Diagnosis In Travellers Research Articles

Differential diagnosis of illness in patients under investigation for the novel coronavirus (SARS-CoV-2), Italy, February 2020.

A novel coronavirus (SARS-CoV-2) has been identified as the causative pathogen of an ongoing outbreak of respiratory disease, now named COVID-19. Most cases and sustained transmission occurred in China, but travel-associated cases have been reported in other countries, including Europe and Italy. Since the symptoms are similar to other respiratory infections, differential diagnosis in travellers arriving from countries with wide-spread COVID-19 must include other more common infections such as influenza and other respiratory tract diseases.

Imported Toxin-Producing Cutaneous Diphtheria — Minnesota, Washington, and New Mexico, 2015–2018

From September 2015 to March 2018, CDC confirmed four cases of cutaneous diphtheria caused by toxin-producing Corynebacterium diphtheriae in patients from Minnesota (two), Washington (one), and New Mexico (one). All patients had recently returned to the United States after travel to countries where diphtheria is endemic. C. diphtheriae infection was not clinically suspected in any of the patients; treating institutions detected the organism through matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF) testing of wound-derived coryneform isolates. MALDI-TOF is a rapid screening platform that uses mass spectrometry to identify bacterial pathogens. State public health laboratories confirmed C. diphtheriae through culture and sent isolates to CDC's Pertussis and Diphtheria Laboratory for biotyping, polymerase chain reaction (PCR) testing, and toxin production testing. All isolates were identified as toxin-producing C. diphtheriae. The recommended public health response for cutaneous diphtheria is similar to that for respiratory diphtheria and includes treating the index patient with antibiotics, identifying close contacts and observing them for development of diphtheria, providing chemoprophylaxis to close contacts, testing patients and close contacts for C. diphtheriae carriage in the nose and throat, and providing diphtheria toxoid-containing vaccine to incompletely immunized patients and close contacts. This report summarizes the patient clinical information and response efforts conducted by the Minnesota, Washington, and New Mexico state health departments and CDC and emphasizes that health care providers should consider cutaneous diphtheria as a diagnosis in travelers with wound infections who have returned from countries with endemic diphtheria.

Sandmückenfieber – eine „vernachlässigte“ Krankheit

A45-year-old woman presented at the outpatient department of acenter for tropical diseases with fever, diarrhea, headache, myalgia, malaise, and an itchy papular rash. She had been on holiday with her family for 11days in amountain village in northern Cyprus. The place was infested with alot of small, stinging flies or mosquitoes. She and her family became sick after they returned home. The physical examination was normal apart from the rash on the inside of the extremities. Significantly elevated transaminases and aslightly increased C‑reactive protein level were found in the blood examination. Considering the country of travel, the report of the "stinging flies" and the clinical presentation, sandfly fever was also taken into account as adifferential diagnosis for the hepatitis. Antibodies to the sandfly fever Sicilian virus (SFSV) were detected. They showed the typical dynamics during the course of the illness and thus "pappataci fever" was diagnosed. The case report and ashort review of up-to-date literature is meant encourage consideration of phlebovirus infection as apossible differential diagnosis in travelers or refugees suffering from severe febrile hepatitis and rash or aseptic viral meningitis after their stay in the Mediterranean area.

Retrospective clinical case series study in 2017 identifies Plasmodium knowlesi as most frequent Plasmodium species in returning travellers from Thailand to Germany.

Febrile illnesses are common in travellers returning from south-east Asia. However, malaria is a rare diagnosis in this population. A series of Plasmodium knowlesi infections was noted in German travellers returning from Thailand since 2012. Infectious disease and tropical medicine facilities registered by the German Society for Tropical Medicine and International Health were contacted in March 2017, and asked to report previous P. knowlesi cases. In addition, surveillance data from the Robert Koch-Institute were analysed. The facilities reported a total of six P. knowlesi-positive cases, all were returning travellers from Thailand. The P. knowlesi-positive cases made up 6/9 of all diagnosed malaria cases imported from Thailand in the time period 2012 to 2017. In 4/5 of cases where a malaria rapid diagnostic test had been applied it revealed a negative result. P. knowlesi is an important differential diagnosis in travellers returning from south-east Asia with itineraries that include Thailand. This study highlights the importance of this Plasmodium species in this patient subgroup. Whenever malaria is suspected in a returning traveller from Thailand, P. knowlesi should be taken into consideration and a differential PCR be executed as currently the unequivocal diagnosis of P. knowlesi is based on nuclear amplification techniques.

