It can be concluded that the instrument designed in the preliminary stage of psychometrics properties had good validity and reliability indicators. Also, the constructs of the health belief model well explain the determinants of the intention to receive the COVID-19 vaccine at the individual level.

Effectiveness of different vaccine platforms in reducing mortality and length of ICU stay in severe and critical cases of COVID-19 in the Omicron variant era: A national cohort study in Iran.

Various severe acute respiratory syndrome coronavirus 2 vaccines with different platforms have been administered worldwide; however, their effectiveness in critical cases of COVID-19 has remained a concern. In this national cohort study, 24 016 intensive care unit (ICU) coronavirus disease-2019 (COVID-19) admissions were included from January to April 2022. The mortality and length of ICU stay were compared between the vaccinated and unvaccinated patients. A total of 9428 (39.25%) patients were unvaccinated, and 14 588 (60.75%) patients had received at least one dose of the vaccine. Compared with the unvaccinated, the first, second, and third doses of vaccine resulted in 8%, 20%, and 33% lower risk of ICU mortality in the adjusted model, with risk ratio (RR): 0.92, 95% confidence interval (CI): 0.84-1.001, RR: 0.80, 95% CI: 0.77-0.83, and RR: 0.67, 95% CI: 0.64-0.71, respectively. The mean survival time was significantly shorter in the unvaccinated versus the fully vaccinated patients (hazard ratio [HR]: 0.84, 95% CI: 0.80-0.88); p < 0.001). All vaccine platforms successfully decreased the hazard of ICU death compared with the unvaccinated group. The duration of ICU stay was significantly shorter in the fully vaccinated than in unvaccinated group (MD, -0.62, 95% CI: -0.82 to -0.42; p < 0.001). Since COVID-19 vaccination in all doses and platforms has been able to reduce the risk of mortality and length of ICU-stay, universal vaccination is recommended based on vaccine availability.

Risk Communication in Early Containment of COVID-19 Pandemic in Iran: Implementation of the World Health Organization Strategic Preparedness and Response Plan (WHO-SPRP).

Background: Health systems must have functional and efficient preparedness and response plans to manage pandemics. Moreover, it is essential to adjust to changing circumstances and the dynamic character of pandemics. The World Health Organization (WHO) introduced the Strategic Preparedness and Response Plan (SPRP), emphasizing 144 measures across 10 pillars, helping governments prepare and respond to the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to determine how the Iranian health system, based on the WHO-SPRP, addresses strategic preparedness and response plan in the COVID-19 pandemic at the national level. Methods: The WHO-SPRP was adopted and translated into Persian by 2 bilingual natives. The chief of the health office requested that authorized officers complete the SPRP. Then, a meeting was held by officers of related units involved in COVID-19 management to address the SPRP at regional and national levels. Results: Our findings suggest that up to August 2020, effective risk communication and community engagement were not fully established. Our response plan lacked evidence-based information and educational messaging to consistently shape public opinion and impression of a respiratory pandemic. Conclusion: The Iranian health care system and services were almost able to address the SPRP and perform the major indicators that the WHO had proposed. However, special attention should be paid to risk communication and community engagement to empower informed decision-making by individuals and communities.

Vaccine hesitancy from the parent perspectives: protocol for a qualitative study in Iran.

INTRODUCTION: WHO declared vaccine hesitancy as a global public health threat in 2019. Since even a slight reduction in vaccine coverage rates can lead to a decrease in herd immunity, it is imperative to explore the underlying factors affecting vaccine hesitancy. This qualitative study protocol aims to explore determinant factors that influence vaccine hesitancy in Iran from the parent's perspective. METHODS AND ANALYSIS: Descriptive-Interpretive Qualitative research will be conducted to gain an insight into vaccine hesitancy in the west of Tehran province in Iran. Participants in the study will be recruited from vaccine-hesitant parents of children under 5 years' old who will be recognised as being hesitant to extract from the national health information system. The semistructured interviews and in-depth questions will be performed both face-to-face in an open space such as a park near their homes and via video call because of the COVID-19 pandemic and social distancing. Interviews will be conducted by a trained qualitative person. Transcribed data will be analysed through thematic analysis. ETHICS AND DISSEMINATION: Ethics approval was obtained from the research ethics committee at the Iran University of Medical Sciences (Approval ID #IR.IUMS.REC.1399.273). The results of the study are expected to be presented by the end of 2022 year. A variety of dissemination methods will be employed to communicate research findings, including presentations at conferences and peer-reviewed publications.

