Prognosis of neonatal tetanus in the modern management era: an observational study in 107 Vietnamese infants

Heart Rate Variability Measured from Wearable Devices as a Marker of Disease Severity in Tetanus

Tetanus is a disease associated with significant morbidity and mortality. Heart rate variability (HRV) is an objective clinical marker with potential value in tetanus. This study aimed to investigate the use of wearable devices to collect HRV data and the relationship between HRV and tetanus severity. Data were collected from 110 patients admitted to the intensive care unit in a tertiary hospital in Vietnam. HRV indices were calculated from 5-minute segments of 24-hour electrocardiogram recordings collected using wearable devices. HRV was found to be inversely related to disease severity. The standard deviation of NN intervals and interquartile range of RR intervals (IRRR) were significantly associated with the presence of muscle spasms; low frequency (LF) and high frequency (HF) indices were significantly associated with severe respiratory compromise; and the standard deviation of differences between adjacent NN intervals, root mean square of successive differences between normal heartbeats, LF to HF ratio, total frequency power, and IRRR, were significantly associated with autonomic nervous system dysfunction. The findings support the potential value of HRV as a marker for tetanus severity, identifying specific indices associated with clinical severity thresholds. Data were recorded using wearable devices, demonstrating this approach in resource-limited settings where most tetanus occurs.

Classification of Tetanus Severity in Intensive-Care Settings for Low-Income Countries Using Wearable Sensing

Infectious diseases remain a common problem in low- and middle-income countries, including in Vietnam. Tetanus is a severe infectious disease characterized by muscle spasms and complicated by autonomic nervous system dysfunction in severe cases. Patients require careful monitoring using electrocardiograms (ECGs) to detect deterioration and the onset of autonomic nervous system dysfunction as early as possible. Machine learning analysis of ECG has been shown of extra value in predicting tetanus severity, however any additional ECG signal analysis places a high demand on time-limited hospital staff and requires specialist equipment. Therefore, we present a novel approach to tetanus monitoring from low-cost wearable sensors combined with a deep-learning-based automatic severity detection. This approach can automatically triage tetanus patients and reduce the burden on hospital staff. In this study, we propose a two-dimensional (2D) convolutional neural network with a channel-wise attention mechanism for the binary classification of ECG signals. According to the Ablett classification of tetanus severity, we define grades 1 and 2 as mild tetanus and grades 3 and 4 as severe tetanus. The one-dimensional ECG time series signals are transformed into 2D spectrograms. The 2D attention-based network is designed to extract the features from the input spectrograms. Experiments demonstrate a promising performance for the proposed method in tetanus classification with an F1 score of 0.79 ± 0.03, precision of 0.78 ± 0.08, recall of 0.82 ± 0.05, specificity of 0.85 ± 0.08, accuracy of 0.84 ± 0.04 and AUC of 0.84 ± 0.03.

Neonatal tetanus with good outcomes at a regional referral hospital in Eastern Uganda: a case report

Background

Neonatal tetanus, though now rare in developed countries, is still a significant cause of mortality in developing countries. Mortality, which can be as high as 100% without medical intervention, can be reduced to less than 10% with intensive care. Low-resource settings still lack sophisticated intensive care that has been shown to improve outcomes in high-income countries. However, there are low-cost interventions that have been shown to improve outcomes such as the use of magnesium sulfate in the management of severe tetanus.

Case presentation

A 9-day-old term Itesot neonate presented to our facility with inability to breast feed, excessive crying, and stiffening of the body when touched that started on the fourth day of life. On admission, she had signs of respiratory distress, fever, and labile heart rate. A diagnosis of neonatal tetanus with autonomic dysfunction was made, and the neonate was started on diazepam and magnesium sulfate infusion. She showed remarkable improvement and was discharged after 24 days of inpatient care.

Conclusion

There is still need to improve case management modalities for neonatal tetanus in low-income settings to improve outcomes. This case report summarizes how adopting a low-cost treatment modality for neonatal tetanus resulted in good outcomes at a regional referral hospital in Eastern Uganda.

Mortality Rate and Prognostic Factors in Neonatal Tetanus: A 3-Year Analysis of Cases Presented to Turkey-Somalia Mogadishu Training and Research Hospital

Objective The aim of this study was to evaluate mortality rate and prognostic factors in neonatal tetanus cases presented to Turkey-Somalia Mogadishu Training and Research Hospital.

Methods A total of 35 neonatal tetanus cases presented to Turkey-Somalia Mogadishu Training and Research Hospital between 2014 and 2017 were included in this prospective observational study. Data on demographic, clinical and maternal obstetric characteristics, and laboratory findings including complete blood count and blood biochemistry were recorded in each patient. Study parameters were evaluated with respect to survivorship status, while multiple logistic regression analysis was performed to determine independent predictors of increased mortality risk.

