156: Miscellaneous Bacterial Infections with Cutaneous Manifestations Flashcards
What is the primary mode of transmission for Bacillus anthracis in humans?
The primary mode of transmission for Bacillus anthracis in humans is through percutaneous inoculation of anthrax spores, which accounts for approximately 95% of cases. Other modes include inhalation and gastrointestinal disease.
What are the major virulence factors of Bacillus anthracis?
The major virulence factors of Bacillus anthracis include:
- Poly-Y-D-glutamic acid capsule: Provides protection against phagocytosis.
- Tripartite anthrax toxin: Contains three proteins: Protective antigen (best target for vaccines or immunotherapy), Lethal factor, Edema factor.
What are the clinical findings associated with cutaneous anthrax?
Clinical findings associated with cutaneous anthrax include:
- Incubation period: 1-7 days.
- Symptoms: Low-grade fever, malaise, and development of a painless papule at the exposed site, which becomes edematous.
- Pain: If present, results from edema-associated pressure or secondary infection.
Describe the progression of cutaneous anthrax lesions.
The progression of cutaneous anthrax lesions follows these phases:
- Dermal papule
- Vesicle
- Pustule
- Eschar
Lesions may appear with regional lymphadenitis, malaise, and fever. Individual lesions may be pustular, leading to the term malignant pustule, but true pustules are rare. Lesions can enlarge into a pseudobulla with hemorrhagic necrosis and may be umbilicated.
What is the recommended treatment for naturally occurring anthrax?
The recommended treatment for naturally occurring anthrax includes:
- Penicillin or doxycycline.
- For suspected bioterrorism-associated anthrax, fluoroquinolone is recommended (safe for pregnant women and children).
- Raxibacumab is used for inhalational anthrax.
- Treatment of primary cutaneous anthrax continues with parenteral therapy until local edema disappears or the lesion dries up over 1-2 weeks.
What is the causative agent of anthrax?
Bacillus anthracis, a large aerobic, spore-forming Gram-positive rod.
How can anthrax be contracted?
Through direct handling of infected animals, contaminated soil, or processing of hides, wool, hair, or meat.
What is the incubation period for anthrax?
1 to 7 days.
What are the initial symptoms of cutaneous anthrax?
Low grade fever, malaise, and a painless papule at the exposed site that becomes edematous.
What are the phases of cutaneous anthrax lesions?
Dermal papule -> vesicle -> pustule -> eschar phases.
What is a characteristic feature of lesions caused by cutaneous anthrax?
Lesions may appear pustular but do not suppurate; true pustules are rare in anthrax.
What is the treatment for naturally occurring anthrax?
Penicillin or doxycycline.
What is the significance of the protective antigen in anthrax?
It is the best target for vaccines or immunotherapy.
What is the term for the syndrome associated with cutaneous anthrax?
Ulceroglandular syndrome, characterized by fatigue, fever, chills, and tender regional adenopathy.
What happens to the eschar in cutaneous anthrax lesions?
The eschar dries and separates in 1 to 2 weeks.
A farmer presents with a painless papule on his hand that has progressed to a black eschar surrounded by non-pitting edema. What is the most likely diagnosis, and what is the first-line treatment?
The most likely diagnosis is cutaneous anthrax. The first-line treatment is penicillin or doxycycline for naturally occurring anthrax, or fluoroquinolone for suspected bioterrorism-associated anthrax.
A patient presents with a painless ulcer on the hand and regional lymphadenopathy after handling contaminated animal hides. What is the diagnosis, and what are the major virulence factors of the causative organism?
The diagnosis is cutaneous anthrax. Major virulence factors include the poly-γ-D-glutamic acid capsule and the tripartite anthrax toxin (protective antigen, lethal factor, and edema factor).
What are the major virulence factors of Bacillus anthracis and their significance in anthrax infection?
The major virulence factors of Bacillus anthracis include:
- Poly-Y-D-glutamic acid capsule: A protective capsule that helps the bacteria evade the immune system. Best target for vaccines or immunotherapy.
- Tripartite anthrax toxin: Composed of three proteins: Protective antigen, Lethal factor, and Edema factor. Contributes to the pathogenicity and severity of the disease.
Describe the progression of cutaneous anthrax lesions and their clinical implications.
The progression of cutaneous anthrax lesions follows these phases:
- Dermal papule - initial painless papule at the exposed site.
- Vesicle - develops from the papule.
- Pustule - may appear but true pustules are rare in anthrax.
- Eschar - the lesion dries and separates in 1-2 weeks.
Lesions may be accompanied by regional lymphadenitis, malaise, and fever. The lesions are caused by toxins and are unaffected by antibiotics, indicating the need for timely treatment to prevent complications.
What is the recommended treatment for primary cutaneous anthrax and the rationale behind it?
The recommended treatment for primary cutaneous anthrax includes:
- Penicillin or doxycycline for naturally occurring anthrax.
- Fluoroquinolone for suspected bioterrorism-associated anthrax, even in pregnant women and children.
- Raxibacumab for inhalational anthrax.
Treatment is continued with parenteral therapy until local edema disappears or the lesion dries up over 1-2 weeks, ensuring effective management of the infection and prevention of severe complications.
What is the prognosis for untreated cutaneous anthrax?
Untreated cutaneous anthrax, particularly if nonedematous, is self-resolving. However, lesions with massive edema pose a risk of bacteremia with subsequent septicemia, and the mortality rate of untreated cutaneous anthrax is 5-20%.
What are the major clinical presentations of tularemia?
The six major clinical presentations of tularemia are:
- Glandular
- Ulceroglandular
- Oculoglandular
- Oropharyngeal
- Typhoidal
- Pneumonic.
