The document provides guidance on evaluating returned travelers presenting with fever. It outlines important elements of the medical history, including travel itinerary, timing of illness, exposures, and immunization history. Common infections are associated with fever onset within 2 weeks of travel, such as dengue, malaria, and enteric fever. Certain findings should prompt urgent evaluation, like hemorrhage, neurological symptoms, or respiratory distress. The differential diagnosis is guided by the travel history and clinical findings.

1. Travelers’ Health
Part 2
(Post-Travel Evaluation)
By
Mohammed Ezz El-din Abd El-monem
Assistant Lecturer of Tropical Medicine & Gastroenterology
Faculty of Medicine, Assiut University
Email: squint_2008@yahoo.com

2. General Approach to the Returned Traveler

3. THE POST-TRAVEL EVALUATION
• Most post-travel infections become apparent soon after
travel, but because incubation periods vary, some syndromes
can present months to years after initial infection.
• When evaluating a patient with a probable travel-related
illness, the clinician should consider this items:

4. Important elements of a medical history in an ill returned traveler
• Severity of illness
• Travel itinerary and duration of travel
• Timing of onset of illness in relation to
international travel
• Past medical history and medications
• History of a pre-travel consultation
• Travel immunizations
• Adherence to malaria chemoprophylaxis
• Individual exposures
• Type of accommodations
• Insect precautions taken (such as
repellent, bed nets)
• Source of drinking water
• Ingestion of raw meat or seafood or
unpasteurized dairy products
• Insect or arthropod bites
• Freshwater exposure (such as swimming,
rafting)
• Animal bites and scratches
• Body fluid exposure (such as tattoos,
sexual activity)
• Medical care while overseas (such as
injections, transfusions)

5. Travel Itinerary
• The itinerary is crucial to formulating a differential diagnosis, because
potential exposures differ depending on the region of travel.
• A 2013 study from the GeoSentinel Surveillance Network found a
distinct pattern of diagnoses depending on the region of the world
visited. In travelers to sub-Saharan Africa presenting with fever,
malaria was the most common specific diagnosis. On the other hand,
febrile patients who traveled to Latin America or Southeast Asia were
much more likely to have dengue.
• The duration of travel is also important, since the risk of a travel-
related illness increases with the length of the trip.

6. Timing of Illness in Relation to Travel
• Most ill travelers will seek medical attention within 1 month
of return from their destination, because most common
travel-related infections have short incubation periods.
• Occasionally, however, infections such as schistosomiasis,
leishmaniasis, or tuberculosis can manifest months or even
years later.
• Therefore, a detailed history that extends beyond a few
months before presentation can be helpful.

7. Illnesses associated with fever presenting in the first 2 weeks after travel
• Systemic febrile illness with
initial nonspecific symptoms
Malaria
Dengue
Typhoid fever
Rickettsial diseases (such as scrub
typhus, relapsing fever)
East African trypanosomiasis
Acute HIV infection
Leptospirosis
• Fever with central nervous
system involvement
Meningococcal meningitis
Malaria
Arboviral encephalitis (such as Japanese
encephalitis virus, West Nile virus)
East African trypanosomiasis
Angiostrongyliasis
Rabies

8. • Fever with respiratory
complaints
Influenza
Bacterial pneumonia
Acute histoplasmosis or
coccidioidomycosis, Legionella
pneumonia
Q fever
Malaria
Tularemia
Pneumonic plague
• Fever and skin rash
Dengue
Measles
Varicella
Spotted-fever or typhus group
rickettsiosis
Typhoid fever
Parvovirus B19
Mononucleosis
Acute HIV infection

9. Underlying Medical Illness
• Comorbidities can affect the susceptibility to infection, as
well as the clinical manifestations and severity of illness.
• An increasing number of immunosuppressed people (due to
organ transplants, immune-modulating medications, HIV
infection, or other primary or acquired immunodeficiencies)
are international travelers.