Results Overall, mortality occurred in 22 (62.9%) of 35 neonates diagnosed with neonatal tetanus. Tetanus prophylaxis was absent in the majority of neonates, regardless of survivorship status (100.0% in nonsurvivors vs. 84.6% in survivors, p = 0.131). In nonsurvivor versus survivor groups, significantly higher likelihood of constipation (50.0 vs. 7.7%, p = 0.002), contracture (81.8 vs. 46.2%, p = 0.035), and ventilator support (95.4 vs. 53.8%, p = 0.006) as well as significantly lower hemoglobin (14.45 ± 2.06 vs. 17.15 ± 1.77, p = 0.003) and potassium (3.50 ± 0.86 vs. 4.14 ± 0.93, p = 0.003) levels and neutrophil (3.34 ± 1.75 vs. 4.47 ± 1.08, p = 0.047, white blood cell (WBC) (5.54 ± 2.30 vs. 7.78 ± 1.70, p = 0.003) and platelet (median [min-max] 133.5 [68–332] vs. 196 [123–550], p = 0.006) counts were noted. Presence of contracture (odds ratio [OR]: 14.525, 95% confidence interval [CI]: 1.398–150.870, p = 0.025) and ventilator support (OR: 22.282, 95% CI: 1.269–391.131, p = 0.034) was the independent determinants of increased risk of mortality.

Conclusion Our findings emphasize high mortality in neonatal tetanus cases in Somalia along with lack of maternal tetanus prophylaxis in majority of cases. Presence of contractures and ventilator support were significant determinants of poor survival, while factors such as constipation, lower hemoglobin, and potassium levels and lower neutrophil, WBC and platelet counts were also more common among nonsurvivors, albeit not found to be associated with mortality risk in the multivariate analysis.

Severity detection tool for patients with infectious disease

Hand foot and mouth disease (HFMD) and tetanus are serious infectious diseases in low- and middle-income countries. Tetanus, in particular, has a high mortality rate and its treatment is resource-demanding. Furthermore, HFMD often affects a large number of infants and young children. As a result, its treatment consumes enormous healthcare resources, especially when outbreaks occur. Autonomic nervous system dysfunction (ANSD) is the main cause of death for both HFMD and tetanus patients. However, early detection of ANSD is a difficult and challenging problem. The authors aim to provide a proof-of-principle to detect the ANSD level automatically by applying machine learning techniques to physiological patient data, such as electrocardiogram waveforms, which can be collected using low-cost wearable sensors. Efficient features are extracted that encode variations in the waveforms in the time and frequency domains. The proposed approach is validated on multiple datasets of HFMD and tetanus patients in Vietnam. Results show that encouraging performance is achieved. Moreover, the proposed features are simple, more generalisable and outperformed the standard heart rate variability analysis. The proposed approach would facilitate both the diagnosis and treatment of infectious diseases in low- and middle-income countries, and thereby improve patient care.

Multi-Modal Diagnosis of Infectious Diseases in the Developing World

In low and middle income countries, infectious diseases continue to have a significant impact, particularly amongst the poorest in society. Tetanus and hand foot and mouth disease (HFMD) are two such diseases and, in both, death is associated with autonomic nervous system dysfunction (ANSD). Currently, photoplethysmogram or electrocardiogram monitoring is used to detect deterioration in these patients, however expensive clinical monitors are often required. In this study, we employ low-cost and mobile wearable devices to collect patient vital signs unobtrusively; and we develop machine learning algorithms for automatic and rapid triage of patients that provide efficient use of clinical resources. Existing methods are mainly dependent on the prior detection of clinical features with limited exploitation of multi-modal physiological data. Moreover, the latest developments in deep learning (e.g. cross-domain transfer learning) have not been sufficiently applied for infectious disease diagnosis. In this paper, we present a fusion of multi-modal physiological data to predict the severity of ANSD with a hierarchy of resource-aware decision making. First, an on-site triage process is performed using a simple classifier. Second, personalised longitudinal modelling is employed that takes the previous states of the patient into consideration. We have also employed a spectrogram representation of the physiological waveforms to exploit existing networks for cross-domain transfer learning, which avoids the laborious and data intensive process of training a network from scratch. Results show that the proposed framework has promising potential in supporting severity grading of infectious diseases in low-resources settings, such as in the developing world.

Retrospective evaluation of 155 adult equids and 21 foals with tetanus from Western, Northern, and Central Europe (2000-2014). Part 2: Prognostic assessment

OBJECTIVE

To identify prognostic variables for adult equids and foals with tetanus.

DESIGN

Multicenter retrospective study (2000-2014).

SETTING

Twenty Western, Northern, and Central European university teaching hospitals and private referral centers.

