Autonomic nervous system dysfunction predicts poor prognosis in patients with mild to moderate tetanus

Clinical profile and outcomes of tetanus patients in a tertiary hospital in the Philippines: a ten-year retrospective study

BACKGROUND

Tetanus is a life-threatening but preventable neurologic disorder characterized by trismus and muscle spasms. Despite its decreasing global incidence, it remains to be endemic in resource-limited settings such as the Philippines. This study aimed to determine the incidence, demographic characteristics, risk factors, clinical presentation, management, complications, and outcomes of non-neonatal tetanus cases in a tertiary hospital in the Philippines. It also aimed to compare the clinical profile and outcomes between the adult and pediatric subgroups.

METHODS

This study used a retrospective cross-sectional design including all adult and pediatric non-neonatal tetanus patients admitted at the University of the Philippines - Philippine General Hospital from January 2012 to June 2023. Data was extracted from department censuses and inpatient charts.

RESULTS

One hundred thirty-eight cases were included. The incidence rate was 0.03%, while mortality rate was 29%. Majority of patients were males presenting with trismus and spasms after sustaining a puncture wound. Chronic hypertension was associated with an increased hazard of death by 4.5 times (p = 0.004), while treatment with magnesium sulfate was associated with a decreased hazard of death by 35 times (p = 0.005). The mode of infection and the medications administered differed between the adult and pediatric subgroups.

CONCLUSIONS

Although the total number of cases has decreased over the past decade, tetanus remains to have a high incidence and mortality rate in the Philippines. Increasing vaccination coverage, improving public awareness, and educating health professionals can help reduce morbidity and mortality from this disease.

Risk assessment of severe adult tetanus using the NLR and AST level and construction of a nomogram prediction model

We sought to examine high-risk factors for severe tetanus, construct a nomogram model, and predict the risk probability of severe tetanus in adult patients to provide a theoretical basis for clinical intervention. Methods: A retrospective analysis was employed in this study, which enrolled 65 adult patients with tetanus diagnosed at the Second Affiliated Hospital of Hainan Medical University from January 2017 to September 2022. Study participants were divided into severe and mild groups based on the Ablett classification. The general data and laboratory markers of both groups were compared, and logistic regression analysis was used to screen for independent risk factors for severe tetanus. A nomogram prediction model was constructed, and receiver operating characteristic (ROC), calibration curve, and decision curve analysis (DCA) were constructed and used to assess discrimination, calibration, and net benefit. Results: Of the 65 adults patients with tetanus, 28 were placed in the severe group and 37 were placed in the mild group. Univariate logistic regression analysis showed that there were statistically significant differences in the incubation period, time from disease onset to treatment, white blood cell count (WBC), neutrophil count (NEU), lymphocyte count (LYM), platelet count (PLT), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lactate dehydrogenase level (LDH), myoglobin level (Mb), and aspartate aminotransferase (AST) level between the two groups (P < 0.05). while the differences in age; sex; and creatine kinase, creatine kinase isoenzyme, and alanine aminotransferase levels were not statistically significant (P > 0.05). Multivariate analysis showed that NLR (odds ratio [OR] = 4.998, 95 % confidence interval [CI] = 1.154-21.649, P = 0.031), AST (OR = 1.074, 95 % CI = 1.007-1.146, P = 0.031), PLT (OR = 1.055, 95 % CI = 1.006-1.106, P = 0.027), and incubation period (OR = 0.597, 95 % CI = 0.423-0.843, P = 0.003) are independent risk factor for severe tetanus. A Nomogram for predicting Severe Tetanus (N-ST) prediction model was constructed based on variables in the multivariate analysis with P < 0.05. The ROC curve showed that the optimal cutoff point was 108.044 points. At this point, the sensitivity was 86.5 %, the specificity was 89.3 %, the area under the ROC curve was 0.936, and model discrimination was good. The calibration curve overlapped with the ideal curve, and the DCA curve showed that the model can provide clinical benefits. Conclusion: NLR, AST, PLT, and incubation period are predictors of severe tetanus. The constructed N-ST model can provide a new, convenient, and rapid method to predict the risk probability of severe tetanus in adults and guide early clinical intervention.