10. Vaccines Received and Prophylaxis Used
• The history of vaccinations and malaria chemoprophylaxis should be
reviewed when evaluating an ill returned traveler.
• Although adherence to malaria chemoprophylaxis does not rule out the
possibility of malaria, it reduces the risk and increases the chance of an
alternative diagnosis.
• Fever and a rash in a traveler without an up-to-date measles vaccination
would raise concern about measles.
• The most common vaccine preventable diseases found in a large 2010
GeoSentinel study of returned travelers included enteric fever (typhoid and
paratyphoid), viral hepatitis, and influenza. More than half of these
patients with vaccine-preventable diseases were hospitalized.

11. Individual Exposure History
• Knowledge of the patient’s exposures during travel, including insect bites, contaminated
food or water, or freshwater swimming, can also assist with the differential diagnosis.
• In addition to malarial parasites, mosquitoes can transmit viruses (such as dengue virus,
yellow fever virus, and chikungunya virus) and filarial parasites (such as Wuchereria
bancrofti).
• Depending on the clinical syndrome and location of exposure, a history of a tick bite
could suggest a diagnosis of tickborne encephalitis, African tick-bite fever, or other
rickettsial infections.
• Tsetse flies are large, and their bites are painful and often recalled by the patient. They
can carry Trypanosoma brucei, the protozoan that causes African sleeping sickness.

12. • Freshwater swimming or other water contact can put the patient at risk for
schistosomiasis, leptospirosis, and other diseases.
• The purpose of the patient’s trip and the type of accommodations can also
influence the risk for acquiring certain diseases.
• Travelers who visit friends and relatives are at higher risk of malaria, typhoid
fever, and certain other diseases because, compared with tourists, they stay
longer, travel to more remote destinations, have more contact with local
water sources, and are less likely to seek pre-travel advice.
• Someone backpacking and camping in rural areas will also have a higher risk
of certain diseases than those staying in air-conditioned hotels.

13. COMMON SYNDROMES
• The most common clinical presentations after travel to developing
countries include systemic febrile illness, acute diarrhea, and
dermatologic conditions.
• Respiratory complaints and eosinophilia are also conditions of
importance in returning travelers.
• Fever in a traveler returning from a malaria-endemic country needs to
be evaluated immediately.

14. Respiratory Complaints
• Respiratory complaints are frequent among returned travelers and are typically associated
with common respiratory viruses.
• Influenza is among the most common vaccine-preventable diseases associated with
international travel.
• Severe respiratory symptoms—especially associated with fever—in a returned traveler should
alert the physician to common infectious diseases such as seasonal influenza, bacterial
pneumonia, and malaria but could also suggest more unusual entities, such as Legionnaires’
disease.
• Emerging respiratory infections such as Middle East respiratory syndrome (MERS) and H7N9
avian influenza should be in the differential if the travel history is appropriate and respiratory
symptoms do not have a clear alternative diagnosis. In these suspected cases, local public
health authorities and CDC should be alerted immediately.

15. • Delayed onset and chronic cough after travel could be tuberculosis,
especially in a long-term traveler or health care worker.
• Other uncommon infections causing respiratory illness after travel to
specific regions are histoplasmosis, coccidioidomycosis, Q fever,
plague, tularemia, and melioidosis.
• Helminth infections that produce pulmonary disease include
strongyloidiasis, paragonimiasis, and schistosomiasis.

16. Eosinophilia
• Eosinophilia in a returning traveler suggests a possible helminth infection.
• Allergic diseases, hematologic disorders, and some viral, fungal, and protozoan infections
can also cause eosinophilia.
• Fever and eosinophilia can be present during pulmonary migration of parasites, such as
hookworm, Ascaris, and Strongyloides.
• Acute schistosomiasis, or Katayama syndrome, is also a cause of fever and eosinophilia
and can be associated with pulmonary infiltrates.
• Other parasitic infections associated with eosinophilia include chronic strongyloidiasis,
visceral larval migrans, lymphatic filariasis, and acute trichinellosis.

