Changes in monocyte subsets in volunteers who received an oral wild-type Salmonella Typhi challenge and reached typhoid diagnosis criteria.

An oral Controlled Human Infection Model (CHIM) with wild-type S. Typhi was re-established allowing us to explore the development of immunity. In this model, ~55% of volunteers who received the challenge reached typhoid diagnosis criteria (TD), while ~45% did not (NoTD). Intestinal macrophages are one of the first lines of defense against enteric pathogens. Most organs have self-renewing macrophages derived from tissue-resident progenitor cells seeded during the embryonic stage; however, the gut lacks these progenitors, and all intestinal macrophages are derived from circulating monocytes. After infecting gut-associated lymphoid tissues underlying microfold (M) cells, S. Typhi causes a primary bacteremia seeding organs of the reticuloendothelial system. Following days of incubation, a second bacteremia and clinical disease ensue. S. Typhi likely interacts with circulating monocytes or their progenitors in the bone marrow. We assessed changes in circulating monocytes after CHIM. The timepoints studied included 0 hours (pre-challenge) and days 1, 2, 4, 7, 9, 14, 21 and 28 after challenge. TD participants provided extra samples at the time of typhoid diagnosis, and 48-96 hours later (referred as ToD). We report changes in Classical Monocytes -CM-, Intermediate Monocytes -IM- and Non-classical Monocytes -NCM-. Changes in monocyte activation markers were identified only in TD participants and during ToD. CM and IM upregulated molecules related to interaction with bacterial antigens (TLR4, TLR5, CD36 and CD206). Of importance, CM and IM showed enhanced binding of S. Typhi. Upregulation of inflammatory molecules like TNF-α were detected, but mechanisms involved in limiting inflammation were also activated (CD163 and CD354 downregulation). CM upregulated molecules to interact/modulate cells of the adaptive immunity, including T cells (HLA-DR, CD274 and CD86) and B cells (CD257). Both CM and IM showed potential to migrate to the gut as integrin α4ß7 was upregulated. Unsupervised analysis revealed 7 dynamic cell clusters. Five of these belonged to CM showing that this is the main population activated during ToD. Overall, we provide new insights into the changes that diverse circulating monocyte subsets undergo after typhoid diagnosis, which might be important to control this disease since these cells will ultimately become intestinal macrophages once they reach the gut.

Evaluation of a point-of-care multiplex immunochromatographic assay for the diagnosis of typhoid: results from a retrospective diagnostic accuracy study.

There is a clear medical need for an accurate diagnostic test for typhoid that can be performed at point of care. Two antigens (lipopolysaccharide [LPS] and hemolysin E [HlyE]) have recently been identified that can distinguish typhoid from other bacterial infections. Here, we present the results of a diagnostic accuracy study of the Dual Path Platform (DPP) Typhoid assay (Chembio) that detects IgA to both LPS and HlyE using blood culture as the reference standard. This was a retrospective, observational, laboratory study conducted at the Aga Khan University research laboratory, Pakistan, to evaluate the sensitivity and specificity of the DPP Typhoid assay, using archived frozen serum samples collected during a previous typhoid diagnostic accuracy study (NCT04801602). The sensitivity, specificity, and accuracy (area under the receptor operating characteristics curve [AUC]) were then assessed using the manufacturer's and Youden's optimal thresholds. In total, 385 samples were included in the analysis. Using the manufacturer's thresholds, the sensitivity, specificity, and AUC were 97.8% (95% confidence interval [CI] 94.6-99.2), 65.3% (95% CI 58.5-71.6), and 81.5% (95% CI 75.5-85.3), respectively. At Youden's optimal threshold, the overall sensitivity of the DPP Typhoid assay was 89.7% and the specificity was 82.2%. In latent class modeling compared with other nine rapid diagnostic tests evaluated from the same cohort sample, the DPP Typhoid assay demonstrated the highest balanced accuracy (89.2%). The DPP Typhoid assay demonstrated a high diagnostic accuracy for typhoid fever. However, further adjustment to new thresholds is recommended to enhance its performance capabilities. IMPORTANCE: Currently available diagnostic tests for typhoid have several limitations, including low sensitivity and specificity. Dual Path Platform Typhoid assay is a multiplex rapid test that detects IgA antibodies to lipopolysaccharide and hemolysin E antigen. It is considered to have high sensitivity and specificity, and its results were found to be highly correlated with ELISA results. However, very few studies have been conducted to evaluate this test and limited information about the accuracy of this test is present. Hence, this study evaluated the new typhoid test.