Determinants of COVID-19 vaccine acceptance in healthcare workers in Iran: National Survey.

BACKGROUND AND AIM: It seems that acceptance of COVID-19 vaccination is the most effective way to tackle the COVID-19 pandemic now. Health care workers (HCWs) are one of the most important groups who are at risk for COVID-19 infection. This study aimed to assess the COVID-19 vaccine acceptance among HCWs in Iran and its determinants. METHODS: A cross-sectional survey was carried out among 3600 HCWs in Iran. Data were collected through a self-administered questionnaire by a trained team from February to March 2021. Multi-stage cluster sampling method was used for selecting respondents of the study. Multivariate logistic regression analysis was used to determine the key factors of COVID-19 vaccine acceptance among participants. P-value < 0.05 was considered statistically significant. RESULTS: Out of the 3536 respondents, 2191 (62.1%) intended to uptake the COVID-19 vaccine. Only about 10 percent of respondents said they did not trust any vaccine (domestic or foreign). Willing to accept a COVID-19 vaccine was relatively high among males, doctors, and those who had a history of hospitalization due to COVID-19 infection. The multivariate regression analysis showed respondents who were 40-50 years (aOR: 1.56; 95% CI: 1.47-1.66), had a history of COVID-19 infection (aOR: 0.85; 95% CI: 0.83-0.88), and hospitalized due to COVID-19 infection (aOR: 2.18; 95% CI: 1.97-2.39), were significantly associated with vaccine acceptance (p < 0.05). CONCLUSION: Our study showed moderate acceptance of COVID-19 vaccination in the HCWs in the Islamic Republic of Iran. The most important factor in the acceptance of the COVID-19 vaccine by the health staff is having a history of hospitalization. Further training and justification of health personnel is needed to increase the acceptance of COVID 19 vaccine.

A Nationwide Study on the Seroprevalence of Measles, Mumps, and Rubella in Iranian Children and Adolescents.

Background: Assessing the prevalence of infections, which are preventable by vaccination, is crucial to monitor the vaccination program efficacy, and it can demonstrate the gaps in population immunity. The current study attempted to assess the specific Immunoglobulin (IgG) antibody against measles, mumps, and rubella (MMR) in Iranian children and adolescents, years after their vaccination. Methods: This cross-sectional study was conducted in Iran. Serum samples of 2100 students, aged 7-18 years, included in a national health survey, were tested for MMR antibodies by ELISA assay. Multistage random cluster sampling was used to select subjects from 30 provinces in Iran. Results: Overall, 1871, 1718, and 1678 serums were tested for measles, mumps, and rubella antibodies, respectively. The prevalence of positive test was 1231 (65.8%) for measles, 1327 (77.2%) for mumps and 1344 (80.1%) for rubella. Conclusion: Despite high vaccination coverage in Iran, IgG antibody against measles, mumps, and rubella was not detected in a considerable proportion of children and adolescents aged 7-18 years. In case of contacts with residents of other countries, where measles or rubella have not yet been eliminated, it may create problems for Iranian children.

Immunization coverage of children aged 24-35 months in the Islamic Republic of Iran: a national cluster coverage survey.

