[Tetanus vaccination--tolerance and prevention of side effects]

Tetanus prophylaxis in horses: guidelines for New Zealand and Australia based on a critical appraisal of the evidence

Horses are exquisitely sensitive to tetanus neurotoxin and are exposed to the risk of infection with Clostridium tetani throughout life. The vaccine against tetanus is highly effective at preventing disease, whereas tetanus in unvaccinated populations is associated with high mortality rates. Current guidelines in New Zealand and Australia for the available vaccine contain contradictions and limitations surrounding the optimal tetanus immunisation protocols for both adult horses and foals. This review critically evaluates the scientific literature on tetanus prophylaxis in horses within the context of equine practice and available products in New Zealand and Australia. The review was conducted by a panel of industry and specialist veterinarians to obtain agreement on nine equine tetanus prophylaxis guidelines for practising veterinarians. The primary protocol for tetanus toxoid (TT) immunisation consists of a three-dose series IM for all horses ≥ 6 months of age, and a four-dose series IM is proposed if commencing vaccination in foals between 3 and 6 months of age. Tetanus prophylaxis in foals < 3 months of age relies on passive immunity strategies. Following the completion of the primary protocol, a TT booster dose IM should be administered within 5 years, and every 5 years thereafter. When followed, these protocols should provide adequate protection against tetanus in horses. Additional tetanus prophylaxis guidelines are provided for veterinarians attending a horse experiencing a known "risk event" (e.g. wound, hoof abscess, surgery, umbilical infection). When a correctly vaccinated horse experiences a risk event, pre-existing immunity provides protection against tetanus. When an unvaccinated horse or one with unknown vaccination status, or a foal born to an unvaccinated dam, experiences a risk event, TT IM and tetanus antitoxin (TAT) 1,500 IU SC should be administered simultaneously at separate sites, and the TT primary immunisation protocol should subsequently be completed for the horse's respective age. In previously immunised pregnant broodmares, a TT booster dose administered 4-8 weeks prior to parturition optimises the transfer of passive immunity against tetanus to the newborn foal via colostrum; provided that post-natal IgG concentration in serum is > 800 mg/dL (8 g/L), such foals should be passively protected against tetanus up to 6 months of age. Survivors of clinical tetanus must still receive the primary protocol for vaccination against tetanus. In summary, all horses in New Zealand and Australia should be vaccinated against tetanus with protection maintained throughout life via TT booster doses, facilitated by accurate medical record keeping and client education.

Point-of-care testing for tetanus immunity: a systematic review and meta-analysis

BACKGROUND

The current standard of care for tetanus prophylaxis management in patients with open wounds likely results in overtreatment and unnecessary costs. Point-of-care immunochromatographic tests, known as Tetanus Quick Sticks (TQS), have been developed to qualitatively measure tetanus immunoglobulin levels. Multiple studies advocate their use in EDs. We aim to evaluate the diagnostic accuracy and cost-effectiveness of TQS to assess their relevance in frontline emergency care.

METHODS

A systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search was conducted in MEDLINE, Embase, Global Health, The Health Management Information Consortium and The Cochrane Library. Studies were eligible if sensitivity, specificity or cost-efficacy of TQS was reported. At least two authors independently assessed and extracted data from each study. A meta-analysis was conducted to evaluate summary sensitivity and specificity estimates for TQS.

RESULTS

12 studies were suitable for inclusion (n=1 662 865 participants): 1 modelling and 11 prospective observational cohort studies. Eight studies assessed diagnostic accuracy; the summary estimate for sensitivity was 90% (95% CI, 89% to 90%) with specificity 97% (95% CI, 95% to 100%). Six studies investigated cost-efficacy, reporting lower healthcare costs when using TQS instead of the current method of vaccination history, due to a decrease in unnecessary tetanus vaccine and immunoglobulin administration. Based on the current NHS supply chain data, TQS use could save £173.05 per tetanus-prone patient.

CONCLUSION

TQS could confer the greatest cost savings if used in combination with vaccination history in patients with tetanus-prone wounds. A quality assurance process is recommended prior to implementation of TQS in EDs.

Vaccination of adults against travel-related infectious diseases, and new developments in vaccines

The number of people travelling to tropical or subtropical countries, whether for holidays or for business, is steadily increasing. Many of these travellers are at risk of acquiring an infectious disease. Protection against certain infectious diseases is possible by vaccination. Vaccinations required or recommended for adults are reviewed here. Progress in the refinement of available vaccines, as well as the development of new vaccines, is discussed.

Acute midbrain syndrome as an adverse reaction to tetanus immunization

An acute midbrain syndrome III/IV developed twice after tetanus immunization. The occurrence of nearly identical episodes was remarkable, as well as the relatively rapid return to normal consciousness and neurological status after deep coma. Special emphasis is placed upon the chronological relationship of the coma to the immunization and upon immunological tests (tetanus antibody titres) performed to confirm the diagnosis.