17. MANAGEMENT
• Most post-travel illnesses can be managed on an outpatient basis, but
some patients, especially those with systemic febrile illnesses, may
need to be hospitalized.
• Severe presentations, such as acute respiratory distress, mental status
change, and hemodynamic instability, require inpatient care.
• Clinicians should have a low threshold for admitting febrile patients if
malaria is suspected. Confirmation of diagnosis can be delayed, and
complications can occur rapidly.

18. • Management in an inpatient setting is especially important if the
patient may not reliably follow up or when no one is at home to assist
if symptoms worsen quickly.
• Consultation with an infectious disease physician is recommended in
severe travel-related infections, when management is complicated, or
when the diagnosis remains unclear.
• A travel medicine or infectious disease specialist should be involved in
cases that require specialized treatment, such as neurocysticercosis,
severe malaria, and leishmaniasis, among others.

19. Fever in Returned Travelers

20. INITIAL FOCUS
• The initial focus in evaluating a febrile returned traveler
should be on identifying infections that are rapidly
progressive, treatable, or transmissible.
• In some instances, public health officials must be alerted if
the traveler may have been contagious while traveling or
infected with a pathogen of public health importance (such
as yellow fever) at the origin or destination.

21. USE OF HISTORY, LOCATION OF EXPOSURE, AND INCUBATION TO LIMIT
DIFFERENTIAL DIAGNOSIS
• A large proportion of illnesses in returned travelers is caused
by common, cosmopolitan infections (such as bacterial
pneumonia or pyelonephritis), so these must be considered
along with unusual infections.
• Because the geographic area of travel determines the
relative likelihood of major causes of fever, it is essential to
identify where the febrile patient has traveled and lived.

22. Common causes of fever, by geographic area
GEOGRAPHIC AREA COMMON TROPICAL DISEASE CAUSING FEVER
OTHER INFECTIONS CAUSING OUTBREAKS OR
CLUSTERS IN TRAVELERS
Caribbean Dengue, malaria (Haiti) Acute histoplasmosis, leptospirosis, chikungunya
Central America Dengue, malaria (primarily Plasmodium vivax) Leptospirosis, histoplasmosis, coccidioidomycosis
South America Dengue, malaria (primarily P. vivax) Bartonellosis, leptospirosis, enteric fever, histoplasmosis
South-central Asia
Dengue, enteric fever, malaria (primarily non-
falciparum)
Chikungunya
Southeast Asia Dengue, malaria (primarily non-falciparum) Chikungunya, leptospirosis
Sub-Saharan Africa
Malaria (primarily P. falciparum), tickborne rickettsiae
(main cause of fever in southern Africa), acute
schistosomiasis, filariasis
African trypanosomiasis, chikungunya, enteric fever,
filariasis

23. • Details about activities (such as freshwater exposure in
schistosomiasis-endemic areas, animal bites, sexual activities, tattoos,
or local medical care with injections) and accommodations in areas
with malaria (bed nets, window screens, air conditioning) during travel
may provide useful clues.
• Preparation before travel (such as hepatitis A vaccine or yellow fever
vaccine) will markedly reduce the likelihood of some infections, so this
is a relevant part of the history.
• A history of travel and residence should be an integral part of every
medical history.

24. • Because each infection has a characteristic incubation period
(although the range is extremely wide with some infections), the time
of exposures needs to be defined in different geographic areas.
• This knowledge will allow the clinician to exclude some infections
from the differential diagnosis.
• Most serious febrile infections manifest within the first month after
return from tropical travel, yet infections related to travel exposures
can occasionally occur months or even >1 year after return.

25. Common infections, by incubation period
DISEASE USUAL INCUBATION PERIOD (RANGE) DISTRIBUTION
Incubation <14 days
Chikungunya 2–4 days (1–14 days) Tropics, subtropics
Dengue 4–8 days (3–14 days) Topics, subtropics
Encephalitis, arboviral (Japanese encephalitis,
tickborne encephalitis, West Nile virus, other)
3–14 days (1–20 days) Specific agents vary by region
Enteric fever 7–18 days (3–60 days) Especially in Indian subcontinent
Acute HIV 10–28 days (10 days to 6 weeks) Worldwide
Influenza 1–3 days Worldwide, can also be acquired while traveling
Legionellosis 5–6 days (2–10 days) Widespread
Leptospirosis 7–12 days (2–26 days) Widespread, most common in tropical areas
Malaria, Plasmodium falciparum 6–30 days (98% onset within 3 months of travel) Tropics, subtropics

