Bartonellosis

Bartonellosis (Carrion's disease) is infection by Bartonella bacilliformis, transmitted by sandflies. It has two phases: Oroya fever (acute fever/hemolytic anemia) and verruga peruana (cutaneous lesions). Named after Daniel Carrion, who first described it in Peru in 1855.

Common Symptoms

Coma; fatigue; low fever; myalgia

Causes and Pathogenesis

(1) Etiology: Alberto Barton first described the bacillus in Oroya fever RBCs in 1905; cultured in 1920 and transmitted to monkeys. B. bacilliformis is a small Gram-negative coccobacillus (0.2-0.5 × 1-2 µm), motile, pleomorphic (spherical/ring/ovoid/granular), with 1-10 polar flagella 3-10 µm; in acute phase it is mostly spherical within RBC/endothelial cytoplasm, Giemsa-purple. It requires enriched media (blood agar), grows slowly at 28°C in 5% CO2, no growth at 42°C, biochemically inert, non-hemolytic, susceptible to many antibiotics. Fatty acids: C16:1ω7c ~18%, plus C12:0/C14:0. 16S rRNA (1431 bp) is 91.7% homologous with B. quintana. ialA/ialB invasiveness genes have been cloned; flagella are key virulence factors enabling RBC penetration. (2) Pathogenesis: After entering blood, it proliferates in vascular endothelium and then within RBCs; severe cases show up to 20 organisms/RBC causing massive hemolysis; peripheral smear shows normoblasts, macrocytes, reticulocytes up to 50%; WBC normal, thrombocytopenia; reticuloendothelial cells in liver/spleen/nodes phagocytose organisms/RBCs/hemosiderin; hepatomegaly with centrilobular necrosis; splenomegaly; endothelial swelling may occlude capillaries causing ischemia; CSF may show pleocytosis and organisms. Clinical disease depends on host immunity; non-immune patients develop Oroya fever.

Treatment

Traditional Chinese medicine, supportive therapy

Preventive Measures

Kill sandflies; spray insecticides indoors/outdoors; personal repellents and bednets.

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.