How is tularemia transmitted?
Tularemia is transmitted through:
- Tick vectors (e.g., Dermatocentor variabilis, Amblyomma americanum, Ixodes sp.)
- Arthropod vectors (e.g., Chrysops discalis, mosquitoes)
- Domestic cats via direct contact, bite, or aerosol
- Aquatic rodents (muskrats and beavers), household rodents, and contaminated drinking water
- Direct inoculation into conjunctivae
- Ingestion of poorly cooked, contaminated meat.
What are the clinical findings associated with ulceroglandular tularemia?
In ulceroglandular tularemia, a painful red papule appears at the inoculation site, which enlarges and evolves into a necrotic chancriform ulcer covered by a black eschar. Regional lymph nodes are large and tender, and bacteremia may cause sepsis and pneumonia.
What is the incubation period for tularemia and its initial symptoms?
The incubation period for tularemia is from 2 to 10 days, with initial symptoms resembling a sudden flu-like illness.
What is the prognosis for untreated cutaneous anthrax?
It is self-resolving, but lesions with massive edema pose a risk of bacteremia and septicemia, with a mortality rate of 5-20%.
What is the causative agent of tularemia?
Francisella tularensis, a pleomorphic Gram-negative coccobacillus.
What are the major clinical presentations of tularemia?
Glandular, ulceroglandular, oculoglandular, oropharyngeal, typhoidal, and pneumonic.
How is tularemia primarily transmitted?
Through tick vectors, arthropod vectors, direct contact with infected animals, and ingestion of contaminated meat.
What are the clinical findings associated with ulceroglandular tularemia?
A painful red papule appears at the inoculation site, enlarges into a necrotic ulcer, and regional lymph nodes become large and tender.
What is the incubation period for tularemia?
It ranges from 2 to 10 days.
Is there human-to-human transmission of tularemia?
No, there is no human-to-human transmission.
What potential does tularemia have in terms of bioweapons?
It has potential as a class A bioweapon.
What is the treatment recommendation for cutaneous anthrax after edema resolves?
Patients may complete a 60-day treatment with oral therapy, and incision and debridement of the lesion is unnecessary.
A patient develops flu-like symptoms and a painful red papule that evolves into a necrotic ulcer with a black eschar after handling a rabbit carcass. What is the diagnosis, and what is the recommended treatment?
The diagnosis is ulceroglandular tularemia. The recommended treatment is an aminoglycoside (gentamicin or streptomycin) or fluoroquinolone for at least 10 days.
A patient develops purulent conjunctivitis with pain and local adenopathy after direct inoculation of bacteria into the conjunctiva. What is the diagnosis, and what is the causative organism?
The diagnosis is oculoglandular tularemia. The causative organism is Francisella tularensis.
A patient presents with fever, chills, and tender regional adenopathy after developing a necrotic chancriform ulcer covered by a black eschar. What is the diagnosis, and what is the mode of transmission?
The diagnosis is ulceroglandular tularemia. The mode of transmission is through tick or arthropod vectors, direct contact with infected animals, or ingestion of contaminated meat.
A patient develops a painful red papule on the hand that ulcerates and is surrounded by tender lymphadenopathy after handling contaminated water. What is the diagnosis, and what is the treatment?
The diagnosis is ulceroglandular tularemia. The treatment is an aminoglycoside (gentamicin or streptomycin) or fluoroquinolone for at least 10 days.
A patient presents with fever, malaise, and a painless papule that progresses to a hemorrhagic lesion with central necrosis. What is the diagnosis, and what is the prognosis if untreated?
The diagnosis is cutaneous anthrax. If untreated, the mortality rate is 5-20%.
A patient develops a necrotic ulcer with a black eschar and tender regional lymphadenopathy after being bitten by a tick. What is the diagnosis, and what is the causative organism?
The diagnosis is ulceroglandular tularemia. The causative organism is Francisella tularensis.
What is the prognosis for untreated cutaneous anthrax, particularly if it is nonedematous?
Untreated cutaneous anthrax, particularly if nonedematous, is self-resolving. However, lesions with massive edema pose a risk of bacteremia with subsequent septicemia, and the mortality rate of untreated cutaneous anthrax is between 5-20%.
What are the common vectors for the transmission of tularemia?
Common vectors for the transmission of tularemia include:
- Tick vectors:
- Dermatocentor variabilis
- Amblyomma americanum
- Ixodes sp.
- Arthropod vectors:
- Chrysops discalis (deerfly)
- Mosquitoes
- Other transmission routes:
- Domestic cats via direct contact, bite, or aerosol
- Aquatic rodents (muskrats and beavers), household rodents, and contaminated drinking water
- Direct inoculation into conjunctivae
- Ingestion of poorly cooked, contaminated meat.
What are the clinical findings associated with ulceroglandular tularemia?
Clinical findings associated with ulceroglandular tularemia include:
- A painful red papule at the inoculation site that enlarges and evolves into a necrotic chancriform ulcer covered by a black eschar.
- Regional lymph nodes are large and tender.
- Bacteremia may cause sepsis and pneumonia.
What is the incubation period for tularemia and what are the initial symptoms?
The incubation period for tularemia is from 2 to 10 days, with initial symptoms resembling a sudden flu-like illness.
What are the laboratory findings associated with pulmonary tularemia?
F. tularensis grows best on cysteine-supplemented blood agar, producing nonmotile, nonsporulating, pleomorphic, Gram-negative coccobacilli.
What is the prognosis for untreated pulmonary and typhoid tularemia?
