VIRAL EXANTHEMS
OTHER SYSTEMIC
INFECTIONS
LEARNING OBJECTIVES
1. Recognize common viral exanthems based on
clinical manifestations.
2. Characterize common systemic infections based on
etiologic agent, , signs, clinical manifestations, diagnosis,
treatment and prevention.
3. Compare and contrast mosquito-borne viral
diseases such as dengue, chikungunya, and zika virus
disease according to etiologic agent, signs and
symptoms, diagnosis, and prevention.
OVERVIEW OF VIRAL EXANTHEMS
 An exanthem is a skin rash accompanied by
systemic symptoms such as fever, headache, and
malaise.
 Etiologies include infectious pathogens, medication
reactions, and sometimes, a combination of both.
 In children, exanthems are most often related to
infection, the most common of which are of viral
etiology.
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
 Measles is a highly contagious acute viral infection
primarily affecting the respiratory system.
 Incubation period: 11-12 days
 Typically presents with:
 An initial phase (prodrome: 2-4 days) marked by high
fever (up to 105°F), general discomfort, and the classic
triad of cough, coryza (runny nose), and conjunctivitis
(3C’s)
 Koplik spots, a distinctive enanthema inside the mouth
may also appear 2–3 days after symptoms first appear.
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
▪ A subsequent maculopapular rash
❖The rash usually emerges around 14 days after
exposure, beginning on the face and gradually
spreading to the trunk and lower limbs.
 Individuals are contagious from 4 days before to 4
days after the onset of the rash. In some cases,
especially among immunocompromised patients, the
rash may not develop.
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
 Measles rash:
 Coalescing erythematous macules and papules that
appear on the face at the hairline and spread
downward to the neck, trunk, arms, legs, and feet;
 When the rash appears, a person’s fever may spike
to more than 40°C
 Eruption typically resolves in the same order as its
appearance, and will often desquamate.
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
https://www.cdc.gov/measles/symptoms/photos.html
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
Complications:
 Individuals that are more likely to suffer from measles
complications:
 Children younger than 5 years of age
 Adults older than 20 years of age
 Pregnant women
 People with compromised immune systems, such as from
leukemia or HIV infection
 Common complications
 Ear infections occur in about one out of every 10 children
with measles.
 Diarrhea is reported in less than one out of 10 people with
measles.
https://www.cdc.gov/measles/symptoms/complications.html
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
Severe complications
https://www.cdc.gov/measles/symptoms/complications.html
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
Transmission:
 by direct contact with infectious droplets or by
airborne spread when an infected person breathes,
coughs, or sneezes.
 infectious 4 days before and 4 days after rash onset
 Measles virus can remain infectious in the air for up to
two hours after an infected person leaves an area.
 up to 9 out of 10 susceptible persons with close
contact to a measles patient will develop measles.
MACULAR & MACULOPAPULAR EXANTHEMS
MEASLES (RUBEOLA)
Treatment and prevention
• no specific antiviral therapy for measles
• supportive management to help relieve symptoms and
address complications
• isolation for four days after development of rash
• airborne precautions should be followed in healthcare
settings.
• Vaccination: measles-mumps-rubella (MMR) vaccine;
measles-mumps-rubella-varicella (MMRV) vaccine;
MACULAR & MACULOPAPULAR EXANTHEMS
RUBELLA (GERMAN MEASLES)
 Caused by Rubella virus: an enveloped, positive-stranded RNA
virus classified as a Rubivirus in the Matonaviridae family
 The average incubation period of rubella virus is 17 days, with
a range of 12 to 23 days.
 characterized by a mild, maculopapular rash along with
lymphadenopathy, and a slight fever.
 Rash occurs in 50-80% of infected people, which usually
starts on the face, becomes generalized within 24 hours,
and lasts a median of 3 days;
 Lymphadenopathy: often involves posterior auricular or
suboccipital lymph nodes, lasting between 5 and 8 days.
 About 25% to 50% of infections are asymptomatic.
MACULAR & MACULOPAPULAR EXANTHEMS
RUBELLA (GERMAN MEASLES)
Complications
 Arthralgia or arthritis may occur in up to 70% of adult women with
rubella.
 Rare complications include thrombocytopenic purpura and
encephalitis.