26. Malaria, P. vivax
8 days to 12 months (almost half have onset >30 days
after completion of travel)
Widespread in tropics and subtropics
Spotted-fever rickettsiae Few days to 2–3 weeks Causative species vary by region
Incubation 14 Days to 6 Weeks
Encephalitis, arboviral; enteric fever; acute HIV;
leptospirosis; malaria
See above incubation periods for relevant diseases See above distribution for relevant diseases
Amebic liver abscess Weeks to months Most common in developing countries
Hepatitis A 28–30 days (15–50 days) Most common in developing countries
Hepatitis E 26–42 days (2–9 weeks) Widespread
Acute schistosomiasis (Katayama syndrome) 4–8 weeks Most common in sub-Saharan Africa
Incubation >6 weeks
Amebic liver abscess, hepatitis E, malaria, acute
schistosomiasis
See above incubation periods for relevant diseases See above distribution for relevant diseases
Hepatitis B 90 days (60–150 days) Widespread
Leishmaniasis, visceral 2–10 months (10 days to years)
Asia, Africa, Latin America, southern Europe, and the
Middle East
Tuberculosis Primary, weeks; reactivation, years
Global distribution, rates and levels of resistance vary
widely

27. FINDINGS REQUIRING URGENT ATTENTION
• Presence of associated signs, symptoms, or laboratory findings can focus
attention on specific infections.
• Findings that should prompt urgent attention include hemorrhage, neurologic
impairment, and acute respiratory distress.
• Even if an initial physical examination is unremarkable, it is worth repeating the
examination, as new findings may appear that will help in the diagnostic process
(such as skin lesions or tender liver).
• Although most febrile illnesses in returned travelers are related to infections, the
clinician should bear in mind that other problems, including pulmonary emboli
and drug hypersensitivity reactions, can be associated with fever.

28. Common clinical findings and associated infections
COMMON CLINICAL FINDINGS INFECTIONS TO CONSIDER AFTER TROPICAL TRAVEL
Fever and rash
Dengue, chikungunya, rickettsial infections, enteric fever (skin lesions may be sparse
or absent), acute HIV infection, measles
Fever and abdominal pain Enteric fever, amebic liver abscess
Undifferentiated fever and normal or low white blood cell count Dengue, malaria, rickettsial infection, enteric fever, chikungunya
Fever and hemorrhage
Viral hemorrhagic fevers (dengue and others), meningococcemia, leptospirosis,
rickettsial infections
Fever and eosinophilia
Acute schistosomiasis, drug hypersensitivity reaction, fascioliasis and other parasitic
infections (rare)
Fever and pulmonary infiltrates
Common bacterial and viral pathogens, legionellosis, acute schistosomiasis, Q fever,
leptospirosis
Fever and altered mental status
Cerebral malaria, viral or bacterial meningoencephalitis, African trypanosomiasis,
scrub typhus
Mononucleosis syndrome Epstein–Barr virus infection, cytomegalovirus infection, toxoplasmosis, acute HIV
Fever persisting >2 weeks
Malaria, enteric fever, Epstein-Barr virus infection, cytomegalovirus infection,
toxoplasmosis, acute HIV, acute schistosomiasis, brucellosis, tuberculosis, Q fever,
visceral leishmaniasis (rare)
Fever with onset >6 weeks after travel
Plasmodium vivax or ovale malaria, acute hepatitis (B, C, or E), tuberculosis, amebic
liver abscess

29. Bruising or unusual bleeding (without previous
injury)
Persistent diarrhea
Persistent vomiting (other than air or motion
sickness)
Jaundice
Paralysis of recent onset
• Fever accompanied by any of the following syndromes deserves further scrutiny,
because it may indicate a disease of public health importance:
Skin rash
Difficulty breathing
Shortness of breath
Persistent cough
Decreased consciousness
• People who travel to visit friends and relatives (VFRs) often do not seek pre-travel
medical advice and are at higher risk for some diseases than other travelers.
• A review of GeoSentinel Surveillance Network data showed that a larger
proportion of immigrant VFRs than tourist travelers presented with serious
(requiring hospitalization), potentially preventable travel-related illnesses.

