Table 1.
Sizes and Minimal Infective Doses (MID) of zoonotic pathogens. Courtesy of Wenner et al. [7].
| Microorganism | Pathogen | Size | Minimal Infective Dose |
|---|---|---|---|
| Viruses | Influenza A | 120 nm | Unknown |
| Lyssa (rabies) | 65 × 180 nm | Unknown | |
| Avula (NDV) | 150–250 nm | Unknown | |
| Herpesvirus (eg, herpes B) | 150–200 nm | Unknown (CHV-1) | |
| Coronavirus (eg, SARS-COV) | 80–160 nm | Unknown | |
| Bacteria | Mycoplasma sp. | 0.05–0.5 × 0.3–2 μm | <100 CFU (M. pneumoniae) |
| Francisella tularensis | 0.2–0.7 × 0.2 μm | 5–10 organisms | |
| Brucella sp. | 0.5–0.7 × 0.6–1.5 μm | Unknown | |
| Coxiella burnetti | 0.2–0.4 × 0.4–1 μm | 1–10 | |
| Staphylococcus sp. | 0.5–1.5 μm | >1,000,000 (S. aureus) | |
| Streptococcus sp. | 0.5–1 μm | Unknown | |
| Mycobacterium tuberculosis | 0.2–0.6 × 1–10 μm | <10 bacilli | |
| Bacillus anthracis | 0.4–1.8 × 0.9–10 μm | 8000—50,000 | |
| Leptospira interrogans | 0.1 × 6–12 μm | Unknown | |
| Salmonella sp. | 0.75–1.5 × 2–5 μm | 103–105 | |
| Escherichia coli | 0.6–1 × 1.2–3 μm | 10 EHEC 106 EPEC 108 ETEC | |
| Yersinia pestis | 0.5–0.8 × 1–3 μm | Unknown | |
| Fungi | Histoplasma | 2–4 μm, 8–15 μm | 5 yeast cells |
| Aspergillus sp. | 3–8 μm | Unknown | |
| Cryptococcus | 3–5 μm | Unknown | |
| Parasites | Toxoplasma | 10–12 μm | <10 sporulated oocysts (T. gondii) |
| Echinococcus sp. (eggs) | 34 × 27 μm | Unknown |
CFU, colony-forming units; CHV-1, Cercopithecine Herpesvirus-1; EHEC, Enterohemorrhagic E. coli; EPEC, Entero-pathogenic E. coli; ETEC, Enterotoxic E. coli; NDV, Newcastle Disease Virus; SARS-CoV, SARS Coronavirus.