Typhoid Fever - Causes, Pathogenesis, Signs and Symptoms, Diagnosis, Treatment and Prevention

Summary

Typhoid fever, also known as enteric fever, is a potentially fatal multi-systemic illness caused primarily by Salmonella typhi and sometimes by Salmonella paratyphi. It spreads through contaminated food, water, or poor hygiene, particularly in developing regions. If untreated, the disease can lead to severe complications such as delirium, intestinal obstruction, and death. Symptoms include fever, gastrointestinal issues, and in severe cases, neurological and cardiovascular complications. Diagnosis is confirmed through cultures, and treatment involves antibiotics. Preventive measures include vaccination and maintaining good hygiene, especially for travelers to endemic regions.

Takeaways

• 🔬 Typhoid fever, also known as enteric fever, is a systemic illness primarily caused by Salmonella typhi and, to a lesser extent, by Salmonella paratyphi.
• 💊 With proper treatment, typhoid fever has a high cure rate, but untreated cases can lead to severe complications like delirium, intestinal obstruction, and death.
• 🌍 The disease is most prevalent in developing countries with poor sanitary conditions and is endemic in parts of Asia, Africa, Latin America, and the Caribbean.
• 🚫 Transmission occurs mainly through the ingestion of contaminated food and water, with food handlers often being asymptomatic carriers.
• 👤 Factors such as reduced gastric acidity and certain genetic polymorphisms can increase an individual's susceptibility to typhoid fever.
• 🧬 Pathogenic Salmonella species infect the host by adhering to the epithelium in the distal ileum and then spreading through the lymphatic system to the liver and spleen.
• 🤒 The classic symptoms of typhoid fever include a stepwise fever pattern, abdominal pain, and rose spots, with symptoms typically appearing 7-14 days post-infection.
• 🏥 Complications of typhoid fever can affect multiple organ systems, including the neuropsychiatric, respiratory, cardiovascular, hepatobiliary, intestinal, genitourinary, and hematologic systems.
• 🩺 Diagnosis is primarily clinical, based on symptoms and travel history, with laboratory confirmation through culture of the organism.
• 💊 Treatment involves antibiotics, with fluoroquinolones not recommended due to resistance; third-generation cephalosporins and carbapenems are used for severe cases.
• 🛡 Prevention strategies include maintaining good personal hygiene and vaccination, with two types of vaccines available: inactivated and live attenuated.

Q & A

What is typhoid fever?

Typhoid fever, also known as enteric fever, is a potentially fatal multisystemic illness caused primarily by Salmonella typhi and, to a lesser extent, by Salmonella paratyphi.

What are the consequences of untreated typhoid fever?

Untreated typhoid fever may progress to delirium, intestinal obstruction, intestinal hemorrhage, bowel perforation, and death within one month of the onset of the disease.

How is typhoid fever commonly transmitted?

Typhoid fever is most commonly transmitted orally via ingestion of contaminated food and beverages, often handled by asymptomatic carriers who shed the bacteria through feces or urine.

Which regions have a high prevalence of typhoid fever?

Typhoid fever is endemic in Asia, Africa, Latin America, and the Caribbean, with travelers to these regions being at high risk.

What factors can increase the risk of developing typhoid fever?

Factors that can increase the risk of typhoid fever include reduced gastric acidity due to antacids, proton pump inhibitors, H2 receptor blockers, gastrectomy, and conditions like achlorhydria, as well as genetic polymorphisms that dampen macrophage activity.

How does Salmonella typhi enter the host system?

Salmonella typhi enters the host system primarily through the distal ileum, where it adheres to the epithelium over clusters of lymphoid tissue known as Payer's patches, and is then phagocytosed by macrophages.

What are the typical signs and symptoms of typhoid fever?

Typical signs and symptoms of typhoid fever include a stepwise fever pattern, abdominal pain, constipation, dry cough, headache, delirium, and rose spots. The symptoms usually appear after seven to fourteen days of ingestion of the bacteria.