Background: Although vaccination coverage against a disease is not exactly the same as community immunity against that disease, it is undoubtedly directly related to it and provides an estimate of the coherence and efficacy of community health infrastructure. Aims: To evaluate the vaccination coverage of children throughout the Islamic Republic of Iran in 2019. Methods: This was a cross-sectional study. A probability proportional to size cluster sampling method was used and the vaccination data of 8682 children aged 24-35 months were collected in the form of 1447 clusters, each comprising six participants. Only valid data, including vaccination card or electronic health files, were used. The results were reported in the form of descriptive tables. Results: Overall, 97.82% of Iranian participants (8068 of 8248) and 90.32% of non-Iranian participants (392 of 434) had received all essential childhood vaccination by the time of interview. In total, 93.02% of all participants had presentable vaccination cards, and the immunization history of 535 (6.16%) children was retrieved using their electronic health files. The dropout rate between receiving pentavalent vaccine 1 and pentavalent vaccine 3 was 0.01%. In 29 provinces, vaccination coverage was ≥ 95%. In the other two provinces, the figure was 93.30%. Conclusion: Immunization coverage of children aged 24-35 months fully complied with eradication/elimination goals of vaccine-preventable diseases. In 2019, measles and rubella elimination was certified in the Islamic Republic of Iran. However, non-Iranian residents with immunization coverage < 95% constitute a high-risk group for possible outbreaks.

Molecular typing of enteroviruses and parechoviruses in acute flaccid paralysis patients in Iran in 2019.

Enteroviruses (EVs) and parechoviruses (PeVs) are among the viral pathogens that can cause acute flaccid paralysis (AFP). There is not sufficient information about direct detection of EVs and PeVs in AFP patients in Iran. The aim of this study was to conduct a one-year study for direct detection and molecular typing of EVs and PeVs from stool samples of AFP patients in Iran. One hundred stool samples from polio-negative AFP patients who were referred to the Iran National Polio Laboratory were randomly chosen and analyzed during 2019. A one-step TaqMan probe-based real-time RT-PCR assay targeting the 5'-untranslated region (5' -UTR) was used to screen for EVs and PeVs. All positive samples were genotyped by direct sequencing, targeting the VP1 region of the genome. In total, twelve (12%) and four (4%) stool samples from polio-negative AFP children were positive for EVs and PeVs, respectively. Sequence analysis revealed the presence of echovirus 2 (E2), echovirus 13 (E13), echovirus 25 (E25), echovirus 30 (E30), coxsackievirus A2 (CVA2), coxsackievirus A9 (CVA9), coxsackievirus A16 (CVA16), human enterovirus A76 (HEV-A76), and human parechovirus 1 (HPeV1) in children with AFP-like symptoms. Phylogenetic analysis showed that E2 strains clustered together with the strains circulating in the Netherlands during 2014, whereas the PeV strains belonged to different lineages. This study demonstrates that different EV types are associated with AFP cases in Iran. However, the frequency of association of PeVs with AFP cases appears to be low.

Immunogenicity and Safety of Three WHO Prequalified (DTwP -HB-Hib) Pentavalent Combination Vaccines Administered As Per Iranian National Immunization Plan in Iranian Infants: A Randomized, Phase III Study.

BACKGROUND: The pentavalent vaccine Pentavac was officially introduced in the Iranian National Immunization Plan in November, 2014. OBJECTIVE: To compare the immunogenicity and safety of Pentavac vaccine (Serum Institute of India Ltd.) with two other pentavalent vaccines available in Iran, i.e., Pentabio (PT Bio Farma (Persero)) and Shan 5 (Shantha Biotechnics Ltd.). DESIGN: Randomized, phase III study. PARTICIPANTS: 900 infants attending the study sites to receive the vaccine at 2, 4, and 6 months of age. INTERVENTION: Infants were randomly assigned to one of the Pentavac, Pentabio, and Shan 5 vaccine groups. OUTCOMES: The antibody titers were measured against five antigens, diphtheria, tetanus, pertussis, Haemophilus influenzae B, and hepatitis B before receiving the first dose and one month after the last dose. The adverse events following vaccination after each dose were recorded in the adverse events diary. RESULTS: All vaccines showed similar immunogenicity against four of the five antigens except pertussis. While vaccination with Shan 5 resulted in the highest immunogenicity against pertussis, Pentabio was significantly lower than the other two vaccines (P<0.001). The incidence of local adverse events significantly differed among the three vaccine brands (P<0.001), but the incidence of most of the evaluated systemic adverse events was similar (P>0.05). CONCLUSIONS: Pentavac and Shan 5 had similar immunogenicity, the former having better immunogenicity against pertussis than Pentabio. Pentavac and Pentabio had a comparable safety profile.

Epidemiology incidence and geographical distribution of Pertussis using GIS and its incidence prediction in Iran in 2021.

