Download MBBS (Bachelor of Medicine, Bachelor of Surgery) General Medicine 2022 PPT 5 Spirochete Infections Lecture Notes
Infectious diseases
4/5th Semester Classes on Infectious Diseases, 8-9AM, Tuesdays (LT-1)
Topics
1
Approach to Infectious Diseases and their prevention
2
Antibiotic stewardship practices
3
Community-Acquired Infections
4
Health Care?Associated Infections
5
Gram-Positive Bacteria (part-1)
6
Gram-Positive Bacteria (part-2)
7
Gram-Negative Bacteria (part-1)
8
Gram-Negative Bacteria (part-2)
9
Spirochetal Diseases
10
Diseases Caused by Atypical/Miscellaneous Bacterial Infections
11
Revision-cum-exam on bacteria (Must to know type)
12
Infections Due to DNA Viruses
1
13
Infections Due to RNA Viruses (part 1)
14
Infections Due to RNA Viruses (part 2)
15
HIV/AIDS ? part 1
16
HIV/AIDS ? part 2
17
Fungal Infections
18
Parasitic Infections (part 1)
19
Parasitic Infections (part 2)
20
Revision-cum-exam on Virus, Fungal, and Parasite (Must to know type)
Spirochaetales
Leptospira species, which cause leptospirosis
Borrelia species, which cause relapsing fever and Lyme
Brachyspira species, which cause intestinal infections; and
Treponema species, which cause the diseases treponematoses
The Treponema species include
T. pallidum subspecies pallidum, which causes venereal syphilis;
T. pallidum subspecies pertenue, which causes yaws;
T. pallidum subspecies endemicum, which causes endemic syphilis; and
T. carateum, which causes pinta
T. pallidum cannot be cultured in vitro and only known natural host is the human
Jarisch- Herxheimer reaction is always a possibility in all spirochetes
Nearly all cases of syphilis are acquired by sexual contact with infectious lesions
(i.e., the chancre, mucous patch, skin rash, or condylomata lata)
Others: personal contact, infection in utero, blood transfusion, and organ
transplantation
IP ? average 21 days
Rapidly penetrates intact mucous membranes or abrasions in skin and, within a few
hours, enters the lymphatics and blood to produce systemic infection
Identification and examination of sexual contacts are most important for patients
with syphilis of <1 year's duration
The clinical appearance depends on the number of treponemes inoculated and on
the immunologic status of the patient
Primary Syphilis - primary chancre
Secondary Syphilis - parenchymal, constitutional, and mucocutaneous manifestations
Tertiary Syphilis ? gumma (a usually benign granulomatous lesion); cardiovascular
syphilis (usually ascending aorta and resulting in aneurysm); and neurosyphilis
(asymptomatic, meningeal, meningovascular, and parenchymatous (tabes dorsalis
and paresis) syphilis)
Latent Syphilis - Positive serologic tests for syphilis, together with a normal CSF
examination and the absence of clinical manifestations
Congenital Syphilis - fetal damage generally does not occur until after the fourth month
of gestation; most common clinical problem is the healthy-appearing baby born to a
mother with a positive serologic test Routine serologic testing in early
Screening or diagnosis (RPR or VDRL)
Quantitative measurement of antibody to assess clinical syphilis activity or to monitor
response to therapy (RPR or VDRL)
Confirmation of a syphilis diagnosis in a patient with a reactive RPR or VDRL test (FTA-
ABS, TPPA, EIA/CIA)
Persons with newly diagnosed HIV infection should be tested for syphilis; conversely, all
patients with newly diagnosed syphilis should be tested for HIV infection
An infant should be treated at birth
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if the treatment status of the seropositive mother is unknown;
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if the mother has received inadequate or nonpenicillin therapy;
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if the mother received penicillin therapy in the third trimester; or
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if the infant may be difficult to follow
Leptospirosis
Recent outbreaks on virtual y al continents (mainly in the tropics and subtropics)
By pathogenic species, L. interrogans designated as L. interrogans sensu lato
Underappreciated problem with a broad spectrum of clinical manifestations,
varying from asymptomatic infection to fulminant, fatal disease
Rodents, especially rats, are the most important reservoir
Transmission may follow direct contact with urine, blood, or tissue from an infected
animal or, more commonly, exposure to environmental contamination through cuts,
abraded skin, or mucous membranes
IP - 1 to 30 days
Leptospiremic phase ? evade complement-mediated killing by binding factor H
Immune phase - bacteria persist in various organs
Mild Leptospirosis - usually presents as a flu-like il ness, with fever, conjunctival
suffusion, pharyngeal injection, muscle tenderness, lymphadenopathy, rash,
meningismus, hepatomegaly, and splenomegaly
Severe Leptospirosis - Weil's syndrome, encompasses the triad of hemorrhage,
jaundice, and acute kidney injury; Other syndromes include (necrotizing)
pancreatitis, cholecystitis, rhabdomyolysis, and neurologic manifestations including
aseptic meningitis
Clinical diagnosis should be based on an appropriate exposure history combined
with any of the protean manifestations
Definitive diagnosis is based on isolation of the organism, polymerase chain reaction
(PCR), or seroconversion or a rise in antibody titer (by MAT/ELISA)
Nonoliguric hypokalemic renal insuf iciency is characteristic of early leptospirosis
Thank you
This post was last modified on 05 April 2022