30. CHANGE OVER TIME
• Clinicians have access to resources on the Internet that provide
information about geographic specific risks, disease activity, and other
useful information, such as drug-susceptibility patterns for pathogens.
• Infectious diseases are dynamic.
• Common infections in returned travelers may be seen at unexpected times
of the year.
• Travelers may acquire infections caused by common bacteria that are
unusually resistant.
• In most studies, a specific cause for fever is not identified in about 25% of
returned travelers.

31. KEEP IN MIND
• Initial symptoms of life-threatening and self-limited infections can be
identical.
• Fever in returned travelers is often caused by common, cosmopolitan
infections, such as pneumonia and pyelonephritis, which should not
be overlooked in the search for more exotic diagnoses.
• Patients with malaria may be afebrile at the time of evaluation but
typically give a history of fever or chills.
• Malaria is the most common cause of acute undifferentiated fever
after travel to sub-Saharan Africa and to some other tropical areas.

32. • Malaria, especially P. falciparum, can progress rapidly. Diagnostic
studies should be done promptly and treatment instituted
immediately if malaria is diagnosed.
• A history of taking malaria chemoprophylaxis does not exclude the
possibility of malaria.
• Patients with malaria can have prominent respiratory (including acute
respiratory distress syndrome), gastrointestinal, or central nervous
system findings.
• Dengue is the most common cause of febrile illness among people
who seek medical care after travel to Latin America or Asia.

33. • Viral hemorrhagic fevers are important to identify but are rare in
travelers; bacterial infections, such as leptospirosis,
meningococcemia, and rickettsial infections, can also cause fever and
hemorrhage and should be always be considered because of the need
to institute prompt, specific treatment.
• Sexually transmitted diseases, including acute HIV, can cause acute
febrile infections.
• Consider infection control, public health implications, and
requirements for reportable diseases.

34. Persistent Travelers’ Diarrhea

35. • Although most cases of travelers’ diarrhea are acute and self-
limited, a certain percentage of travelers will develop
persistent (>14 days) gastrointestinal symptoms.
• The pathogenesis of persistent travelers’ diarrhea generally
falls into one of the following broad categories:
Persistent infection or coinfection with a second organism
not targeted by initial therapy.
Previously undiagnosed gastrointestinal disease unmasked
by the enteric infection.
A postinfectious phenomenon.

36. PERSISTENT INFECTION
• Most cases of travelers’ diarrhea are the result of bacterial infection
and are short-lived and self limited. Travelers may experience
prolonged diarrheal symptoms if they are immunosuppressed, are
infected sequentially with diarrheal pathogens, or are infected with
protozoan parasites.
• Giardia is by far the most likely persistent pathogen to be
encountered.
• Suspicion for giardiasis should be particularly high when upper
gastrointestinal symptoms predominate.

37. • Untreated, symptoms may last for months, even in
immunocompetent hosts.
• The diagnosis can often be made through stool microscopy,
antigen detection, or immunofluorescence.
• However, as Giardia infects the proximal small bowel, even
multiple stool specimens may fail to detect it, and a duodenal
aspirate may be necessary for definitive diagnosis.
• Given the high prevalence of Giardia in persistent travelers’
diarrhea, empiric therapy is a reasonable option in the clinical
setting after negative stool microscopy and in lieu of duodenal
sampling.

38. • Other intestinal parasites that may cause persistent symptoms
include Cryptosporidium species, Entamoeba histolytica, Isospora
belli, Microsporidia, Dientamoeba fragilis, and Cyclospora
cayetanensis.
• Individual bacterial infections rarely cause persistence of symptoms,
although persistent diarrhea has been reported in children infected
with enteroaggregative or enteropathogenic Escherichia coli and
among people with diarrhea due to Clostridium difficile.

