Survival from adult tetanus in Lagos,Nigeria

Introduction

Tetanus is a severe disease caused by Clostridium tetani, an obligate, anaerobic Gram-positive spore-bearing bacillus. Tetanus is a medical emergency. Globally, it causes about one million deaths annually with an average mortality of 50% ¹ . It is a major cause of death in children and adults in resource-poor countries located in warm humid climates. In several African countries the survival rates remain low^1–6 and the social and economic burden is high. ² The medical care is expensive and skill-intensive, and the mortality rate is high even where advanced medical facilities exist.

We report on adult tetanus cases seen at the Lagos State University Teaching Hospital (LASUTH), Ikeja. The objective of the study was to estimate the survival rate of adult tetanus and the determinants of the risk of dying from the infection within the limited resources available to our hospital.

Materials and methods

Results

One hundred and sixty-four patients were admitted suffering from tetanus during the study period. All but two had generalized tetanus. Table 1 contains data on the socio-demographic and medical history of the patients. The mean age was 29.61 ± 12.88 years. The portal of entry was from wounds in 83 (50.6%) but unknown in 60 (36.6%).

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Table 1

Socio-demographic characteristics and the medical history of tetanus cases seen in Lagos, Nigeria

Variable	N (n = 164)	%
Age group (years)
<20	35	21.3
20–29	61	37.2
30–39	34	20.7
40–49	18	11.0
50–59	6	3.7
>=60	10	6.1
Gender
Female	40	24.4
Male	124	75.6
History of tetanus toxoid immunization
Yes	3	1.8
No	161	98.2
Portal of entry
Wounds/injuries	83	50.6
Infections	21	12.8
Unknown	60	36.6

Forty-nine patients survived, giving a survival rate of 29.9%. There were 115 deaths (case fatality rate of 70.1%). The age-adjusted survival rate in the various age groups was: 37% in those under 20 years; 34% (20–29 years); 27% (30–39 years); 28% (40–49 years); 6% (50–59 years); and 0% in those above 60 years. The trend was significant (P = 0.02). Seventy-two (62.6%) of the deaths occurred within 24 hours of admission. Most deaths occurred within the first two days with a higher survival rate after the second day – there were no more deaths after the seventh day of admission. The major causes of death were severe uncontrollable spasms (41%) and cardiac arrest from autonomic dysfunction (20%). Other causes of death included: asphyxia from laryngeal spasm (10%); hyperpyrexia (10%); sepsis (8%); acute renal failure (5%); and ‘unknown’ (6%). Determinants of survival from tetanus are shown in Table 2. The only significant determinant of survival was younger age (P = 0.017).

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Table 2

Determinants of survival from tetanus in Lagos, Nigeria

Variable	N (n = 164)	P
Gender
Male	34/124 (27.4%)
Female	15/40 (37.5%)	0.31
Received tetanus toxoid
Yes	0/3 (0.0%)
No	49/161 (30.4%)	0.55
Mean age
Survived	25.9 ± 9.5
Died	31.2 ± 13.8	0.02

Discussion

The peak age incidence and male dominance of the cases in this study conform with the pattern reported from Ghana. ³ This is partly related to the increased exposure to potential sources of injury and contamination of such wounds among young males. The survival rate for this study is very low, lower than previous reports from Nigeria (74%, 56%),^2,5,6 Ghana (50%)^1,3 and Ethiopia (73%). ⁴ This may be due to the large proportion of unimmunized patients, the severity of infection and late presentation: 99% suffered from generalized tetanus and 40% of the deaths occurred within a few hours of arrival in hospital, and 62.6% died within the first 24 hours after admission. The severity of the disease is a well known poor prognosticator.^3,5

Other contributory factors include inadequate wound management at the health facilities, ⁷ poor perception of the risk of tetanus in the community and the quality of care (there was no functional intensive care unit at the hospital during the period under review).

Tetanus patients were managed in an open general emergency ward along with 20 other patients with diverse illnesses. We believe that some of the 40% deaths due to severe uncontrollable spasms might have been prevented with a neuromuscular blockade if an intensive care unit had been available. ⁸ However, this is an expensive option and may not be sustainable in a resource-poor country such as Nigeria. Age was the only significant determinant of death from tetanus – more of the older patients died which is in agreement with other published reports.^7,9,10

This study throws up a number of challenges for tetanus care in hospitals and within the community. There is the need for a dedicated tetanus treatment area within emergency units which can provide the quality of care required by this disease. All patients with wounds and infections that could potentially lead to tetanus should receive tetanus immunoglobulin and tetanus toxoid in addition to proper wound care.

Conclusion

Thirty percent of the tetanus patients at our hospital survived. Survival rate can be increased by improved hospital care, but adult immunization and ten yearly booster doses for the immunized is considered the most cost-effective measure for survival from tetanus.