Untreated pulmonary and typhoid tularemia have mortality rates of 30%. Ulceroglandular disease without antibiotics lasts many weeks and has a mortality rate of 5%.
What are the three clinical forms of plague caused by Yersinia pestis?
The three clinical forms of plague are:
- Bubonic
- Bubonic-septicemic (more virulent resulting from secondary bacteremia and sepsis)
- Pneumonic (fulminant disease resulting.
What are the three clinical forms of plague caused by Yersinia pestis?
The three clinical forms of plague are: 1. Bubonic 2. Bubonic-septicemic (more virulent resulting from secondary bacteremia and sepsis) 3. Pneumonic (fulminant disease resulting from respiratory spread).
How is Yersinia pestis transmitted?
Yersinia pestis is transmitted through: - Wild rodents - Fleas - Direct handling of infected rodents, rabbits, or their carcasses - Direct contact with pet dogs or cats that become ill after contact with infected wild animals.
What are the clinical findings associated with plague?
Clinical findings include: - Incubation period of 2-6 days - Sudden onset of high fever - Prostration - Malaise - Myalgia - Backache - Tachycardia - Primary pneumonic plague has a shorter incubation time.
What is the causative agent of plague?
Yersinia pestis, an aerobic Gram-negative bacillus.
What is the incubation period for plague?
2 to 6 days.
What is the mortality rate for untreated pulmonary tularemia?
30%.
What antibiotic is recommended for treating tularemia?
Aminoglycoside (gentamicin or streptomycin) or fluoroquinolone.
What precautions should hunters take to prevent tularemia?
Wear impervious gloves when handling game and cook game meat thoroughly.
What is a significant characteristic of Yersinia pestis in terms of its biological threat?
It is classified as a Category A biologic weapon.
What are the symptoms of primary pneumonic plague?
Sudden onset of high fever, prostration, malaise, myalgia, backache, and tachycardia.
What are the laboratory findings associated with pulmonary tularemia?
Laboratory findings for pulmonary tularemia include that F. tularensis grows best on cysteine-supplemented blood agar, producing nonmotile, nonsporulating, pleomorphic, Gram-negative coccobacilli. The pathogen survives intracellularly in phagocytes, leading to the development of small granulomas in lymph nodes, liver, and spleen.
What are the treatment options for tularemia and the recommended duration for each?
Treatment options for tularemia include: 1. Aminoglycoside (gentamicin or streptomycin) or Fluoroquinolone - Given for at least 10 days 2. Tetracycline antibiotic (Doxycycline) - Given for 15 days as an alternative. Treatment should continue for 7-10 afebrile days to reduce the risk of relapse.
What are the hallmark cutaneous lesions associated with plague?
The hallmark cutaneous lesions of plague include: - Prominent, tender regional lymphadenopathy with extensive subcutaneous edema. - Inguinal buboes are common in adults. - Axillary buboes are common in children. - Purpura and gangrene are most severe on distal extremities.
What are the primary physical findings in septicemic plague?
In primary septicemic plague, the following findings are observed: - Lacks buboes and presents with typical Gram-negative sepsis. - Many patients experience severe abdominal pain, nausea/vomiting, and bloody diarrhea.
What is the preferred treatment for bubonic plague?
The preferred treatment for bubonic plague is Gentamicin, although it has not been FDA approved for this indication. Other options include: - Doxycycline for oral therapy or postexposure prophylaxis. - Cotrimoxazole when combination therapy is desired.
What is the prognosis for untreated pneumonic and septicemic plague?
The prognosis for untreated pneumonic and septicemic plague is nearly always fatal. For untreated bubonic plague, the mortality rate is approximately 50%, but early antibiotic therapy has reduced this to 5-10%.
What are the key prevention strategies for plague?
Key prevention strategies for plague include: - Avoiding rodent nests, burrows, and dead animals. - Controlling rodents around homes. - Providing flea treatments for pets. - Rabbit hunters should wear gloves when handling carcasses. - Respiratory isolation for pneumonic cases and prophylaxis with doxycycline or cotrimoxazole for close contacts. - The most important prevention method is through rodent control.
What are the main transmission routes for Brucella species?
The main transmission routes for Brucella species include: - Contact with infected animals or animal products through conjunctiva or open skin. - Ingestion of unpasteurized or contaminated dairy products, which is the most common source of infection. - Inhalation of aerosolized bacteria.
What is the incubation period for brucellosis and how does it present clinically?
The incubation period for brucellosis is 1-3 weeks, but it may be 2 months or longer. It presents as either an acute febrile, flu-like bacteremic syndrome or as a chronic disease with nonspecific signs and symptoms.
What are the common cutaneous lesions associated with brucellosis in children?
In children with acute brucellosis, skin lesions occur in <5% and may appear as vasculitis, EN, panniculitis, abscess, polymorphous papules, pustules, or papulosquamous lesions. A violaceous papulonodular eruption is commonly seen on the trunk and lower extremities.
What are the laboratory findings indicative of brucellosis?
Laboratory findings in brucellosis may include leukopenia, anemia, elevated liver enzymes, positive blood cultures during acute illness, and a bone marrow specimen yield that is highest for cultures. An agglutination titer of greater than 1:160 is sufficient to start treatment.
What is the optimal treatment regimen for brucellosis?
The optimal treatment for brucellosis is a combination of doxycycline and streptomycin or gentamicin.
What are the related physical findings in brucellosis?
Related physical findings in brucellosis include no pathognomonic clinical findings, a debilitating but rarely fatal disease, and a characteristic undulating fever pattern. The most frequently involved organs are joints, reproductive organs, liver, and CNS, with a predilection for reproductive organs causing miscarriages and stillbirths.