Prolonged Care for Presumed Typhoid Encephalitis in Indonesia.

Despite advancements in military medical treatment and evacuation, soldiers in austere environments remain vulnerable to disease and non-battle injury and may face prolonged evacuation before receiving definitive care. In particular, arranging care for a soldier presenting with a conditions that has a wide differential diagnosis, such as acute altered mental status (AMS), can be especially challenging. We highlight the case of an otherwise young, healthy U.S. Soldier serving in Indonesia, who presented with acute AMS concerning for undifferentiated infection. Subsequent workup at the receiving hospital following evacuation revealed Salmonella enterica infection, more commonly known as typhoid. However, even with clinical findings of typhoid encephalitis and initiation of empiric treatment, medical care proved challenging in the resource-limited local facilities, despite multiple escalations of care. Ultimately, the patient was evacuated to a tertiary facility in Singapore, where his condition improved, and 4 days after initial presentation the patient had no definitive findings of infections on lumbar puncture. This case not only highlights the threat of typhoid and other infectious diseases in modern operations but also the challenges of suboptimal medical care in both the prehospital and hospital settings when utilizing host nation facilities.

Typhoid fever: the challenging diagnosis of a pseudo-outbreak in Benguet, Philippines.

Objective: The event-based surveillance and response report from the municipality of Buguias in the Philippines covering the period 1 January to 29 October 2022 indicated an unusual increase in the number of typhoid cases that surpassed the epidemic threshold for consecutive weeks. An investigation was conducted to confirm the existence of an outbreak, identify the source(s) of transmission and recommend prevention and control measures. Methods: The investigation employed a descriptive design. Medical records were reviewed to verify diagnoses and to identify cases that met case definitions. Key informant interviews were conducted to identify possible sources of transmission and investigate the reporting of cases in the Philippine Integrated Disease Surveillance and Response (PIDSR) system. Results: A total of 220 cases of typhoid fever were captured by the PIDSR system. Of the 208 suspected cases that were reviewed, only 15 (7.2%) met the case definition used in this investigation. Fourteen of these 15 verified cases were interviewed; five (35.7%) were farmers and 13 (92.8%) reported using springs as their main water source and source of drinking-water. Reporting of cases in the PIDSR system was largely based on the final chart diagnosis or a positive Typhidot or Tubex rapid diagnostic test result. The PIDSR case definition was not followed in the reporting of cases. Discussion: This study provides evidence of endemicity of typhoid fever in Buguias, Benguet, Philippines. However, from January to October 2022, cases were overreported by the surveillance system. Medical record reviews showed that most reported suspected cases did not meet case definition criteria. This finding emphasizes the need to improve typhoid guidelines with regards to diagnosis using rapid diagnostic tests and to investigate the cost-effectiveness of making confirmatory laboratory tests for typhoid available in the Philippines.

A portable label-free electrochemical DNA biosensor for rapid detection of Salmonella Typhi.