What complications can arise from typhoid fever?

Complications of typhoid fever can affect multiple organ systems and include toxic confusional state, myocarditis, intestinal hemorrhage and perforation, nephritis, and hematologic disorders like disseminated intravascular coagulation.

How is typhoid fever diagnosed?

Typhoid fever is primarily diagnosed clinically based on history and symptoms. Culture of the organism from blood, intestinal secretions, and feces can confirm the diagnosis and test antibiotic sensitivity.

What are the treatment options for typhoid fever?

Proper treatment of typhoid fever includes antibiotics; fluoroquinolones are not recommended due to resistance. Third-generation cephalosporins are often used for severe or complicated disease, and different antibiotics may be used for travelers to specific regions like Pakistan.

How can typhoid fever be prevented?

Maintaining good personal hygiene and vaccination are recommended for prevention. There are two types of vaccines available: inactivated, given as an intramuscular injection, and live attenuated, given orally as a capsule.

Outlines

00:00

🤒 Typhoid Fever: Causes, Transmission, and Symptoms

Typhoid fever, a severe systemic illness, is primarily caused by Salmonella typhi and, to a lesser extent, Salmonella paratyphi. It can be fatal if untreated, progressing to delirium, intestinal obstruction, and death. The disease is transmitted orally through contaminated food and water, often by asymptomatic food handlers. It is prevalent in developing countries, particularly in Asia, Africa, and Latin America. Risk factors include reduced gastric acidity and certain genetic polymorphisms. The pathophysiology involves the bacteria's entry into the host system through the distal ileum, leading to infection of the gallbladder and gastrointestinal tract, causing symptoms such as fever, abdominal pain, and rose spots.

05:02

🏥 Typhoid Fever: Clinical Progression and Complications

The clinical presentation of typhoid fever includes a stepwise fever pattern, abdominal pain, and rose spots. The disease can progress to more severe symptoms like distended abdomen, splenomegaly, and diarrhea. In severe cases, it can lead to neuropsychiatric manifestations, respiratory complications, and even death. Complications may affect various organ systems, including the nervous, respiratory, cardiovascular, hepatobiliary, intestinal, genitourinary, and hematologic systems. The classic 'stepladder' fever pattern is now less common, and symptoms can vary by region, race, and infecting bacterial species.

10:03

💊 Typhoid Fever: Diagnosis, Treatment, and Prevention

Diagnosis of typhoid fever relies on clinical signs and symptoms, with travel history being crucial. Confirmation is through bacterial culture, which is specific but may not always be sensitive. Treatment involves antibiotics, with fluoroquinolones not recommended due to resistance. Different antibiotics are advised for travelers to specific regions and for severe cases. Prevention strategies include maintaining personal hygiene and vaccination, with two types of vaccines available: inactivated, given intravenously, and live attenuated, given orally. The inactivated vaccine is recommended for those at持续 risk, with boosters every two years.

Keywords

💡Typhoid fever

Typhoid fever, also known as enteric fever, is a bacterial infection caused by Salmonella typhi. The video script discusses how it is a potentially fatal systemic illness if left untreated. The term is central to the video's theme as it sets the stage for discussing the disease's transmission, symptoms, treatment, and prevention.

💡Salmonella typhi

Salmonella typhi is the primary bacterial agent responsible for typhoid fever. The script mentions that it is transmitted through contaminated food and water, highlighting its role in the disease's pathogenesis. Understanding this bacterium is crucial for grasping the video's focus on typhoid fever.

💡Oral transmission

Oral transmission refers to the ingestion of contaminated food or beverages, which is the most common way typhoid fever spreads. The script explains that food handlers who are asymptomatic can unknowingly spread the bacteria, making this concept vital for understanding the disease's epidemiology.

