Volume 31, Number 10—October 2025
Research
Spotted Fever Group Rickettsioses among Hospitalized Patients and Circulation of Rickettsia in Ticks, Kazakhstan, 2019
, Dmitriy V. Berezovskiy, Bakhytkul T. Zhakipbayeva, Roberta Z. Horth, Alexander J. Millman, William L. Nicholson, Galina E. Zemtsova, Victoria Seffren, Elina R. Maltseva, Zhanna A. Berdygulova, Yekaterina O. Ostapchuk, Yuliya V. Perfilyeva, Andrey M. Dmitrovskiy, Zhansulu K. Dukayeva, and Zhanna Zh. Shapiyeva
Table 2
Characteristics of 62 human rickettsiosis cases by Rickettsia species in study of spotted fever group rickettsioses among hospitalized patients and circulation of Rickettsia in ticks, Kazakhstan, 2019*
| Characteristic | Total | R. sibirica | R. raoultii | SFGR | R. slovaca |
|---|---|---|---|---|---|
| No. patients |
62 (100) |
29 (100) |
19 (100) |
10 (100) |
4 (100) |
| Symptoms and signs | |||||
| Fever >38°C | 62 (100) | 29 (100) | 19 (100) | 10 (100) | 4 (100) |
| Headache | 56 (90) | 27 (93) | 17 (89) | 9 (90) | 3 (75) |
| Rash | 49 (79) | 26 (90) | 12 (63) | 8 (80) | 3 (75) |
| Myalgia | 38 (61) | 21 (72) | 11 (58) | 5 (50) | 1 (25) |
| Primary skin lesion: eschar | 30 (48) | 23 (79) | 2 (11) | 4 (40) | 1 (25) |
| Nausea | 18 (29) | 8 (28) | 7 (37) | 3 (30) | 0 |
| Vomiting | 11 (18) | 5 (17) | 4 (21) | 2 (20) | 0 |
| Swollen lymph nodes | 3 (5) | 1 (4) | 1 (5) | 0 | 1 (25) |
| Any rash, eschar, or swollen lymph nodes† |
54 (87) |
28 (97) |
14 (74) |
9 (90) |
3 (75) |
| Severe disease‡† | |||||
| Had severe disease | 9 (15) | 6 (21) | 1 (5) | 2 (20) | 0 |
| Had acute respiratory distress syndrome | 6 (10) | 5 (17) | 1 (5) | 0 | 0 |
| Had disseminated intravascular coagulation | 4 (6) | 2 (7) | 0 | 2 (20) | 0 |
| Had renal failure |
2 (3) |
2 (7) |
0 |
0 |
0 |
| Blood abnormalities | |||||
| Thrombocytopenia | 33 (53) | 18 (62) | 12 (63) | 3 (30) | 0 |
| AST elevation§ | 23 (39) | 12 (46) | 8 (44) | 2 (20) | 1 (25) |
| ALT elevation§ | 11 (19) | 6 (23) | 1 (6) | 1 (10) | 3 (75) |
| Anemia | 6 (10) | 3 (10) | 1 (5) | 2 (20) | 0 |
*Values are no. (%). The 62 patients include 55 confirmed (35 by PCR and 20 by indirect immunofluorescence assay with 4-fold seroconversion) and 7 probable cases (IgG titers >1:128). Probable cases with the only available acute serum had IgG titers of 1:128. The species of Rickettsia implicated in the disease for patients with paired or single serum samples were defined in indirect immunofluorescence assay as the species with the highest difference in titers or the highest titer. Bold indicates cutaneous signs and lymphadenopathy (swollen lymph nodes). ALT, alanine aminotransferase; AST, aspartate aminotransferase; SFGR, spotted fever group rickettsia. †All patients with swollen lymph nodes had a rash or eschar. ‡Severe disease was diagnosed on the basis of the following criteria: 1) renal failure (oliguria up to anuria and accompanied by proteinuria of >0.5 g/L, serum creatinine >117 mkmol/L, blood serum urea >8 mmol/L); 2) acute respiratory distress syndrome (shortness of breath (respiration rate >25 breaths/min), cyanosis, bilateral infiltrates on the lung radiograph, progressive hypoxemia (SpO2 <90%); 3) disseminated intravascular coagulation (blood clotting time (>12 s), plasma D-dimer (>250 µg/l), platelet count (<120*109/l), plasma fibrinogen (<1.5 g/L), prothrombin time (PT) (>16 s). Blood abnormalities assessment was done by clinicians using the following levels: thrombocytopenia, platelet (<150 × 109/L); leukopenia, leukocytes <4 × 109 cells/L); anemia, hemoglobin <130 g/L for men, <120 g/L for women, <115 g/L for children; AST elevation, >40 U/L for men, 31 U/L for women, >43 U/L for children; ALT elevation, >40 U/L for men, 33 U/L for women, >36 U/L for children). §Three R. sibirica cases had no data on AST or ALT.