Assessing clonal correlation of epidemic Vibrio cholerae isolates during 2011 in 16 provinces of Iran

Secondary Use of Laboratory Data: Potentialities and Limitations

Clinical databases have been developed in recent years especially during the course of all medical concerns including laboratory results. The information produced by the diagnostic laboratories have great impact on health care system with various secondary uses. These uses are sometimes as publishing new extracted information of laboratory reports which have been widely applied in the scientific journals. Nowadays, some large scale or national databases are also formed from the integration of these data from smaller centers in the field of human health in many countries. These databases are beneficial for different stakeholders who may need this information. Unfortunately, reviewing some of these uses has indicated lots of errors in quality control, test validity, uniformity and so on. More importantly, some of the diagnostic procedures have been applied in the clinical diagnostic laboratories without even preliminary clinical evaluation studies. Therefore, any taken conclusion from these analyzed data may not be reliable. This use requires checking the several specifications that have been notified in this study. Current review also intends to show how the correct information should be to extract for the scientific reports, or integrated in large scale databases.

In silico characteristics for re-emerging possibility of Vibrio cholerae genotypes in Iran

Epidemic cholera has been registered several times within recent years in Iran. The dominant genotype was Ogawa until 2011, but this gradually changed to Inaba. However, in 2015, the re-appearance of a previous Ogawa genotype was detected by the Iranian CDC. This raised worries because no evidence was found for its origin abroad. The aim of the present study was to identify clearly the source of this outbreak. Pulsed field gel electrophoresis (PFGE) was used to compare the recently detected Vibrio cholerae strains with those isolated from 2011 to 2015. We selected one strain per PFGE pattern, and compared the distinct patterns. BioNumerics software was applied, which enables interpretation of phenotypic and genotypic differences. In total, we studied 33 V. cholerae Ogawa strains. Analysis showed that strains could be discriminated on the basis of annual clusters but with a similarity of more than 80%. The highest homology was observed among those isolated each year from 2011 to 2014. In contrast, strains isolated in 2015 also exhibited close correlation with each other but were located in distinct clusters. The analysis also proved genetic variations among some strains. All 2015 strains showed differences with regard to previous genotypes despite some similarities. The new genotypes were probably imported into Iran from neighbouring countries such as Iraq by travellers or contaminated food sources since 2015. However, more investigations are required to identify the exact source of the 2015 outbreak.

The Enduring Health Challenges of Afghan Immigrants and Refugees in Iran: A Systematic Review

INTRODUCTION

Iran is the third country in the world with the highest number of registered refugees with the majority coming from Afghanistan. They suffer major health and social risks yet their health status has never been comprehensively determined.

METHODS

This systematic review of the literature highlights major disparities among documented immigrants in health access, communicable and non-communicable diseases and the increasingly desperate plight of undocumented immigrants.

RESULTS

Comparing with Iranian population, the findings suggest the higher prevalence of most diseases among Afghan immigrants and refugees. This highlights the importance of increasing the migrants' access to health services from both public health as well as human rights perspectives.

DISCUSSION

Although the Iranian government has taken new initiatives to overcome this challenge, certain issues have still remained unaddressed. Potential solutions to improve this process are discussed.

Multi-locus variable number tandem repeat analysis of Vibrio cholerae isolates from 2012 to 2013 cholera outbreaks in Iran

