Retrospective Analysis of Wound Characteristics and Tetanus Development in Captive Macaques

Abstract

Traumatic wounds and access to outdoor enclosures containing soil contribute to development of tetanus in non-human primates. A retrospective matched case-control study was conducted at a primate center to evaluate these factors by analysis of medical records of animals sustaining traumatic injuries during a three year study period: 31 macaques with traumatic injuries and a clinical diagnosis of tetanus were selected as cases and 62 macaques with traumatic injuries and no diagnosis of tetanus were selected as controls. For an animal with injuries to the digits, the odds of developing tetanus were 9.6 times those of a similar animal without injuries to the digits (OR = 9.55, 95% CI = 1.56 – 58.59); with injuries to the tail, the odds of developing tetanus were 8.0 times those of a similar animal without injuries to the tail (OR = 7.95, 95% CI = 0.82 – 77.04); and with injuries in more than one location, the odds of developing tetanus were 8.5 times those for a similar animal with injuries in just one location (OR = 8.45, 95% CI = 1.01 – 70.46). A non-human primate with injuries to the leg was less likely to develop tetanus than a similar non-human primate without injuries to the leg (OR = 0.19, 95% CI = 0.03 – 1.2). Results indicated that wound location is associated with development of tetanus infection in rhesus macaques. Identification of high risk trauma cases will allow better allocation of wound management and tetanus prophylaxis in institutions, especially those housing non-human primates outdoors.

Long‐term effects of tetanus toxoid inoculation on the demography and life expectancy of the Cayo Santiago rhesus macaques

“…Hill [] also observed bipedal locomotion and hopping. The classical human triad of trismus (lock jaw and risus sardonicus ), extensor rigidity and opisthotonus, along with the other signs reported by Hill [] are similar to those reported in other macaques, baboons and squirrel monkeys [DiGiacomo & Missakian, ; Goodwin et al, ; Kessler & Brown, ; Nakano et al, ; Rawlins & Kessler, ; Springer et al, ]. Unlike many other diseases of the central nervous system, victims of tetanus remain conscious until death [Hill, ; Rawlins & Kessler, ; Wassilak & Kretsinger, ].…”

“…This compares with 57 fatal cases among 67 total tetanus cases observed from 1976 through 1981 prior to TTI [Kessler et al, ; Rawlins & Kessler, ]. Thus, the TTI program begun in 1985, for all intents and purposes, eradicated tetanus infections in the colony as similar programs have done in other outdoor colonies of monkeys [Goodwin et al, ; Goss, ; Kessler & Brown, ; Kessler & Martinez, ; Springer et al, .] The reduction in the total mortality rate was greater than expected from the number of observed tetanus cases in two previous studies of the disease in the colony [Kessler et al, ; Rawlins & Kessler, ] but less than the 42.2% decrease in the total mortality rate in the two years immediately following TTI [Kessler et al, ].…”

“…The significantly different rate of growth among the six social groups was due to the lower survival rate in Group L. Higher tetanus mortality and lower survival rates for Group L were not related to greater levels of aggression. Kaplan [] showed the frequency of both aggression and affiliative encounters within Group L was significantly below that observed in the other social groups, so it is unlikely that Group L sustained relatively greater wounding as the primary cause of tetanus infections [Rawlins & Kessler, ; Springer et al, ]. The comparatively high incidence of tetanus in Group L was probably due to its restricted range on the Small Cay [Lauer, ] where, from 1970 to 1972, a horse was corralled [Sade et al, ].…”

“…Second cases of tetanus have been reported in the same humans and macaques [DiGiacomo & Missakian, ; Hill, ; Kessler & Rawlins, ; Wassilak & Kretsinger, ]. There are no pathognomic gross or histological lesions of tetanus although necropsy findings almost always include lock jaw and extensor rigor, and necrotic wounds can be found in many cases [DiGiacomo & Missakian, ; Rawlins & Kessler, ; Springer et al, ; Wassilak & Kretsinger, ].…”

“…Most tetanus cases occurred during the mating seasons from contaminated fight wounds but post‐partum and neonatal cases were also observed [Rawlins & Kessler, ]. Although Hill [] was successful in saving three of five tetanic toque macaques by administering intrathecal tetanus antitoxin and some rhesus have been recovered using intravenous tetanus antitoxin combined with intramuscular tetanus toxoid and high doses of systemic antibiotics, the case fatality rate in the Cayo Santiago rhesus macaques ranged from 83% to 85% [DiGiacomo & Missakian, ; Rawlins & Kessler, ] and in some species, such as squirrel monkeys, can reach 100% despite treatment [Kessler & Brown, ; Kessler & Martinez, 1979; Springer et al, ].…”