 When rubella infection occurs during pregnancy, especially during
the first trimester, serious consequences can result.
 miscarriages, fetal deaths/stillbirths
 severe birth defects known as congenital rubella syndrome (CRS)
o cataracts
o heart defects
o hearing impairment
MACULAR & MACULOPAPULAR EXANTHEMS
RUBELLA (GERMAN MEASLES)
Transmission
• By direct or droplet contact from nasopharyngeal secretions.
• Humans are the only natural hosts.
• People infected with rubella are most contagious when the
rash is erupting, but they can be contagious from 7 days before
to 7 days after the rash appears.
Treatment and Prevention
• supportive
• prompt isolation of people suspected to have rubella, should
be isolated for 7 days after they develop rash.
• Vaccination: MMR, MMRV
MACULAR & MACULOPAPULAR EXANTHEMS
ROSEOLA INFANTUM
 caused by human herpesvirus (HHV) types 6 and 7 or the
Roseolovirus genus in the subfamily of Betaherpesvirinae.
 highly prevalent in the healthy population
 By the end of the second year of life, approximately 75% of
all children are seropositive for HHV-6
 approximately 24% of all children with HHV-6 infection will
manifest clinical symptoms of Roseola.
 frequently shed in saliva of healthy donors
 the pathogenic potential of reactivated virus ranges from
asymptomatic infection to severe diseases in transplant
recipients.
 Incubation period of 5–15 days
MACULAR & MACULOPAPULAR EXANTHEMS
ROSEOLA INFANTUM
• Infected children develop high
fevers that last 3–5 days,
followed by the acute onset
of a rosey pink, nonpruritic
macular rash, predominantly
on the neck and trunk.
• Roseola infection can cause leukopenia, and rarely,
thrombocytopenia and hepatitis.
• Patients generally recover without sequelae.
• However, approximately 22% of patients with roseola may
develop febrile seizures.
• Management is supportive.
• No vaccine is available
MACULAR & MACULOPAPULAR EXANTHEMS
ERYTHEMA INFECTIOSUM – 5TH DISEASE
 caused by parvovirus B19 – a nonenveloped, ssDNA virus
belonging to the Parvoviridae family.
 the only parvovirus that has been linked directly to disease
in humans.
 spreads through respiratory secretions, such as saliva, sputum,
or nasal mucus, when an infected person coughs or sneezes.
 most contagious during period of “just a fever and/or cold”
and before the appearance of the rash or joint pain and
swelling
 No longer contagious when the rash appears
 Incubation period: 1 – 2 weeks
MACULAR & MACULOPAPULAR EXANTHEMS
ERYTHEMA INFECTIOSUM
 manifests in three overlapping stages.
 First stage: fiery-red facial erythema described as having a
'slapped cheeks' appearance
 Second stage: a reticulate macular or urticarial exanthem 1–
4 days after the slapped cheek eruption
 third stage: intermittent exanthem recurring in response to
stimuli, such as local irritation, high temperatures and
emotional stress.
 Arthropathy may occur in up to 60% of adults and in
approximately 10% of children
MACULAR & MACULOPAPULAR EXANTHEMS
ERYTHEMA INFECTIOSUM
classic 'slapped cheek'
appearance of erythema
infectiosum.
MACULAR & MACULOPAPULAR EXANTHEMS
ERYTHEMA INFECTIOSUM
 Parvovirus B19 infection can suppress red blood cell
production, causing transient aplastic crisis, chronic red cell
aplasia, hydrops fetalis or congenital anemia.
Treatment and prevention
 Supportive/ symptomatic relief
 Although treatment is supportive, at-risk patients may require
transfusions or intravenous immunoglobulin therapy
 No antiviral medication available
 No vaccine available
 strict infection control practices
NUMBERED DISEASES OF CHILDHOOD: RASHES
“ in 1905 when pediatricians tried to describe the six
then known diseases which cause rashes by giving
them numbers.”
http://pediatric-house-calls.djmed.net/numbered-skin-rashdiseases-childhood/
CHICKENPOX
 caused by varicella-zoster virus (VZV), a DNA virus, of the
herpesvirus group.
 Primary infection with VZV causes varicella.
 After the primary infection, VZV stays in the body (in the
sensory nerve ganglia) as a latent infection.
 Reactivation of latent infection causes herpes zoster
(shingles)
 incubation period for varicella is 10 to 21 days (average: 14-16
days) after exposure to a varicella or a herpes zoster rash
 A mild prodrome of fever and malaise may occur 1 to 2 days
before rash onset, particularly in adults.