39. • C. difficile–associated diarrhea may follow treatment of a bacterial
pathogen with a fluoroquinolone or other antibiotic, or may even follow
malaria chemoprophylaxis.
• This is especially important to consider in the patient with persistent
travelers’ diarrhea that seems refractory to multiple courses of empiric
antibiotic therapy.
• The initial work-up of persistent travelers’ diarrhea should always include a
C. difficile stool toxin assay.
• Treatment of C. difficile infection is with metronidazole, oral vancomycin,
or fidaxomicin, although increasing reports of resistance to the first 2 drugs
have been noted.

40. • Persistent travelers’ diarrhea has also been associated with tropical sprue
and Brainerd diarrhea.
• These syndromes are suspected to result from infectious diseases, but
specific pathogens have not been identified.
• Tropical sprue is associated with deficiencies of vitamins absorbed in the
proximal and distal small bowel and most commonly affects long-term
travelers to tropical areas.
• Investigation of an outbreak of Brainerd diarrhea among passengers on a
cruise ship to the Galápagos Islands of Ecuador revealed that diarrhea
persisted from 7 to more than 42 months and did not respond to
antimicrobial therapy.

41. UNDERLYING GASTROINTESTINAL DISEASE
• In some cases, persistence of gastrointestinal symptoms relates to
chronic underlying gastrointestinal disease or susceptibility unmasked
by the enteric infection. Most prominent among these is celiac
disease.
• Idiopathic inflammatory bowel disease, both Crohn disease and
ulcerative colitis, may be seen after acute bouts of travelers’ diarrhea.
• Colorectal cancer should be considered, particularly in patients
passing occult or gross blood rectally or with the onset of a new iron-
deficiency anemia.

42. POSTINFECTIOUS PHENOMENA
• In a certain percentage of patients who present with persistent
gastrointestinal symptoms, no specific source will be found.
• Patients may experience temporary enteropathy following an acute
diarrheal infection, with villous atrophy, decreased absorptive surface area,
and disaccharidase deficiencies.
• This can lead to osmotic diarrhea, particularly when large amounts of
lactose, sucrose, sorbitol, or fructose are consumed.
• Use of antimicrobial medications during the initial days of diarrhea may
also lead to alterations in intestinal flora and diarrhea symptoms.

43. • Occasionally, the onset of symptoms of irritable bowel syndrome (IBS)
can be traced to an acute bout of gastroenteritis.
• IBS that develops after acute enteritis has been termed postinfectious
(PI)-IBS.
• To be labeled PI-IBS, symptoms should follow an episode of
gastroenteritis or travelers’ diarrhea if the work-up for microbial
pathogens and underlying gastrointestinal disease is negative.

44. EVALUATION
• Three or more stool examinations should be performed for ova and
parasites, including acid-fast stains for Cryptosporidium, Cyclospora, and
Isospora; Giardia antigen testing; C. difficile toxin assay; and a D-xylose
absorption test to determine if nutrients are being properly absorbed.
• Patients may also be given empiric treatment for Giardia infection.
• If underlying gastrointestinal disease is suspected, an initial evaluation
should include serologic tests for celiac and inflammatory bowel disease.
Subsequently, other studies to visualize both the upper and lower
gastrointestinal tracts, with biopsies, may be indicated.

45. MANAGEMENT
• Dietary modifications may help those with malabsorption.
• If stools are bloody or when disease is caused by C. difficile, antidiarrheal
medications such as loperamide or diphenoxylate should not be used in children
and should be used cautiously, if at all, in adults.
• Probiotic medications have been shown to reduce the duration of persistent
diarrhea among children in some settings.
• Antimicrobial medications may be useful in treating persistent diarrhea caused by
parasites.
• Nonabsorbable antibiotics may help if small intestinal bacterial overgrowth
accompanies the symptom complex.