💡Rose spots

Rose spots are a characteristic symptom of typhoid fever, described in the script as salmon-colored, 1 to 4 centimeters in size, appearing on the patient's body. These spots are significant for diagnosing the disease and are a key detail in the video's discussion of typhoid fever's clinical presentation.

💡Gastric acidity

Gastric acidity is mentioned in the context of how a reduction in it can increase the risk of developing typhoid fever. The script explains that certain conditions and medications can lower stomach pH, facilitating bacterial growth. This concept is important for understanding the video's discussion on how the body's natural defenses can be compromised.

💡Macrophages

Macrophages are a type of white blood cell that plays a critical role in the immune system. The script describes how Salmonella typhi can manipulate macrophages to survive and reproduce within the host. This concept is central to understanding the pathophysiology of typhoid fever as presented in the video.

💡Peyer's patches

Peyer's patches are lymphoid tissue in the small intestine that the script identifies as a primary site for Salmonella typhi to adhere and invade the host's system. Understanding the role of Peyer's patches is essential for grasping the video's explanation of how typhoid fever progresses within the body.

💡Complications

The script outlines various complications of typhoid fever, including neuropsychiatric manifestations, respiratory issues, and intestinal problems. These complications highlight the severity of the disease when untreated and are a key part of the video's discussion on the disease's impact on the body.

💡Antibiotics

Antibiotics are medications used to treat bacterial infections, and the script discusses their importance in treating typhoid fever. The video emphasizes the need for proper antibiotic treatment to reduce the mortality rate, making this term central to the discussion on managing the disease.

💡Vaccination

Vaccination is a preventive measure against typhoid fever, as mentioned in the script. It discusses the availability of two types of vaccines: inactivated and live attenuated. Understanding the role of vaccination is crucial for the video's message on preventing typhoid fever, especially for travelers and those living in endemic areas.

Highlights

Typhoid fever, also known as enteric fever, is a potentially fatal multisystemic illness caused by Salmonella typhi and, to a lesser extent, by Salmonella paratyphi.

With proper treatment, typhoid fever has a high cure rate, but untreated cases can lead to severe complications and death.

The most common transmission method of typhoid fever is through the ingestion of contaminated food and beverages.

Typhoid fever is prevalent in developing nations with poor sanitary conditions, particularly in Asia, Africa, Latin America, and the Caribbean.

Travelers to endemic countries are at high risk of developing typhoid fever.

Certain medications and conditions that reduce gastric acidity can increase the risk of typhoid fever.

Some individuals may have genetic polymorphisms that facilitate bacterial growth and increase the risk of typhoid fever.

Salmonella typhi and paratyphi primarily enter the host system through the distal ileum, adhering to the epithelium over Peyer's patches.

The bacteria induce their host macrophages to attract more macrophages, facilitating their spread throughout the body.

Typhoid fever can cause a range of symptoms, including high fever, abdominal pain, and rose spots.

Complications of typhoid fever can affect multiple organ systems, including the neuropsychiatric, respiratory, cardiovascular, hepatobiliary, intestinal, genitourinary, and hematologic systems.

Diagnosis of typhoid fever is primarily clinical, based on history, signs, and symptoms, with culture of the organism for confirmation.

Empiric treatment options for typhoid fever should not include fluoroquinolones due to resistance in most strains.

Third-generation cephalosporins are recommended for severe or complicated typhoid fever.

Vaccination is recommended for travelers to typhoid-endemic areas, as well as for people living in endemic areas and laboratory workers.

There are two types of vaccines available for typhoid fever: inactivated and live attenuated.

Maintaining good personal hygiene and getting vaccinated are effective preventive measures against typhoid fever.