What type of pathogens invade reticuloendothelial tissues and evade host defenses?
Intracellular pathogens.
What is the highest incidence of brucellosis associated with?
Underdeveloped agrarian areas with poor health controls for herds and consumption of raw dairy products.
Who is at high risk for brucellosis?
Herders, farmers, veterinarians, abattoir workers, and hunters who handle carcasses of large game.
What is the incubation period for brucellosis?
1 to 3 weeks, but may be 2 months or longer.
What are the common clinical presentations of brucellosis?
Acute febrile, flu-like bacteremic syndrome or chronic disease with nonspecific signs and symptoms.
What percentage of patients experience relapses after an ineffective antibiotic regimen?
15%.
What types of skin lesions can occur in children with acute brucellosis?
Vasculitis, EN, panniculitis, abscess, polymorphous papules, pustules, and papulosquamous lesions.
What is a characteristic symptom seen in nearly all patients with brucellosis?
Characteristic undulating fever.
What laboratory finding is indicative of brucellosis?
Leukopenia, anemia, and elevated liver enzymes.
What is the optimal treatment for brucellosis?
Doxycycline combined with streptomycin or gentamicin.
A farmer develops a violaceous papulonodular eruption on the trunk and lower extremities. What is the likely diagnosis, and what is the optimal treatment regimen?
The likely diagnosis is acute brucellosis. The optimal treatment regimen is doxycycline plus streptomycin or gentamicin for at least 6 weeks.
A patient presents with fever, chills, and a violaceous papulonodular eruption on the trunk after consuming unpasteurized dairy products. What is the diagnosis, and what is the treatment?
The diagnosis is brucellosis. The treatment is doxycycline plus streptomycin or gentamicin.
What is the diagnosis for a patient who consumes unpasteurized dairy products and presents with fever, chills, and a violaceous papulonodular eruption?
The diagnosis is acute brucellosis.
What is the treatment for acute brucellosis?
The treatment is doxycycline plus streptomycin or gentamicin for at least 6 weeks.
What are the high-risk groups for brucellosis?
High-risk groups for brucellosis include:
1. Herders
2. Farmers
3. Veterinarians
4. Abattoir workers
5. Hunters who handle carcasses of large game.
Why are high-risk groups particularly vulnerable to brucellosis?
These individuals are particularly vulnerable due to:
- Poor health controls for herds
- Consumption of raw dairy products
- Nomadic lifestyles with limited access to medical care.
What are the characteristic clinical findings associated with brucellosis?
Characteristic clinical findings of brucellosis include:
- Incubation period: 1-3 weeks, may extend to 2 months or longer
- Presentation: Acute febrile, flu-like bacteremic syndrome or chronic disease with nonspecific signs
- Relapses: Occur in 15% after ineffective antibiotic treatment
- Skin lesions: Less than 5% occurrence, more common in children, can appear as vasculitis, abscesses, or papules.
What laboratory findings are indicative of brucellosis?
Laboratory findings indicative of brucellosis include:
- Leukopenia, anemia, and elevated liver enzymes
- Positive blood cultures during acute infection.
What are the positive blood cultures associated with acute illness?
Positive blood cultures during acute illness indicate the presence of ate liver enzymes.
What type of specimens yield the highest cultures?
Bone marrow specimens yield the highest cultures.
What is the agglutination titer sufficient to start treatment?
Agglutination titer greater than 1:160 is sufficient to start treatment.
What is the optimal treatment regimen for brucellosis?
The optimal treatment regimen for brucellosis consists of:
- Doxycycline
- Streptomycin or Gentamicin
What is the effectiveness of the treatment combination for brucellosis?
This combination is effective in managing the infection and preventing complications.
How does the clinical presentation of brucellosis differ in children compared to adults?
In children, brucellosis may present with:
- Violaceous papulonodular eruptions on the trunk and lower extremities
- Skin lesions are more common (<5%) and can vary in appearance (e.g., vasculitis, abscesses).
What symptoms do adults experience with brucellosis?
Adults may experience more systemic symptoms such as fever and joint involvement without the distinctive skin manifestations seen in children.
What is the recommended treatment regimen for B. melitensis endocarditis according to WHO?
The WHO recommends an oral regimen of doxycycline and rifampin for at least 6 weeks to reduce the risk of relapse.
What is the prognosis for patients with B. melitensis endocarditis?
Approximately 5% of patients die due to B. melitensis endocarditis, and relapses occur in 10-15% of cases with suboptimal treatment.
Who are the high-risk groups for contracting glanders?
High-risk groups for glanders include:
- Animal handlers
- Veterinarians
- Abattoir workers due to direct exposure to animal reservoirs.
What are the two types of cutaneous lesions associated with glanders?
The two types of cutaneous lesions are:
- Acute, febrile, disseminated, infectious process
- Indolent, relapsing, chronic infection with multiple cutaneous or subcutaneous abscesses and draining sinuses.
What are the clinical findings associated with acute glanders?
Clinical findings of acute glanders include:
- A nodule surrounded by cellulitis at the site of inoculation, leading to swelling and suppuration.
- The lesion ulcerates, causing regional lymphadenopathy.
- The ulcer is painful with irregular edges and a gray-yellow base.
- Nodules may develop along lymphatics that drain the initial lesion, leading to widespread dissemination and multiple necrotic abscesses in subcutaneous tissues and muscle.
What is the transmission method for glanders?
Glanders is transmitted through direct exposure to animal reservoirs, particularly from horses, mules, and donkeys.
What is the typical time frame for local ulcers to develop after cutaneous inoculation of glanders?
Local ulcers typically develop within 1 to 5 days after cutaneous inoculation of glanders.
