Typhoid fever, or enteric fever, is a widespread illness that poses a significant public health challenge, particularly in developing countries. Its causative agents are Salmonella paratyphi and Salmonella typhi. Enteric fever is a collective term encompassing both typhoid and paratyphoid fevers. Since paratyphoid fever closely resembles typhoid fever in its clinical presentation, the terms enteric fever and typhoid fever are often used interchangeably.
In densely populated and unsanitary areas, typhoid fever remains a major cause of both mortality and morbidity, although extensive research and public health interventions have succeeded in reducing its incidence. The disease progression varies from initial gastrointestinal symptoms to nonspecific systemic manifestations, potentially leading to various complications.
The transmission of Salmonella bacteria is commonly associated with the “four Fs”: flies, feces, fingers and fomites. Characteristic features of typhoid fever include a step-wise pattern of fever, where temperature rises and falls alternatively, accompanied by symptoms such as headache and abdominal pain.
Epidemiology
While the incidence of culture-confirmed typhoid fever and paratyphoid A cases in the United States has been relatively low since 2008, enteric fever remains a significant global health concern. Worldwide, there are over 26 million cases of typhoid fever and 5 million cases of paratyphoid infection each year, resulting in approximately 215,000 deaths. Low- and middle-income countries in southern Africa and south-central Asia have a higher typhoid fever incidence than developed nations.
In developed countries, most cases are seen in travelers returning from endemic regions or individuals visiting these areas, as they are more likely to have increased exposure to contaminated food and water sources. Those who fail to seek pretravel consultation and vaccination are also at a higher risk. Typhoid fever is more prevalent in regions with tropical and temperate climates and is closely associated with inadequate sanitation, lack of proper sewage systems, and insufficient water treatment facilities.
Salmonella typhi is more common than Salmonella paratyphi, with Salmonella paratyphi A being the most prevalent subtype. The global increase in population, pollution, and shortage of clean drinking water has contributed to the rising number of new cases of typhoid fever. However, advancements in research, changes in treatment approaches, and the development of new drugs have led to a decrease in mortality rates despite the emergence of multidrug-resistant strains. With the widespread use of antibiotics, the classic clinical presentations of typhoid fever may not always be observed. In the United States, only a small percentage of cases exhibit splenomegaly and rose spots.
Additionally, around 4% of patients with typhoid fever become chronic carriers, remaining asymptomatic after acute treatment but potentially shedding Salmonella in their stool or, less commonly, their urine for up to a year. Chronic carriage is more frequently observed in women and individuals with biliary abnormalities, such as cholelithiasis. Certain blood group antigens may also be associated with increased susceptibility to chronic carriage of S. typhi.
Anatomy
Pathophysiology
Etiology
The primary causative agents of typhoid fever are Salmonella paratyphi and Salmonella typhi, belonging to the Enterobacteriaceae family. Salmonella is a genus of two species: enterica serovar and enteritidis, classified using multiplex quantitative polymerase chain reaction analysis. Salmonella typhi and Salmonella paratyphi (A, B, C) are specific serotypes within the Salmonella enterica species. On the other hand, nontyphoidal Salmonella is more commonly associated with gastroenteritis and is typically seen in children. The transmission of Salmonella occurs through the fecal-oral route, primarily via contaminated water, undercooked foods, and fomites contaminated with the bacteria.
It is prevalent in areas characterized by overcrowding, social instability, and poor sanitation. The transmission is exclusively from infected individuals to others, as humans are the only host for Salmonella. To a lesser extent, poultry, eggs, and turtles are considered major sources of Salmonella contamination. In a study conducted in China on the distribution of Salmonella isolates in chicken slaughterhouses using whole-genome sequencing, approximately 57% of the samples tested positive for Salmonella.
The normal flora of the gut provides a protective barrier against Salmonella infection. However, using antibiotics, such as streptomycin, can disrupt the normal gut flora, making it easier for Salmonella to invade. Malnutrition can also reduce the normal gut flora, increasing susceptibility to infection. Therefore, the use of broad-spectrum antibiotics and poor nutrition can contribute to an increased incidence of typhoid fever.