Transcripts

typhoid fever also known as enteric

fever is a potentially fatal multi

systemic illness caused primarily by

salmonella typhi and to a lesser extent

by salmonella para typhi with proper

treatment enteric fever yields a high

cure rate but untreated typhoid fever

may progress to delirium which is an

abrupt change in the brain that causes

mental confusion and emotional

disruption intestinal obstruction

intestinal hemorrhage bowel perforation

and death within one month of onset of

the disease

most common transmission method of

typhoid fever is oral transmission via

ingestion of contaminated food and

beverages these food handlers are often

asymptomatic and they chronically shed

the bacteria through feces or less

commonly urine due to poor personal

hygiene of these people food is often

contaminated with bacteria bacteria can

also be transmitted by drinking sewage

contaminated water and eating shellfish

and neglecting hand hygiene after using

a contaminated toilet is another method

of transmission typhoid fever occurs

worldwide primarily in developing

nations whose sanitary conditions are

poor thyroid fever is endemic in Asia

Africa Latin America and Caribbean which

are colored in red color on the map

travelers who are travelling to these

endemic countries are at high risk of

developing typhoid fever typhoid LaSalle

monalee are able to survive a stomach pH

as low as 1.5 reduction in gastric

acidity may increase the risk of

developing typhoid fever antacids proton

pump inhibitors h2 receptor blockers

gastrectomy and conditions like a

chlorhydris can cause reduction in

gastric acidity and facilitate bacterial

growth and some people may possess

genetic polymorphisms which dampen the

macrophage activity and facilitate

bacterial growth

now let's discuss about the

pathophysiology of typhoid fever all

pathogenic Salmonella species when

present in the gut are engulfed by

phagocytic cells which then passed

through the mucosa and present them to

the macrophages in limine appropriate

non typhoid will Salman Olli are fergus

oddest throughout the distal ileum and

colon with toll-like receptors

macrophages recognized pathogen

associated molecular patterns such as

flagella and lipopolysaccharides

macrophages and intestinal epithelial

cells then attract t-cells and

neutrophils with interleukin 8 causing

inflammation and suppressing the

infection

in contrast to non typhoid 'el

Salmonella Salmonella typhi and parrot I

fee enter the host system primarily

through the distal ileum they adhere to

the epithelium over clusters of lymphoid

tissue in the I liam also known as payer

patches they have specialized fin brie

to adhere to the epithelial cells the

bacteria are then focus oddest by the

macrophages located in payer patches the

bacteria then induced their host

macrophages to attract more macrophages

Salman le containing macrophages then

reach the mesenteric lymph nodes

thoracic duct and reticuloendothelial

system which consists of liver spleen

bone marrow and associated lymph nodes

while traveling bacteria used the

macrophage cellular mechanisms for their

own reproduction once a critical density

of organisms reached they induce

macrophage apoptosis breaking out into

the bloodstream to invade rest of the

body the bacteria then infect the gall

bladder via either bacteremia or direct

extension of infected bile the result is

that the organism re-enters the

gastrointestinal tract and bile and

reinfect Speyer patches bacteria that do

not reinfect the hosts are typically

shed in the stools and are then

available to infect other hosts

now I'm going to discuss about the signs

and symptoms of classic typhoid fever

the clinical syndromes associated with

salmonella typhi and para typhi are

indistinguishable thus both organisms

generate a similar type of clinical

presentation signs and symptoms usually

appear after seven to fourteen days of

ingestion of the bacterial fever pattern

is stepwise characterized by rising

temperature over the course of each day

that drops by the subsequent morning the

peaks and troughs rise progressively

over time relative braddock rd avenue

stalls pressure can also be observed

over the course of the first week of

illness the notorious gastrointestinal

manifestations develop these include

diffuse abdominal pain and tenderness

and in some cases fierce right upper

quadrant pain monocytic infiltration

causes inflammation of payer patches

this may lead to narrowing of bowel

lumen causing constipation that lasts

the duration of the illness in addition

the patient may present with a dry cough

dull frontal headache delirium and

malice

at the end of the first week of illness

fever plateaus at around 39 to 40

degrees Celsius the patient develops

rose spots which are salmon-colored and

1 to 4 centimeters in size these