 In children, the rash is often the first sign of disease.
CHICKENPOX
 Varicella in Unvaccinated Persons
 The rash is generalized and pruritic.
 It progresses rapidly from macular to papular to
vesicular lesions before crusting.
 The rash usually appears first on the chest, back,
and face, then spreads over the entire body
 Symptoms typically last 4 to 7 days.
• Varicella in vaccinated Persons (Breakthrough
Varicella)
– Infection occurring in a vaccinated person more than
42 days after varicella vaccination.
– is usually mild; typically with low grade or no fever, and
fewer than 50 skin lesions.
– 25% to 30% of people will have clinical features similar
to unvaccinated people with varicella.
CHICKENPOX
 Transmission
 spread from person to person by direct contact, inhalation
of aerosols from vesicular fluid of skin lesions of acute
varicella or zoster, and possibly through aerosolized
infected respiratory secretions
 A person with varicella is considered contagious beginning
one to two days before rash onset until all the chickenpox
lesions have crusted.
 Vaccinated people may develop lesions that do not crust.
These people are considered contagious until no new
lesions have appeared for 24 hours.
CHICKENPOX
•
Complications
o Most common complications
- In children: Bacterial infections of the skin and soft
tissues
- In adults: Pneumonia
o Severe complications
- caused by the virus: cerebellar ataxia, encephalitis, viral
pneumonia, and hemorrhagic conditions.
- Due to bacterial infections: Septicemia, Toxic shock
syndrome, Necrotizing fasciitis Osteomyelitis, Bacterial
pneumonia, Septic arthritis
CHICKENPOX
•
Treatment and Prevention
o varicella-zoster immune globulin can prevent varicella
from developing or lessen the severity of the disease.
o Antiviral drug: oral acyclovir or valacyclovir treatment,
recommended for:
- Healthy people older than 12 years of age
- People with chronic cutaneous or pulmonary
disorders
- People receiving long-term salicylate therapy
- People receiving short, intermittent, or aerosolized
courses of corticosteroids
o standard precautions plus airborne precautions (negative
air-flow rooms) and contact precautions until lesions are
dry and crusted.
SHINGLES
 People with herpes zoster most commonly have a rash in one
or two adjacent dermatomes (localized zoster); does not usually
cross the body’s midline.
 Disseminated zoster can be difficult to distinguish from
varicella.
 The rash is usually painful, itchy, or tingly.
 The rash develops into clusters of vesicles.
 New vesicles continue to form over three to five days and
progressively dry and crust over.
 They usually heal in two to four weeks.
SHINGLES
 Complications:
 Postherpetic neuralgia (PHN)
➢ is the most common complication of herpes zoster.
➢ persists in the area where the rash once was for more than
90 days after rash onset.
➢ can last for weeks or months, and occasionally, for years.
- Other complications
➢ ophthalmic involvement (herpes zoster ophthalmicus)
➢ bacterial superinfection of the lesions,
➢ cranial and peripheral nerve palsies
➢ visceral involvement, such as meningoencephalitis,
pneumonitis, hepatitis, and acute retinal necrosis.
SHINGLES
SHINGLES
SHINGLES
Management
• Recombinant zoster vaccine (RZV, Shingrix) is the recommended
vaccine to prevent shingles and its complications for adults 50
years and older.
• Several antiviral medicines—acyclovir, valacyclovir, and famciclovi
• most effective when started as soon as possible after the
rash appears.
• Pain medicine may help relieve the pain caused by shingles.
• Wet compresses, calamine lotion, and colloidal oatmeal baths (a
lukewarm bath mixed with ground up oatmeal) may help relieve
itching.
OTHER SYSTEMIC INFECTIONS
DENGUE
 Dengue is common in more than 100 countries
around the world.
 Each year, up to 400 million people get infected
with dengue.
 Approximately 100 million people get sick
from infection
 22,000 die from severe dengue.
DENGUE CASES IN THE PHILIPPINES
2023
2022
2021
2020
2019
2018
0
50000
100000
150000
DEATHS
2018
2019
2020
2021
2022
2023
200000
250000
CASES
CASES
216190
237563
90135
79872
252700
195603
DEATHS
1083
1869
324
285
894
657
300000
DENGUE
 Dengue is caused by one of any of four related
viruses: Dengue virus 1, 2, 3, and 4.