Genetics
Prognostic Factors
Typhoid fever poses a significant global burden in terms of both mortality and morbidity, with the highest impact observed in countries in Africa and South Asia. However, advancements in treatment modalities and the availability of antibiotics have significantly reduced the overall mortality rate to less than 1%. This is a substantial improvement compared to the 1940s when treatment options were limited to symptomatic and supportive measures, resulting in a mortality rate of around 12.75%.
Early diagnosis and prompt treatment play a crucial role in preventing complications associated with typhoid fever. Despite a relatively high frequency of episodes with complications, the current mortality rate remains low due to effective medical interventions. It is worth noting that untreated patients face certain risks, as approximately 10% of them may experience relapses, while about 4% may become chronic carriers of the infection. Therefore, timely diagnosis and appropriate treatment are essential in mitigating the impact of typhoid fever.
Clinical History
Physical Examination
Age group
Associated comorbidity
Associated activity
Acuity of presentation
Differential Diagnoses
Laboratory Studies
Imaging Studies
Procedures
Histologic Findings
Staging
Treatment Paradigm
by Stage
by Modality
Chemotherapy
Radiation Therapy
Surgical Interventions
Hormone Therapy
Immunotherapy
Hyperthermia
Photodynamic Therapy
Stem Cell Transplant
Targeted Therapy
Palliative Care
Medication
Future Trends
Media Gallary
References
News
Female Surgeons in NHS Face Rampant Sexual Harassment
Posted on
News
Gene Therapy Promises Restoration of Motor Function
Posted on
News
Ultra-Processed Foods Linked to Elevated Depression Risk in Women
Posted on
News
Research Reveals How Language Shapes Social Memory in the Brain
Typhoid fever, or enteric fever, is a widespread illness that poses a significant public health challenge, particularly in developing countries. Its causative agents are Salmonella paratyphi and Salmonella typhi. Enteric fever is a collective term encompassing both typhoid and paratyphoid fevers. Since paratyphoid fever closely resembles typhoid fever in its clinical presentation, the terms enteric fever and typhoid fever are often used interchangeably.
In densely populated and unsanitary areas, typhoid fever remains a major cause of both mortality and morbidity, although extensive research and public health interventions have succeeded in reducing its incidence. The disease progression varies from initial gastrointestinal symptoms to nonspecific systemic manifestations, potentially leading to various complications.
The transmission of Salmonella bacteria is commonly associated with the “four Fs”: flies, feces, fingers and fomites. Characteristic features of typhoid fever include a step-wise pattern of fever, where temperature rises and falls alternatively, accompanied by symptoms such as headache and abdominal pain.
While the incidence of culture-confirmed typhoid fever and paratyphoid A cases in the United States has been relatively low since 2008, enteric fever remains a significant global health concern. Worldwide, there are over 26 million cases of typhoid fever and 5 million cases of paratyphoid infection each year, resulting in approximately 215,000 deaths. Low- and middle-income countries in southern Africa and south-central Asia have a higher typhoid fever incidence than developed nations.
In developed countries, most cases are seen in travelers returning from endemic regions or individuals visiting these areas, as they are more likely to have increased exposure to contaminated food and water sources. Those who fail to seek pretravel consultation and vaccination are also at a higher risk. Typhoid fever is more prevalent in regions with tropical and temperate climates and is closely associated with inadequate sanitation, lack of proper sewage systems, and insufficient water treatment facilities.
Salmonella typhi is more common than Salmonella paratyphi, with Salmonella paratyphi A being the most prevalent subtype. The global increase in population, pollution, and shortage of clean drinking water has contributed to the rising number of new cases of typhoid fever. However, advancements in research, changes in treatment approaches, and the development of new drugs have led to a decrease in mortality rates despite the emergence of multidrug-resistant strains. With the widespread use of antibiotics, the classic clinical presentations of typhoid fever may not always be observed. In the United States, only a small percentage of cases exhibit splenomegaly and rose spots.