A highly accurate, rapid, portable, and robust platform for detecting Salmonella enterica serovar Typhi (S. Typhi) is crucial for early-stage diagnosis of typhoid to avert and control the outbreaks of this pathogen, which threaten global public health. This study presents a proof-of-concept for our developed label-free electrochemical DNA biosensor system for S. Typhi detection, which employs a printed circuit board gold electrode (PCBGE), integrated with a portable potentiostat reader. Initially, the functionalized DNA biosensor and target detection were characterized using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) methods using a benchtop potentiostat. Interestingly, the newly developed DNA biosensor can identify target single-stranded DNA concentrations ranging from 10 nM to 20 µM, achieving a detection limit of 7.6 nM within a brief 5 minute timeframe. Under optimal detection conditions, the DNA biosensor exhibits remarkable selectivity, capable of distinguishing a single mismatch base pair from the target single-stranded DNA sequence. We then evaluated the feasibility of the developed DNA biosensor system as a diagnostic tool by detecting S. Typhi in 50 clinical samples using a portable potentiostat reader based on the DPV technique. Remarkably, the developed biosensor can distinctly distinguish between positive and negative samples, indicating that the miniaturised DNA biosensor system is practical for detecting S. Typhi in real biological samples. The developed DNA biosensor device in this work proves to be a promising point-of-care (POC) device for Salmonella detection due to its swift detection time, uncomplicated design, and streamlined workflow detection system.

Clinical characteristics of enteric fever and performance of TUBEX TF IgM test in Indonesian hospitals.

BACKGROUND: Accurate diagnosis of enteric fever is challenging, particularly in low- and middle-income countries, due to the overlap of clinical and laboratory features with other pathogens. To better understand the difficulties in enteric fever diagnosis, we evaluated the characteristics of patients clinically diagnosed with enteric fever and the real-world performance of TUBEX TF, one of the most used tests in Indonesia. METHODOLOGY/PRINCIPAL FINDINGS: Patients were recruited through the AFIRE (Etiology of Acute Febrile Illness Requiring Hospitalization) study at eight Indonesian hospitals. Blood culture was performed for all patients, and TUBEX TF was performed for suspected enteric cases. Salmonella PCR and ELISA tests were performed at a reference lab. Sensitivity and specificity of TUBEX TF and IgM and IgG anti-S. Typhi ELISA were determined. Of 301 patients clinically diagnosed with enteric fever, 50 (16.6%) were confirmed by blood culture and/or PCR. Confirmed cases were mostly school-aged children presenting with fever, anorexia, dizziness and/or abdominal pain with normal leukocyte count or leukopenia. TUBEX TF demonstrated a sensitivity of 97.6% to 70.7% and specificity of 38.3% to 67.2% at cutoffs of 4 and 6, respectively. Acute IgG demonstrated the best sensitivity and specificity, at 90.7% and 82.7%, respectively, and the best ROC characteristics. CONCLUSIONS/SIGNIFICANCE: A substantial proportion of enteric fever was misdiagnosed at all study hospitals, likely due to the overlap of clinical characteristics and lab parameters with those of other common pathogens. The TUBEX TF rapid serological assay demonstrated suboptimal performance in our setting and tended to over-diagnose enteric fever. The role of IgG from acute specimens for identification of enteric fever cases merits additional consideration.

Molecular Detection of Salmonella typhi Isolated from Patients Undergoing Gallbladder Cholecystectomy in Baghdad.

BACKGROUND: Salmonella typhi is a specific strain of the Salmonella bacterium, responsible for triggering typhoid fever; a significant public health concern in developing nations. OBJECTIVE: The current study aimed to identify the bacteria from the gallbladder, taken during cholecystectomies of patients, by isolating Salmonella typhi and by using microscopic characteristics, biochemical and polymerase chain reaction (PCR) tests. METHODS: A total of 120 specimens were collected from the Baghdad Teaching Hospital, Iraq. A cross-sectional descriptive study was carried out from October, 2021, to July, 2022. During that study, 26 (54.2%) male patient tested positive for Salmonella typhias well as 22 (45.8%) female patients. The age of the patients varied from < 30 to > 60 years. p-value > 0.05 was considered significant to confirm a relationship between age and Salmonella typhi effect for patients. RESULTS: Out of the 120 blood samples taken for this study, 48 (40%) tested positive by use of PCR test, 40 (33.3%) tested positive by use of the Widal test, 35 (29.1%) were positive for biopsy culture, and 35 (29.1%) were positive for blood culture. All Salmonella typhi isolates were found to be sensitive to the imipenem, cefepime, and ceftriaxone, but were resistant to gentamycin, ciprofloxacin, amikacin, erythromycin, and tetracycline (72%, 29%, 43%, 100%, 100%, respectively). CONCLUSIONS: The real time polymerase chain reaction (RT-PCR) tests and the Vitek 2 compact system showed a high level of accuracy in the detection of Salmonella typhi. Multidrug resistance was observed, which should be a signal to reduce antibiotic consumption.