Case report: A severe case of generalized tetanus in a young cat

A 10-month-old, 3 kg, female spayed Domestic Shorthair cat was presented with a chronic, infected wound at the level of the proximo-lateral left pelvic limb. General physical examination revealed a weight-bearing lameness of the left pelvic limb, which was moderately and circumferentially swollen and edematous proximal to the tarsal joint. On the lateral aspect of the proximal thigh, there was a chronic wound of 1 cm in diameter and an additional exudative skin lesion was present throughout the whole length of the caudo-lateral thigh. Complete blood count and serum biochemistry profile revealed mild anemia, increased serum amyloid A, hyponatraemia, hypochloraemia, hypocalcaemia, hyperkalaemia, hypermagnesaemia, hyperglycaemia, increased creatine kinase, and increased liver parameters. Surgical exploration of the wound was performed, and necrotizing fasciitis was suspected. The affected limb was amputated and swabs for bacterial culture were taken from both the skin lesions and surgical site before wound closure. One day after surgery, mild muscular contractions on the forehead and an increased muscle tone of the right pelvic limb were evident. One day later, the cat developed a generalized increase in extensor tone, with intermittent opisthotonos, resulting in lateral recumbency. Based on these clinical signs, a diagnosis of generalized tetanus was made and treatment with midazolam, methocarbamol, and metronidazole was started. Despite an improvement of all blood parameters, the cat progressively deteriorated and 4 days after surgery, it developed episodes of tetanic convulsions, associated with hyperthermia and ventricular arrhythmias. Despite intensive care and medical management, the cat died following a cardio-respiratory arrest 3 days later. This case report describes a rare case of severe generalized tetanus in a young cat.

Case Report: A Challenging Case of Tetanus Presenting with Headache

Tetanus is a life-threatening infectious neurological condition that has become uncommon due to large-scale immunization campaigns. We describe a rare instance of generalized tetanus presenting with a headache on a tropical island in Malaysia. A 43-year-old woman presenting with headaches and generalized body weakness, which progressed into trismus and neck stiffness. Her medical history indicated a wound on the sole of her foot caused by shattered glass in an unhygienic area, but no tetanus prophylaxis had been administered. The patient was subsequently given immunoglobulin, tetanus toxoid, metronidazole, and sedatives in the recommended dosages. Her neurological condition improved remarkably, but she suffered blood pressure fluctuations due to dysautonomia. She was successfully discharged with complete recovery after 6 months of follow-up. The case demonstrates the significance of appropriate identification and care of tetanus, as well as the lethal effects of untreated wounds in vulnerable patients.

Magnitude, Patterns, and Associated Predictors of Cardiovascular Events in Tetanus: A 2-Year, Single-Center, Ambidirectional Cohort Study Involving 572 Patients

Background

Cardiovascular events (CEs) remain the leading cause of death in patients with tetanus. We examined the incidence, patterns, and associated predictors of CEs among patients with tetanus in Vietnam.

Methods

An ambidirectional cohort study was conducted on hospitalized adult patients with tetanus at the Hospital for Tropical Diseases between 2019 and 2020. Information on demographics, tetanus disease, CEs and outcomes were collected.