Background: Pertussis is a respiratory tract infection caused by Bordetella pertussis, which causes inflammation of the lungs and respiratory tract. The purpose of this study was to investigate the incidence and geographical distribution of pertussis using the geographic information system (GIS) and to predict its incidence in Iran in 2021. Methods: This was a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2009-2015. In the next step, the ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency. Therefore, the disease prediction map was drawn. using the Raster Calculator tool. Results: The results showed that the highest incidence of pertussis during 2009-2015 was in Zanjan, Qom, Mazandaran, and Qazvin provinces. The incidence of pertussis in Iran increased from 0.74 in 2009 to 1.53 in 2015. Based on the modeling results for Iran, Qom, Mazandaran, Tehran, Qazvin, and Zanjan provinces, with 76.76%, 73.69%, 66.32%, 30.94% and 24.18% of their areas (Km2), are at high risk for pertussis in the coming years, respectively. Conclusion: The incidence of the disease has been increasing in recent years, indicating the emergence of the disease in Iran. The modeling maps show that the Iranian provinces of Qom, Tehran, Zanjan, and Qazvin are at risk of the disease incidence in the coming years, indicating the need for planning, appropriate interventions and more precise implementation of the vaccination program against the disease.

Epidemiology incidence and geographical distribution of Meningitis using GIS and its incidence prediction in Iran in 2021.

Background: Meningitis is classified as a medical emergency where the identification and early treatment of bacterial meningitis can eliminate serious consequences, such as hearing loss, memory problems, learning disabilities, brain damage, seizures, and death. The purpose of this study was to investigate the incidence and geographical distribution of meningitis using Geographic Information system (GIS) and to predict its incidence in Iran in 2021. Methods: This was a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2010-2015. In the next step, ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency. Then, the disease prediction map was drawn using the Raster Calculator tool. Results: The results showed that the highest incidence of meningitis during 2010-2015 was in Qazvin, Qom, and Kurdistan provinces. The incidence of meningitis in Iran increased from 9.77 in 2010 to 10.33 in 2015. Based on the modeling results for Iran, Qom, Qazvin, Kurdistan, Hamadan, and Mazandaran provinces with 78.89%, 74.68%, 70.07%, 43.97%, and 22.93% of their areas (Km2) are at high risk for meningitis in the coming years, respectively. Conclusion: According to the results of this study, it can be concluded that Qom, Qazvin, Kurdistan, Hamedan, and Mazandaran provinces are at risk of the disease. Monitoring vaccination in high-risk groups can partially prevent the incidence of the disease in these areas.

Geographical distribution of Typhoid using Geographic Information System (GIS) during 2009-2014 in Iran.

Background: Salmonella induced infections remain one of the most important health problems worldwide. The purpose of this study is to investigate the incidence and geographical distribution of typhoid using GIS and to predict its incidence in Iran in 2021. Methods: This study is a descriptive analytical study. Information on pertussis was obtained from the Center for Communicable Diseases Control during 2009-2015. In the next step, ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency Therefore, using the Raster Calculator tool, the disease prediction map was drawn. Results: The results showed that the highest incidence of typhoid during 2009-2014 was in Kermanshah, Lorestan, Hamadan, Kurdistan, and Ilam provinces. The incidence of typhoid in Iran increased during 2009-2010. The annual incidence of typhoid decreased from 0.85 per 100,000 in 2010 to 0.5 in 2014. Based on the modeling results for Iran, Kermanshah, Lorestan, Kurdistan, Ilam and Hamadan provinces with 92.17%, 46.56%, 31.74%, 25.62% and 22.96% of their areas (Km2) are at high risk for typhoid in the coming years, respectively. Conclusion: Considering that the provinces of Kermanshah, Lorestan, Kurdistan, Ilam, and Hamadan are at risk of typhoid incidence in the coming years in Iran, and given that salmonella infections have a direct relationship with the individual's health status and individual's environmental health and socioeconomic status, improving the health status and disease control in carriers as well as improving the socio-economic status of the population living in these areas can prevent the disease in the years to come.

Seroprevalence of Bordetella pertussis among a nationally representative sample of Iranian pediatric population: The childhood and adolescence surveillance and prevention of adult noncommunicable disease-V study.