What is the recommended treatment regimen for B. mallei endocarditis according to WHO?
Doxycycline and rifampin for at least 6 weeks.
What is the prognosis for patients with B. mallei endocarditis?
5% of patients die, and relapses occur in 10-15% with suboptimal treatment.
What are the high-risk groups for contracting glanders?
Animal handlers, veterinarians, and abattoir workers.
What is the causative agent of glanders?
Burkholderia mallei.
What is the causative agent of glanders?
Burkholderia mallei, a gram-negative bacillus.
How does glanders typically transmit to humans?
Through direct exposure to animal reservoirs.
What are the two types of cutaneous lesions associated with glanders?
Acute, febrile, disseminated lesions and indolent, relapsing chronic infections.
What are the symptoms of acute glanders?
Nodules surrounded by cellulitis, swelling, suppuration, and regional lymphadenopathy.
What is a common characteristic of the ulcer in acute glanders?
It is painful with irregular edges and a gray-yellow base.
What is the typical time frame for local ulcers to develop after exposure to glanders?
1 to 5 days.
What is the clinical significance of ulceroglandular syndrome?
It indicates regional lymph node enlargement due to glanders infection.
What is the recommended duration for treatment of B. mallei endocarditis and why is this duration important?
The recommended treatment duration for B. mallei endocarditis is at least 6 weeks. This duration is important because shorter courses carry a risk of relapse, with relapses occurring in 10-15% of cases with suboptimal treatment.
What are the two types of cutaneous glanders and how do they differ in presentation?
The two types of cutaneous glanders are:
Type | Description |
|—|—|
| Acute Glanders | Characterized by a febrile, disseminated infectious process with painful nodules, ulceration, and regional lymphadenopathy. Nodules develop along lymphatics and can lead to widespread dissemination. |
| Chronic Glanders | Involves cutaneous and subcutaneous nodules that appear on extremities and other areas.
What are the characteristics of subcutaneous nodules associated with glanders?
Subcutaneous nodules appear on extremities and occasionally on the face, which ulcerate and develop draining sinuses.
What are the high-risk groups for contracting glanders?
High-risk groups for contracting glanders include animal handlers, veterinarians, and abattoir workers.
What is the primary mode of transmission for glanders?
The primary mode of transmission is direct exposure to animal reservoirs such as horses, mules, and donkeys.
What are the clinical implications of the ulceroglandular syndrome associated with glanders?
Ulceroglandular syndrome is characterized by the development of local ulcers within 1-5 days after exposure, along with enlargement of regional lymph nodes. This indicates a cutaneous inoculation or respiratory inhalation infection, which can lead to more severe complications such as septicemia if not treated promptly.
What are the key clinical findings associated with acute glanders?
Key clinical findings associated with acute glanders include:
- Nodules at the site of inoculation surrounded by cellulitis, leading to swelling and suppuration.
- Ulceration of the lesion with painful, irregular edges and a gray-yellow base.
- Development of nodules along lymphatics that drain the initial lesion.
- Bacteremic spread resulting in fevers, rigors, night sweats, and a characteristic eruption of crops of papules, bullae, and pustules. Mucopurulent, bloody nasal discharge is also common.
What is the recommended treatment for glanders according to the CDC?
Sulfadiazine is recommended by the CDC for the treatment of glanders.
What are the clinical findings associated with Pasteurella multocida infections after an animal bite?
Clinical findings include local pain and swelling within a few days after the animal bite, redness, swelling, ulceration, and seropurulent drainage at the bite site, and possible progression to cellulitis, lymphangitis, and local necrosis.
What is the prognosis for untreated septicemic glanders?
Untreated septicemic glanders is nearly always fatal.
What are the laboratory findings associated with Pasteurella multocida infections?
Laboratory findings may include mild leukocytosis, radiographs showing osteomyelitis, and Gram-negative and Wright-Giemsa stain revealing a bipolar appearance, along with histopathology indicating an acute pyogenic response.
What preventive measures can be taken to avoid Pasteurella multocida infections?
Preventive measures include judicious selection of pets and providing instruction to children regarding animal interactions.
What is the treatment of choice for Pasteurella multocida if it is cultured?
Penicillin is the drug of choice if only Pasteurella is cultured; Amoxicillin-clavulanic acid should be started after a bite.
What is the causative agent of rat-bite fever?
The causative agent of rat-bite fever is Streptobacillus moniliformis, which is a pleomorphic, Gram-negative rod.
What is the recommended treatment for patients with glanders according to the CDC?
Sulfadiazine is recommended by CDC.
What type of organism is Pasteurella multocida?
It is a small, ovoid, Gram-negative rod.
How does Pasteurella multocida typically transmit to humans?
Through animal bites, scratches, or…
How is Pasteurella multocida transmitted to humans?
Through animal bites, scratches, or licking.
What are the common cutaneous lesions associated with Pasteurella multocida infections?
Redness, swelling, ulceration, and seropurulent drainage at the bite site.
What is the prognosis for untreated septicemic glanders?
It is nearly always fatal.
What should be done to prevent Pasteurella multocida infections?
Judicious selection of pets and instruction to children.
What is the first-line treatment for a bite from an animal that may carry Pasteurella multocida?
Amoxicillin-clavulanic acid should be started after a bite.
What laboratory findings are associated with Pasteurella multocida infections?
Mild leukocytosis and radiographs may show osteomyelitis.
What is the causative agent of rat-bite fever?
Streptobacillus moniliformis, a pleomorphic, Gram-negative rod.
A patient presents with a painful ulcer with irregular edges and a gray-yellow base on the hand after handling a horse. What is the diagnosis, and what is the recommended treatment?
