جستجوی مقالات مرتبط با کلیدواژه « diphtheria » در نشریات گروه « پزشکی »

 Diphtheria is an infectious disease caused by exotoxin-producing Corynebacterium diphteriae and was a leading cause of death in childhood during the prevaccine era. This toxin is usually localized in the upper respiratory tract and may cause fatal airway obstruction. Many have used orotracheal intubation to secure the airway in diphtheria cases. However, the efficacy of tracheostomy under sedation while maintaining spontaneous ventilation and analgesia using trans-tracheal and superficial cervical block remains to be elucidated.

 A 6-year-old presented to the emergency room with respiratory distress and was diagnosed with diphtheria. A thick membrane in the oropharyngeal area and chest X-ray showed infiltrations indicative of pneumonia. The patient successfully underwent emergency tracheostomy under sedation using a combination of sevoflurane and dexmedetomidine to achieve prompt sedation and trans-tracheal injection and bilateral superficial cervical block as analgesia for the intra-tracheal and the incision. The patient’s condition deteriorated the next day, and the bronchoscopy showed that the carina and main bronchus were covered by a pseudomembrane, obstructing the airway below the tracheostomy. The patient eventually died two days after admission.

 Dexmedetomidine has minimal impact on ventilatory function and anti-sialagogue properties, while sevoflurane has minimal effect on respiratory depression. This case presentation showed that a combination of sevoflurane and dexmedetomidine with spontaneous assisted ventilation could be helpful in tracheostomy procedures in pediatric patients with airway obstruction due to diphtheria, along with the use of trans-tracheal and superficial cervical block as the analgesia. This report also indicates that being vigilant in rapidly-progressing and fatal pediatric diphtheria cases is vital.

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Corynebacterium diphtheriae, C. ulcerans, andC. pseudotuberculosis are known as diphtheria-causing bacteria. Although diphtheria therapy is administered based on the clinical manifestations, some cases are mild and atypical. The immediate and accurate identification of diphtheria-causing bacteria is of paramount importance to prevent the spread of the disease and provide case management as early as possible. Unfortunately, conventional methods as the gold standard are time-consuming.

This study aimed to develop and implement a multiplex real-time PCR with the dtxR and tox genes as the target to identify three species of diphtheria-causing bacteria and screen their toxigenicity quickly and accurately.

The research sample encompassed seven reference strains, one synthetic DNA, 30 archived isolates, and 924 clinical specimens isolated from 311 diphtheria cases and 613 close contacts. The conventional methods as the gold standard and the established PCR assay were used to verify the results of multiplex real-time PCR developed in this study.

Themultiplex real-time PCR could identify seven reference strains, one synthetic DNA, and 30 archived isolates as accurately as the conventional methods and the established PCR. Similar to established PCR, the multiplex real-time PCR identified diphtheriacausing bacteria in 120 (38.6%) out of 311 and 12 (2%) out of 613 clinical specimens from diphtheria cases and close contacts, respectively. Meanwhile, the conventional methods identified diphtheria-causing bacteria in 79 (25.4%) out of 311 and three (0.5%) out of 613 clinical specimens.

The multiplex real-time PCR developed in this study can be used to identify three species of diphtheria-causing bacteria and screen their toxigenicity quickly and accurately. However, in this study, no diphtheria-causing bacteria other than C. diphtheriae was found in the clinical samples using the PCR or conventional methods. PCR is more sensitive than the conventional methods and can be used as an additional test in diphtheria laboratories.

The World Health Organization reported Indonesia as one of the countries with the most prevalent cases of diphtheria worldwide. The microbiological aspects of diphtheria-inducing bacteria are of great significance in tracing disease transmission and case management; however, clinical aspects are critical for updating clinical features and case management in the field, which may sometimes differ from theoretical foundations.

This study aimed to identify the microbiological and clinical aspects, including molecular typing and case-fatality rates, in diphtheria confirmed cases from Capital City of Indonesia, Jakarta and surrounding areas, in 2017.

The microbiological aspect of 40 diphtheria confirmed cases were obtained by re-identify diphtheria-inducing bacteria isolated from the samples, while the clinical aspects of the cases were obtained from the medical record and epidemiological data. Chi-squared test was used to examine the correlation between fatal cases and myocarditis and diphtheria antitoxin (DAT) administration delay. In this study, p < 0.05 was set as the significance level.

All 40 diphtheria confirmed cases were induced by toxigenic Corynebacterium diphtheriae with two biotypes, namely intermidius (60.0%) and mitis (40.0%). There are six sequence types of bacteria with two main sequence types, ST534 (46.4%) and ST377 (35.7%). The proportion of cases that had a fever and sore throat were 72.5% and 77.5%; however, the prevalence rates of the cases with pseudomembrane and bull neck were 100% and 47%, respectively. Most cases were administered a combination of penicillin or erythromycin with other antibiotics (40%), and 22.5% of the cases only received penicillin. Myocarditis was noticed in three fatal cases and their relationship was statistically significant (p=0.000). All five fatal cases (12.5% cases) were received DAT lately or have not received it yet.

The toxigenic C. diphtheriae with two biotypes (namely mitis and intermedius) and two main sequence types (i.e., ST534 and ST377) was the causative agent of diphtheria confirmed cases from Jakarta and surrounding area in 2017. It was also concluded that those fatal cases were correlated with myocarditis complications.

Indonesia is one of the five countries with the highest number of diphtheria cases worldwide. Diphtheria is caused by the toxigenic strains Corynebacterium diphtheriae, C. ulcerans, and C. pseudotuberculosis. The diphtheria-causing bacteria can be identified using conventional and molecular methods, including polymerase chain reaction (PCR) assay. We used the PCR assay as additional testing, because in island countries like Indonesia, specimen transport is a serious challenge to maintaining bacterial survival.

This study aimed to evaluate the PCR assay as additional testing to identify diphtheria-causing bacteria in the diphtheria laboratory.

In this cross-sectional study, a total of 178 pairs of the throat and nasal swabs from diphtheria suspected cases and close contacts were collected from seven provinces in Indonesia in 2016. All samples were directly identified by the conventional method and multiplex PCR assay. Statistical analysis was conducted using the 2 × 2 tables to determine the sensitivity and specificity of both methods, while the χ 2 test was used to examine the correlation between specimen examination delay and the differentiation of results. A P-value < 0.05 was considered as statistically significant.

Out of 178 examined samples, eight samples were identified as diphtheria-positive by both the conventional method and PCR assay, while nine samples were only detected by the PCR assay. All diphtheria-causing bacteria found in the positive samples were toxigenic C. diphtheriae. The diphtheria-causing bacteria were found in 27.6% of cases and 6.0% of close contacts using the PCR assay versus 13.8% of cases and 2.7% of close contacts using the conventional method. Statistical analysis showed that the PCR assay is about twice more sensitive than the conventional method. There was a significant correlation between the differentiation of results and > 72 hours’ specimen examination delay with a P-value of 0.04 (< 0.05).

The PCR assay is more sensitive than the conventional method to identify diphtheria-causing bacteria and may be applied as additional testing to increase the positivity rate of diphtheria-confirmed cases in Indonesia as an archipelago country where geographical factors and specimen transport are real obstacles.