Imported malaria in Spain (2009\u20132016): results from the +REDIVI Collaborative Network

BackgroundImported malaria is a frequent diagnosis in travellers and migrants. The objective of this study was to describe the epidemiological and clinical characteristics of patients diagnosed with imported malaria within a Spanish collaborative network registering imported diseases (+REDIVI). In addition, the possible association between malaria and type of case, gender, age or area of exposure was explored.MethodsCases of imported malaria were identified among all cases registered in the +REDIVI database during the period October 2009–October 2016. Demographic, epidemiological and clinical characteristics were analysed.ResultsIn total, 11,816 cases of imported infectious diseases were registered in +REDIVI’s database between October 2009 and October 2016. Immigrants seen for the first time after migration accounted for 60.2% of cases, 21.0% of patients were travellers, and 18.8% were travellers/immigrants visiting friends and relatives (VFRs). There were 850 cases of malaria (850/11,816, 7.2%). Malaria was significantly more frequent in men than in women (56.8% vs 43.2%) and in VFR-immigrants (52.6%) as compared to travellers (21.3%), immigrants (20.7%) and VFR-travellers (5.4%) (p < 0.001). Although this data was not available for most patients with malaria, only a minority (29/217, 13.4%) mentioned correct anti-malarial prophylaxis. Sub-Saharan Africa was found to be the most common region of acquisition of malaria. Most common reason for consultation after travel was a febrile syndrome although an important proportion of immigrants were asymptomatic and presented only for health screening (27.3%). Around 5% of travellers presented with severe malaria. The most prevalent species of Plasmodium diagnosed was Plasmodium falciparum (81.5%). Malaria due to Plasmodium ovale/Plasmodium vivax was frequent among travellers (17%) and nearly 5% of all malaria cases in immigrants were caused by Plasmodium malariae.ConclusionsMalaria was among the five most frequent diagnoses registered in +REDIVI’s database. Some significant differences were found in the distribution of malaria according to gender, type of case, species. Among all malaria cases, the most frequent diagnosis was P. falciparum infection in VFR-immigrant men.

Spot the difference-development of a syndrome based protein microarray for specific serological detection of multiple flavivirus infections in travelers.

BackgroundThe family Flaviviridae, genus Flavivirus, holds many of the world’s most prevalent arboviral diseases that are also considered the most important travel related arboviral infections. In most cases, flavivirus diagnosis in travelers is primarily based on serology as viremia is often low and typically has already been reduced to undetectable levels when symptoms set in and patients seek medical attention. Serological differentiation between flaviviruses and the false-positive results caused by vaccination and cross-reactivity among the different species, are problematic for surveillance and diagnostics of flaviviruses. Their partially overlapping geographic distribution and symptoms, combined with increase in travel, and preexisting antibodies due to flavivirus vaccinations, expand the need for rapid and reliable multiplex diagnostic tests to supplement currently used methods.GoalWe describe the development of a multiplex serological protein microarray using recombinant NS1 proteins for detection of medically important viruses within the genus Flavivirus. Sera from clinical flavivirus patients were used for primary development of the protein microarray.ResultsResults show a high IgG and IgM sensitivity and specificity for individual NS1 antigens, and limited cross reactivity, even within serocomplexes. In addition, the serology based on this array allows for discrimination between infection and vaccination response for JEV vaccine, and no cross-reactivity with TBEV and YFV vaccine induced antibodies when testing for antibodies to other flaviviruses.ConclusionBased on these data, multiplex NS1-based protein microarray is a promising tool for surveillance and diagnosis of flaviviruses.