Additionally, around 4% of patients with typhoid fever become chronic carriers, remaining asymptomatic after acute treatment but potentially shedding Salmonella in their stool or, less commonly, their urine for up to a year. Chronic carriage is more frequently observed in women and individuals with biliary abnormalities, such as cholelithiasis. Certain blood group antigens may also be associated with increased susceptibility to chronic carriage of S. typhi.
The primary causative agents of typhoid fever are Salmonella paratyphi and Salmonella typhi, belonging to the Enterobacteriaceae family. Salmonella is a genus of two species: enterica serovar and enteritidis, classified using multiplex quantitative polymerase chain reaction analysis. Salmonella typhi and Salmonella paratyphi (A, B, C) are specific serotypes within the Salmonella enterica species. On the other hand, nontyphoidal Salmonella is more commonly associated with gastroenteritis and is typically seen in children. The transmission of Salmonella occurs through the fecal-oral route, primarily via contaminated water, undercooked foods, and fomites contaminated with the bacteria.
It is prevalent in areas characterized by overcrowding, social instability, and poor sanitation. The transmission is exclusively from infected individuals to others, as humans are the only host for Salmonella. To a lesser extent, poultry, eggs, and turtles are considered major sources of Salmonella contamination. In a study conducted in China on the distribution of Salmonella isolates in chicken slaughterhouses using whole-genome sequencing, approximately 57% of the samples tested positive for Salmonella.
The normal flora of the gut provides a protective barrier against Salmonella infection. However, using antibiotics, such as streptomycin, can disrupt the normal gut flora, making it easier for Salmonella to invade. Malnutrition can also reduce the normal gut flora, increasing susceptibility to infection. Therefore, the use of broad-spectrum antibiotics and poor nutrition can contribute to an increased incidence of typhoid fever.
Typhoid fever poses a significant global burden in terms of both mortality and morbidity, with the highest impact observed in countries in Africa and South Asia. However, advancements in treatment modalities and the availability of antibiotics have significantly reduced the overall mortality rate to less than 1%. This is a substantial improvement compared to the 1940s when treatment options were limited to symptomatic and supportive measures, resulting in a mortality rate of around 12.75%.
Early diagnosis and prompt treatment play a crucial role in preventing complications associated with typhoid fever. Despite a relatively high frequency of episodes with complications, the current mortality rate remains low due to effective medical interventions. It is worth noting that untreated patients face certain risks, as approximately 10% of them may experience relapses, while about 4% may become chronic carriers of the infection. Therefore, timely diagnosis and appropriate treatment are essential in mitigating the impact of typhoid fever.
medtigo
Typhoid fever
Updated :
September 4, 2023
Typhoid fever, or enteric fever, is a widespread illness that poses a significant public health challenge, particularly in developing countries. Its causative agents are Salmonella paratyphi and Salmonella typhi. Enteric fever is a collective term encompassing both typhoid and paratyphoid fevers. Since paratyphoid fever closely resembles typhoid fever in its clinical presentation, the terms enteric fever and typhoid fever are often used interchangeably.
In densely populated and unsanitary areas, typhoid fever remains a major cause of both mortality and morbidity, although extensive research and public health interventions have succeeded in reducing its incidence. The disease progression varies from initial gastrointestinal symptoms to nonspecific systemic manifestations, potentially leading to various complications.
The transmission of Salmonella bacteria is commonly associated with the “four Fs”: flies, feces, fingers and fomites. Characteristic features of typhoid fever include a step-wise pattern of fever, where temperature rises and falls alternatively, accompanied by symptoms such as headache and abdominal pain.
While the incidence of culture-confirmed typhoid fever and paratyphoid A cases in the United States has been relatively low since 2008, enteric fever remains a significant global health concern. Worldwide, there are over 26 million cases of typhoid fever and 5 million cases of paratyphoid infection each year, resulting in approximately 215,000 deaths. Low- and middle-income countries in southern Africa and south-central Asia have a higher typhoid fever incidence than developed nations.
In developed countries, most cases are seen in travelers returning from endemic regions or individuals visiting these areas, as they are more likely to have increased exposure to contaminated food and water sources. Those who fail to seek pretravel consultation and vaccination are also at a higher risk. Typhoid fever is more prevalent in regions with tropical and temperate climates and is closely associated with inadequate sanitation, lack of proper sewage systems, and insufficient water treatment facilities.