Results

Among all 572 included patients, CEs accounted for 10.8% (95%CI 8.6-13.7%) and included Takotsubo cardiomyopathy (40.3%, 95%CI 29.0-52.8%), arrhythmia (19.4%, 95%CI 11.4-30.9%), sudden cardiac arrest (16.1%, 95%CI 9.0-27.2%), myocardial infarction (11.3%, 95%CI 5.6-21.5%), heart failure (6.5%, 95%CI 2.5-15.4%) and pulmonary embolism (6.5%, 95%CI 2.5-15.4%). CEs occurred from day 5 to 20 of illness. Among 62 CE patients, 21% (95%CI 12.7-32.6%) died and 61.3% (95%CI 48.9-72.4%) developed autonomic nervous system dysfunction (ANSD). Three-fourths (24/32) of patients with Takotsubo cardiomyopathy or myocardial infarction had ANSD. CEs were significantly associated with modified Ablett scores (AOR = 2.42, 95%CI 1.1-5.6, P = .04), underlying diseases (AOR = 2.7, 95%CI 1.1-6.8, P = .04) and overweight (AOR = 0.18, 95%CI .04-.8, P = .02).

Conclusions

CEs are not rare and associated with high mortality. The most common CE is Takotsubo cardiomyopathy. CEs can occur at any stage of illness, with or without ANSD. To prevent mortality, it is pivotal to screen CEs in patients with tetanus, especially those with underlying diseases, high modified Ablett scores, and a normal or low BMI. More studies are needed to fully elucidate the impact of ANSD on the cardiovascular function and the CE associated mortality in tetanus.

Survival in canine tetanus - retrospective analysis of 42 cases (2006-2020)

Objective

To define factors associated with survival in dogs with tetanus and to evaluate the prognostic significance of an established severity classification scheme.

Methods

Medical records of dogs with the clinical diagnosis of tetanus were retrospectively reviewed with regard to signalment, clinical signs, clinicopathological findings on admission, wound characteristics, complications, therapeutic measures, and survival to discharge. Based on the extracted data, dogs were graded according to a previously published 4-class severity scheme. Non-parametric tests were applied for comparisons between survival categories.

Results

Forty-two dogs fulfilled inclusion criteria, of which 32 survived. Of 10 non-survivors, 4 died and 6 were euthanised. Non-survivors were more often younger than 2 years of age (6/10 vs. 7/32 dogs, p = 0.023), had shorter duration of specific signs of tetanus (time from onset of typical signs to presentation) (2 vs. 4 days, p = 0.016), were prescribed less often antibiotics prior to presentation (p = 0.006), had higher tetanus severity grade (10/12 dogs in Class III or IV died, p < 0.001), more often received acepromazine (p = 0.009) and atropine (p = 0.012), and more often had hyperthermia (p = 0.005) and respiratory complications (pneumonia, laryngeal spasm; p = 0.008). Wound characteristics, the use of tube feeding, metronidazole, methocarbamol, magnesium and antitoxin were not significantly different between non-survivors and survivors.

Clinical significance and conclusion

Young dogs with a rapid course of severe generalized tetanus have a guarded prognosis. The previously described severity classification scheme proved valuable in predicting survival. Prospective multi-center studies are needed to clarify the prognostic significance of age, sedative usage and modified versions of an established classification scheme, including the presence of respiratory complications.

Safety and efficacy of Magnesium Sulfate in the management of Tetanus: A systematic review

Tetanus is a rare life-threatening condition often complicated by repetitive spasms, dysautonomia and neuromuscular respiratory failure contributing to high fatality rates in its severe form. Benzodiazepines used to treat muscle spasms pose a high risk of respiratory failure requiring mechanical ventilation, which is unaffordable and inaccessible for many. Magnesium sulfate, a cheap and widely available medication in all urban and rural health centres of LMICs for the treatment of eclampsia, can be used to control muscle spasms and dysautonomia. We thus conducted a systematic review of evidence to assess the safety and efficacy of magnesium sulfate in the treatment of tetanus. Any study published before April 15, 2021, discussing the efficacy and/or safety of MgSO4 infusion in the treatment of tetanus was systemically reviewed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Our systematic review included data from 13 studies, three were randomised, double-blind and controlled trials. The remaining ten studies were observational; six prospective and four retrospective studies. Our review showed no mortality benefit associated with the use of magnesium sulfate. However, magnesium sulfate was found to be effective in reducing spasms along with diazepam, leading to better control of dysautonomia, reduced need for mechanical ventilation and shorter hospital stay by 3-7 days. The incidence of magnesium toxicity was very low in the studies included.