An Unusual Hematological Complication of Typhoid Fever Case Report.

Typhoid fever is caused by Salmonella species. The most common hematological complications described are anemia and disseminated intravascular coagulation. Splenic infarction is an unusual complication of typhoid fever, and this presentation is rarely described. We report the case of a young female who presented with complaints of severe left upper quadrant pain after being diagnosed with typhoid fever. Computed tomography (CT) revealed multiple wedge-shaped splenic infarcts. She was treated with antibiotics and was also started on antiplatelets. She had a complete recovery with this management, and antiplatelets were tapered off on subsequent visits.

Primary Aortoenteric Fistula Due to Salmonella typhi-related Mycotic Aneurysm.

Primary aortoenteric fistulas (AEF) are rare. The majority of these are due to atherosclerotic aortic aneurysms. Mycotic aortic aneurysms leading to primary AEF are exceedingly uncommon. Here we report a rare case of primary AEF secondary to Salmonella-related mycotic aneurysm and discuss the diagnostic and therapeutic issues.

Etiological spectrum and diagnostic challenges of short-duration fever in West Bengal (India). A cross-sectional tertiary care study.

INTRODUCTION: The scarcity of epidemiological data on acute febrile illnesses from South Asia impairs evidence-based clinical decision-making. Our study aimed to explore the etiological spectrum of short-duration fever in patients admitted to a tertiary care hospital in West Bengal, India. METHODS: We conducted a cross-sectional study from May 2021 to April 2022 involving 150 adult patients presenting with a fever lasting less than two weeks at Burdwan Medical College and Hospital (West Bengal, India). We performed comprehensive clinical assessments, including microbiological, serological, and other specific investigations, to identify the causes of the fever. RESULTS: The demographic profile predominantly included individuals aged 21-40 years, with a male-to-female ratio of 1.9:1; 60.7% of participants were from rural areas. The primary etiological agents identified were scrub typhus (25.3%), dengue (15.3%), and enteric fever (13.3%). Notably, 80% of patients presented with non-localizing symptoms, while 14.7% had respiratory symptoms. Blood cultures pinpointed Salmonella typhi and Staphylococcus aureus in a minority of cases (3.3%); malaria, primarily Plasmodium vivax, was diagnosed in 12% of the cases. CONCLUSION: Our findings highlight the complexity of diagnosing short-duration fevers, dominated by a wide range of etiological agents, with a notable prevalence of scrub typhus. These results underscore the urgent need for enhanced diagnostic facilities, including the availability of scrub typhus testing at primary healthcare centers. We recommend empirical doxycycline therapy for suspected cases and emphasize the need for further research to develop management guidelines for acute febrile illnesses. This study also highlights the importance of raising both community and clinician awareness to prevent irrational antibiotic use.

Case Report: Salmonella typhi Iliopsoas Abscess with Concomitant Sacroiliitis in a Young Immunocompetent Male: A Rare Case.

Iliopsoas abscess is an infrequent condition characterized by the collection of pus in the iliopsoas compartment. The prevalence of the disease has been increasing in recent years with the emergence of various comorbidities and risk factors. The availability of newer imaging modalities has also improved the detection of new cases. Salmonellosis is an uncommon etiology in iliopsoas abscess and sacroiliitis. Most cases reported in the literature are associated with Staphylococcus aureus, Streptococci species, and Escherichia coli. Diabetes, hematological malignancies, HIV, and other immunocompromised states are important comorbidities/risk factors for iliopsoas abscess. We report a case of an 18-year-old male who presented with a history of fever and right hip pain for 10 days. Radioimaging revealed right sacroiliitis and iliopsoas abscess. Blood culture revealed pan-sensitive Salmonella typhi. After the prolonged course of antibiotics (intravenous ceftriaxone followed by oral levofloxacin), the patient improved with no further relapse in symptoms. Salmonella typhi should be an important differential of iliopsoas abscess in endemic regions after ruling out the common etiology such as S. aureus and Mycobacterium tuberculosis.

