Distinguishing between primary infection and reinfection with rubella vaccine virus by IgG avidity assay in pregnant women.

During the mass measles/rubella vaccination campaign in 2003 in Iran, many pregnant women were vaccinated mistakenly or became pregnant within 1 month of vaccination. To distinguish pregnant women who were affected by rubella vaccine as primary infection from those who had rubella reinfection from the vaccine, serum samples were collected 1-3 months after the campaign from 812 pregnant women. IgG avidity assay showed that 0.3% of the women had no rubella-specific IgG response; 14.4% had low-avidity anti-rubella IgG and were therefore not immune to rubella before vaccination; 85.3% had high-avidity anti-rubella IgG and were regarded as cases of reinfection.

Distinguishing between primary measles infection and vaccine failure reinfection by IgG avidity assay.

In this study in the Islamic Republic of Iran 365 measles cases were evaluated to distinguish between primary infection with measles and reinfection due to secondary vaccine failure. All cases previously confirmed by detection of specific IgM were tested for IgG avidity. A secondary immune response was seen in 18.4% of patients. All unvaccinated patients (16.7%) showed a primary immune response. Of 244 patients with documented vaccination, 75.8% showed a primary immune response and 24.2% showed a secondary immune response, thereby indicating a secondary vaccine failure. Almost all measles reinfections (99%) were seen in patients >10 years old, indicating that vaccination for 10-year-old children is recommended.

Prevalence of human papillomavirus in Mazandaran Province, Islamic Republic of Iran.

We report the prevalence of human papillomavirus (HPV) types in 100 cervical biopsy specimens in Mazandaran province. HPV DNA was detected in 78.6% of cervical carcinoma cases, 64.3% of dys/ metaplasia and 9% of normal cases. Significant correlation was found between the presence of HPV DNA and development of cervical carcinoma. HPV types 16 and 18 were detected in 60.6% of HPV-positive cervical carcinoma cases, whereas HPV31 and 33 were found in 21.2%, and HPV6 and 11 in 18.2%. Among HPV-positive dys/metaplasia cases, 55.6% were positive for HPV16 and 18, 22.3% for HPV6 and 11, and 11.1% for HPV31 and 33. Only HPV6 and 11 were detected in 4 (100%) normal biopsy specimens.

Molecular Epidemiology of Measles Virus before and after the 2003 Mass Vaccination Campaign for Measles/Rubella in Iran.

BACKGROUND: Molecular epidemiology of measles virus (MV) is important, not only to measure the success of measles vaccination programs but also to monitor the circulation and elimination of the virus worldwide. In this study, we compared MV obtained from patients before the 2003 mass vaccination MR campaign and viruses detected after 2003 until 2008 in Iran. METHODS: The nucleoprotein (N) gene of 29 MV strains circulating in Iran between 2002 and 2008 were amplified by RT-PCR and subjected to sequence and phylogenetic analysis. RESULTS: Molecular characterization of MV studied here revealed that although the outbreaks in Iran were associated with MV genotype D4, the isolated viruses clearly belonged to several different lineages. Maximum and minimum homology within the 29 Iranian strains in our study was100% and 94.9% within the carboxyl terminus of the N gene, respectively. Using ClustalX program, the alignment of Iranian MV sequences showed nine lineages. CONCLUSION: This study provides the usefulness of MV sequence analysis for the demonstration of local interruption of indigenous strain transmission as well as providing a valuable means for monitoring the elimination processes of MV control.

Prevalence of Rotavirus, Adenovirus, and Astrovirus Infections among Patients with Acute Gastroenteritis in, Northern Iran.

BACKGROUND: The aim of the study was to determine the incidence of non-bacterial acute gastroenteritis associated with diarrheal diseases in Mazandaran Province, northern Iran. METHODS: A total of 400 symptomatic cases from patients with acute gastroenteritis from Mazandaran Province in Iran were screened using EIA method for the presence of rotavirus, adenovirus and astrovirus during 2005-2006. Chi-square tests were used for testing relationships between different variables. RESULTS: Rotavirus, adenovirus and astrovirus were detected in 62%, 2.3%, and 3% of samples, respectively. The maximum rate of rotaviruses was detected in the <1-year-old age group, while minimum rate was found in the 10 years and older age group. Astrovirus and adenovirus were detected predominantly in the 2-5-year-old age group of children, with a prevalence of 8.3% and 3.5% respectively. All studied viral gastroenteritis peaked in the winter, and minimum rate were found in summer. CONCLUSION: Our statistical analyzes indicated that viral gastroenteritis, especially Rota-viral, had the highest number of occurrences in colder seasons notably in winter and more frequently were observed among younger children.

Comparative Detection of Measles Specific IgM Antibody in Serum and Saliva by an Antibody-Capture IgM Enzyme Immunoassay (EIA).

Laboratory diagnosis of acute measles is usually achieved by serology assays for measle-specific IgM antibody. For comparison of measle-specific IgM antibody in saliva and serum, 95 paired blood and saliva samples were collected 1-14 days after the onset of rash. The specimens were tested for specific IgM antibody by an IgM antibody-capture Enzyme Immunoassay (EIA). Measles IgM antibody was detected in 89 (93.7%) of serum samples and in 85(89.5%) of saliva specimens. Of the 6(6.3%) serum samples that were IgM antibody-negative, 2 (2.1%) of the paired saliva samples were IgM antibody-positive. The sensitivity and specificity of saliva testing compared with serum was 95.5% and 66.7% respectively. Positive predictive value (PPV) and negative predictive value (NPV) of saliva testing were 97.7% and 50.0% respectively and the accuracy of saliva testing was 93.7%. Our results indicate that saliva samples provided Enzyme Immunoassay results that were in good agreement with results from serum samples. Salivary IgM antibody detection is a suitable non-invasive method for diagnosing recent measles infections and epidemiological studies, especially in children.