Tetanus
Tetanus (or lockjaw) is a disease whose main symptom is acute muscle spasm; it is caused by an anaerobic bacterium called Clostridium tetani, found in soil and animal manure.
The most common cause of tetanus in developed countries is via an open wound, which becomes infected by spores of the bacteria, often by ordinary soil (the disease is common, therefore, among farmers and gardeners), though body piercing and tattoos can also be responsible. The wound may be very small, and so go unnoticed until the infection becomes more severe. The incubation period varies between two days and a fortnight. The bacteria release a neurotoxin called tetanospasmin which attacks the nervous system, causing fatigue and weakness, and then muscle spasms in the jaw (hence the disease's alternative name).
These symptoms are followed by difficulty in swallowing, by a more general stiffness and spasms of the muscles (especially in the neck and back), perspiration, problems urinating, heightened blood pressure, and a raised heart rate. Without treatment, the disease can be fatal.
Neonatal tetanus can occurs when childbirth takes place in unsterile conditions, and especially via contamination of the umbilical cord; though once common in the West, routine tetanus immunisation means that mothers pass on their protection to their babies. The problems continues to be severe in the developing world, however, especially where there is a custom of using animal dung to dressing a newborn's umbilical cord stump.
Reading
- C.L. Wells and T.D. Wilkins "Clostridia: Sporeforming Anaerobic Bacilli" in S. Baron et al. [edd] Baron's Medical Microbiology [4th edition]. University of Texas Medical Branch, 1996. ISBN 0-9631172-1-1