Schistosomiasis: Current Epidemiology and Management in Travelers

Schistosomiasis is increasingly encountered among travelers returning from the tropics, mainly from Africa. Schistosoma-infected travelers have served as sentinels for the existence of unknown foci of transmission even outside Africa. Acute schistosomiasis (also termed Katayama syndrome) is the common manifestation among travelers and may follow exposure to any of the Schistosoma species. Neuroschistosomiasis is a rare complication but may result in severe disability. Diagnosis in travelers is hampered by the poor sensitivity of microscopy in urine and stool, especially during acute infections, while seroconversion may be delayed for a period of weeks. During acute schistosomiasis, symptomatic treatment is the only available therapy, while for chronic schistosomiasis, praziquantel is the only drug available, despite reports of emerging resistance to it. Since the potential for exposure to Schistosoma through travel will probably continue to increase, it is clear that new, sensitive diagnostic methods and drugs affecting the parasite in all its stages are needed.

Ongoing outbreak of an acute muscular Sarcocystis-like illness among travellers returning from Tioman Island, Malaysia, 2011-2012

As of 4 November, 2012, 100 patients with an acute muscular Sarcocystis-like illness associated with travel to Tioman Island, Malaysia, have been identified. Thirty-five travelled there mostly during July and August 2011 and 65 mostly during July and August 2012, suggesting an ongoing outbreak. Epidemiological investigations are ongoing. Public health agencies and practicing clinicians should be aware of this rarely-reported disease in humans and consider it as differential diagnosis in travellers returning from Tioman Island.

Therapiemanagement bei Malaria

Plasmodium falciparum and to some extent malaria caused by other species of Plasmodia can quickly lead to cerebral malaria, acute renal failure, or acute respiratory distress syndrome. The mortality rate for patients with severe malaria lies around 10%. Malaria must be given priority in the differential diagnosis of travelers returning febrile from endemic areas. Treatment requires prompt administration of safe and fast-acting antimalarials, which in severe malaria is treatment with quinine or artesunate. Hospitals must be prepared to diagnose and treat malaria patients-or have a standard operating procedure for transferring the patient to a specialized center.

Tularaemia in Berlin – two independent cases in travellers returning from central Anatolia, Turkey, February 2011

Tularaemia, though rare, has recently been increasingly reported in Germany. Most cases are indigenous infections. This report describes two epidemiologically independent infections with Francisella tularensis subspecies holarctica detected in Berlin in February 2011 that were acquired in central Anatolia, Turkey. In Turkey, there have been repeated tularaemia outbreaks since 2000 and the disease should therefore be considered as a differential diagnosis in travellers returning from that country.

Validity of Malaria Diagnosis in Nonimmune Travelers in Endemic Areas

Malaria has to be considered in all febrile travelers during or after a stay in endemic areas. However, malaria diagnosis in endemic countries may be inaccurate due to limited capacity and lack of resources of local health services. To assess the validity of malaria diagnosis in travelers in endemic areas, we investigated the retrospective confirmation of malaria by detection of specific antibodies. Sera of 105 nonimmune travelers who presented between 2003 and 2005 with a history of diagnosis and treatment of malaria during a stay in malaria-endemic countries within the previous 6 months were analyzed for antibodies against Plasmodium falciparum and Plasmodium vivax blood forms by an indirect immunofluorescence test. About 241 follow-up sera from 176 nonimmune patients with microscopically confirmed malaria served as a control group. Antibodies against plasmodia were detectable within 180 days after reported date of diagnosis and treatment in 16 of 105 travelers (15.2%) only. In the control group, 71.6% of analyzed sera (151 of 211) showed positive results within this interval. Within 8 to 60 days after diagnosis of malaria, the seropositivity rates were 17.9% for travelers (n = 56) and 92.4% for controls (n = 92). Although the sensitivity of malaria serology for retrospective confirmation of malaria is limited, the results of this analysis strongly suggest that the majority of travelers with a recent history of malaria diagnosed and treated in endemic countries did not have malaria and that diagnosis of malaria during travel in endemic areas is frequently incorrect.