Cholera remains to be an international threat, with high rates of illness and death. In 2012 and 2013, two cholera outbreak happened in Iran, affecting lots of people. Vibrio cholerae O1 was confirmed as the etiological agent. Source identification and controlling the spread of the cholera disease are two critical approaches in cholera outbreaks. In this study, thirty V. cholerae O1 isolates were selected and has been evaluated for antimicrobial resistant as well as molecular typing by multilocus variable-number tandem-repeat analysis (MLVA) method. Twenty-nine (97%) isolates were sero-grouped as El Tor (one isolate was classical) and 100% were related to Inaba serotype. All of the isolates were susceptible to ciprofloxacin, chloramphenicol, ampicillin and gentamicin. On the other hand, 60% of the isolates were MDR (resistant to 3 or more classes). There were three resistance patterns. The most prevalent pattern was resistance to streptomycin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline (ST-SXT-E-T) which was seen in 50% of isolates. Using MLVA method 14 MLVA types were identified. MLVA type 2 (5-7-7-16-15) accounted for 43% of isolates. Isolates with the same genotype often did not have the same antibiogram. Overall, the data indicate that the Iranian V. cholerae were MDR and clonaly related. Furthermore, the results of this study shows that MLVA can be used as useful method for V. cholerae genotyping in epidemiological investigations.

A cholera outbreak in Alborz Province, Iran: a matched case-control study

OBJECTIVES

A total of 229 confirmed cholera cases were reported in Alborz Province during an outbreak that lasted from June 2011 to August 2011. This study aimed to identify potential sources of transmission in order to determine suitable interventions in similar outbreaks. In other words, the lessons learned from this retrospective study can be utilized to manage future similar outbreaks.

METHODS

An age-matched and sex-matched case-control study was conducted during the outbreak. For each case, two control subjects were selected from the neighborhood. A case of cholera was defined as a bacteriologically confirmed case with signs and symptoms of cholera. This study was conducted from June 14, 2011 through August 23, 2011. The data were analyzed by calculating odds ratios (ORs) using the logistic regression method.

RESULTS

In this outbreak, 229 confirmed cholera cases were diagnosed. The following risk factors were found to be associated with cholera: consumption of unrefrigerated leftover food (OR, 3.05; 95% confidence interval [CI], 1.72 to 5.41), consumption of vegetables and fruits in the previous three days (OR, 2.75; 95% CI, 1.95 to 3.89), and a history of traveling in the previous five days (OR, 5.31; 95% CI, 2.21 to 9.72).

CONCLUSIONS

Consumption of vegetables and fruits has remained an unresolved risk factor in cholera outbreaks in Iran in recent years. In order to reduce the risk of cholera, sanitary standards for fruits and vegetables should be observed at all points from production to consumption, the population should be educated regarding hygienic food storage during outbreaks, and sanitary standards should be maintained when traveling during cholera outbreaks.

Clonal Dissemination of a Single Vibrio cholerae O1 Biotype El Tor Strain in Sistan-Baluchestan Province of Iran During 2013

Although much is known about the mechanisms affecting cholera spread, cholera outbreaks occur annually in Iran. The aim of this study was to characterize and assess the clonal correlation of strains obtained from an outbreak in 2013 in Iran. Thirty-three strains of Vibrio cholerae were isolated from stool sample of patients majority of them belonged to Afghan nationality. PCR and sequencing analysis was performed to characterize virulence and resistance associates genes and cassettes. Clonality of isolates was assessed by Pulsed-field gel electrophoresis (PFGE) method. The ctx, zot, and tcp genes were present in 100 % of isolates. The wbeT gene was absent in all V. cholerae outbreak isolates, integrity of which is essential for Ogawa phenotype. This correlates with Inaba phenotype of all isolates under study. Sequencing of the ctxB (+) strains revealed that all isolates (El Tor strains) possessed the ctxB sequence of classical biotype allele known as El Tor variant strains. No class 1 or 2 integrons were detected among the isolates which indicate that in spite of high rate of resistance, integrons do not play an important role in V. cholerae resistance. All isolates were chloramphenicol sensitive all of which showed resistance to tetracycline and harbored the tetB resistance gene. PFGE analysis showed identical pulsotypes indicative of clonal dissemination of a single V. cholerae strain among the patients under study. Clonal cholera outbreak in boarder cities is alarming due to fear of import and spread of V. cholerae strains from out of the country which may lead to more spreading epidemics.