The diagnosis is acute glanders. The recommended treatment is sulfonamides, and treatment may last up to 1 year for subcutaneous or visceral abscesses.
A child develops redness, swelling, and seropurulent drainage at the site of a cat bite. What is the likely bacterial infection, and what is the first-line treatment?
The likely bacterial infection is Pasteurella multocida infection. The first-line treatment is amoxicillin-clavulanic acid.
A patient presents with fever, night sweats, and crops of papules and pustules localized to the face and neck after handling a horse. What is the diagnosis, and what is the characteristic histopathological finding?
The diagnosis is likely cutaneous anthrax. The characteristic histopathological finding is necrotizing granulomatous inflammation.
What is the diagnosis for a patient with acute glanders?
The diagnosis is acute glanders.
What is the characteristic histopathological finding in acute glanders?
The characteristic histopathological finding is supportive, necrotic processes containing numerous intracellular and extracellular bacteria.
What is the diagnosis for a patient who develops a painful ulcer with irregular edges and a gray-yellow base after handling a horse?
The diagnosis is acute glanders.
What is the recommended treatment for acute glanders?
The recommended treatment is sulfa-diazine, and treatment may last up to 1 year for subcutaneous or visceral abscesses.
What is the likely bacterial infection for a child with redness, swelling, and seropurulent drainage at the site of a cat bite?
The likely bacterial infection is Pasteurella multocida infection.
What is the first-line treatment for Pasteurella multocida infection?
The first-line treatment is amoxicillin-clavulanic acid.
What is the diagnosis for a patient with fever, night sweats, and crops of papules and pustules localized to the face and neck after handling a horse?
The diagnosis is acute glanders.
What are the recommended treatments for infections caused by Pasteurella multocida after an animal bite?
- Amoxicillin-clavulanic acid should be started after a bite.
- Penicillin is the drug of choice if only Pasteurella is cultured.
- P. multocida is also susceptible to doxycycline, later-generation cephalosporins, and TMP-SMX.
What are the clinical implications of untreated septicemic glanders?
Untreated septicemic glanders can lead to severe systemic complications.
What is the prognosis of untreated septicemic glanders?
Untreated septicemic glanders is nearly always fatal, highlighting the importance of early diagnosis and treatment.
What are the common cutaneous lesions associated with Pasteurella multocida infections following an animal bite?
- Redness, swelling, and ulceration at the bite site.
- Seropurulent drainage may develop.
- Cellulitis may progress to lymphangitis and local necrosis.
What preventive measures should be taken to avoid infections from Pasteurella multocida?
- Judicious selection of pets to minimize risk of bites.
- Instruction to children on safe interactions with animals.
What laboratory findings are indicative of a Pasteurella multocida infection?
- Mild leukocytosis.
- Radiograph of bone may show osteomyelitis.
- Gram-negative and Wright-Giemsa stain reveals a bipolar appearance.
- Histopathology shows an acute pyogenic response.
What is the clinical triad associated with streptobacillary disease?
The clinical triad includes fever, polyarthralgias/arthritis, and rash.
What are the common cutaneous lesions associated with streptobacillary fever?
Common cutaneous lesions include:
- Morbiliform eruption developing 2-3 days after fever.
- Individual lesions can be macular, morbiliform, or petechial.
- More prominent on the palms, soles, and around joints but may become generalized, resembling measles.
- Possible hemorrhagic acral vesicles.
- Characteristic desquamation on palms and soles after a week.
What laboratory findings are indicative of S. moniliformis infection?
Laboratory findings include:
What is niliformis infection?
Laboratory findings include:
- Gram stains showing Gram-negative filamentous branching chains with bead-like swellings.
- Histopathology revealing purpuric lesions and lymphocytic vasculitis with focal intravascular thrombii.
- Blood cultures are the best way to confirm the diagnosis of streptobacillary rat bite fever.
What is the treatment of choice for streptobacillary rat bite fever?
The treatment of choice is Amoxicillin-clavulanic acid. Alternatives include Doxycycline for those with penicillin allergy, and Penicillin if S. moniliformis is identified. Tetanus immunization status should also be checked.
What are the transmission methods for Spirillum minus?
Transmission methods for Spirillum minus include:
- Direct contact with infected animals through a bite.
- Ingestion of food or drink contaminated by rat urine, feces, or other secretions.
What is the causative agent of streptobacillary disease?
Spirillum minus, a gram-negative spirochete.
What are the common clinical findings in streptobacillary disease?
Fever, polyarthralgias/arthritis, and rash.
What is the incubation period for spirillary rat bite fever?
More than 14 days.
What type of eruption develops in 75% of streptobacillary fever cases?
A morbilliform eruption, 2-3 days after the fever.
What are the characteristics of the rash associated with streptobacillary fever?
Lesions can be macular, morbilliform, or petechial, more prominent on palms and soles.
What laboratory findings are associated with S. moniliformis infection?
Gram-negative filamentous branching chains.
What are the clinical findings associated with Streptobacillary disease following a rat bite?
The clinical findings include:
- Incubation period: 1-7 days
- Symptoms: Often, the rat bite has healed by the time flu-like illness begins.
- Clinical triad: Fever, polyarthralgias/arthritis, rash.
- Cutaneous lesions: 75% develop a morbilliform eruption 2-3 days after fever, with lesions that can be macular, morbilliform, or petechial, more prominent on palms.
What is a common complication of S. moniliformis infection?
Non-supportive, asymmetric arthritis involving large joints.
What should be checked in patients diagnosed with S. moniliformis?
Tetanus immunization status.