Salmonella typhi is more common than Salmonella paratyphi, with Salmonella paratyphi A being the most prevalent subtype. The global increase in population, pollution, and shortage of clean drinking water has contributed to the rising number of new cases of typhoid fever. However, advancements in research, changes in treatment approaches, and the development of new drugs have led to a decrease in mortality rates despite the emergence of multidrug-resistant strains. With the widespread use of antibiotics, the classic clinical presentations of typhoid fever may not always be observed. In the United States, only a small percentage of cases exhibit splenomegaly and rose spots.
Additionally, around 4% of patients with typhoid fever become chronic carriers, remaining asymptomatic after acute treatment but potentially shedding Salmonella in their stool or, less commonly, their urine for up to a year. Chronic carriage is more frequently observed in women and individuals with biliary abnormalities, such as cholelithiasis. Certain blood group antigens may also be associated with increased susceptibility to chronic carriage of S. typhi.
The primary causative agents of typhoid fever are Salmonella paratyphi and Salmonella typhi, belonging to the Enterobacteriaceae family. Salmonella is a genus of two species: enterica serovar and enteritidis, classified using multiplex quantitative polymerase chain reaction analysis. Salmonella typhi and Salmonella paratyphi (A, B, C) are specific serotypes within the Salmonella enterica species. On the other hand, nontyphoidal Salmonella is more commonly associated with gastroenteritis and is typically seen in children. The transmission of Salmonella occurs through the fecal-oral route, primarily via contaminated water, undercooked foods, and fomites contaminated with the bacteria.
It is prevalent in areas characterized by overcrowding, social instability, and poor sanitation. The transmission is exclusively from infected individuals to others, as humans are the only host for Salmonella. To a lesser extent, poultry, eggs, and turtles are considered major sources of Salmonella contamination. In a study conducted in China on the distribution of Salmonella isolates in chicken slaughterhouses using whole-genome sequencing, approximately 57% of the samples tested positive for Salmonella.
The normal flora of the gut provides a protective barrier against Salmonella infection. However, using antibiotics, such as streptomycin, can disrupt the normal gut flora, making it easier for Salmonella to invade. Malnutrition can also reduce the normal gut flora, increasing susceptibility to infection. Therefore, the use of broad-spectrum antibiotics and poor nutrition can contribute to an increased incidence of typhoid fever.
Typhoid fever poses a significant global burden in terms of both mortality and morbidity, with the highest impact observed in countries in Africa and South Asia. However, advancements in treatment modalities and the availability of antibiotics have significantly reduced the overall mortality rate to less than 1%. This is a substantial improvement compared to the 1940s when treatment options were limited to symptomatic and supportive measures, resulting in a mortality rate of around 12.75%.
Early diagnosis and prompt treatment play a crucial role in preventing complications associated with typhoid fever. Despite a relatively high frequency of episodes with complications, the current mortality rate remains low due to effective medical interventions. It is worth noting that untreated patients face certain risks, as approximately 10% of them may experience relapses, while about 4% may become chronic carriers of the infection. Therefore, timely diagnosis and appropriate treatment are essential in mitigating the impact of typhoid fever.
Free CME credits
Both our subscription plans include Free CME/CPD AMA PRA Category 1 credits.
Digital Certificate PDF
On course completion, you will receive a full-sized presentation quality digital certificate.
medtigo Simulation
A dynamic medical simulation platform designed to train healthcare professionals and students to effectively run code situations through an immersive hands-on experience in a live, interactive 3D environment.
medtigo Points
medtigo points is our unique point redemption system created to award users for interacting on our site. These points can be redeemed for special discounts on the medtigo marketplace as well as towards the membership cost itself.
Community Forum post/reply = 5 points
*Redemption of points can occur only through the medtigo marketplace, courses, or simulation system. Money will not be credited to your bank account. 10 points = $1.
All Your Certificates in One Place
When you have your licenses, certificates and CMEs in one place, it's easier to track your career growth. You can easily share these with hospitals as well, using your medtigo app.
