Volume 30, Number 7—July 2024
Dispatch
Rocky Mountain Spotted Fever Mimicking Multisystem Inflammatory Syndrome in Hospitalized Children, Sonora, Mexico
, Cristian N. Rivera-Rosas, J.R. Tadeo Calleja-López, David W. McCormick, Christopher D. Paddock, Jehan Bonizú Álvarez-Meza, and Fabián Correa-Morales
Table 1
Demographic, clinical, and laboratory test characteristics of patients at hospital admission in study of Rocky Mountain spotted fever mimicking multisystem inflammatory syndrome in hospitalized children, Sonora, Mexico*
| Variable | Reference range | Case 1 | Case 2 | Case 3 | Case 4 | Case 5 |
|---|---|---|---|---|---|---|
| Age, y | 6.2 | 17.9 | 11.0 | 7.1 | 8.7 | |
| Sex | M | M | F | M | M | |
| BMI Z-score† | 0–1 | 1–2 | 1–2 | 1–2 | >2 | |
| Laboratory confirmation of SARS-CoV-2 infection‡ | Antigen+, IgM+ | IgG+ | IgG+, IgM+ | IgG+ | IgG+ | |
| Laboratory confirmation of Rickettsia rickettsii infection | IFA IgG 1:256 | PCR | PCR | IFA IgG 1:2,048 | PCR, Rickettsia spp. | |
| Leukocyte count, × 103/μL | 4.6–10.2 | 4.3 | 6.8 | 15.7 | 10.5 | 19.9 |
| Platelet count, × 103/μL | 150–450 | 72.0 | 57.0 | 45.0 | 22.0 | 317.0 |
| Procalcitonin, ng/mL | 0–0.5 | 10.8 | 2.6 | 75.4 | 6.6 | 0.8 |
| C-Reactive protein, mg/dL | <0.5 | 10.8 | 17.1 | 10.2 | 6.6 | NA |
| D-dimer, μg/mL | 0–0.5 | 17.6 | NA | 7.9 | 3.6 | NA |
| Ferritin, ng/mL | 21–274 | 1,099.8 | NA | 5,474.4 | 3,229.2 | 1,260.30 |
| Prothrombin time, s | 11.1–14.1 | 14.7 | 16.0 | 14.0 | 17.6 | 16.3 |
| Fibrinogen, mg/dL | 200–400 | 215.0 | NA | 134.0 | 329.0 | 379.0 |
| ESR, mm/h | 3–10 | 35.0 | 26.0 | 20.0 | 65.0 | 40.0 |
| LDH, U/L | 240–480 | NA | 738.0 | 754.0 | 880.0 | 569.0 |
| AST, U/L | 5–34 | 91.0 | 186.0 | 111.0 | 121.0 | 69.0 |
| ALT, U/L | 0–55 | 44.0 | 76.0 | 47.0 | 54.0 | 77.0 |
*ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; ESR, erythrocyte sedimentation rate; IFA, indirect immunofluorescence assay; LDH, lactate dehydrogenase; NA, not available; ; +, positive. †Calculated by using data from the World Health Organization (https://www.who.int/tools/growth-reference-data-for-5to19-years/indicators/bmi-for-age). According to those data, a normal BMI is defined as a Z-score of −1 to 1, an overweight BMI is defined as a Z-score of 1–2, and an obese BMI is defined as a Z-score of >2. ‡Confirmed by presence of SARS-CoV-2–specific IgG or IgM in serum samples or a positive antigen test from a nasopharyngeal swab sample.