What is the diagnosis and treatment of choice for a patient presenting with fever, migratory arthritis, and a morbilliform rash on the palms and soles after being bitten by a rat?
The diagnosis is streptobacillary rat-bite fever. The treatment of choice is amoxicillin-clavulanic acid.
What is the causative organism of streptobacillary rat-bite fever?
Streptobacillus moniliformis.
What are the terms used to describe certain skin conditions?
The terms are ‘lar’, ‘morbilliform’, and ‘petechial’.
Where are ‘lar’, ‘morbilliform’, and ‘petechial’ conditions more prominent?
‘Lar’, ‘morbilliform’, and ‘petechial’ conditions are more prominent on palms and soles.
What is the significance of the incubation period in diagnosing spirillary rat bite fever?
The incubation period for spirillary rat bite fever is greater than 14 days. This extended period can complicate diagnosis, as symptoms may not appear until well after the initial exposure, making it crucial to consider recent rat bites in patients presenting with fever and rash.
What laboratory findings are indicative of S. moniliformis infection in a patient with rat bite fever?
Laboratory findings for S. moniliformis infection include:
- Gram stain: Shows Gram-negative filamentous branching chains with bead-like swellings.
- Histopathology: Purpuric lesions with lymphocytic vasculitis and focal intravascular thrombii.
- Blood cultures: Best method to confirm diagnosis of streptobacillary rat bite fever.
- VDRL tests: 1/3 may show false-positive results.
What are the recommended treatments for streptobacillary rat bite fever?
The recommended treatments include:
- Amoxicillin-clavulanic acid: Treatment of choice.
- Doxycycline: Alternative for patients with penicillin allergy.
- Penicillin: Drug of choice if S. moniliformis is identified.
- Tetanus immunization status: Should be checked and updated if necessary.
How do the cutaneous lesions of streptobacillary fever differ from those of spirillary fever?
The cutaneous lesions differ as follows:
Feature | Streptobacillary Fever | Spirillary Fever |
|—|—|—|
| Lesion Type | Morbilliform eruption, macular, petechial | Tender, red, indurated or ulcerated lesions |
What is the definition of ‘echial’?
Tender, red, indurated or ulcerated lesions.
Where is ‘echial’ more prominent?
More prominent on palms, soles, around joints; larger and prominent on the abdomen.
What are the associated symptoms of ‘echial’?
Hemorrhagic acral vesicles; tender regional lymphadenopathy and lymphangitis.
What is the prognosis for untreated disease related to seal finger?
Untreated disease for 10-20% is fatal, usually from endocarditis. Migratory arthritis may persist after bacteriologic cure.
What preventive measures should be taken to avoid seal finger?
Preventive measures include:
1. Dwellings should be rat-proofed.
2. Open water supply should be protected from contamination.
3. Persons handling rats should wear gloves, wash hands frequently, and avoid hand-to-mouth contact when around rats.
What are the clinical findings associated with seal finger?
Clinical findings include:
- Incubation period of 4 days.
- Furuncle-like lesion appears at the inoculation site, followed by severe pain, marked swelling, and stiffness.
What is the treatment of choice for seal finger?
The treatment of choice for seal finger is tetracyclines, which must be continued for 4-6 weeks. Seal finger does not respond to B-lactam antibiotics.
What are the high-risk groups for listeriosis?
High-risk groups for listeriosis include:
- Very young
- Very old
- Pregnant individuals
- Immunocompromised individuals.
What are the clinical findings of early-onset neonatal listeriosis?
Clinical findings of early-onset neonatal listeriosis include:
- Infants infected in utero by untreated bacteremic mothers.
- Findings evident at birth or within the first few days.
What is the incubation period for seal finger?
4 days.
What is the treatment of choice for seal finger?
Tetracyclines, continued for 4-6 weeks.
What is Listeria monocytogenes?
An anaerobic, Gram-positive bacillus found in soil, water, vegetation, and gut flora.
Who is at high risk for listeriosis?
Very young, very old, pregnant, and immunocompromised individuals.
What are the common settings for human listeriosis?
Sporadic disease in pregnant women and neonates, sporadic disease in AIDS patients, and foodborne outbreaks.
What is the highest incidence of human listeriosis seen among?
Infants in the perinatal period.
What are the clinical findings of early-onset neonatal listeriosis?
Generalized pustular, popular, or petechial skin lesions.
What transmission methods are associated with listeriosis?
Eating contaminated, unpasteurized, or improperly pasteurized dairy products.
What transmission methods are associated with listeriosis?
Direct cutaneous inoculation from animal products of conception, leading to primary cutaneous listeriosis (rare and follows occupational exposure).
What is the prognosis for untreated disease related to seal finger?
10-20% is fatal, usually from endocarditis.
What preventive measures should be taken to avoid seal finger?
Dwellings should be rat-proofed and open water should be protected from contamination.
What is seal finger characterized by?
Intensely painful red nodules on the distal phalanx.
What generalized skin lesions are seen at birth or within the first few days?
Generalized pustular, popular, or petechial skin lesions.
What is the diagnosis after handling a seal?
The diagnosis is seal finger.
What is the recommended treatment for seal finger?
The recommended treatment is tetracyclines for 4-6 weeks.
What are the key preventive measures for individuals who handle rats to avoid seal finger infection?
Preventive measures include:
1. Wearing gloves when handling rats.
2. Washing hands frequently.
3. Avoiding hand-to-mouth contact when around rats.
What is the primary treatment for seal finger and how long should it be continued?
The primary treatment for seal finger is tetracyclines, which must be continued for 4-6 weeks. Seal finger does not respond to B-lactam antibiotics.