BACKGROUND: Pertussis is a vaccine-preventable respiratory infection and seroepidemiology of the infection could be a marker of the pertussis immunity in a population. In many countries, despite vaccination coverage, high prevalence of pertussis has been observed. The present study aimed to evaluate the immunoglobulin G (IgG) antibody against pertussis and the role of demographic and anthropometric variables on the immunity rate in the Iranian pediatric population to evaluate the impact of existing immunization program in order to envisage future vaccination strategies to prevent infection. METHODS: In a cross-sectional multi-centric study, 1593 samples of the students aged 7-18 years, who had been enrolled in a national survey (Childhood and Adolescence Surveillance and Prevention of Adult Noncommunicable disease-V), were randomly selected and tested for IgG antibody against Bordetella pertussis (BP) by enzyme-linked immunosorbent assay. The age, gender, education, residency, geographical region, and body mass index (BMI) were extracted from the questionnaires of the COSPIAN-Survey. Multiple logistic regression models were used to assess the associations between the variables with the IgG antibody against BP. Data were presented by odds ratio (OR), 95% confidence interval (95% CI) and P values (P): (OR [95% CI]; P). RESULTS: Subjects were consisted of 774 boys and 750 girls, with a mean (standard deviation) age of 12.39 (3.03) years. Overall, BP seroprevalence was 59.8%. There were higher BMI values in seronegative ones versus seropositive (18.62 ± 4.07 vs. 18.15 ± 3.94, P = 0.041, 95% CI = 0.23 [0.02-0.92]). However, the categorized BMI for age was not significantly associated with IgG levels (0.27 [0.25-0.29]; 0.27). BP seroprevalence was not significantly different between geographical regions (0.06 [0.05-0.07]; 0.06), genders (1.17 [0.93-1.47]; 0.18), area of residence (1.07 [0.82-1.4]; 0.61), and educational levels (0.94 [0.75-1.19]; 0.62). CONCLUSION: IgG antibody against pertussis was not detected in nearly 40% of the subjects who had history of vaccination against pertussis. It is recommended to monitor the incidence of pertussis in high-risk populations closely and administer a booster dose of acellular pertussis vaccine in adolescents.

Effect of Haemophilus influenzae Type b Vaccination on Nasopharyngeal Carriage Rate in Children, Tehran, 2019.

BACKGROUND: Haemophilus influenzae (H. influenzae) strains, which commonly reside as commensals within the human pharynx and can remain as an asymptomatic carrier, but become invasive leading to pneumonia, septic arthritis, or meningitis. The Pentavac (pentavalent vaccine, manufactured by India, SII (DTwP-HepB-Hib)) was introduced to the Iranian National Immunization Plan in November 2014. The aim of this study is to investigate H. influenzae type b (Hib) carrier rate among children under 6 years old in Tehran. METHODS: This cross-sectional study was performed on 902 children including vaccinated/unvaccinated in the age of 6 months to 6 years, in Tehran. Sampling was performed from July 2019 to September 2019. Nasopharyngeal samples were taken from children by sterile swab. The PCR method was used to extract DNA. Then, all H. influenzae isolates were initially confirmed by molecular tests. BexA was used to distinguish typeable H. influenzae strains from nontypeable Haemophilus influenzae (NTHi). RESULTS: A total of 902 children were enrolled in the study: 452 were female (51%). H. influenzae carriage rate was 267 (29%), of that 150 samples (16.6%) were typeable. The nasopharyngeal Hib carrier rate in the children was 2.6% (24/902). 262 cases did not receive Hib vaccine. Analysis in nonnursery's children aged 4 to 6 (unvaccinated) years showed that the lower educational level of father, mother, and family number correlated with increased odds of colonization of children with Hib. CONCLUSION: Our findings showed a significant decrease (60%) in the overall Hib nasopharyngeal carriage in healthy children under six years after 5 years after the start of Hib vaccination.

Epidemiological Profile of Meningitis following Pentavalent Vaccination in Iran: Impact of Vaccine Introduction.

