Palmira Ventosilla

Identification of Bartonella bacilliformis Genotypes and Their Relevance to Epidemiological Investigations of Human Bartonellosis

ABSTRACT Genotypic diversity among 26 isolates of Bartonella bacilliformis obtained from different areas of Peru, and at different times, was assessed by comparison of DNA sequences derived from 16S-23S ribosomal DNA intergenic spacer regions (ISR) and a citrate synthase gene (gltA) fragment and by amplified fragment length polymorphism (AFLP) analysis. gltA comparison divided the isolates into two groups, whereas ISR comparison revealed six sequences. AFLP analysis using a selective primer delineated five profiles that correlated well with those obtained by sequence comparison. Combination of all three data sets divided the isolates into six genotypes. One of these genotypes was common to isolates collected from a large area in western Peru that corresponded to the region of endemicity for bartonellosis; however, isolates belonging to two other genotypes were also found within this region. Two of these genotypes were found in isolates isolated more than 35 years apart. The remaining three genotypes were each specifically associated with three outbreaks of bartonellosis that have recently occurred in areas where the disease had not previously been recognized. Demonstration of the unique nature of these isolates indicates that the outbreaks with which they were associated did not result from the introduction of disease by individuals who acquired their infection in the recognized region of endemicity. The sources of these outbreaks remain unknown. A consensus approach to bacterial typing using comparative sequence analysis of multiple genetic loci and the pan-genomic sampling of AFLP appears to offer a well-supported assessment of B. bacilliformis diversity, and the genotypic differences identified appear to have epidemiological significance.

A prospective study of cat-scratch disease in Lima-Peru

Cat-Scratch Disease (CSD) is a benign lymphadenitis that may progress to severe or recurrent forms, and it is occasionally associated with morbidity. Between January of 1998 and March of 1999, forty-three suspected CSD patients were assessed in the Hospital Cayetano Heredia and the Instituto de Salud del Niño, in Lima, Peru. Twelve patients had a confirmed diagnosis, 8 of whom were women, and the mean age was 10 years old. The majority (53%) of the cases were encountered in the summer. All patients reported having had contact with cats. Fever, malaise, lymphadenopathy and skin lesions were the most frequent clinical features. Twelve patients had indirect immunofluorescence antibody test titers of between 1/50 and 1/800 for Bartonella henselae and Bartonella clarridgeiae. Two lymph node biopsies were histologically compatible with CSD. No positive blood cultures could be obtained. This is the first Peruvian prospective study able to identify B. henselae and B. clarridgeiae in pediatric patients.

Cytokines and T-Lymphocute count in patients in the acute and chronic phases of Bartonella bacilliformis infection in an endemic area in peru: a pilot study

Human Bartonellosis has an acute phase characterized by fever and hemolytic anemia, and a chronic phase with bacillary angiomatosis-like lesions. This cross-sectional pilot study evaluated the immunology patterns using pre- and post-treatment samples in patients with Human Bartonellosis. Patients between five and 60 years of age, from endemic areas in Peru, in the acute or chronic phases were included. In patients in the acute phase of Bartonellosis a state of immune peripheral tolerance should be established for persistence of the infection. Our findings were that elevation of the anti-inflammatory cytokine IL-10 and numeric abnormalities of CD4(+) and CD8(+) T-Lymphocyte counts correlated significantly with an unfavorable immune state. During the chronic phase, the elevated levels of IFN-γ and IL-4 observed in our series correlated with previous findings of endothelial invasion of B. henselae in animal models.

A statistical model for assessing the relationship between meteorological variables and the incidence of Plasmodium falciparum and Plasmodium vivax in a Peruvian endemic area

The objective of this study was to analyse, through a statistical model based on autoregressive procedures, the effect of the malaria incidence rate during the previous month and of meteorological variables (temperature, total precipitation and humidity) on the incidence of Plasmodium falciparum and Plasmodium vivax malaria in the observed month, in the main endemic areas Luciano Castillo and Colonna Health Region, Piura, Peru, during the period 1995?2002. The developed models captured an important part of the data variability. The coefficients of determination (R²) were 0.776 for P. vivax and 0.924 for P. falciparum. Similar models need to be validated in different ecological environments, such as the Peruvian jungle or other countries.