Balto and Togo during the cold winter of Alaska (1925): the two canine heroes in the fight against diphtheria.

In recent years, diphtheria has re-emerged in areas with inadequate vaccination coverage, and Europe has not been spared with several cases among migrants. Diphtheria is a potentially fatal infection caused mainly by toxigenic strains of Corynebacterium diphtheriae. Due to the high mortality rate, especially among young children, the fight against diphtheria is considered one of the first conquests of immunization. In the history of medicine, there is a unique case of an unconventional response to a diphtheria outbreak in which sled dogs were used to overcome the supply difficulties of diphtheria antitoxin. The mass media followed the medical response to the outbreak and raised audience awareness of public health issues. The facts of Nome, Alaska, in 1925 can serve as a catalyst to rethink conventional responses to diphtheria outbreaks in low-income countries today and promote mass media awareness of public health importance.

Recurrent diphtheria outbreaks in Nigeria: A review of the underlying factors and remedies.

INTRODUCTION: The introduction of the diphtheria-tetanus-pertussis (DTP) vaccine into childhood immunization programs resulted in its widespread elimination in high-income countries. However, Nigeria is currently experiencing an outbreak. The primary cause of diphtheria outbreaks and its high mortality rates in Nigeria was waning herd immunity due to low DTP coverage and a lack of diphtheria antitoxin (DAT), respectively. However, the underlying causes of Nigeria's low DTP coverage and DAT supply remain unknown. METHOD: Relevant studies and reports included in our review were obtained by a search through Google Scholar, PubMed, and organization websites using the terms "Diphtheria-Pertussis-Tetanus vaccine OR Diphtheria antitoxin and Nigeria OR Diphtheria Outbreak." All articles considering diphtheria outbreaks, DTP vaccine, and DAT supply in Nigeria were considered without time restriction due to the paucity of data. We used the narrative synthesis approach to critically appraise, analyze, and draw inferences from the selected articles. RESULTS: The main causes of low DTP coverage are insufficient supply, an inefficient cold chain system, and low uptake due to poor health literacy and negative sociocultural and religious beliefs, whereas the key barriers to DAT availability are insufficient production by pharmaceutical industries because of low demand and priority. CONCLUSION: The underlying causes of Nigeria's low DTP coverage and DAT supply are multifactorial. Both short-term and long-term measures are needed to control this outbreak and prevent future occurrences.

Collaborative study for the calibration of a replacement International Standard for Diphtheria Antitoxin Equine.

The International Standard for Diphtheria Antitoxin Equine is essential for the standardisation of assays used to determine the potency of therapeutic diphtheria antitoxin products produced from equine serum. This paper describes the production and characterization of the 2nd International Standard for Diphtheria Antitoxin Equine and its calibration in International Units. Calibration was performed by toxin neutralization test in vivo and in vitro (Vero cell assay), and potency was expressed relative to the 1st International Standard to ensure continuity of the International Unit. The candidate standard (NIBSC product code 18/180) was assigned a unitage of 57 IU/ampoule based on results from 14 laboratories in 9 different countries and was established by the World Health Organisation Expert Committee on Biological Standardization in 2021.

A case of fulminant respiratory diphtheria in a 24-year-old Afghan refugee in Austria in May 2022: a case report.

PURPOSE: Raising awareness of respiratory diphtheria and for the importance of early antitoxin administration. METHODS: Report of a case of fulminant, imported respiratory diphtheria in an otherwise healthy 24-year-old Afghan refugee in Austria in May 2022. RESULT: This was the first case of respiratory diphtheria in Austria since 1993. Diphtheria antitoxin was administered at an already progressed disease stage. This delay contributed to a fulminant disease course with multiorgan failure and death. CONCLUSION: In high-income countries with low case numbers, awareness of respiratory diphtheria and for the importance of early antitoxin administration must be raised.

Seroprevalence of IgG antibodies against diphtheria antitoxin among migrant workers in Singapore, 2016-2019.

BACKGROUND: Since the last local case of diphtheria in 1992, there had not been any case in Singapore until an autochthonous case was reported in 2017. This fatal diphtheria case of a migrant worker raised concerns about the potential re-emergence of locally transmitted toxigenic diphtheria in Singapore. We conducted a seroprevalence study to assess the immunity levels to diphtheria among migrant workers in Singapore. METHODS: Residual sera from migrant workers who hailed from Bangladesh, China, India, Indonesia, Malaysia, Myanmar and the Philippines were tested for anti-diphtheria toxoid immunoglobulin G (IgG) antibodies. These migrant workers previously participated in a survey between 2016 and 2019 and had provided blood samples as part of the survey procedure. RESULTS: A total of 2176 migrant workers were included in the study. Their overall mean age was 27.1 years (standard deviation 5.0), range was 20-43 years. The proportion having at least basic protection against diphtheria (antitoxin titres ≥ 0.01 IU/ml) ranged from 77.9% (95% confidence interval [CI] 72.8 - 82.3%) among migrant workers from Bangladesh to 96.7% (95% CI 92.5 - 98.6%) in those hailing from Malaysia. The proportion showing full protection (antitoxin titres ≥ 0.10 IU/ml) ranged from 10.1% (95% CI 6.5 - 15.4%) in Chinese workers to 23.0% (95% CI 17.1 - 30.3%) in Malaysian workers. There were no significant differences in the proportion with at least basic protection across birth cohorts, except for those from Bangladesh where the seroprevalence was significantly lower in younger migrant workers born after 1989. CONCLUSIONS: The proportions having at least basic protection against diphtheria in migrant workers from five out of seven Asian countries (India, Indonesia, Malaysia, Myanmar and the Philippines) were higher than 85%, the threshold for diphtheria herd immunity. Seroprevalence surveys should be conducted periodically to assess the level of immunity against diphtheria and other vaccine preventable diseases in migrant worker population, so that appropriate interventions such as booster vaccination can be implemented proactively to prevent sporadic outbreaks.