Tetanus Complicated by Dysautonomia: A Case Report and Review of Management

Tetanus is a life-threatening infectious neurological disorder that is now a rare disease due to the institution of wide-spread vaccination strategies. We present an uncommon case of generalized severe tetanus with consequent respiratory failure requiring mechanical ventilation, which was associated with dysautonomia. A 20-year-old unvaccinated female presented with neck stiffness and diffuse muscle spasms following a laceration sustained 3 weeks prior. She was admitted to the intensive care unit for mechanical ventilation and was treated with immunoglobulin, tetanus toxoid, metronidazole, and high doses of sedatives. She also developed dysautonomia, with alternating bradycardia and tachycardia, as well as fluctuating blood pressure. She was successfully extubated and discharged. We also review the epidemiology, pathophysiology, and management of tetanus and discuss dysautonomia in the setting of tetanus.

Autonomic dysfunction in the neurological intensive care unit

Autonomic dysfunction is common in neuro-critical care patients and may compromise the function of various organs. Among the many diseases causing or being associated with autonomic dysfunction are traumatic brain injury, cerebrovascular diseases, epilepsy, Guillain-Barré syndrome (GBS), alcohol withdrawal syndrome, botulism and tetanus, among many others. Autonomic dysfunction may afflict various organs and may involve hyper- or hypo-activity of the sympathetic or parasympathetic system. In this short overview, we address only a small number of neuro-intensive care diseases with autonomic dysfunction. In GBS, autonomic dysfunction is frequent and may account for increased mortality rates; rapid changes between sympathetic and parasympathetic hypo- or hyper-activity may cause life-threatening cardiovascular complications. Paroxysmal sympathetic hyperactivity occurs after brain injury, hypoxia and cerebrovascular and other events, causes paroxysmal tachycardia, hypertension, tachypnoea and hyperthermia and is associated with a poorer prognosis and prolonged intensive care treatment. Other, at times life-threatening autonomic complications with exaggerated sympathetic activity and compromised baroreflex sensitivity arise during the alcohol withdrawal syndrome triggered by abrupt cessation of alcohol consumption. Botulism and tetanus are examples of life-threatening autonomic dysfunction caused by bacterial neurotoxins. Common neurological diseases, such as epilepsy, stroke or subarachnoid haemorrhage, are also associated with autonomic dysfunction that can on occasion cause critical deterioration of disease severity and prognosis.

Post-neonatal Tetanus in a PICU of a Developing Economy: Intensive Care Needs, Outcome and Predictors of Mortality

OBJECTIVES

To evaluate pediatric intensive care unit (PICU) needs, outcome and predictors of mortality in post-neonatal tetanus.

MATERIALS AND METHODS

Review of 30 consecutive post-neonatal tetanus cases aged 1 months to 12 years admitted to a PICU in north India over a period of 10 years (January 2006 to December 2015).

RESULTS

Chronic suppurative otitis media was the commonest portal of entry. All received tetanus toxoid, human tetanus immunoglobulin (HTIG) and appropriate antibiotics; 7 (23.3%) received intrathecal HTIG. Common complications were respiratory failure, rhabdomyolysis, autonomic dysfunction, acute kidney injury and healthcare-associated infections. PICU needs were as follows: ventilation; benzodiazepine, morphine and magnesium sulfate infusion; neuromuscular blockers, inotropes, tracheostomy and renal replacement therapy. Mortality rate was 40%; severity Grade IIIb, autonomic dysfunction, use of vasoactive drugs and those who did not receive intrathecal HTIG were significantly associated with mortality.

CONCLUSION

Post-neonatal tetanus is associated with high mortality, and PICU needs include management of spasms, autonomic dysfunction and complications and cardiorespiratory support.

