post‐exposure prophylaxis (PEP) with ciprofloxacin or doxycycline should begin and continue for 60 days. Patients suspected of being infected with anthrax and requiring hospitalization should be immediately started on IV antibiotics [41–43]. Vaccination for PEP should be administered because of the persistence of anthrax spores in the lungs. Three licensed anthrax antitoxins are available from the U.S. Strategic National Stockpile. All work by binding to protective antigen, which blocks movement of toxins into cells and therefore the effects of toxins within the cells. Antitoxin use is indicated in all adults and children for the treatment of inhalation anthrax due to B. anthracis, in combination with other appropriate post‐exposure treatments.
Quarantine is not indicated for individuals exposed to anthrax as they are not contagious. A clinical framework and medical countermeasure is available that outlines an approach to an anthrax mass casualty incident [44].
Botulism
Botulism is caused by a neurotoxin produced by Clostridium botulinum, which ultimately leads to a flaccid paralysis. There are four forms of botulism based on site of toxin production: food‐borne, wound, intestinal, and inhalational [45].
In food‐borne botulism, early symptoms are non‐specific and gastrointestinal, including nausea, vomiting, and diarrhea. This may progress to blurred vision, double vision, dry mouth, and difficulty in swallowing, breathing, and speaking. Descending muscle paralysis occurs, starting with shoulders, and progressing to upper arms, lower arms, thighs, and then calves. Respiratory muscle paralysis ultimately leads to death. Food‐borne botulism is caused by the ingestion of C. botulinum toxin present in contaminated food, or by deliberate contamination as a biologic weapon. The case‐fatality rate in the US is 5‐10%.
Intestinal botulism is rare and occurs mainly in infants. It causes a striking loss of head control, diminished suckling and crying ability, constipation, and respiratory failure. Intestinal botulism occurs with ingestion of botulism spores, rather than ingestion of toxin. Spores, which may come from honey, food, and dust, germinate in the colon [45]. The case‐fatality rate of hospitalized cases is less than 1%.
Wound botulism causes the same symptoms as food‐borne botulism. This is rare and is caused by spores entering an open wound from soil or gravel.
Inhalational botulism is the most common form in the case of use of botulinum toxin as a biologic weapon. Symptoms are the same as food‐borne botulism, but the incubation period may be longer.
Botulism is not transmitted person to person. Therefore, EMS personnel should use standard precautions when caring for patients with suspected or known botulism. No special equipment is required. In the case of suspected aerosol exposure to the toxin, clothing should be removed and placed in plastic bags, and the exposed person should shower thoroughly.
Treatment in the prehospital setting consists of supportive care and transport to the hospital. Botulinum antitoxin administered as soon as possible will arrest progression of symptoms but will not reverse paralysis. Recovery follows the regeneration of new neuromuscular connections. Treatment for wound botulism may also include antibiotic therapy and wound debridement to remove the source of toxin‐producing bacteria.
Plague
Plague is caused by the bacterium Yersinia pestis. The incubation period is typically 1‐6 days, with non‐specific initial signs and symptoms, including fever, chills, sore throat, malaise, and headache. Tender, swollen, warm, and suppurative lymph nodes, mainly in the inguinal area, often follow. Patients infected with the plague may progress to septicemia, meningitis, pneumonia, or shock. Untreated plague has a case‐fatality rate of 50‐90%; if treated, mortality is 15%.
Plague is transmitted to humans by bites, scratches, respiratory droplets, or by direct skin contact. Bites from infected rat fleas are the most frequent source of transmission, but bites or scratches from cats may also transmit plague. Direct contact with tissue or body fluids of a plague‐infected sick or dead animal can lead to transmission to humans through a break in the skin [46].
For patients with pneumonic plague, strict isolation is indicated with precautions against airborne spread until 48 hours after the start of antibiotic therapy. Close contacts of patients infected with pneumonic plague should receive chemoprophylaxis and be placed under surveillance for 7 days. Articles soiled with sputum or purulent discharges should be disinfected.
Yersinia pestis could be used as a potential biological weapon leading to pneumonic plague [47]. In case of deliberate use as a biological weapon, plague bacilli would be transmitted via aerosolized airborne droplets. Many patients presenting with fever and cough, particularly hemoptysis in a fulminant course with high case fatality, should raise suspicions for a biological weapon [48–50].
Smallpox
Smallpox is a disease caused by the variola virus. The last naturally occurring cases of smallpox were identified in 1977, and in 1980 the World Health Organization declared smallpox officially eradicated from the planet. However, there remain two sources of smallpox virus in storage and for research purposes, one in the United States and one in Russia. Any new cases of smallpox will be a medical and public health emergency. Strict respiratory and contact isolation of confirmed or suspected smallpox cases are essential to prevent spread of this virus.
There are four main clinical forms of smallpox: ordinary smallpox (variola major), modified‐type smallpox, malignant smallpox, and hemorrhagic smallpox [51, 52]. All forms of smallpox infection begin with an incubation period usually lasting between 10 and 14 days. During this time, the infected person does not have symptoms, is not contagious, and may feel fine. Symptoms begin with a prodrome that typically lasts 2‐4 days, starting abruptly with fever, headache, abdominal pain, nausea, vomiting, muscle pain, headache, and malaise. In patients with pale‐skins, an erythematous or petechial rash may be visible.
Ordinary smallpox is the most common and severe form of disease, accounting for over 85% of cases during the smallpox era. After the prodrome, mucous membrane lesions called enanthem begin in the mouth. This consists of red spots on the tongue and mucosa that enlarge and ulcerate quickly, followed by a rash on the face. The rash then progresses from the proximal extremities to the distal extremities and trunk within 24 hours. The macules progress to papules, vesicles, pustules, and crusts. Crusts later separate leaving depigmented skin and pitted scars. The case‐fatality rate for ordinary smallpox is about 30%.
Transmission of smallpox is via virus inhalation from airborne droplets or fine particle aerosols from the oral, pharyngeal, or nasal mucosa of an infected person, physical contact with an infected person, or with contaminated articles through skin inoculation.
Medical personnel in contact with suspected or confirmed smallpox cases should be wearing N95 respirators and should take other standard precautions. All bedding and clothing should be autoclaved or laundered in hot water with bleach.
Treatment of smallpox patients generally involves supportive care. Smallpox vaccines can prevent or lessen the severity of disease if given within 2‐3 days of the initial exposure. They may decrease symptoms if given within the first week of exposure. There are antiviral therapies shown to be effective against poxviruses, including variola. However, no treatment has been tested and proven effective for people who are sick from smallpox.
Given that smallpox no longer exists as a naturally occurring disease, even a single suspected or known case should be considered an outbreak and public health authorities must be alerted immediately.
Tularemia
Tularemia,