 For this reason, a person can be infected with
a dengue virus as many as four times in his or
her lifetime
 Dengue virus (DENV), a single-stranded
positive sense RNA virus
DENGUE
TRANSMISSION
 Dengue viruses are spread to humans through the
bite of an infected Aedes species (Ae. aegypti or Ae.
albopictus) mosquito.
 typically lay eggs near standing water in containers
that hold water
 usually bite during the day, peaking during early
morning and late afternoon/evening
 become infected when they bite a person infected
with the virus.
DENGUE
TRANSMISSION
 From mother to child
 A pregnant woman already infected with dengue can pass
the virus to her fetus during pregnancy or around the time
of birth.
 To date, there has been one documented report of dengue
spread through breast milk.
 Through infected blood, laboratory, or healthcare setting
exposures
 Rarely, dengue can be spread through blood transfusion,
organ transplant, or through a needle stick injury.
DENGUE
CLINICAL MANIFESTATIONS
 1 in 4: About one in four people infected with dengue
virus will get sick.
 For people who get sick with dengue, symptoms can
be mild or severe.
 Severe dengue can be life-threatening within a few
hours and often requires care at a hospital.
DENGUE
CLINICAL MANIFESTATIONS
 Severe Dengue
 About 1 in 20 people who get sick with dengue will develop
severe dengue.
 Severe dengue can result in shock, internal bleeding, and even
death.
 When there is history of dengue in the past, the person is
more likely to develop severe dengue.
 Dengue begins abruptly after a typical incubation period of 5–7
days, and the course follows 3 phases: febrile, critical, and
convalescent.
 Symptoms of dengue typically last 2–7 days.
 Most people will recover after about a week.
DENGUE
CLINICAL MANIFESTATIONS
From 1975 through 2009, symptomatic dengue
virus infections were classified according to the
WHO guidelines as:
•
dengue fever
• dengue hemorrhagic fever (DHF)
• dengue shock syndrome
DENGUE
CLINICAL MANIFESTATIONS
Guideline on classification of symptomatic cases as dengue or
severe dengue (WHO, 2009)
• Dengue is defined by a combination of ≥2 clinical findings in a
febrile person who traveled to or lives in a dengue-endemic
area.
➢ Clinical findings include nausea, vomiting, rash, aches and
pains, a positive tourniquet test, leukopenia, and the
following warning signs: abdominal pain or tenderness,
persistent vomiting, clinical fluid accumulation, mucosal
bleeding, lethargy, restlessness, and liver enlargement.
DENGUE
CLINICAL MANIFESTATIONS
Guideline on classification of symptomatic cases as dengue
or severe dengue (WHO, 2009)
• Severe dengue is defined as dengue with any of the
following symptoms: severe plasma leakage leading to
shock or fluid accumulation with respiratory distress;
severe bleeding; or severe organ impairment such as
elevated transaminases ≥1,000 IU/L, impaired
consciousness, or heart impairment.
DENGUE
PHASES OF DENGUE
Febrile Phase
• Fever typically lasts 2–7 days, may be biphasic.
• Other signs and symptoms:
o severe headache; retro-orbital eye pain
o muscle, joint, and bone pain;
o macular or maculopapular rash;
o minor hemorrhagic manifestations
o Warning signs of progression to severe dengue may occur in the late
febrile phase to resolution of fever (defervescence)
• persistent vomiting, severe abdominal pain,
• fluid accumulation, liver enlargement, difficulty breathing
• lethargy/restlessness,
• postural hypotension,
• progressive increase in hematocrit
• mucosal bleeding
DENGUE
CLINICAL MANIFESTATIONS
Critical Phase
•
Begins at defervescence and typically lasts 24–48 hours.
•
Most patients clinically improve during this phase
•
Patients with significant extravasation of fluid, within a few hours, can
develop severe dengue due to increased capillary permeability
•
pleural effusions, ascites, hypoproteinemia, or hemoconcentration;
compensatory narrowing of pulse pressure
•
Hypotension and irreversible shock and death
•
Patients can also develop severe hemorrhagic manifestations
•
Rarely, patients may develop hepatitis, myocarditis, pancreatitis, and
encephalitis.