An approach to fever in the returning traveller

AbstractThe traveller who presents with fever on return requires a comprehensive assessment. This paper outlines the salient features in assessing these patients. A detailed history, examination and knowledge of diseases prevalent in the areas that were visited is essential if one is to arrive at a diagnosis and institute appropriate treatment or referral.Malaria remains the first differential diagnosis in travellers returning from an endemic area irrespective of precautions taken.The most common illnesses that result in a fever in travellers are presented and a resource list is provided.

Borreliosis: A rare and alternative diagnosis in travellers’ febrile illness

We report a case of borreliosis mimicking uncomplicated malaria in a patient returning from Mali. Identification of spirochetes through examination of a thick blood smear completed by an acridine-orange quantitative buffy coat allowed the diagnosis of borreliosis. All symptoms rapidly resolved following tetracycline therapy. Epidemiological and clinical features of borreliosis, diagnostic tools and management are discussed.

Illness in Returned Travelers and Immigrants/Refugees: The 6‐Year Experience of Two Australian Infectious Diseases Units

Data comparing returned travelers and immigrants/refugees managed in a hospital setting is lacking. We prospectively collected data on 1,106 patients with an illness likely acquired overseas who presented to two hospital-based Australian infectious diseases units over a 6-year period. Eighty-three percent of patients were travelers and 17% immigrants/refugees. In travelers, malaria (19%), gastroenteritis/diarrhea (15%), and upper respiratory tract infection (URTI) (7%) were the most common diagnoses. When compared with immigrants/refugees, travelers were significantly more likely to be diagnosed with gastroenteritis/diarrhea [odds ratio (OR) 8], malaria (OR 7), pneumonia (OR 6), URTI (OR 3), skin infection, dengue fever, typhoid/paratyphoid fever, influenza, and rickettsial disease. They were significantly less likely to be diagnosed with leprosy (OR 0.03), chronic hepatitis (OR 0.04), tuberculosis (OR 0.05), schistosomiasis (OR 0.3), and helminthic infection (OR 0.3). In addition, travelers were more likely to present within 1 month of entry into Australia (OR 96), and have fever (OR 8), skin (OR 6), gastrointestinal (OR 5), or neurological symptoms (OR 5) but were less likely to be asymptomatic (OR 0.1) or have anaemia (OR 0.4) or eosinophilia (OR 0.3). Diseases in travelers were more likely to have been acquired via a vector (OR 13) or food and water (OR 4), and less likely to have been acquired via the respiratory (OR 0.2) or skin (OR 0.6) routes. We also found that travel destination and classification of traveler can significantly influence the likelihood of a specific diagnosis in travelers. Six percent of travelers developed a potentially vaccine-preventable disease, with failure to vaccinate occurring in 31% of these cases in the pretravel medical consultation. There are important differences in the spectrum of illness, clinical features, and mode of disease transmission between returned travelers and immigrants/refugees presenting to hospital-based Australian infectious diseases units with an illness acquired overseas.

Leptospirosis masquerading as infectious enteritis

Leptospirosis is a zoonosis caused by a ubiquitous spirochete of the genus Leptospira and is endemic to the tropics. Prompt diagnosis and treatment are important in reducing the morbidity and mortality that can be associated with this illness. We report the case of a 30-year-old Israeli traveler who had returned from Thailand and developed fever, chills, vomiting and diarrhea. An unexpectedly high value of creatinine expanded the diagnostic possibilities beyond travelers' diarrhea. Leptospirosis was confirmed serologically and the traveler eventually recovered. Leptospirosis should be considered in the differential diagnosis of travelers returning with fever and gastrointestinal complaints.

Could it be lymphatic filariasis?

