INFECTIOUS DISEASE Flashcards
What is the causative organism in Whitmore disease?
What is the treatment of choice?
Burkholderia pseudomallei
Whitmore disease also known as Meloidosis is characterized by
Pulmonary disease,
Septicemia
Miliary abscesses
It is caused by Burkholderia pseudomallei.
The antibiotic of choice is ceftazidime.
[19] While various antibiotics are active in vitro (e.g., chloramphenicol, doxycycline, co-trimoxazole), they have been proven to be inferior in vivo for the treatment of acute melioidosis.[29]
What is melioidosis? What causes melioidosis?
Melioidosis, also called Whitmore’s Disease, is an infectious disease caused by a bacterium called Burkholderia pseudomallei (previously known as Pseudomonas pseudomallei). The bacteria are found in contaminated water and soil and spread to humans and animals through direct contact with the contaminated source. The bacteria are also of some concern as a potential agent for biological warfare and biological terrorism.
Melioidosis is similar to glanders disease, which is passed to humans from infected domestic animals.
Where does melioidosis occur?
Melioidosis is most frequently reported in Southeast Asia and Northern Australia. It also occurs in South Pacific, Africa, India, and the Middle East. The bacterium that causes the disease is found in the soil, rice paddies, and stagnant waters of the area. People acquire the disease by inhaling dust contaminated by the bacteria and when the contaminated soil comes in contact with abraded (scraped) area of the skin. Infection most commonly occurs during the rainy season.
In the United States, confirmed cases range from none to five each year and occur among travelers and immigrants, according to the U.S. Centers for Disease Control and Prevention (CDC).
What are symptoms of melioidosis?
Melioidosis symptoms most commonly stem from lung disease where the infection can form a cavity of pus (abscess). The effects can range from mild bronchitis to severe pneumonia. As a result, patients also may experience fever, headache, loss of appetite, cough, chest pain, and general muscle soreness.
The effects can also be localized to infection on the skin (cellulitis) with associated fever and muscle aches. It can spread from the skin through the blood to become a chronic form of melioidosis affecting the heart, brain, liver, kidneys, joints, and eyes.
Melioidosis can be spread from person to person as well.
Glanders:
A bacterial infection that causes a chronic debilitating disease of equids (horses, mules, and donkeys) as well as some members of the cat family and is transmissible to people. The bacterium responsible for glanders is Burkholderia mallei (formerly called Pseudomonas mallei).
Glanders attacks the mucous membranes of the nostrils, producing increased secretion and discharge of mucus, and enlargement and induration of the lymph glands of the lower jaw. Hence, the name glanders from the French glandres meaning glands.
Glanders occurs in central and southeast Asia, the Middle East, parts of Africa, and possibly South America. It usually is acquired through direct skin or mucous membrane contact with infected animal tissues. The incubation period is 1 to 14 days. The clinical presentation varies; skin inoculation can result in localized infection with nodule formation and swollen glands. The disease often manifests as pneumonia, bronchopneumonia, or lobar pneumonia, with or without bacteremia (bacterial blood stream infection). There may be liver and spleen involvement.
Antibiotics such as trimethoprim/sulfamethoxazole have been used to treat humans. The mortality from this infection was approximately 95% before the use of antimicrobial agents; however, except when bacteremia develops, better diagnosis and more appropriate therapy have lowered mortality. No vaccine against this infection is available. – The General Accounting Office, the investigative arm of the US Congress, in a 1999 report considered glanders to be a “potential” biologic threat for terrorism, but noted it is difficult to acquire seed stock of the agent (Burkholderia mallei) and moderately difficult to process and disseminate it. The agent is very stable. Its lethal effects were deemed to be “moderate to high.”
A laboratory worker undergoes injection of vaccinia virus for vaccination against smallpox. What type of reaction is needed to ensure adequate development of immunity?
1 Vesicle or ulcer surrounded by 4 cm of erythema
2 Lichenoid plaque
3 Development of vesicles at site separate from injection
4 Targetoid plaque
5 Systemic flu-like reaction with fever and myalgia
Vesicle or ulcer surrounded by 4 cm of erythema.
Vaccinia virus is used to vaccinate high-risk individuals against smallpox virus. Development of a vesicle or ulcer with 4 cm of surrounding erythema is a reaction considered to have a high rate of adequate immunization.
A normal primary vaccination appears as a papule in 3-4 days, and rapidly progresses to a vesicle with the surrounding erythema by the 5th-6th day. The vesicle center becomes depressed and progresses to a well-formed pustule by the 8th-9th day. By the twelfth day, or soon thereafter, the pustule crusts over forming a brown scab, which progresses from the center of the pustule to the periphery. After 2.5 to 3 weeks, the scab detaches and a well formed scar remains.
Normal Reaction Time
Day Description
0 Vaccination
3-4 Papule
5-6 Vesicle with surrounding erythema → vesicle with depressed center
8-9 Well-formed pustule 12+ Pustule crusts over → scab
17-21 Scab detaches revealing scar
Guarneri bodies are associated with:
1 Measles
2 Orf
3 CMV
4 Smallpox
5 Anthrax
Smallpox
Guarnieri’s bodies are cytoplasmic eosinophillic inclusions found on light microscopy.
This biopsy is from a patient from Somalia.
Exanthem Subitum is caused by which of the following?
1 Group A Steptococcus
2 Coxsackie virus
3 Human Herpes Virus-6 (HHV-6)
4 Parvovirus B19
5 Epstein-Barr Virus
Human Herpes Virus-6 (HHV-6) Exanthem Subitum (Roseola Infantum, Sixth Disease) is caused by human herpesvirus 6, and 7 (HHV-6, HHV-7).
Granuloma Inguinale is caused by:
Granuloma Inguinale is caused by:
3 Calymmatobacterium granulomatis
Granuloma inguinale is caused by an infection of Calymmatobacterium granulomatis. It is a granulomatous skin disease of the genitals caused by sexual transmission. It is a gram negative rod that is similar to the Enterobacteriaceae. It is a smll, raised papule or subcutaneous nodule that rapidly ulcerates, rarely with lymphadenopathy. It is not self healing and spreads by radial extension. Hemophilis ducreyi is the cause of chancroid, Chlamydia trachomatis causes Lymphogranuloma Venereum, Treponema pertenue causes Yaws and T. pallidum is the cause of syphilis.
A patient recently had pharyngitis and now has an eruption of guttate psoriasis. Which of the following tests would be helpful in determining that this patient had a Streptococcal infection?
1 A complete blood count
2 FTA-ABS
3 U1-RNP
4 DNAse B
5 Serum calcium
DNAse B
The DNAse B, hyaluronidase or streptolysin O (ASLO) antibodies in serum can be helpful for confirming streptococcal infection in situations where streptococci cannot be isolated. The FTA-ABS is used for detecting syphilis, and is the only test that is positive in the first 14 days of infection. U1-RNP is an extractable nuclear antibody which is a marker for Mixed Connective Tissue Disease.