•
Laboratory findings: leukopenia, thrombocytopenia, hyponatremia, elevated
hepatic transaminases, and a normal erythrocyte sedimentation rate.
DENGUE
CLINICAL MANIFESTATIONS
Convalescent Phase
•
•
As plasma leakage subsides, reabsorption of extravasated fluids
begins, stabilizing hemodynamic status.
•
diuresis ensues
•
Hematocrit decreases
•
WBC and platelet counts start to rise normal.
The convalescent-phase rash may desquamate and be pruritic.
DENGUE
DIAGNOSIS
• “Clinicians should consider dengue in a patient with a
clinically compatible illness, and who lives in or recently
traveled to a disease-endemic area in the 2 weeks before
symptom onset.
• Patients typically present with acute onset of fever,
headache, body aches, and sometimes rash spreading
from the trunk.
• All patients with clinically suspected dengue should
receive appropriate management to monitor for shock
and reduce the risk of complications resulting from
increased vascular permeability and plasma leakage and
organ damage without waiting for diagnostic test results
to be received.”
https://www.cdc.gov/dengue/healthcare-providers/diagnosis.html
https://www.cdc.gov/dengue/healthcare-providers/diagnosis.html
DENGUE
DIAGNOSIS: TESTING
Molecular test: Nucleic Acid Amplification Test (NAAT)
- A NAAT is a generic term referring to molecular tests used to detect
viral genomic material (example: RT-PCR)
- NAAT assays provide confirmed evidence of infection
Dengue Virus Antigen Detection: NS1
- NS1 tests detect the non-structural protein NS1 of dengue virus, a
protein secreted during dengue infection.
DENGUE
TREATMENT
 No specific antiviral agent is available.
 Supportive care is advised:
 Adequate hydration
 No aspirin containing drugs, no NSAID (like ibuprofen) because
of their anticoagulant properties
 Control of fever by paracetamol and tepid sponge baths
 Avoid mosquito bites (to reduce risk of further transmission)
 For severe dengue:
 close observation and frequent monitoring
 Prophylactic platelet transfusions in dengue patients are not
beneficial and may contribute to fluid overload.
 Administration of corticosteroids has no demonstrated benefit,
except in the case of autoimmune-related complication
DENGUE
PREVENTION AND CONTROL
 Vaccine: (Dengvaxia®)
 for people ages 9-45 years old.
 3 shots, 6 months apart
 WHO: recommends that the vaccine only be given to persons
with confirmed prior dengue virus infection.
 people who receive the vaccine and have not been previously
infected with a dengue virus may be at risk of developing
severe dengue if they get dengue after being vaccinated.
 No prophylaxis is available to prevent dengue.
 Travelers going to areas with risk of dengue should take steps to
avoid mosquito bites.
CHIKUNGUNYA
 Mosquito-borne viral disease that often occurs as large
outbreaks
 Seen in countries in Africa, Asia, Europe, Indian and Pacific
Oceans, and in Caribbean islands
 Characterized by acute onset of fever and severe
polyarthralgia
 Caused by: Chikungunya virus
 Single-stranded RNA virus of Genus Alphavirus; Family
Togaviridae
 Insect vector: Aedes aegypti and Aedes albopictus
CHIKUNGUNYA
CLINICAL MANIFESTATIONS
 Most are symptomatic
 Incubation period: usually 3–7 days (range 1–12 days)
 Primary clinical findings: acute onset of fever and polyarthralgia
 Joint symptoms usually symmetric, often involving the hands
and feet; can be severe and debilitating
 Other symptoms: Headache, myalgia, arthritis, conjunctivitis,
nausea/vomiting, maculopapular rash
 Laboratory findings: Lymphopenia, thrombocytopenia, elevated
creatinine, elevated hepatic transaminases are
CHIKUNGUNYA VIRUS VERSUS DENGUE VIRUS
 Difficult to clinically distinguish chikungunya and dengue based
 Both are transmitted by the same mosquitoes
 Both can circulate in the same area and cause occasional
co-infections in the same patient
 Chikungunya virus more likely to cause high fever, severe
polyarthralgia, arthritis, rash, and lymphopenia
 Dengue virus more likely to cause neutropenia,
thrombocytopenia, hemorrhage, shock, and deaths
 Patients with suspected chikungunya should be managed as
dengue until dengue has been ruled out
CHIKUNGUNYA
MANAGEMENT
 No specific antiviral therapy is available
 Supportive, symptomatic treatment
 Adequate Hydration; fever and pain management
 Evaluate for other serious conditions (e.g., dengue, malaria, and
bacterial infections
 Fever and pain control
 Initially managed with paracetamol
 If the patient may have dengue, do not use aspirin or other
NSAIDs until
 they have been afebrile ≥48 hours
 have no warning signs for severe dengue*
 For persistent joint pain; may benefit from use of NSAIDs,
corticosteroids, or physiotherapy
CHIKUNGUNYA
PREVENTION AND CONTROL
 No vaccine or medication is available to prevent infection
 Avoid mosquito bites
 Empty standing water from outdoor containers
 Support local vector control programs
 People suspected to have chikungunya or dengue should be
protected from further mosquito exposure during the first
week of illness to reduce the risk of further transmission
 People at increased risk for severe disease should consider
not traveling to areas with ongoing chikungunya outbreaks
ZIKA
 Caused by a mosquito-borne flavivirus
 Transmitted primarily by Aedes mosquitoes
 Incubation perod: 3–14 days.