Ultrasensitive detection of Salmonella typhi using a PAM-free Cas14a-based biosensor.

The effectiveness of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas14a1, widely utilized for pathogenic microorganism detection, has been limited by the requirement of a protospacer adjacent motif (PAM) on the target DNA strands. To overcome this limitation, this study developed a Single Primer isothermal amplification integrated-Cas14a1 biosensor (SPCas) for detecting Salmonella typhi that does not rely on a PAM sequence. The SPCas biosensor utilizes a novel primer design featuring an RNA-DNA primer and a 3'-biotin-modified primer capable of binding to the same single-stranded DNA (ssDNA) in the presence of the target gene. The RNA-DNA primer undergoes amplification and is blocked at the biotin-modified end. Subsequently, strand replacement is initiated to generate ssDNA assisted by RNase H and Bst enzymes, which activate the trans-cleavage activity of Cas14a1 even in the absence of a PAM sequence. Leveraging both cyclic chain replacement reaction amplification and Cas14a1 trans-cleavage activity, the SPCas biosensor exhibits a remarkable diagnostic sensitivity of 5 CFU/mL. Additionally, in the assessment of 20 milk samples, the SPCas platform demonstrated 100% diagnostic accuracy, which is consistent with the gold standard qPCR. This platform introduces a novel approach for developing innovative CRISPR-Cas-dependent biosensors without a PAM sequence.

Development, confirmation, and application of a seeded Escherichia coli process control organism to validate Salmonella enterica serovar Typhi environmental surveillance methods.

Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of Typhoid fever. Blood culture is the gold standard for clinical diagnosis, but this is often difficult to employ in resource limited settings. Environmental surveillance of waste-impacted waters is a promising supplement to clinical surveillance, however validating methods is challenging in regions where S. Typhi concentrations are low. To evaluate existing S. Typhi environmental surveillance methods, a novel process control organism (PCO) was created as a biosafe surrogate. Using a previous described qPCR assay, a modified PCR amplicon for the staG gene was cloned into E. coli. We developed a target region that was recognized by the Typhoid primers in addition to a non-coding internal probe sequence. A multiplex qPCR reaction was developed that differentiates between the typhoid and control targets, with no cross-reactivity or inhibition of the two probes. The PCO was shown to mimic S. Typhi in lab-based experiments with concentration methods using primary wastewater: filter cartridge, recirculating Moore swabs, membrane filtration, and differential centrifugation. Across all methods, the PCO seeded at 10 CFU/mL and 100 CFU/mL was detected in 100% of replicates. The PCO is detected at similar quantification cycle (Cq) values across all methods at 10 CFU/mL (Average = 32.4, STDEV = 1.62). The PCO was also seeded into wastewater at collection sites in Vellore (India) and Blantyre (Malawi) where S. Typhi is endemic. All methods tested in both countries were positive for the seeded PCO. The PCO is an effective way to validate performance of environmental surveillance methods targeting S. Typhi in surface water.

Typhoid fever in children in Goroka, Papua New Guinea.