Diphtheria Antitoxin and Tales of Mercy in Northern Health Care.

This article examines the history of diphtheria in the Yukon and the Mackenzie district of the Northwest Territories in the first half of the 20th century. This analysis follows the traces of this now largely forgotten disease and its treatment to illuminate the constraints - intrinsic and constructed - on the provision of health care commensurate with the expectations and needs of northern Indigenous peoples. While diphtheria was never the most serious infectious disease, nor a major cause of death compared with tuberculosis or influenza at this time, examining its history offers significant insight into the creation of medical and public health infrastructures in Canada's northern territories, and the ways in which those infrastructures served, and failed to serve, different northern populations.

Niveles de antitoxina tetánica y diftérica relacionadas con el alelo HLA-B27 en pacientes cubanos con uveítis anterior no infecciosa / Tetanus and diphtheria antitoxin levels related to the HLA-B27 allele in Cuban patients with non-infectious anterior uveitis

La uveítis anterior no infecciosa es una enfermedad inflamatoria del ojo que afecta al tracto uveal y que puede causar ceguera total y otras discapacidades visuales. Esta enfermedad se ubica en el espectro de enfermedades autoinmunes y autoinflamatorias. Se han descrito respuestas no adecuadas a la vacunación en enfermedades mediadas por el sistema inmune, por lo que se evaluaron los niveles de antitoxina tetánica y diftérica en pacientes cubanos con uveítis anterior no infecciosa, relacionada con el alelo HLA-B27. Se determinaron los niveles de antitoxina tetánica y diftérica mediante ELISA en 190 pacientes con uveítis anterior no infecciosa y controles supuestamente sanos. El 97,37 por ciento de los pacientes con uveítis mostraron niveles de protección de antitoxina tetánica mayor o igual a 0,1 UI/mL, similar a lo observado en los controles sanos (98,95 por ciento) (p=0,4385). Las proporciones de pacientes con uveítis anterior no infecciosa y sus controles en los diferentes niveles de protección de antitoxina tetánica fueron similares (p>0,05), al igual que los títulos medios geométricos (p=0,2907). En los pacientes con uveítis, de 65 años o más, se detectó una mayor proporción de individuos con títulos protectores de larga duración (>1,0 UI/mL) de antitoxina diftérica (p=0,0065). En los pacientes con uveítis no se observó asociación entre la presencia del alelo HLA-B27 y la respuesta de anticuerpos frente al toxoide tetánico (p=0,6196) y diftérico (p=0,1917). El 37,9 por ciento de los pacientes con uveítis y el 42 por ciento de los controles, presentaron títulos no protectores (<0,1 UI/mL) de antitoxina diftérica (0,1148). La mayoría de los pacientes con uveítis anterior no infecciosa y los controles supuestamente sanos presentaron protección frente al toxoide tetánico; mientras que, en los pacientes con uveítis, así como en los controles supuestamente sanos, con edad igual o más de 18 años, se debe reevaluar incluir refuerzos con toxoide diftérico para alcanzar mayores niveles de protección frente a la difteria(AU)

Non-infectious anterior uveitis is an inflammatory disease of the eye that affects the uveal tract and can cause total blindness and other visual disabilities. Autoimmune and inflammatory diseases are associated with qualitative and quantitative alterations in the immune response; therefore, the levels of tetanus and diphtheria antitoxin related to the HLA-B27 allele were evaluated in Cuban patients with non-infectious anterior uveitis. Tetanus and diphtheria antitoxin levels were determined by ELISA in 190 patients with non-infectious anterior uveitis and healthy control individuals. 97.37 percent of patients with uveitis showed protective tetanus antitoxin levels greater than and equal to 0.1 IU/mL as well as healthy controls (98.95 percent) (p=0.4385). The proportions of patients with non-infectious anterior uveitis and presumably healthy controls in the different levels of protective tetanus antitoxin were similar (p>0.05) at all levels of protection, as were the geometric mean titers for this antitoxin (p=0.2907). Patients with uveitis aged 65 years or older had a higher proportion of individuals with long-term reliable protective titers (>1.0 IU/mL) of diphtheria antitoxin (p=0.0065). In uveitis patients, no association was observed between the presence of the HLA-B27 allele and the antibody response against tetanus toxoid (p=0.6196) and diphtheria (p=0.1917). Similarly, 37.9 percent of patients with uveitis and 42 percent of their controls had non-protective titers (<0.1 IU/mL) of diphtheria antitoxin (0.1148). Most patients with anterior uveitis and control subjects were protected against tetanus (p>0.05), while in patients with uveitis and supposedly healthy controls, aged 18 years or older, the administration of booster doses with diphtheria toxoid should be reevaluated to achieve higher levels of protection against diphtheria(AU)