By Joan Connelly and Emily Cohn
Image courtesy of Blake Patterson on Flickr, CC
Tetanus is a non-communicable disease caused by exposure to the toxin-producing spores of the ubiquitous bacterium, Clostridium tetani. The bacteria are commonly found in soil and both animal and human digestive tracts worldwide [1]. Its existence in soil and fecal matter can make tetanus viable for cross-contamination on surfaces and substances, including those in common household areas. C. Tetani usually enters the body through breaks in the skin, allowing for the potent toxin, tetanospasmin, to produce and disseminate via the neuromuscular junction and spinal cord or blood and lymphatics, both compromising the central nervous system. [2, 4]. Despite being a vaccine preventable disease, there were a total of 197 cases and 16 deaths from tetanus in the US from 2009 to 2015 [4]. In a grueling 8-week stay from hospital to rehabilitation clinic to, one young boy’s infection with tetanus amassed medical costs of over $800,000 for what could have been an entirely preventable [5].
Tetanus can be prevented through immunization with tetanus-toxoid-containing vaccines (TTCV) and because recovery from initial infection does not grant natural immunity, one can be infected again. Cases of tetanus in individuals who have been immunized up to 10 years prior to infection are extremely rare, suggesting an efficacy rate of nearly 100% [3]. However, boosters against tetanus are recommended every 10 years for full efficacy since immunity levels do decline with time [3]. It is recommended by the World Health Organization (WHO) to receive a three-dose primary vaccination followed by three booster doses. The primary vaccination schedule should start as early as six weeks of age, with subsequent doses given with a minimum interval of four weeks between doses. The three booster doses should be given during the second year of life, at four to seven years, and finally at nine to fifteen years of age [1].
What are the symptoms of tetanus?
There are multiple types of tetanus. Generalized tetanus, accounting for roughly 80% of reported cases [2], usually presents with a predictable descending pattern of lockjaw, followed by stiffness of the neck, difficulty swallowing, painful muscle spasms, and rigidity of abdominal muscles that later becomes generalized [2]. Often, cases of tetanus-induced lockjaw can be so severe that the infected person cannot open his or her mouth at all. Laryngospasms, or spasms of the vocal cords or muscles of respiration can interfere with breathing [2]. Fractures of the spine or long bones can occur from sustained contractions and convulsions [2]. These symptoms can be coupled with high temperature, sweating, high blood pressure, and accelerated heart beat or tachycardia. Tetanus can also cause seizure-like activity and lead to severe nervous system disorders [3]. With an incubation period ranging from three to twenty-one days, the onset of symptoms is not immediate [2].
Local tetanus, an uncommon form of the disease, presents contractions in the muscles at the anatomic site of the injury that can last for many weeks before gradually subsiding [2]. Cephalic tetanus, another rare form of the disease, occasionally occurs in ear infections involving C. tetani or following injuries to the head. This can exhibit itself as tonic spasms in the face and throat, involving cranial nerves [2]. Tetanus can be transmitted when C. Tetani toxins from unvaccinated pregnant woman are passed to her baby, known as maternal and neonatal tetanus. Without passive immunity from vaccinated mothers, the symptoms of tetanus can exhibit four to fourteen days after birth in infected newborns [2].
Since the early 1900s, mortality due to tetanus has declined at a constant rate in the United States [4]. Several factors have contributed to the decline in tetanus morbidity and mortality, including tetanus toxoid-containing vaccines being available since the late 1940s. Advances in wound care and rural-to-urban migration may have also contributed to the decline in tetanus mortality noted during the first half of the 20th century [4]. From 2009 to 2015, a total of 197 cases and 16 deaths from tetanus were reported in the United States. All deaths were among patients above 55 years of age [4].
Case Study
Unvaccinated children are particularly at risk because of their inclination to play in areas with soil infected with Clostridium tetani. This is exactly what happened to a six year old boy in Oregon who was playing in the soil on a farm in 2017 [5]. This story has recently come to light after Oregon’s passing of a bill that put tighter restrictions on parents’ opting out of vaccinations due to religious and philosophical beliefs after measles cases in the US surpassed the highest number on record since its elimination nationwide in 2000 [6]. While playing, he sustained a laceration to his forehead and was sterilized and sutured at home [5]. Six days later, he experienced terrifying involuntary upper body muscle spasms, opisthotonus or arching of the neck and back, and trismus or lockjaw, a defining feature of the disease. After he experienced difficulty breathing, the parents contacted emergency medical services and he was air-transported to a tertiary pediatric medical center where he was given intravenous metronidazole, a common antibiotic, and his first DTap Vaccine [5], a vaccine protecting against Diphtheria, Tetanus, and Pertussis, that is normally given in five doses starting at two months of age [7].
His opisthotonus worsened along with his elevated blood pressure, rapid heartbeat, and body temperature. He was given ventilator support and multiple continuous intravenous medication infusions with neuromuscular blockade to manage his muscle spasms [5]. On the fifth day of hospitalization, a tracheostomy was placed for prolonged ventilator support. On day 35, he was weaned off of neuromuscular blockade and by day 44, his ventilator was discontinued [5]. On day 38, he was finally able to walk 20 feet without assistance. On day 54, his tracheostomy was removed and three days later he was transferred to a rehabilitation facility for 17 days. One month later, he was able to return to normal activities, including riding his bike and running. The 8 week inpatient ordeal to mitigate a completely preventable disease accrued a total cost of $811,929 [5]. Despite this insurmountable cost, his family declined a second dose of DTap and other recommended immunizations [5].
References
[1] https://www.who.int/immunization/diseases/tetanus/en/
[3] https://www.historyofvaccines.org/index.php/content/articles/tetanus
[4] https://www.cdc.gov/vaccines/pubs/surv-manual/chpt16-tetanus.html
[5] https://www.cdc.gov/mmwr/volumes/68/wr/mm6809a3.htm?s_cid=mm6809a3_e
[6] https://www.cnn.com/2019/05/07/politics/oregon-vaccine-bill/index.html
[7] https://www.cdc.gov/vaccines/hcp/vis/vis-statements/dtap.html