Neonatal Tetanus in Vietnam: Comprehensive Intensive Care Support Improves Mortality

We report a 66% reduction in neonatal tetanus mortality after introducing a new management bundle integrating antibiotic therapy, muscle relaxation and invasive monitoring. The latter allowed rapid detection of autonomic instability which was treated with magnesium sulphate. This is the first report of its use in neonatal tetanus.

Vitamin C for preventing and treating tetanus

BACKGROUND

Tetanus is a severe disease that can be prevented by vaccination. In developing countries vaccination coverage is not always high. Cases still occur also in developed countries, particularly in elderly people owing to their reduced immuno protection. There are about 1 million tetanus cases per year globally. In animal studies, vitamin C has protected against various infections and bacterial toxins. In a study with rats, vitamin C protected against the purified tetanus toxin.

OBJECTIVES

To assess the prophylactic and therapeutic effect of vitamin C on tetanus.

SEARCH METHODS

In May 2013 we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations ); and Ovid EMBASE for this third update.

SELECTION CRITERIA

Controlled trials of vitamin C as a prevention or treatment for tetanus, whether or not these were placebo controlled, in any language, published or unpublished. Two review authors independently made inclusion decisions.

DATA COLLECTION AND ANALYSIS

Both review authors independently extracted data from trial reports and assessed methodological quality. Since one of the cells in a 2 × 2 table had no events, we calculated the odds ratio (OR) and its 95% confidence interval (CI) for case fatality rate by using the Peto-method. Another of the 2 × 2 tables had no empty cells and the inverse-variance method was used to calculate its risk ratio (RR) estimate and 95% CI. We also used the Fisher's exact test to calculate the exact 95% CI for the OR of the 2 × 2 table with the empty cell.

MAIN RESULTS

One single trial was eligible for inclusion. This non-randomised, unblinded, controlled trial undertaken in Bangladesh involved 117 tetanus patients. Vitamin C at a dosage of 1 g/day was administered intravenously alongside conventional treatment. At recruitment, the participants were stratified into two age groups and the results were reported by age. There was a significant difference in the vitamin C effect between the two age groups (P = 0.01). In the tetanus patients aged 1 to 12 years (n = 62), vitamin C treatment was associated with a 100% reduction in case fatality rate (95% CI from -100% to -94%). In patients aged 13 to 30 years (n = 55), vitamin C treatment was associated with a 45% reduction in case fatality rate (95% CI from -69% to -5%).

AUTHORS' CONCLUSIONS

A single, non-randomised, poorly reported trial of vitamin C as a treatment for tetanus suggests a considerable reduction in mortality. However, concerns about trial quality mean that this result must be interpreted with caution and vitamin C cannot be recommended as a treatment for tetanus on the basis of this evidence. New trials should be carried out to examine the effect of vitamin C on tetanus treatment.

Tetanus in adults: clinical presentation, treatment and predictors of mortality in a tertiary hospital in Ethiopia

BACKGROUND

Tetanus remains a major health problem in the developing world. The aim of this study was to evaluate the clinical presentation, risk factors, complications, treatment, outcome and predictors of death in patients with tetanus.

METHODS

Patients aged ≥ 13 years admitted to Tikur Anbessa Hospital from June 2001 to May 2009 with the diagnosis of tetanus were included in this retrospective study.

RESULTS

Data from 68 patients were analyzed; majority (77.9%) were males, the mean age was 33.8 years. None of them was vaccinated for tetanus. The types were: generalized (91.2%), cephalic (7.4%), localized (1.5%), severe (72.1%), moderate (19.1%) and mild (8.8%). One or more complication(s) occurred in 75%; dysautonomia (58.8%), pneumonia (44.1%) and hypoxemia (41.2%). Tracheostomy and mechanical ventilation was used in 45.6% and 11.8%, respectively. Case-fatality was 35.3%. Predictors of mortality were age ≥ 40 years, duration of symptoms prior to presentation < 4 days, severe tetanus, incubation period < 7 days, period of onset < 3 days and dysautonomia. The cause of death was early acute respiratory failure due to uncontrolled spasms in 87.5%.