Lymphatic filariasis (LF) is, after malaria, the second most common mosquito-borne disease globally. LF is caused by three species of nematode parasites, which can be spread by a wide range of mosquito species.The World Health Organization (WHO) estimates the global burden of infection to be 120 million, with 1 billion people at risk of infection.1 LF is, after mental illness, the second most important cause of long-term disability worldwide. LF, which has recently been extensively reviewed, also occurs in travelers, military expeditionary forces,and other expatriates. LF should therefore always be considered in the differential diagnosis of travelers returning from endemic areas, and experiencing acute episodes of fever, pain and swelling of the limbs or external genitalia,or lymphatic system affectation. There have been several recent case reports of LF occurring in travelers.

Dengue fever: diagnostic importance of a camelback fever pattern

We present a case of imported dengue fever in a 52-year-old man acquired during a recent trip to Ecuador. Fever in a returning traveler from tropical areas often presents a diagnostic problem for clinicians. Our patient presented with severe arthralgias and myalgias and had a camelback/saddleback fever pattern accompanied by relative bradycardia, which was a clue to the diagnosis. He had conjunctival suffusion and the truncal rash, but adenopathy was not present. He also had a generalized headache and abdominal pain. Nonspecific laboratory abnormalities included leukopenia, lymphopenia, atypical lymphocytes, thrombocytopenia, and mildly increased serum transaminases. Clinicians should consider dengue fever in the differential diagnosis in travelers returning from dengue fever endemic areas of Southeast Asia, Latin America, and Africa. Although early findings are nonspecific, a truncal rash accompanied by leukopenia and thrombocytopenia, if followed by biphasic fever pattern (ie, camelback/saddleback fever curve with relative bradycardia), suggest dengue fever as the primary diagnostic consideration.

Acute Histoplasmosis in Spelunkers Returning from Mato Grosso, Peru.

Background: Histoplasmosis is a fungal disease with a worldwide distribution. Travelers returning from endemic areas with a history of exposure to fungal spores have a high risk of infection. Methods: We report four cases of acute pulmonary disease in Italian spelunkers returning from Mato Grosso, Peru. Results: Symptoms and radiologic findings were consistent with acute pulmonary illness. Laboratory data supported the hypothesis of histoplasmosis. Conclusions: Histoplasmosis should be considered in the differential diagnosis in travelers returning from endemic areas, who report a risk of exposure, and present with respiratory illness. In this setting, seroconversion may be considered diagnostic of pulmonary histoplasmosis.

Evaluation of a New Latex Agglutination Test for Fecal Lactoferrin in Travelers' Diarrhea.

The detection and diagnosis of travelers' diarrhea by fecal culture method, often insensitive, expensive, and time consuming, could well be replaced with the latex agglutination test to detect fecal lactoferrin. As an initial screening, this test could be useful to differentiate between those patients who are more likely to have an invasive enteropathogen and those patients requiring antidiarrheal chemotherapy only. Fecal samples from 92 patients with travelers' diarrhea were tested for occult blood, fecal leukocytes, and fecal lactoferrin at stool dilutions of 1:50 and 1:200. The results were compared with findings from fecal cultures for enteropathogens. Statistical analyses were performed measuring the performance of the latex agglutination test for fecal lactoferrin to calculate its sensitivity, specificity, and positive and negative predictive values. Invasive pathogens were identified in 36 (39%), and a noninvasive pathogen was found in 18, or 20%, of the cases. At the stool dilution of 1:50, fecal lactoferrin showed more sensitivity than did leukocytes or occult blood in detecting the presence of invasive enteropathogens and, with a negative predictive value of 94%, was superior in predicting their absence. At the 1:200 dilution, a lower sensitivity of 55%, but a higher specificity of 82%, compared to 55% with the 1:50 dilution, was demonstrated. The determination of fecal lactoferrin might prove to be more useful and less expensive and time consuming as an initial screening for patients presenting with travelers' diarrhea. Further evaluation and antibacterial treatment could, therefore, be reserved for those with a positive lactoferrin test.