Case 2: A five-year-old boy with fever after travel to South America
Bibliographic record
Abstract
A five-year-old boy presented with daily fevers (39°C to 41°C), leg pain and poor appetite after having returned from Venezuela five days previously. There were no other symptoms, and he was well between the episodes of fever. There was no rural exposure. The child and his parents drank bottled water, but shaved ice was consumed. They were exposed to mosquitos and had contact with sea turtles. They ate many different types of foods, including fresh fruits and vegetables, in a family setting. The mother experienced fever and diarrhea, and the father experienced a mild febrile illness during travel. The child was born in Canada and was previously well. His routine vaccinations were up to date but no pretravel care was provided. Examination revealed fever and mild, right upper quadrant abdominal tenderness. The remainder of the examination was otherwise unremarkable. Enteric fever was suspected and treatment was commenced with intravenous ceftriaxone. Laboratory investigations revealed a slightly low hemoglobin level with normal platelet levels and white blood cell count. His lactate dehydrogenase and C-reactive protein levels, as well as his erythrocyte sedimentation rate, were elevated. Urinalysis, liver enzymes and liver function tests were all normal. Three malaria smears were negative. His serology for acute cytomegalovirus, Epstein-Barr virus, dengue and parvovirus were negative. Three stool cultures and tests for ova and parasites were negative. A further test yielded the diagnosis. The patient's blood culture was positive for Salmonella poona, which was susceptible to ceftriaxone, ampicillin, ciprofloxacin and trimethoprim/sulfamethoxazole. S poona is a rare serotype causing human disease, and is infrequently associated with enteric fever. There have been previous outbreaks of S poona related to the consumption of cantaloupe, imported from Mexico or Guatemala, in the United States and Canada (1). From the cases reported, up to 33% of cases required hospitalization. The Public Health Agency of Canada reported a S poona outbreak involving 29 cases in 2008, but the source was not determined. There have been reports of S poona infection related to reptile exposure (2). The cases reported involved household pets (iguana, bearded dragon) or a secondary exposure (county fair with iguanas or turtles, patient's father handled reptiles). The clinical presentations included fever, diarrhea (bloody and nonbloody), abdominal pain and malaise. The treatments for S poona infection vary, including requiring no treatment, to requiring hospitalization and intravenous antibiotics. Immunization with the currently available typhoid vaccine is not expected to protect against nontyphoidal Salmonellae, and is only approximately 70% effective against S typhi. Fever in a returning traveller requires careful and timely investigation and management. The present case demonstrates the importance of a thorough travel exposure history. The lack of rural exposure reduced the suspicion for malaria and increased the likelihood of a viral illness or enteric fever. Typical features of enteric fever include fever and constitutional symptoms, such as headache, malaise, anorexia, lethargy, abdominal pain and tenderness. Hepatomegaly, splenomegaly, diarrhea and mental status changes can also occur. Constipation may occur early in the illness. Young children may present with a nonspecific febrile syndrome. Enteric fever is commonly caused by Salmonella typhi or Salmonella paratyphi. Humans are the only host for S typhi. A history of travel to areas where enteric fever is endemic is the principal risk factor. The majority of enteric fever symptoms are extraintestinal, while nonenteric fever Salmonella bacteremias are usually associated with gastroenteritis, the most common manifestation of salmonellosis. The patient was started on ceftriaxone, the standard empirical treatment for enteric fever. He was subsequently stepped down to oral ciprofloxacin, based on the antibiotic sensitivities of his culture isolates, once he was afebrile. Repeat blood culture tests were negative. If the clinical syndrome of enteric fever and other common causes of fever in the traveller are ruled out (malaria, respiratory tract infections, other bacteremias, dengue) it may be appropriate to treat a child empirically despite negative culture test results. The present case is the first report of S poona presenting as enteric fever in a paediatric returning traveller. Fever in the returning traveller requires thorough and timely investigation, with appropriate management initiated while awaiting the results of the investigations. Food and water ‘mistakes' are common, and consumption of enteric pathogens resulting in gastroenteritis or more severe diseases, such as enteric fever, are common presentations in unwell return travellers. Uncommon but important infections to exclude in the differential diagnosis are malaria and dengue.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.005 | 0.002 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.005 | 0.004 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".