BACKGROUND: Typhoid is endemic in many low-income countries, including in Papua New Guinea. This study aimed to describe the burden and clinical features of typhoid in children in a provincial hospital, to describe environmental conditions that lead to typhoid, and to document the antibiotic sensitivity of Salmonella spp. in the Eastern Highlands Province. METHODS: A combined retrospective and prospective study of children admitted to with clinical features of typhoid to the Goroka Hospital throughout 2022. RESULTS: The study included 98 children, of which 54% were female. The median age was 8 (IQR 5-10.6) years. Over 60% of the patients were from Goroka District, the peri-urban area encompassing the town and surrounds. Ninety-four percent (92) of the patients used a pit latrine as a toilet and only 28% had access to treated water. Neuropsychiatric symptoms were common (60%), as was leukopenia (48%), thrombocytopenia (52%) and anaemia (42%). Thirty-seven patients had positive blood cultures for Salmonella typhi; all isolates were sensitive to third-generation cephalosporins, pefloxacin, ampicillin, trimethoprim and sulfamethoxazole, and only 54% sensitive to chloramphenicol. The median duration of hospitalisation was 6 days (IQR). There were no deaths. CONCLUSION: Prompt public health actions are needed to reduce the burden of typhoid infection in the Papua New Guinea. The conjugate typhoid vaccine should be considered in the highlands region, where typhoid is most endemic.

Hemophagocytic lymphohistiocytosis following enteric fever: A rare autopsy case report.

ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is a severe and frequently underdiagnosed disorder of systemic immune dysregulation resulting in hypercytokinemia and histologically evident hemophagocytosis, We report a case of a 34-year-old man who presented with breathlessness, generalized weakness, and fever of unknown origin with pancytopenia. Clinically the patient was admitted for febrile illness, and treated symptomatically but his general condition worsened leading to death within 21 hours of admission. A complete autopsy was performed. The deceased had a significant past history of repeated episodes of fever, weight loss, and axillary lymphadenopathy over a period of 8 months with multiple hospital admissions. He was also diagnosed with enteric fever (Widal test and Typhi IgM positive) at the start of these episodes. Hemogram during this period revealed persistent pancytopenia. Serum ferritin, serum triglycerides, and liver function tests were consistently deranged. Investigations for the etiology of fever and blood cultures were negative while the bone marrow aspirate revealed a normocellular marrow. CT abdomen-pelvis showed mild hepatomegaly with enlarged retroperitoneal lymph nodes. Infective endocarditis, lymphoma, and bronchopneumonia were being considered the clinical diagnoses. The significant autopsy findings were hepatosplenomegaly with retroperitoneal lymphadenopathy and multiple gastric ulcers. On microscopy, the liver, spleen, bone marrow, and lymph nodes showed characteristic hemophagocytosis. Post-mortem histopathological examination clinched the diagnosis of HLH and fulfilled six out of eight diagnostic criteria of the HLH-2004 protocol. We discuss the clinical course and diagnosis of this unique case and strive to create awareness about secondary HLH induced by common diseases, such as enteric fever.

Typhoid Fever Presenting with Ileal Perforation and Gastric Perforation.

Typhoid fever is caused by Salmonella typhi and Salmonella paratyphi. It is a disease of developing countries and is seen among people of low socio-economic status. Patients can develop complications like typhoid intestinal perforation which is associated with higher mortality. A 15-year-old female presented to the emergency pediatric unit with fever, abdominal pain and abdominal distension. She was septic, in respiratory distress, and had marked generalized abdominal tenderness with guarding. An assessment of generalized peritonitis secondary to typhoid intestinal perforation was made. She had exploratory laparotomy with intra-operative findings of ileal perforation and gastric perforation. She had repair of the intestinal and gastric perforations. Our patient presented late with concurrent use of NSAIDs and overwhelming sepsis which likely contributed to the gastric perforation as this is not a usual finding in patients with typhoid intestinal perforation. Gastric perforation is an unusual finding in patients with typhoid intestinal perforation. Typhoid fever and its complications can be easily prevented by the provision of safe water, proper facilities for sanitation, and practicing good hygiene.