46. Skin & Soft Tissue Infections in Returned Travelers

47. • Skin problems are among the most frequent medical
problems in returned travelers.
• The largest case series of dermatologic problems in returned
travelers from the GeoSentinel Surveillance Network showed
that cutaneous larva migrans, insect bites, and bacterial
infections were the most frequent skin problems in ill
travelers who sought medical care, making up 30% of the
4,742 diagnoses.

48. Skin lesions in returned travelers, by cause
SKIN LESION PERCENTAGE OF ALL DERMATOLOGIC DIAGNOSES (N = 4,742)
Cutaneous larvae migrans 9.8
Insect bite 8.2
Skin abscess 7.7
Superinfected insect bite 6.8
Allergic rash 5.5
Rash, unknown origin 5.5
Dog bite 4.3
Superficial fungal infection 4.0
Dengue 3.4
Leishmaniasis 3.3
Myiasis 2.7
Spotted-fever group rickettsiae 1.5
Scabies 1.5
Cellulitis 1.5

49. • Skin problems generally fall into either of the following
categories:
Those associated with fever, usually a rash or secondary
bacterial infection (cellulitis, lymphangitis, bacteremia, toxin
mediated).
Those not associated with fever.
• Most skin problems are minor and are not accompanied by
fever.

50. • Diagnosis of skin problems in returned travelers is based on the
following:
Pattern recognition of the lesions: papular, macular, nodular, linear,
or ulcerative
Location of the lesions: exposed versus unexposed skin surfaces
Exposure history: freshwater, ocean, insects, animals, or human
contact
Associated symptoms: fever, pain, pruritus
• It is important to recognize that skin conditions in returned travelers
may not have a travel related cause.

51. PAPULAR LESIONS
• Insect bites, the most common cause of papular lesions, may
be associated with secondary infection or hypersensitivity
reactions.
• Onchocerciasis may occur in long-stay travelers living in rural
sub-Saharan Africa and, rarely, Latin America. It usually
manifests as a generalized pruritic, papular dermatitis.

52. NODULAR OR SUBCUTANEOUS LESIONS, INCLUDING BACTERIAL
SKIN INFECTIONS
• Bacterial skin infections may occur more frequently after
bites and other wounds in the tropics, particularly when
good hygiene cannot be maintained. Organisms responsible
are commonly Staphylococcus aureus or Streptococcus
pyogenes.
• Myiasis presents as a painful lesion similar to a boil. It is
caused by infestation with the larval stage of the African
tumbu fly (Cordylobia anthropophaga) or the Latin American
bot fly (Dermatobia hominis).

53. • Tungiasis is caused by a sand flea (Tunga penetrans).
• Loa loa filariasis occurs rarely in long-term travelers living in
rural sub-Saharan Africa.
• Gnathostomiasis is a nematode infection found primarily in
Southeast Asia and less commonly in Africa and Latin
America. Infection results from eating undercooked or raw
freshwater fish.

54. MACULAR LESIONS
• Macular lesions are common and often nonspecific and may be due to drug
reactions or viral exanthems. Superficial mycoses, such as tinea versicolor
and tinea corporis, may also present as macular lesions.
• Tinea versicolor, due to Malassezia furfur (previously Pityrosporumovale).
• Tinea corporis (ringworm) may be caused by a number of different
superficial fungi.
• Lyme disease, a tickborne infection with Borrelia burgdorferi, is common in
North America, Europe, and Russia.

55. LINEAR LESIONS
• Cutaneous larva migrans, a skin infection with the larval
stage of dog or cat hookworm (Ancylostoma braziliense).
• Larva currens (running larva) due to cutaneous migration of
filariform larvae of Strongyloides stercoralis.

56. • Lymphocutaneous spread of infection occurs when
organisms spread along superficial cutaneous lymphatics.
Examples include sporotrichosis, Mycobacterium marinum
infection (associated with exposure to water), leishmaniasis,
bartonellosis (cat-scratch disease), Nocardia infection,
tularemia, melioidosis, and blastomycosis.
• Phytophotodermatitis is a noninfectious condition that
results from interaction of natural psoralens, most
commonly from spilled lime juice, and ultraviolet radiation
from the sun.

