From the Guidelines
For a 5-year-old returning from Chihuahua, Mexico with fever, I strongly recommend a comprehensive panel of laboratory tests to promptly identify the cause of fever and initiate appropriate treatment, as the risk of vector-borne illnesses, parasitic infections, and bacterial diseases is significant in this region. According to the study by 1, the most common etiologies of fever in returning travelers and migrants include tropical infections such as malaria, dengue fever, and parasitic infections, as well as non-tropical infections like acute diarrheal disease, respiratory tract infections, and genitourinary tract infections.
The recommended laboratory tests should include:
- Complete blood count (CBC) with differential
- Basic metabolic panel
- Liver function tests
- Blood cultures
- Malaria thick and thin smears
- Dengue serology (IgM and IgG)
- PCR testing for arboviruses
- Stool studies for ova and parasites
- Bacterial culture
- Urinalysis
Specific testing for rickettsial diseases like Rocky Mountain spotted fever and typhus should be considered, as well as testing for tuberculosis with a tuberculin skin test or interferon-gamma release assay, as suggested by 1. These tests are crucial because northern Mexico presents risks for various infectious diseases that may not be common in the child's home country. The child should be evaluated promptly, as some of these infections can progress rapidly, especially in young children.
While awaiting results, supportive care with appropriate fever management using acetaminophen (10-15 mg/kg every 4-6 hours, not exceeding 5 doses in 24 hours) or ibuprofen (5-10 mg/kg every 6-8 hours with food) should be provided, as per standard pediatric guidelines. The child should stay well-hydrated and be monitored for warning signs like decreased responsiveness, difficulty breathing, or rash.
From the Research
Recommended Lab Tests for a 5-Year-Old Returning from Chihuahua, Mexico with Fever
The following lab tests are recommended based on the provided evidence:
- Complete Blood Count (CBC) to check for thrombocytopenia, leukopenia, and lymphocyte percentage 2
- Liver function tests, including Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), and total bilirubin to assess liver damage and disease severity 3, 4, 5, 6
- Albumin and cholesterol levels to predict the progression to critical phase in dengue hemorrhagic fever 4
- C-reactive protein levels to assess disease severity 6
Key Findings
- Thrombocytopenia and leukopenia are common hematological features of dengue fever 2
- Liver function tests can help assess disease severity and predict complications 3, 4, 5, 6
- Albumin and cholesterol levels can predict the progression to critical phase in dengue hemorrhagic fever 4
- C-reactive protein levels can serve as a severity marker for dengue fever 6