 Most infected persons are asymptomatic
 Generally with mild presentations: fever, rash, conjunctivitis, muscle
and joint pain, malaise or headache.
 Zika virus infection during pregnancy can cause infants to be born
with microcephaly and other congenital malformations, known as
congenital Zika syndrome.
 Infection with Zika virus is also associated with other complications
of pregnancy including preterm birth and miscarriage.
 Associated with An increased risk of neurologic complications in
adults and children, including Guillain-Barré syndrome, neuropathy
and myelitis.
https://www.who.int/news-room/fact-sheets/detail/zika-virus
ZIKA
 Transmission:
 from a pregnant woman to her fetus. Infection during pregnancy
can cause certain birth defects.
 through sex from a person who has Zika to his or her sex
partners.
 There is no treatment available for Zika virus infection
 Supportive management: Hydration and Control of fever and pain
 No vaccine is currently available.
 Prevention:
 Avoid mosquito bites, specially among pregnant women, women
of reproductive age, and young children.
 Vector control programs
https://www.who.int/news-room/fact-sheets/detail/zika-virus
TYPHOID AND PARATYPHOID FEVER
 Typhoid fever: a life-threatening illness caused by
Salmonella typhi
 Paratyphoid fever is a life-threatening illness caused
by Salmonella paratyphi bacteria.
 Globally, each year, typhoid fever affects about 11 to
21 million people and paratyphoid fever affects about
5 million people usually
TYPHOID AND PARATYPHOID FEVER
 Incubation period:
 for typhoid fever: ≈ 6 to 30 days
 for paratyphoid fever: 1 to 10 days for
 Transmission: commonly through the consumption of
drinking water or food contaminated with the feces
of people who have typhoid fever or paratyphoid
fever or of people who are chronic carriers of the
responsible bacteria.
TYPHOID AND PARATYPHOID FEVER
Clinical Presentation:
 Typhoid fever and paratyphoid fever have similar symptoms̵.
 a sustained fever that can be as high as 103–104°F (39–40°C).
 Weakness; headache
 Stomach pain; diarrhea or constipation
 Loss of appetite; cough
 Some develop a rash of flat, rose-colored spots.
 Without treatment, the illness lasts for 3 to 4 weeks, with mortality rate
ranging from 12% to 30%.
 Up to 10% of untreated patients may have relapse about 1 to 3 weeks after
recovering from the initial illness; which is often milder than the initial illness.
 Stool or urine cultures for Salmonella typhi may remain positive for more
than one year, a chronic carrier state occurring in up to 5% of infected
people
TYPHOID AND PARATYPHOID FEVER
Diagnosis
 Multiple cultures are usually needed to identify the pathogen
 Blood culture is the mainstay of diagnosis.
 Bone marrow cultures can remain positive despite antibiotic therapy.
 Stool and urine cultures are positive less frequently.
 Serologic tests, such as the Widal test, are not recommended because of
the high rate of false positives.
 Treatment
 Typhoid fever and paratyphoid fever are treated with antibiotics.
 Antimicrobial resistance in typhoid fever has been increasing.
 Prevention:
 Vaccines are available for Salmonella typhi, none for Salmonella paratyphi
 Safe eating and drinking habits