La fièvre typhoïde est causée par Salmonella typhi et Salmonella paratyphi. C'est une maladie des pays en développement et elle est observée chez les personnes de bas niveau socio-économique. Les patients peuvent développer des complications telles que la perforation intestinale typhoïdique, associée à une mortalité plus élevée. Une adolescente de 15 ans s'est présentée à l'unité de pédiatrie d'urgence avec de la fièvre, des douleurs abdominales et une distension abdominale. Elle était septique, en détresse respiratoire, et présentait une sensibilité abdominale généralisée marquée avec une défense. Une évaluation d'une péritonite généralisée secondaire à une perforation intestinale typhoïdique a été réalisée. Elle a subi une laparotomie exploratrice révélant une perforation iléale et une perforation gastrique. Des réparations ont été effectuées sur les perforations intestinales et gastriques. Notre patiente s'est présentée tardivement avec une utilisation concomitante d'AINS et une septicémie sévère, ce qui a probablement contribué à la perforation gastrique, car cela n'est pas une découverte habituelle chez les patients atteints de perforation intestinale typhoïdique. La perforation gastrique est une découverte inhabituelle chez les patients atteints de perforation intestinale typhoïdique. La fièvre typhoïde et ses complications peuvent être facilement prévenues par la fourniture d'eau potable, d'installations sanitaires adéquates et en pratiquant une bonne hygiène MOTS-CLÉS: fièvre typhoïde, perforation intestinale, perforation gastrique.

Sensorineural hearing loss as an atypical presentation of typhoid fever: A case report.

Typhoid fever, also known as enteric fever, is a multisystemic infection primarily caused by Salmonella enterica serotype Typhi, and less commonly by Salmonella enterica serotypes Paratyphi A, B, and C. The classic presentation includes fever, malaise, diffuse abdominal pain, and constipation. If left untreated, typhoid fever can progress to delirium, obtundation, intestinal haemorrhage, bowel perforation, and death within a month of onset. However, the clinical course can deviate from the classic stepladder fever pattern, which now occurs in as few as 12% of cases.1 In this report, we describe an atypical presentation as sensorineural hearing loss in an otherwise healthy young male.

Large outbreak of typhoid fever on a river cruise ship used as accommodation for asylum seekers, the Netherlands, 2022.

On 6 April 2022, the Public Health Service of Kennemerland, the Netherlands, was notified about an outbreak of fever and abdominal complaints on a retired river cruise ship, used as shelter for asylum seekers. The diagnosis typhoid fever was confirmed on 7 April. An extensive outbreak investigation was performed. Within 47 days, 72 typhoid fever cases were identified among asylum seekers (n = 52) and staff (n = 20), of which 25 were hospitalised. All recovered after treatment. Consumption of food and tap water on the ship was associated with developing typhoid fever. The freshwater and wastewater tanks shared a common wall with severe corrosion and perforations, enabling wastewater to leak into the freshwater tank at high filling levels. Salmonella Typhi was cultured from the wastewater tank, matching the patient isolates. In the freshwater tank, Salmonella species DNA was detected by PCR, suggesting the presence of the bacterium and supporting the conclusion of contaminated freshwater as the probable source of the outbreak. Outbreaks of uncommon infections may occur if persons from endemic countries are accommodated in crowded conditions. Especially when accommodating migrants on ships, strict supervision on water quality and technical installations are indispensable to guarantee the health and safety of the residents.

Practical approach to a patient with fever who travelled to the tropics.

By 2030, an estimated 2 billion international tourist trips are expected annually worldwide, with citizens of Poland as important contributors. Illness rates among returnees from developing regions range between 43% and 79%. Properly diagnosing fever in these travelers is vital due to potentially serious implications. After visiting tropical and subtropical zones, the main health complaints are diarrhea, fever, and skin lesions. A reliable diagnosis begins with taking a comprehensive travel history and identifying potential risks. In travelers returning from sub­Saharan Africa, malaria caused by Plasmodium falciparum is the main cause of fever, affecting 50 in every 1000 cases. Among returnees from Southeast Asia, dengue is dominant, occurring in 50-60 per 1000 cases, and its prevalence rises significantly nowadays. Other significant diseases include chikungunya, Zika, typhoid fever, amebic liver abscess, and occasionally viral hemorrhagic fevers. SARS­CoV­2 and influenza viruses are crucial pathogens as well. An in­depth assessment of the travel history, combined with knowledge on tropical diseases, are key to the diagnostic process, and algorithms may be helpful in selecting appropriate tests and treatment methods.