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Oroya fever, verruga peruviana, asymptomatic carriers |
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Trench fever, bacillary angiomatosis, endocarditis, chronic bacteriaemia |
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Cat-scratch disease, bacillary angiomatosis, visceral peliosis, endocarditis, septicaemia |
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Cat-scratch disease (rare) |
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Endocarditis |
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Endocarditis |
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South American bartonellosis, (Carrión’s disease, Oroya fever, verruga peruana, verruga peruviana) results from infection with the bacterium Bartonella bacilliformis, and is transmitted by sandflies. The infection manifests itself in two very different clinical forms, with the causal connection being recognised by the young Peruvian doctor Daniel Alcides Carrión in 1885. After a dramatic experiment in which he inoculated himself with some fluid from a chronic skin lesion in a patient with verruga peruviana, he died from acute bartonellosis.
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Pre-Columbian mummies with histologically confirmed verruga lesions have been discovered in Peru and bartonellosis occurred in Francisco Pizarro’s army (1471-1541). In Peru between 1869 and 1873 more than 7000 workers building the Lima-La Oroya railway died from the disease. The name "Oroya fever" refers to this. In the small mining town of La Oroya (altitude 3800 m), strangely enough there was no transmission of Oroya fever. In 1936 a large epidemic was seen in the Guaitara valley on the border between Colombia and Ecuador. An epidemic occurred in 1980 in Ecuador and another in 1987 in Peru with a death rate of 88% in the untreated patients. Now and then there have been isolated cases or small outbreaks. In 1997 there was an outbreak in the area of Cuzco, Peru. In an outbreak in Zumba, Ecuador (1995-96), large numbers of dead rodents were found around the places where the cases had occurred. This finding led to the hypothesis that bartonellosis could have an animal reservoir.
Barton described the pathogen in 1909, but he thought that it was a protozoon. The Japanese bacteriologist Hideyo Noguchi demonstrated the bacterial nature of the pathogen. Bartonella bacilliformis is a small Gram-negative coccobacillus (0.6-1 µm), which takes Giemsa and Warthin-Starry stain. The pathogen has one or more polar flagella. It replicates within the vascular endothelium and erythrocytes. The bacterium is related to rickettsiae. The bacillus grows quickly (extracellularly) on non-living culture media with blood or on chicken embryos at 25-28°C. Numerous related organisms are animal pathogens.
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The disease caused by Bartonella bacilliformis only occurs in certain narrow high valleys of the western-most slopes of the Andes at altitudes between 500 and 3200 meters in Peru, Ecuador and Colombia, between 2° N and 13° S. Whether endemic cases occurred in Chili, Bolivia, Guatemala and Honduras is very doubtful. Sporadic cases of so-called "bartonelloses" have been reported in Africa, (Niger, Sudan), in Asia (Pakistan) and in the USA, but it is still not clear whether there is a connection with Carrión’s disease. Our knowledge about Bartonella and related bacteria has greatly increased in recent years but is still very incomplete.
A sandfly, Lutzomyia verrucarum, and perhaps a few related species, is responsible for transmission. Transmission only occurs at night and is seasonal, particularly during the rains. It was formerly assumed that the reservoir was purely human but this was recently cast into doubt (there may be a rodent reservoir). In some of the inhabitants in the endemic valleys, bacteria can be found in the blood, but these carriers are usually without any symptoms. These latent infections which are likely to have been contracted in childhood probably give stable immunity. It is only if non-immune populations enter the endemic area that epidemics occur, sometimes on a large scale, such as in wars or when large public works are being carried out.
The clinical range is wide, going from asymptomatic infections via serious febrile forms with acute haemolytic anaemia, to the angiomatous skin lesions which can be present from the onset or can be preceded by the febrile stage. The mortality of untreated cases varies between epidemics and ranges from 10-40% after 2-3 weeks. The disease is less severe in children and the mortality is far lower. If the course of the disease is favourable, the fever can last for 3 to 4 months. In 40-50% of cases of Oroya fever, concurrent salmonellosis (generally Salmonella typhimurium) complicates the illness and makes the prognosis less favourable. The superinfection causes fever with gastrointestinal symptoms and a deterioration of the patient’s general condition.
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Acute stage or Oroya fever
Incubation takes approximately 3 to 8 weeks (range 10-210 days). It begins insidiously with:
