Complications of Acute Generalized Tetanus: Prevalence and Associated Factors at the Infectious and Tropical Diseases Department of the Fann Hospital, Dakar, Senegal ()
1. Introduction
Tetanus is a severe inoculation-related toxico-infection caused by Clostridium tetani or Nicolaier’s bacillus. It is potentially life-threatening yet preventable through vaccination. Tetanus is a non-contagious, non-immunizing, and notifiable disease. It remains a public health problem given its morbidity and mortality in developing countries, despite the existence of a vaccine that is accessible, effective, and perfectly safe [1].
In Senegal, progress has been achieved thanks to vaccination of pregnant women and the promotion of assisted deliveries, leading to the elimination of neonatal tetanus since 2012 [2]. For children, the vaccination schedule of the Expanded Program on Immunization (EPI) includes doses of tetanus vaccine at the sixth, tenth, and fourteenth weeks, with boosters at 16 months and five years, then every ten years thereafter. Since the EPI only covers children under one year of age, many miss vaccination—particularly booster doses. Consequently, tetanus remains a persistent health problem in Senegal, affecting the most vulnerable populations. It continues to be a frequent cause of hospitalization in the Department of Infectious and Tropical Diseases (SMIT) at Fann Teaching Hospital. Its prognosis can be poor due to the multiple complications it may cause. Understanding these complications will improve patient management and provide a better approach in combating the disease. Many studies on tetanus have been conducted at the SMIT, but few have focused specifically on its complications. This study aimed to identify complications among patients admitted for acute generalized tetanus at the SMIT of Fann Teaching Hospital, and to investigate the factors associated with their occurrence.
2. Patients and Methods
We conducted a retrospective, descriptive, and analytical study by exploring the medical records of patients of all age groups admitted for acute generalized tetanus at the SMIT of Fann Teaching Hospital. Data were collected over a six-year period ranging from 2018 to 2023. All patients, regardless of age or sex, hospitalized during the study period for tetanus, with available hospitalization records and for whom the final diagnosis of acute generalized tetanus was established—whether isolated or associated with another pathology—were included in this study.
3. Results
3.1. Socio-Demographic Characteristics
During the study period, 343 cases of acute generalized tetanus were recorded out of 348 cases of tetanus of all forms, representing a proportional morbidity of 98.56% and an annual average of 57.1 cases. The hospital prevalence was 8.42% (4134 patients hospitalized during the same period). The mean age was 31.08 ± 21.04 years [extremes: 0 - 92], with a median age of 27 years [extremes: 0 - 70]. The age group under 15 years was the most represented (30.6%). There was a clear male predominance (84.5%) with a sex ratio of 5.47. Regarding the occupation, tetanus cases were mainly observed among workers/artisans (30%, n = 103) and pupils/students (29.2%). In our series, 222 patients, representing more than two-thirds of the study population (66.7%), had no formal education, and only 2.9% (n = 10) had reached higher education level. Information regarding vaccination status was available for 8.45% of our patients; thus, 91.55% were either unvaccinated or had uncertain vaccination status. Details are presented in Table 1.
3.2. Clinical Characteristics
The gateway for tetanus was identified in the majority of patients (92.13%). It was mainly cutaneous (84.26%), post-surgical (11.37%), and post-circumcision (4.08%). Among the different cutaneous gateways, the presence of a recent skin wound ranked first (71.6%), followed by chronic wounds (15.90%).
At admission, trismus—the principal sign of tetanus—was found in almost all cases (96.21%), dysphagia in 77.55%, paroxysms in 83.70%, and contractures in all patients (Table 2).
The incubation period was ≥ 7 days in more than half of the cases (54.52%), with a mean of 6.23 ± 2.49 days. The invasion period was less than 48 hours in
Table 1. Distribution of cases of acute generalized tetanus according to socio-demographic characteristics, at the SMIT of Fann Teaching Hospital during the study period (n = 343).
socio-demographic characteristics |
Absolute frequency (n) |
Relative frequency (%) |
Sex |
|
|
Male |
290 |
84.50 |
Female |
53 |
15.50 |
Age |
|
|
[0 - 14] |
105 |
30.60 |
[15 - 29] |
78 |
22.70 |
[30 - 44] |
49 |
14.30 |
[45 - 59] |
63 |
18.40 |
≥60 |
48 |
14.00 |
Level of education |
|
|
Primary |
61 |
17.80 |
Secondary |
43 |
12.50 |
University |
10 |
2.90 |
Not schooled |
229 |
66.80 |
Occupation |
|
|
Worker-artisan |
103 |
30.00 |
Pupil-student |
100 |
29.20 |
Unemployed |
41 |
12.00 |
Trader |
32 |
9.3 |
Household |
23 |
6.7 |
Farmer-breeder |
12 |
3.5 |
Retired |
10 |
2.9 |
Security guard |
6 |
1.7 |
Civil servant |
5 |
1.5 |
Informal sector |
6 |
1.7 |
Comorbidities and medical history |
|
|
Hypertension |
24 |
7.00 |
Diabetes |
12 |
3.5 |
Asthma |
7,00 |
2.04 |
Sickle cell disease |
4,00 |
1.17 |
Other pathologies |
5 |
1.46 |
Previous antitetanus vaccination |
|
|
Yes |
29 |
8.45 |
No |
314 |
91.55 |
Table 2. Distribution of cases of acute generalized tetanus according to gateway and clinical signs, at the SMIT of Fann Teaching Hospital during the study period 2023 (n = 343).
Characteristics |
Absolute frequency (n) |
Relative frequency (%) |
Gateway |
Cutaneous |
289.00 |
84.26 |
Surgical |
39.00 |
11.37 |
Post-circumcision |
14.00 |
4.08 |
Autogenous |
11.00 |
3.21 |
Dentristry |
9.00 |
2.62 |
Uterine (post-abortum) |
6.00 |
1.75 |
Umbilical |
4.00 |
1.17 |
Intramuscular |
1.00 |
0.29 |
Clinical signs |
Trismus |
330.00 |
96.21 |
Dysphagia |
266.00 |
77.55 |
Contracture |
343 |
100.00 |
Paroxysms: |
287 |
83.67 |
- Tonic |
211.00 |
61.52 |
- Tonic-clonic |
73.00 |
21.28 |
- Clonic |
3.00 |
0.87 |
Opisthotonos |
188.00 |
54.81 |
Temperature ≥ 38.4˚C |
29.00 |
10.00 |
Pulse ≥ 120 beats/min |
12.00 |
3,49 |
78.13% of cases, with a mean of 31.87 ± 14.88 hours. The average consultation time was 5.72 ± 33.25 days. Most of the study population had consulted either a hospital (42.57%) or a health center (39.65%) before admission to the SMIT.
A total of 53 patients (15.45%) reportedly received a single dose of anti-tetanus serum (ATS) prior to their admission at the SMIT, and 9.62% underwent debridement of the gateway. Almost all patients (99.9%, n = 342) received antibiotic therapy.
3.3. Laboratory Results
Laboratory tests were not systematically performed in our patients. Among the 343 patients, 227 presented hematological disorders. Hyperleukocytosis was found in 109 patients (31.78%). Sixty-eight patients had thrombocytosis (19.83%), and 21 patients had thrombocytopenia (6.12%). Anemia was observed in 20.70% of patients (n = 71). Regarding hepatic function, 15 patients (4.37%) presented hepatic cytolysis with elevated ALT levels.
3.4. Therapeutic Characteristics
A total of 313 patients (89%) underwent debridement of the gateway. Hydrogen peroxide combined with Dakin’s solution were the main antiseptics used. Antibiotic therapy was administered to all patients (100%), consisting mainly of metronidazole in 99.9% of cases, penicillin G in 34.4%, ceftriaxone (third-generation cephalosporin) in 9.63%, and ampicillin in 0.58%. Anti-tetanus serotherapy combined with tetanus vaccination was performed in 330 patients (96.21%) via the intrathecal route. Six patients received anti-tetanus serotherapy alone, and seven patients underwent vaccination alone. All patients benefited from sensory isolation. The main sedative drug used was diazepam (99.41%), while the most frequently administered muscle relaxant was thiocolchicoside (80.32%).
3.5. Evolutionary and Prognostic Characteristics
At admission, patients were mostly classified as Stage II and Stage IIIa following the Mollaret’s classification (Table 3), representing 70.3% and 24.8% respectively. A median score (Table 4) of 2 was found in more than one-third of patients (38.6%), with extremes ranging from 0 to 6. In more than half of the cases (64.9%), tetanus was considered moderate.
During hospitalization, more than two-thirds of patients (66.18%) developed complications. These were mainly cardiovascular (40.52%), infectious (34.40%), respiratory (32.65%), and metabolic (29.45%). Respiratory complications were dominated by respiratory distress (50%) and thoracic rigidity (33.04%). Cardiac
Table 3. Mollaret classification [1].
Stage I: Mild forms |
Period of onset: 4 to 5 days Trismus, sardonic facies No respiratory trouble No spasms No dysphagia No paroxysm |
Stage II: Acute forms generalized |
Period of onset: 2 to 3 days Trismus, spinal stiffness Abdominal rigidity Respiratory troubles Dysphagia Spontaneous or induced tonic generalized spasms |
Stage III: Severe forms |
Period of onset < 24 hours Generalized contracture Respiratory disorders with chest blockage Severe dysphagia Spontaneous tonic clonic generalized spasms |
Table 4. Dakar score classification [1].
Criteria |
0 point |
1 point |
Incubation |
≥7 jours |
<7 jours |
Invasion |
≥2 jours |
<2 jours |
Gateway |
Other or not found (unknown) |
Umbilical Uterine (childbirth, abortion) Intramuscular Surgical intervention Complex open fractures Intramuscular injection Extensive burns |
Paroxysms |
Absent |
Present |
Rectal temperature |
≤38.4˚C |
>38.4˚C |
Pulse |
Adult |
≤120/min |
>120/min |
Newborn |
≤150/min |
>150/min |
arrest was the most frequently observed cardiovascular complication (98.56%). Infectious complications were most often represented by sepsis (87.29%). A few rare cases of mechanical complications (compression fractures) were observed (n = 5). Regarding metabolic complications, electrolyte disorders were predominant, with 68 cases (73.91%). Hypersensitivity to sedative drugs leading to coma was found in 30 patients (9.04%), as shown in Table 5.
Table 5. Distribution of cases of acute generalized tetanus according to complications, at the SMIT of Fann Teaching Hospital during the study period (n = 227).
Characteristics |
Absolute frequency (n) |
Relative frequency (%) |
Overall complications |
227.00 |
66.18 |
Respiratory complications |
112.00 |
32.65 |
Thoracic blockage |
37.00 |
33.04 |
Respiratory distress |
56.00 |
50.00 |
Laryngospasm |
17.00 |
15.18 |
Pneumothorax |
2.00 |
1.79 |
Cardiovascular complications |
139.00 |
40.52 |
Cardiac arrest |
137.00 |
98.56 |
Arrhythmia |
88.00 |
63.31 |
TED |
11.00 |
7.91 |
Infectious complications |
118.00 |
34.40 |
Sepsis |
103.00 |
87.29 |
Septic shock |
15.00 |
12.71 |
Metabolic complications |
92 |
26.82 |
Hyperglycemia |
8.00 |
8.70 |
Hypoglycemia |
2.00 |
2.17 |
Kidney failure |
3.00 |
3.26 |
Electrolyte disorders |
68.00 |
73.91 |
Nutritional disorders |
11.00 |
11.96 |
Iatrogenic complications |
31 |
9.04 |
Sedative drug-related coma |
30.00 |
96.77 |
Allergies |
1.00 |
3.23 |
Musculoskeletal complications |
7.00 |
2.04 |
Vertebral compression and fracture |
5.00 |
71.43 |
Tendon rupture |
2.00 |
28.57 |
Gastro-intestinal complications |
4.00 |
1.16 |
Digestive hemorrhage |
1.00 |
25.00 |
Ileus paralytic |
3.00 |
75.00 |
Other complications |
8 |
2.33 |
The average hospitalization stay was 11.30 ± 7.32 days, with extremes of 0 and 40 days. Nineteen patients developed sequelae, more than half of which were neurological (52.63%), followed by vertebral deformities and compressions in 26.32% of cases, and tendon contractures in 21.05% of cases.
Regarding overall outcomes, hospital lethality was 25.7%. A few cases of transfer to pediatric department were noted (3.5%).
3.6. Predictors of the Occurrence of Complications
In multivariate analysis, we investigated the factors that were significant to the occurrence of complications in case of acute generalized tetanus (Table 6).
Table 6. Factors associated with the occurrence of complications in case of acute generalized tetanus at the SMIT of Fann Teaching Hospital during the study period (n = 343).
Characteristics |
OR1 |
95% CI1 |
p-value |
Period |
|
|
|
2018-2019 |
— |
— |
|
2020-2021 |
0.46 |
0.25 - 0.83 |
0.010 |
2022-2023 |
0.98 |
0.54 - 1.79 |
>0.9 |
Age > 60 years |
|
|
|
NO |
— |
— |
|
YES |
4.45 |
1.76 - 13.7 |
0.004 |
Hypertension |
|
|
|
NO |
— |
— |
|
YES |
4.27 |
1.06 - 28.9 |
0.070 |
Diabetes |
|
|
|
NO |
— |
— |
|
YES |
4.15 |
0.65 - 81.4 |
0.2 |
Dakar score |
|
|
|
0 - 1 |
— |
— |
|
2 - 3 |
1.37 |
0.75 - 2.50 |
0.3 |
4 - 6 |
2.80 |
1.09 - 7.73 |
0.038 |
Tonic-clonic paroxysms |
|
|
|
NO |
— |
— |
|
YES |
1.91 |
1.03 - 3.63 |
0.043 |
1OR = odds ratios, CI = confidence interval.
Four significantly associated factors to the occurrence of complications were identified:
The period of 2020-2021: OR = 0.46 [0.25 - 0.834], p = 0.010;
Patients aged > 60 years: OR = 4.45 [1.76 - 13.7], p = 0.004;
A Dakar score between 4 - 6: OR = 2.80 [1.09 - 7.73], p = 0.038;
The presence of tonic-clonic paroxysms: OR = 1.91 [1.03 - 3.63], p = 0.043.
4. Discussion
This was a retrospective, descriptive, and analytical study aimed at identifying complications of acute generalized tetanus and evaluating the factors associated with their occurrence.
The limitations of the study: We encountered some difficulties related to the retrospective nature of this work, such as: a number of records could not be located in the archives, the illegibility of some records and the lack of documentation for certain variable keys made their use difficult or even impossible. Furthermore, it is also important to note the single-center nature of the study which may limit the generalizability of the results.
At the end of the study, 343 cases were recorded, corresponding to a hospital prevalence of tetanus of 8.42%, with a sex ratio of 5.7. This male predominance had also been observed in the same Department of Infectious Diseases [3]-[9].
Elsewhere in Africa, authors such as Wateba et al. [10] and Bawe et al. [11] reported in Togo a sex ratio of 5% and 81.2% of male patients, respectively. In Abidjan, Ivory Coast, Diallo et al. [12] found a sex ratio of 4.8. In Mali, Bouh’s study showed that the majority of patients were male, with a frequency of 96.7% and a sex ratio of 29.3 [13].
In Europe, however, the opposite trend has been observed, with a female predominance according to the study by Maja et al. [14]. This may be explained by the fact that in these countries, women are often engaged in gardening and handling sharp objects, and with age, there is a decline in immunity acquired through previous vaccination. Thus, in these countries, tetanus is considered a disease of the elderly [15].
More than two-thirds of our patients (66.18%) developed at least one complication during hospitalization. At the SMIT, a lower prevalence of complications had previously been reported by Fortes, Lakhe, and Barro [7] [9] [16].
Elsewhere in Africa, Bawé in Togo [11], Diallo Z. in Mali [12], and Chukwubike O.A. in Nigeria [17] reported complication rates of 6.25%, 43.5%, and 52.3%, respectively. In India, similar findings were reported by Renuka et al., who reported 47% of patients with complications [18]. Nevertheless, our results corroborate with the work of Camacho et al. [19] in Spain, who observed 76.8% of patients presenting with complications.
The incidence of tetanus-related complications remains high at the SMIT of Fann Teaching Hospital. This may be attributed to several factors, including delayed access to care, inadequate management before admission, neglect of gateways such as tetanigenic wounds, deficiencies in booster vaccination policies, and insufficient communication campaigns on the importance of tetanus prophylaxis.
The main complications observed were cardiovascular (40.52%), infectious (34.40%), respiratory (32.65%), and metabolic (29.45%). These findings confirm previous studies conducted in the same department by Fortes and Lakhe [7] [9], who also identified cardiovascular, respiratory, and infectious complications as the most frequent. Similar trends are reported in the literature, where complications are predominantly infectious and respiratory in nature [11] [12] [17] [18].
Infectious complications were largely represented by sepsis. This can be explained by aspiration broncho pneumopathies, the use of urinary catheters, and the insertion of venous or intra-arterial catheters [7] [12] [20].
Cardiovascular complications (40.52%) included cardiac arrest, arrhythmia, and thromboembolic disease in 11 patients. Our results are comparable to those of Fortes, who reported 45% of patients with cardiovascular complications. Furthermore, Barro, in the same department, found a predominance of cardiovascular complications (26.08%) [16]. Respiratory complications affected 32.65% of our patients and were dominated by respiratory distress (33.04%) and thoracic rigidity (33.04%). These findings are corroborated by other studies in Africa [7] [17] [21]. In tetanus, respiratory complications are mainly mechanical (laryngeal spasm and blockage of respiratory muscles) and carry a poor prognosis, particularly in strong patients. They most often occur in severe forms of tetanus. Metabolic and nutritional disorders were exacerbated by hydro-electrolytic imbalances, which are complications linked to tetanus symptomatology (trismus and dysphagia). In our daily practice, in cases of tetanus, patients’ needs for water and electrolytes are met through intravenous infusion of ion-enriched solutions; otherwise, electrolyte disturbances may occur. Hydro-electrolytic complications are also secondary to insufficient secretion of antidiuretic hormone [22]. Parenteral nutrition could be a solution to improve patients’ nutritional status, but its high cost and associated risks of infection and thromboembolism limit its use.
Other complications were observed, such as iatrogenic complications in 31 patients, mainly coma (96.77%, n = 30). The cause of iatrogenic coma is almost always an overdose of sedative drugs. Musculoskeletal and gastrointestinal complications were also noted in four patients (2.04%).
Multivariate analysis identified the following significant factors associated with complications: the period 2020-2021, patients aged over 60 years, a Dakar score between 4 - 6, and the presence of tonic-clonic paroxysms.
The period 2020-2021 was marked by an increase in tetanus cases at the SMIT and worldwide. This was reported by Sow A. et al. [23] in Senegal and Touré H.A. et al. [24] in Treichville, Côte d’Ivoire. This period was a risk factor for the occurrence of complications, as it coincided with the global COVID-19 pandemic declared on March 10, 2020 (Senegal recorded its first case on March 2, 2020). During this time, the SMIT hosted the first epidemic treatment center in Senegal, with most human resources reassigned to the management of COVID-19 patients. It should also be noted that during this period, there was delayed access to care, as the population was reluctant to visit hospitals, leading to prolonged delays in management. Chippaux, in his study, emphasizes the impact of COVID on public health in sub-Saharan Africa, with a decline in health services, a reduction in their quality, and the closure of specialized services [25].
Advanced age > 60 years predicted the occurrence of complications, as shown in other studies:
The occurrence of complications in elderly patients can be explained by decubitus-related issues during prolonged hospitalization (thromboembolic disease and bedsores), the development of stress-induced ulcers, age-related vulnerability with comorbidities that may be decompensated by tetanus, respiratory complications such as aspiration pneumonia, and a weakened immune system that facilitates nosocomial infections.
In our study, complications were more significant when the score was higher, highlighting the prognostic value of the Dakar score. This has been demonstrated in several studies, notably in Dakar [7]. Similar findings have been reported in the literature from Ethiopia [28], Nigeria [29], and Congo [30].
The presence of tonic-clonic paroxysms and a Dakar score between 4 - 6 were associated with the occurrence of complications. These paroxysms indicate severe involvement, as shown in Mollaret’s classification, where their presence places the patient at Stage III. Tonic-clonic paroxysms may be accompanied by neurovegetative disorders, reflecting dysautonomia, and expose patients to often fatal complications.
Other studies have reported similar results, including those of Amare et al. [27] in Ethiopia and Minta et al. [31] in Mali, who found that the occurrence of complications was statistically linked to clinical severity according to the Dakar score and Mollaret staging.
Our study reported a hospital lethality rate of 25.7%. These data show a relatively high lethality, comparable to results found in the same department by Seydi et al. [3] and Attinsounon et al. [32], who reported lethality rates of 26.7% and 26.9%, respectively.
However, this lethality remains higher than that reported by other authors in the same department. Indeed, lower results were found in the same service by Fortes, with a lethality of 21% [7], and by Seydi and Manga, with 22% and 21.1% respectively [3] [33]. In the sub-region, most studies reported high lethality rates ranging between 31% and 82%, such as those of Ibara B [30] in Congo, Okome K [34] in Gabon, and Bankole in Nigeria, who noted an increase in lethality up to 52.2% in the presence of complications of any nature [35]. Elsewhere, even higher lethality than ours has been reported in other series; for example, in India with the work of Anuradha et al. (37.78%) [36] and in Mali with Dao et al. (38.9%) [37].
5. Conclusion
The results obtained at the end of our study highlight the need to raise awareness among vulnerable populations regarding tetanus complications, particularly individuals over 60 years of age and those with comorbidities such as hypertension or diabetes. These groups must strictly adhere to tetanus booster vaccinations. Furthermore, any chronic wound or injury should be properly managed. In addition, risk factors for complications—such as advanced age, delayed consultation, and comorbidities like hypertension and diabetes—are not currently integrated into prognostic tools (Dakar score classification). It therefore seems relevant to conduct large-scale, multicenter prospective studies that take these parameters into account. This would allow the development of new scores for a more accurate evaluation of tetanus prognosis.