In what settings is human listeriosis most commonly observed?
Human listeriosis is most commonly observed in the following settings:
- Sporadic disease in pregnant women and neonates.
- Sporadic disease in AIDS patients.
- Foodborne outbreaks.
What are the high-risk groups for human listeriosis?
High-risk groups include:
- Very young individuals.
- Very old individuals.
- Pregnant women.
- Immunocompromised individuals.
What are the clinical findings associated with early-onset neonatal listeriosis?
Clinical findings of early-onset neonatal listeriosis include:
- Infants infected in utero by untreated bacteremic mothers.
- Findings evident at birth or within the first few days.
- Generalized pustular, popular, or petechial skin lesions.
What is the incubation period for seal finger and what are its clinical manifestations?
The incubation period for seal finger is 4 days. Clinical manifestations include:
- A furuncle-like lesion at the inoculation site.
- Severe pain.
What are the cutaneous lesions associated with septic infants?
In septic infants, the lesions are generalized petechiae, papules, or pustules.
What are the cutaneous lesions associated with farmers in listeriosis?
For veterinarians or farmers, the lesions are tender red papules on exposed surfaces that evolve into pustules over 2-3 days.
What are the related physical findings in neonates with early onset listeriosis?
Neonates with early onset listeriosis are often meconium-stained at birth, lethargic, and have an enlarged liver and spleen. Additionally, CNS listeriosis has a spectrum of neurologic manifestations.
What is the treatment of choice for neonates with listeriosis?
The treatment of choice for neonates with listeriosis is IV ampicillin (or penicillin). For penicillin allergic patients, Cotrimoxazole or erythromycin can be used.
What are the prevention measures for listeriosis?
Prevention measures include:
1. Farmers should not feed contaminated silage to livestock or use untreated manure to fertilize crops.
2. Avoid foods linked to listeriosis, such as raw (unpasteurized) dairy products, unwashed vegetables, and poorly cooked meats.
3. Vets and farmers should use gloves and protective garments when handling aborted fetuses or placentae.
What is the prognosis for neonatal septicemia or meningitis caused by listeriosis?
In neonatal septicemia or meningitis, the mortality rate is 50% even with treatment. Pregnant women, even if treated, are at risk of miscarriage.
What lesions are associated with septic infants?
Generalized petechiae, papules, or pustules.
What are the related physical findings in neonates with early onset listeriosis?
Meconium-stained at birth, lethargic, and have an enlarged liver and spleen.
What is the treatment of choice for neonates with listeriosis?
IV ampicillin (or penicillin).
What is the prognosis for neonatal septicemia or meningitis?
Mortality is 50% even with treatment.
What should farmers avoid to prevent listeriosis?
Feeding contaminated silage to livestock and using untreated manure to fertilize crops.
What is the drug of choice for suspected bioterrorism-associated anthrax?
Fluoroquinolone.
Which bacterial infections have a category A bioweapon potential?
Anthrax, Tularemia, Plague.
Which bacterial infections have a category B bioweapon potential?
Brucellosis, Glanders (Melioidosis in part 2 as well).
What is a common laboratory finding in adults with meningitis?
CSF contains neutrophils.
What is a histopathological finding in listeriosis?
Focal necrosis, neutrophilic infiltrates, monocytes around blood vessels.
A veterinarian develops tender red papules on exposed skin that evolve into pustules over 2-3 days after handling livestock. What is the likely bacterial infection, and what is the treatment of choice?
The likely bacterial infection is primary cutaneous listeriosis. The treatment of choice is IV ampicillin or penicillin.
A pregnant woman presents with flu-like symptoms after consuming unpasteurized dairy products. What bacterial infection should be suspected, and what are the risks to the fetus?
Listeriosis should be suspected. Risks to the fetus include miscarriage, stillbirth.
What are the risks to the fetus associated with listeriosis?
Risks to the fetus include miscarriage, stillbirth, or neonatal septicemia.
What are the cutaneous lesions associated with septic infants in relation to listeriosis?
In septic infants, the cutaneous lesions present as generalized petechiae, papules, or pustules.
What do the lesions appear as for veterinarians or farmers?
The lesions appear as tender red papules on exposed surfaces that evolve into pustules over 2-3 days.
What are the laboratory findings indicative of listeriosis in adults with meningitis?
Laboratory findings for listeriosis in adults with meningitis include:
- Cultures revealing characteristic Gram (+) rods.
- The organism is B-hemolytic when cultured on sheep blood agar and exhibits tumbling motility when grown in broth.
- CSF contains neutrophils, and 1/3 of meningitic infants show a mononuclear response.
What is the treatment of choice for neonates with listeriosis?
The treatment of choice for neonates with listeriosis is IV ampicillin (or penicillin). For penicillin allergic patients, Cotrimoxazole or erythromycin is recommended. Cephalosporins are ineffective, and primary cutaneous listeriosis is usually self-limited but may require antibiotics.
What are the key prevention strategies for listeriosis in farmers?
Key prevention strategies for listeriosis in farmers include:
- Avoid feeding contaminated silage to livestock.
- Do not use untreated manure to fertilize crops.
- Avoid foods linked to listeriosis, such as raw (unpasteurized) dairy products, unwashed vegetables, and poorly cooked meats.
- Use gloves and protective garments when handling potentially contaminated materials.
What should be used when handling aborted fetuses or placentas?
Use gloves and protective garments.
What is the prognosis for neonatal septicemia or meningitis caused by listeriosis?
The prognosis is serious, with a mortality rate of 50% even with treatment.
What risk do pregnant women face even if treated for listeriosis?
Pregnant women are at risk of miscarriage.