57. SKIN ULCERS
• Ulcerated skin lesions may result from Staphylococcus infections or
may be the direct result of an unseen spider bite.
• The necrotic ulcer of anthrax is often surrounded by edema and
usually results from handling animal hides or products.
• Rarely, a painless destructive ulcer with undermining edges may
result from infection with Mycobacterium ulcerans (Buruli ulcer).
• Of particular concern is the ulcer (or less commonly, nodule) caused
by cutaneous leishmaniasis.

58. MISCELLANEOUS SKIN INFECTIONS
• Skin Infections Associated with Water
M. marinum, Aeromonas spp., Plesiomonas spp., Edwardsiella tarda,
Erysipelothrix rhusiopathiae, Vibrio vulnificus, and Pseudomonas
aeruginosa
• Skin Infections Associated with Bites
S. aureus; α-, β-, and γ-hemolytic streptococci; several genera of gram-
negative organisms; and a number of anaerobic microorganisms;
Pasteurella multocida, and Capnocytophaga canimorsus

59. FEVER AND RASH
• Fever and rash in returned travelers are most often due to a viral infection.
• Dengue is caused by 1 of 4 strains of dengue viruses. The disease is
transmitted by a primarily day-biting Aedes mosquito often found in urban
areas, and its incidence continues to increase.
• Chikungunya, a virus transmitted by a primarily day-biting Aedes mosquito,
has recently caused major outbreaks of illness in southeast Africa, South
Asia, the Americas, and the Caribbean.
• South African tick typhus, or African tick-bite fever (Rickettsia africae), is
the most frequent cause of fever and rash in southern Africa. Transmitted
by ticks.

60. • Rocky Mountain spotted fever (RMSF), although uncommon in
travelers, is an important cause of fever and rash because of its
potential severity and the need for early treatment. This tickborne
infection is found in the United States, Mexico, and parts of Central
and South America.
• The category of fever with rash is large, and providers caring for ill
travelers should also consider the following diagnoses: enteroviruses,
such as echovirus and coxsackievirus; hepatitis B virus; measles;
Epstein-Barr virus; cytomegalovirus; typhus; leptospirosis; syphilis;
and HIV.

61. Screening Asymptomatic Returned Travelers

62. • CDC has no official guidelines or recommendations for
screening asymptomatic international travelers.
• Recommendations for screening the asymptomatic traveler
are necessarily based on opinion and common sense, rather
than convincing evidence.

63. • The following may serve as a general guideline:
For the asymptomatic short stay (<3–6 months) traveler, the yield of
screening is low and should be directed by specific risk factors
revealed in the history.
A history of prolonged (>2 weeks) digestive symptoms during travel
can suggest protozoal infection.
Exposure to fresh water in a region endemic for schistosomiasis,
especially in Africa, merits serologic screening, with the addition of
stool and urine examination in the case of high-intensity exposure.

64. Serology for Strongyloides should be considered in those who have a
high risk of skin exposure to soil likely to be contaminated with
human feces, usually those with a history of frequently walking
barefoot outdoors.
A sexual history should be obtained. Work in a health care setting or
other area at high risk for TB may merit screening.
For longer-stay travelers, as the overall yield of screening increases it
becomes less useful to rely on history for selective testing.

65. The emphasis should be on those with the longest stays and the most
problematic sanitary conditions.
In some cases, employers may require certain tests, partly for reasons
of liability.
Stool examinations are usually done, although they serve mostly to
provide a psychological reassurance.
Serologic testing for schistosomiasis and strongyloidiasis should be
done in those reporting some level of risk.

66. Eosinophil counts are usually done, although results should be
interpreted cautiously. Screening for sexually transmitted infections
should be offered to all except those with the most convincing
absence of risk.
 Mantoux or interferon-γ release assay (IGRA) tests should be limited
to those who have worked in a health care or similar setting, or
who have had intimate and prolonged contact with residents of an
endemic area for ≥ 6 months.
Possible exposure to bloodborne pathogens should be assessed. Any
other screening should be guided by exceptional exposures or
knowledge about local outbreaks.