generally resolved within two to five

days during the second week of illness

the signs and symptoms listed above

progress abdomen becomes distended and

splenomegaly is common relative Braddock

Ardea Vanda chronic pulse may develop

in the third week the individual grows

more toxic and anorexic with significant

weight loss the conjunctiva are infected

and the patient is to kipnuk with the

thready pulse and crackles over the lung

basis

abdominal distension is severe some

patients experience fowl green yellow

liquid diarrhea also known as pea soup

diarrhea inflammation due to the

necrosis of payer patches may cause

bowel perforation and peritonitis at

this point overwhelming toxemia

myocarditis or intestinal hemorrhage may

cause death

if the individual survives to the fourth

week fever mental confusion and

abdominal distension increases over the

next few days intestinal and neurologic

manifestations may still occur weight

loss and weakness increases some

survivors become asymptomatic Salmonella

carriers and have the potential to

transmit the disease to other people the

clinical course of a given individual

may deviate from the above description

of classic disease the signs and

symptoms may vary depending on the

geographic region race factors in the

infecting bacterial species the

stepladder fever pattern that was once

the hallmark of typhoid fever now occurs

only about 12% of all cases in most

recent cases the fever has a steady

insidious onset young children

individuals with AIDS and one-third of

immuno competent adults with typhoid

fever develop diarrhea rather than

constipation

now let's discuss about the

complications of typhoid fever as it is

a multi systemic illness it affects

almost all the organ systems in the body

potential neuropsychiatric

manifestations include the following a

toxic confusional state characterized by

disorientation delirium and restlessness

facial twitching and convulsions stupor

optin Dacian and coma indicates severe

disease in rare cases transverse

myelitis clinical mana neuropathy and

polyneuropathy may occur

paraplegia peripheral or cranial nerve

is Gil and Barre syndrome and depression

are some other rare complications

respiratory complications may include

acute low burn ammonia an ulceration of

the posterior pharynx cardiovascular

complications may include toxic

myocarditis in about one to five percent

of patients this is the leading cause of

death in endemic areas and rarely the

patient may develop pericarditis

hepatobiliary complications may include

jaundice pancreatitis and hepatomegaly

intestinal manifestations include

intestinal hemorrhage and perforation

genitourinary manifestations include

immune complex blue merle itis

proteinuria and rarely nephritic

syndrome hematologic manifestations

include disseminated intravascular

coagulation and rarely hema lytic uremic

syndrome

the diagnosis of typhoid fever is

primarily clinical based on history and

signs and symptoms the doctor should

obtain a travel history from the patient

in addition culture of the organism

should perform to confirm the diagnosis

and test antibiotic sensitivity culture

of the organism is considered 100%

specific blood intestinal secretions and

feces can be used to isolate the

organism

now let's discuss about possible

treatment options for typhoid fever

untreated typhoid fever carries about 15

to 30 percent of mortality rate however

with proper treatment the mortality rate

of typhoid fever is less than 1 percent

carefully consider empiric treatment

options most Salmonella typhi and parrot

I feast strains are not susceptible to

fluoroquinolones thus fluoroquinolones

should not be included in empiric

treatment as CDC indicates as a thrombus

enforce espect Adan complicated disease

and third-generation cephalosporins for

severe or complicated disease are given

people who travel to Pakistan are

treated with different antibiotics as a

thrombus infer uncomplicated disease and

carbapenems for severe or complicated

disease

finally let's come to the prevention of

typhoid fever maintaining of good

personal hygiene is a good way of

prevention of typhoid fever vaccination

is recommended for travelers to parts of

the world where typhoid fever is common

people who live in endemic areas and

laboratory workers who work with

Salmonella typhi bacteria there are two

vaccines are available for typhoid fever

inactivated one and live attenuated one

inactivated vaccine is given as an

intravenous injection and given to

people of two years and older a single

dose vaccine given two weeks before

travel repeated doses are recommended

every two years for people who remain at

risk live attenuated vaccine is given

orally as a capsule and given to people

of six years and older

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