CONCLUSIONS

Most tetanus patients were young males and there was high case fatality due to acute respiratory failure. Age ≥ 40 years and dysautonomia were independent predictors of mortality. Preventing tetanus by vaccination and treating patients in a well equipped ICU is recommended.

Ten-year experiences with Tetanus at a Tertiary hospital in Northwestern Tanzania: A retrospective review of 102 cases

Background

Tetanus is still a major health problem in developing countries and it is associated with a high morbidity and mortality rate. There is paucity of published data regarding the management of tetanus in Tanzania, especially the study area. This study was conducted to describe our own experiences with tetanus outlining the clinical characteristics and treatment outcome of tetanus patients in our environment and to identify predictors of outcome of these patients.

Methods

This was a ten-year period retrospective study of patients who presented with a clinical diagnosis of tetanus at Bugando Medical Centre between January 2001 and December 2010. Data was analyzed using SPSS computer software system.

Results

A total of 102 patients were studied. The male to female ratio was 11.8: 1. The majority of patients (74.5%) were aged < 40 years and 51.0% of them were farmers. Only 23.5% of patients had prior tetanus immunization. 53.5% of patients had a reasonably identifiable acute injury prior to the onset of tetanus and commonly involved the lower limbs (53.8%). The majority of patients (97.1%) had generalized tetanus. The mean incubation period and period of onset were 8.62 ± 4.34 and 3.8 ± 2.2 days respectively. Complication rate was 54.9%. The average overall duration of hospitalization was 34.12 ± 38.44 days (1-120 days). Mortality rate was 43.1%. According to multivariate logistic regression analysis, the age ≥ 40 years (P = 0.002), incubation period < 7 days (P = 0.014), tracheostomy (P = 0.004), severity of tetanus (P = 0.001) and need for ventilatory support (P = 0.013) were found to be significantly associated with higher mortality.

Conclusion

Tetanus remains a major public health problem in our centre and still carries unacceptably high morbidity and mortality despite the available advanced management facilities including ICU care. Young adult males are commonly affected. The incidence of tetanus can be reduced significantly by an effective immunization program and proper wound management of the patients. Early recognition, intense support and prompt treatment improves morbidity and mortality of patients diagnosed with tetanus.

Case-fatality of adult tetanus at Jimma University Teaching Hospital, Southwest Ethiopia

BACKGROUND

Tetanus remains a major health problem in Ethiopia like in most other developing countries.

OBJECTIVES

To assess the clinical presentation, complications and outcome of tetanus patients.

METHODS

In this retrospective study, patients (age > 13 years) who were admitted to Jimma University Teaching Hospital from 1996 to 2009 were included.

RESULTS

Data from 171 patients were analyzed (129 males, 42 females, mean age 33 years). The mean hospital stay for patients discharged cured and deceased was 21.5 ± 12 and 6.5 ± 6.7 days, respectively. None of our patients was immunized for tetanus. Tracheostomy and mechanical ventilation (MV) was done in 10.5% and 11 %, respectively. The case-fatality was 38%. The mean annual admission and case-fatality increased over the study period from 9 to 20.5 and from 21 % to 51%, respectively. Establishment of intensive care unit (ICU) did not improve mortality due to infrequent tracheostomy and MV.

CONCLUSIONS

The case-fatality was high like in most other studies and the majority of patients died in the first few days indicating that adequate respiratory support was not given. Establishment of ICU did not improve mortality. Tetanus can be prevented by vaccination and if it occurs it needs well equipped ICU.

Vitamin C for preventing and treating tetanus

BACKGROUND

Tetanus is a severe infection that can be prevented by vaccination. In developing countries vaccination coverage is not always high and in developed countries cases may still occur, particularly in elderly people owing to their reduced immunoprotection. It has been estimated that there are about one million cases of tetanus per year globally. In animal studies, vitamin C protected against various infections. In a study with rats, vitamin C protected against tetanus toxin.