ANIMALS

One hundred fifty-five adult equids and 21 foals with tetanus.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Variables from history and clinical examination were statistically compared between survivors and nonsurvivors (adults: 49 survivors, 85 nonsurvivors; foals: 7 survivors, 10 nonsurvivors). Cases euthanized for financial reasons were excluded. Mortality rates in adults and foals were 68.4% and 66.7%, respectively. Variables associated with survival in adults included: standing, normal intestinal sounds and defecation, voluntarily drinking, eating soft or normal food, lower heart and respiratory rates, high base excess on admission, longer diagnosis time, treatment and hospitalization delay, and mild severity grade. Variables associated with death included: anorexia, dysphagia, dyspnea, low blood potassium concentration on admission, moderate and severe disease grading, development of dysphagia, dyspnea, recumbency and seizures during hospitalization, treatment with glycerol guaiacolate, intravenous fluids, and intravenous glucose solutions. Variables associated with survival in foals included standing on admission, voluntarily eating soft food and drinking, older age, and longer hospitalization delay. Outcome was not different between different tetanus antitoxin (TAT) dosages, although there was a trend of increasing survival rate with increasing TAT dosages. Cases with appropriate vaccination prior to development of tetanus were rare, but had improved outcome and shorter hospitalization.

CONCLUSIONS

Prognosis for equine tetanus is poor with similar outcome and prognostic factors in foals and adults. The prognostic assessment of cases with tetanus provides clinicians with new evidence-based information related to patient management. Several prognostic indicators relate to the ability to eat or drink, and more severe clinical signs relate to poor outcome. Increasing intravenous dosages of TAT has no significant effect on outcome, but the positive trend identified may support a recommendation for high intravenous TAT dosages. Further evaluation is warranted.

Long-term outcome in survivors of neonatal tetanus following specialist intensive care in Vietnam

BACKGROUND

Neonatal tetanus continues to occur in many resource-limited settings but there are few data regarding long-term neurological outcome from the disease, especially in settings with critical care facilities.

METHODS

We assessed long-term outcome following neonatal tetanus in infants treated in a pediatric intensive care unit in southern Vietnam. Neurological and neurodevelopmental testing was performed in 17 survivors of neonatal tetanus and 18 control children from the same communities using tools previously validated in Vietnamese children.

RESULTS

The median age of children assessed was 36 months. Eight neonatal tetanus survivors and 9 community control cases aged < 42 months were tested using the Bayley III Scales of Infant and Toddler Development (Bayley III-VN) and 8 neonatal tetanus survivors and 9 community controls aged ≥42 months were tested using the Movement Assessment Battery for Children. No significant reductions in growth indices or neurodevelopmental scores were shown in survivors of neonatal tetanus compared to controls although there was a trend towards lower scores in neonatal tetanus survivors. Neurological examination was normal in all children except for two neonatal tetanus survivors with perceptive deafness and one child with mild gross motor abnormality. Neonatal tetanus survivors who had expienced severe disease (Ablett grade ≥ 3) had lower total Bayley III-VN scores than those with mild disease (15 (IQR 14-18) vs 24 (IQR 19-27), p = 0.05) with a significantly lower cognitive domain score (3 (IQR 2-6) severe disease vs 7 (IQR 7-8) mild disease, p = 0.02).

CONCLUSIONS

Neonatal tetanus is associated with long-term sequelae in those with severe disease. In view of these findings, prevention of neonatal tetanus should remain a priority.

Tetanus in Southern Vietnam: Current Situation

In Vietnam, there are no accurate data on tetanus incidence to allow assessment of disease burden or vaccination program efficacy. We analyzed age structure of 786 tetanus cases admitted to a tertiary referral center in Vietnam for three separate years during an 18-year period to examine the impact of tetanus prevention programs, namely the Expanded Program on Immunization (EPI) and the Maternal and Neonatal Tetanus (MNT) initiative. Most cases were born before the initiation of EPI. Median age increased from 33 (interquartile range: 20–52) in 1994, to 46 (32–63) in 2012 (P < 0.001). Birth-year distribution was unchanged, indicating the same birth cohorts presented with tetanus in 1994, 2003, and 2012. Enzyme-linked immunosorbent assay measurements in 90 men and 90 women covered by MNT but not EPI showed 73.3% (95% confidence interval [CI]: 62.9–82.1%) of women had anti-tetanus antibody compared with 24.4% (95% CI: 15.9–34.7%) of men, indicating continued tetanus vulnerability in older men in Vietnam.

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.

Eradication of tetanus

INTRODUCTION

The causative agent of tetanus, Clostridium tetani is widespread in the environment throughout the world and cannot be eradicated. To reduce the number of cases of tetanus efforts are focussed on prevention using vaccination and post-exposure wound care.

SOURCES OF DATA

Medline, Pubmed and Cochrane databases; World Health Organization and United Nations Children's Fund publications.

AREAS OF AGREEMENT

The maternal and neonatal tetanus elimination initiative has resulted in significant reductions in mortality from neonatal tetanus throughout the world.

AREAS OF CONTROVERSY

Although there are few data available it is likely that large numbers of children and adults, particularly men, remain unprotected due to lack of booster immunization.

AREAS TIMELY FOR DEVELOPING RESEARCH

It remains unclear how HIV and malaria affect both responses to vaccination and transplacental transfer of antibodies or how this might affect timing of vaccination doses.