VN October 2023

Oktober 2023 13 practices, and other factors, giving rise to subsequent resistant proliferation [24]. Little is known regarding the prevalence or transmission of clostridium in elephants or at the elephant-human interface. However, elephants may harbor the organism, and the actual transmission between elephants and humans constitutes an occupational risk [12, 24]. Escherichia coli infection Escherichia coli infection is caused by E. coli , a frequently occurring commensal gut microbe, and pathogenically opportunistic organism commonly found in soil and water [76]. One study found that 100% of elephants in human entertainment activities in Asia harbored the bacteria [96]. Escherichia coli is often transmitted through fomite, contaminated food, and fecal-oral routes. In humans, pathogenic infections result in gastrointestinal signs and symptoms, malaise, fever, and sometimes death [21, 30, 76]. In elephants, the infection results in gastrointestinal signs, septicemia, and sometimes death [21]. There is little documentation of the incidence or prevalence of E. coli infection between elephants and humans, although cross-infection is presumed [30]. Gaffkemia Gaffkemia is an emerging yet rare disease caused by Aerococcus viridian . In humans, the infection results in genitourinary issues, arthritis, bacteremia, endocarditis, and meningitis [27, 36]. In elephants, the infection results in genitourinary signs [36]. Transmission is likely through fomite, contaminated food, and fecal- oral routes [27, 36]. Little is known regarding this pathogen and any direct association between elephants and humans, although both are susceptible to infection with the microorganism. Leptospirosis Leptospirosis is a globally important disease caused by Leptospira interrogans. In humans, the infection results in various signs and symptoms, including fever, anorexia, malaise, muscle pain, renal failure, hepatic failure, or death [77, 97]. In elephants, individuals are commonly asymptomatic, but they may act as carriers for transmission [31, 98]. A study of 11 elephants sampled for L. interrogans in Thailand found a prevalence rate of 57%, indicating frequent exposure of these animals to the potential pathogen [97]. While elephants may harbor L. interrogans, they are not clearly implicated in human disease [97]. However, a recent study of environments shared between elephants and humans in Thailand concluded that L. interrogans contamination may pose a potential risk to elephant camp tourists and workers [31]. Transmission is through contaminated urine, surface water, mud, and sewerage overspills, which may introduce the microorganism to its host through open dermal lesions, conjunctiva, genital tract, mucous membranes, lungs, or ingestion [77, 97]. Pasteurellosis (hemorrhagic fever) Pasteurellosis is a globally important disease caused by Pasteurella spp . In humans, the infection results in malaise, fever, anorexia, inflamed mucous membranes, swellings, pain, pneumonia, hemorrhage, septicemia, or death [78, 99]. In elephants, the infection results in respiratory distress, frothy discharge from the trunk, shivering, fever, and sub-mandibular edema [19, 81]. One study showed hemorrhagic tracheitis, hemorrhages in the heart, and septicemia of the major organs [99]. Pasteurella spp . occur in diverse environments, including moist soil, and are frequently commensal to nasopharyngeal and other respiratory tract cavities in animals [78, 99]. Pathogens are transmitted through fomites and direct contact routes [78, 99]. While transmission of Pasteurella spp . from various animals to humans is well documented, very little is known regarding the elephant-to-human (or vice versa) relationship, although there are no strong grounds to presume that infection between elephants and people may not occur. Salmonellosis Salmonellosis is a disease caused by microbial organisms of the genus Salmonella . In humans, the infection typically results in relatively limited gastrointestinal signs and symptoms, anorexia, malaise, weight loss, and pain, but in serious cases also may also cause severe systemic disease, septicemia, meningitis, or death [12, 30, 100, 101]. In elephants, the infection results in lethargy, loss of appetite, hemorrhagic diarrhea, colic, and suspected abdominal discomfort/pain [34]. Salmonella spp . is a very large and diverse family of highly durable microorganisms, commonly found in many environments in soil, water, aerosolized particles, and animals [100, 101]. As for other species, Salmonella is a common commensal microbe, and one study found that 8% of elephants in human entertainment activities in Asia harbored the bacteria [96], which can also be regarded as an opportunistic pathogen [12, 30, 34]. Another study found a low prevalence of Salmonella in the feces of healthy elephants [102]. The microbe is transmitted diversely through fomite transfer, direct contact with open lesions, and ingestion. Salmonella zoonoses can be considered a reasonably ubiquitous yet mostly mild to moderate cross-species risk. Mycobacteriosis (TB) Mycobacteriosis, or TB, is the current primary disease of concern regarding the elephant-human relationship and is one of the world’s most significant diseases. Tuberculosis is caused by microbial organisms of the genus Mycobacterium spp . and includes two common types, Mycobacterium tuberculosis – the typical human infectious agent, and Mycobacterium bovis – the typical bovine infectious agent. However, whereas M. tuberculosis is classically associated with human TB, both types may infect humans. Tuberculosis occurs in both wild and captive Asian and African elephants, has a complex transmission modality and several elements remain unclear [43, 103]. Tuberculosis is typically transmissible from one individual to another through airborne droplets following expulsions, for example, sneezing, coughing, close contact respiration, or vocalization [103–105]. In humans, signs and symptoms of TB include fever, coughing, sneezing, pneumonia, breathlessness, malaise, fever, loss of body condition, systemic disease, pain, or death [104, 105]. Pathological findings may include localized focal or dispersed granulomas of sterile or non-sterile nature, diffuse exudate, and necrosis [103]. Although the disease usually invades the lungs, various body areas may be affected. The disease can be treated and cured using antibiotics and other therapies in the early stages, but chronic infection may result in treatable yet incurable states involving persistent or recurrent illness due to often slow onset, and cyclic active and inactive stages of the disease [106]. At later stages, treatment may necessarily be radical and involve major surgery, with varying degrees of success. Tuberculosis can affect all age groups, although people with