OBJECTIVES

To assess the prophylactic and therapeutic effect of vitamin C in tetanus.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, issue 4), MEDLINE (1950 to January 2008), EMBASE (1980 to 2008 Week 03), the Cochrane Wounds Group Specialised Register (January 2008), the Cochrane Infectious Diseases Group Specialised Register (June 2007), and the reference lists of relevant reviews and monographs.

SELECTION CRITERIA

We included controlled trials of vitamin C as a prevention or treatment for tetanus, whether or not placebo controlled, in any language, published or unpublished. Two authors independently made inclusion decisions.

DATA COLLECTION AND ANALYSIS

Both review authors independently extracted data from trial reports.

MAIN RESULTS

One single trial was eligible for inclusion. This non randomised, controlled, unblinded treatment trial involved 117 tetanus patients and was undertaken in Bangladesh. Vitamin C at a dosage of 1 g/day was administered intravenously alongside conventional treatment. At recruitment, the participants were stratified into two age groups and the results were reported by age. In the children aged 1 to 12 years (n = 62), vitamin C treatment was associated with a 100% reduction in tetanus mortality (95% confidence interval from -100% to -94%). In people aged 13 to 30 years (n = 55), vitamin C treatment was associated with a 45% reduction in tetanus mortality (95% confidence interval from -69% to -5%).

AUTHORS' CONCLUSIONS

A single, non randomised, poorly reported trial of vitamin C as a treatment for tetanus suggests a considerable reduction in mortality. However, concerns about trial quality mean that this result must be interpreted with caution and vitamin C cannot be recommended as a treatment for tetanus on the basis of this evidence. New trials should be carried out to examine the effect of vitamin C on tetanus treatment.

Autonomic impairment in tetanus: delayed baroreflex involvement

Autonomic nervous system impairment plays an important role in the clinical course of tetanus and is thought to be responsible for life-threatening complications. It is believed to be associated with predominance of sympathetic activity. Direct baroreflex involvement has not yet been reported. We hypothesized that impaired baroreflex may contribute to the autonomic cardiovascular dysregulation in tetanus. In a patient with tetanus baroreflex sensitivity was measured on the first 5 consecutive days non-invasively using a Finometer device. Baroreflex gain was calculated as sequential cross-correlation between heart rate and blood pressure. Short-time pulse interval standard deviations (SDNN) were derived. Additionally, heart rate and arterial blood pressure were monitored and recorded continuously. Baroreflex gain values and SDNN were compared to a sex- and age-matched control subject. Compared to the control subject the patient with tetanus initially did not show a significant difference in baroreflex gain values (mean 3.68 vs 3.15, p=0.1). However, in the course of the disease an almost complete baroreflex failure occurred (mean 1.0 vs 3.15 and 0.97 vs 3.15, both p<0.0001). No correlation was found between the dynamics of baroreflex gain values and blood pressure or heart rate variability expressed by standard deviation and variance. All 5 measurements in the tetanus patient showed decreased short-time SDNN when compared to the control subject and healthy standards. In our patient we found baroreflex impairment as a part of complex autonomic dysfunction in tetanus. Furthermore, baroreflex impairment occurred only delayed. Blood pressure instability could not be explained by baroreflex dynamics. We suggest that a shift towards sympathetic activity possibly overruled the effects of decreased baroreflex sensitivity on blood pressure regulation.