Ensuring the effectiveness of the Haemophilus influenza type b (DTwP-Hib-HepB) vaccine in reducing meningitis is an essential approach in evaluating the effectiveness of the vaccine. The study aimed to address the epidemiology of meningitis following pentavalent vaccination in Iran. Data on meningitis patients from 21st March 2011 to 21st July 2018 were extracted from the National Notifiable Diseases Surveillance System. This information was divided into two equal periods before the pentavalent vaccine introduction (21st March 2011 to 17th November 2014) and after the introduction (18th November 2014 to 21st July 2018). The number of patients in the study period was 53,174 cases. More than 55% of patients were under 5 years old. Males (63.34%) were more than females (36.06%). The death rate was reduced to 2.1%; also, the proportion of confirmed cases caused by H. influenzae type b was 6.7% before the pentavalent vaccine introduction. The corresponding value following vaccine introduction equals to 3.6%. The proportion of children under five has decreased from 4.4% to 1.9%. This value indicates a 46.2% decrease in the meningitis of all ages and a 57% decrease in children under five dues to H. influenzae vaccination. The results of the study indicate the effectiveness of the vaccine due to changes in meningitis caused by H. influenzae type b after vaccination compared with no vaccination. Therefore, it is advisable to continue the full immunization coverage with the pentavalent vaccine.

Recombinant Production of a Novel Fusion Protein: Listeriolysin O Fragment Fused to S1 Subunit of Pertussis Toxin.

Background: Some resources have suggested that genetically inactivated pertussis toxoid (PTs) bear a more protective effect than chemically inactivated products. This study aimed to produce new version of PT, by cloning an inactive pertussis toxin S1 subunit (PTS1) in a fusion form with N-terminal half of the listeriolysin O (LLO) pore-forming toxin. Methods: Deposited pdb structure file of the PT was used to model an extra disulfide bond. Codon-optimized ORF of the PTS1 was used to make recombinant constructs of PTS1 and LLO-PTS1 in the pPSG-IBA35 vector. The recombinant PTS1 and LLO-PTS1 proteins were expressed in BL21 DE3 and SHuffle T7 strains of E. coli and purified by affinity chromatography. Cytotoxic effects of the recombinant proteins were examined in the MCF-7 cell line. Results: The purity of the products proved to be more than 85%, and the efficiency of the disulfide bond formation in SHuffle T7 strain was higher than BL21 DE3 strain. No cytotoxicity of the recombinant proteins was observed in MCF-7 cells. Soluble recombinant PTS1 and LLO-PTS1 proteins were produced in SHuffle T7 strain of E. coli with high efficiency of disulfide bonds formation. Conclusion: The LLO-PTS1 with corrected disulfide bonds was successfully expressed in E. coli SHuffle T7 strain. Due to the safety for human cells, this chimeric molecule can be an option to prevent pertussis disease if its immunostimulatory effects would be confirmed in the future.

Alarm Thresholds for Pertussis Outbreaks in Iran: National Data Analysis.

OBJECTIVES: The purpose of the current study was to determine the upper threshold number of cases for which pertussis infection would reach an outbreak level nationally in Iran. METHODS: Data on suspected cases of pertussis from the 25th February 2012 to the 23rd March 2018 from the Center for Disease Control and Prevention in Iran was used. The national upper threshold level was estimated using the exponentially weighted moving average (EWMA) method and the Poisson regression method. RESULTS: In total, 2,577 (33.6%) and 1,714 (22.3%) cases were reported in the Spring and Summer respectively. There were 1,417 (18.5%) and 1,971 (25.6%) cases reported in the Autumn and Winter, respectively. The overall upper threshold using the EWMA and the Poisson regression methods, was estimated as a daily occurrence of 8 (7.55) and 7.50 (4.48-11.06) suspected cases per 10,000,000 people, respectively. The daily seasonal thresholds estimated by the EWMA and the Poisson regression methods were 10, 7, 6, 8 cases and 10, 7, 7, 9 cases for the Spring, Summer, Autumn, and Winter, respectively. CONCLUSION: The overall and seasonal estimated thresholds by the 2 methods were similar. Therefore, the estimated thresholds of 6-10 cases in a day, per 10,000,000 people could be used to detect pertussis outbreaks and epidemics by health policymakers.