Maternal and neonatal tetanus

Maternal and neonatal tetanus are important causes of maternal and neonatal mortality, claiming about 180 000 lives worldwide every year, almost exclusively in developing countries. Although easily prevented by maternal immunisation with tetanus toxoid vaccine, and aseptic obstetric and postnatal umbilical-cord care practices, maternal and neonatal tetanus persist as public-health problems in 48 countries, mainly in Asia and Africa. Survival of tetanus patients has improved substantially for those treated in hospitals with modern intensive-care facilities; however, such facilities are often unavailable where the tetanus burden is highest. The Maternal and Neonatal Tetanus Elimination Initiative assists countries in which maternal and neonatal tetanus has not been eliminated to provide immunisation with tetanus toxoid to women of childbearing age. The ultimate goal of this initiative is the worldwide elimination of maternal and neonatal tetanus. Since tetanus spores cannot be removed from the environment, sustaining elimination will require improvements to presently inadequate immunisation and health-service infrastructures, and universal access to those services. The renewed worldwide commitment to the reduction of maternal and child mortality, if translated into effective action, could help to provide the systemic changes needed for long-term elimination of maternal and neonatal tetanus.

Risk factors associated with outcome in dogs with tetanus: 38 cases (1987–2005)

OBJECTIVE

To assess the clinical course of disease and risk factors associated with outcome in dogs with tetanus.

DESIGN

Retrospective case series.

ANIMALS

38 dogs with tetanus.

PROCEDURES

Data were collected from medical records of dogs with tetanus, including signalment; wound characteristics; initial clinical signs; severity of worst clinical signs; time to wound management, antimicrobial treatment, and antitoxin administration; and 28-day survival rate. Statistical analyses were performed to evaluate relationships between the potentially predictive variables and disease progression and outcome.

RESULTS

The 28-day survival rate was 77% (among 35 uncensored dogs). The most common initial clinical signs in affected dogs were ocular (n = 18) and facial (11) abnormalities. Nineteen dogs progressed to recumbency with severe muscle spasms, and 14 dogs had high or low heart rate or blood pressure values. Eight dogs died or were euthanized because of complications of tetanus. There was a significant association between younger age and development of more severe clinical signs. Furthermore, a significant inverse relationship between development of severe clinical signs and survival was identified. There was no association between earlier initiation of wound management, antimicrobial administration, or antitoxin administration and either progression of signs or 28-day survival rate. Wound type was not associated with 28-day survival rate.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that younger dogs with tetanus may be more likely to develop severe clinical signs. The prognosis for survival in dogs with tetanus is good if abnormalities in heart rate or blood pressure values do not develop.

Transynaptic effects of tetanus neurotoxin in the oculomotor system

The question whether general tetanus arises from the independent sum of multiple local tetani or results from the actions of the transynaptic tetanus neurotoxin (TeNT) in higher brain centres remains unresolved. Despite the blood-borne dissemination of TeNT from an infected wound, the access to the central nervous system is probably prevented by the blood-brain barrier. However, several long-term sequelae (e.g. autonomic dysfunction, seizures, myoclonus, and sleep disturbances) present after the subsidence of muscle spasms might be indicative of central actions that occur farther away from lower motoneurons. Subsequently, the obvious entry route is the peripheral neurons followed by the transynaptic passage to the brain. We aimed at describing the pathophysiological correlates of TeNT translocation using the oculomotor system as a comprehensive model of cell connectivity and neuronal firing properties. In this study, we report that injection of TeNT into the medial rectus muscle of one eye resulted in bilateral gaze palsy attributed to firing alterations found in the contralaterally projecting abducens internuclear neurons. Functional alterations in the abducens-to-oculomotor internuclear pathway resembled in part the classically described TeNT disinhibition. We confirmed the transynaptic targeted action of TeNT by analysing vesicle-associated membrane protein2 (VAMP2) immunoreactivity (the SNARE protein cleaved by TeNT). VAMP2 immunoreactivity decreased by 94.4% in the oculomotor nucleus (the first synaptic relay) and by 62.1% presynaptic to abducens neurons (the second synaptic relay). These results are the first demonstration of physiological changes in chains of connected neurons that are best explained by the transynaptic action of TeNT on premotor neurons as shown with VAMP2 immunoreactivity which serves as an indicator of TeNT activity.