Characteristics of human intestinal Escherichia coli with changing environments.

To investigate if the characteristics of human intestinal Escherichia coli are changing with the environment of the host, we studied intestinal E. coli from subjects having recently migrated from a temperate to a tropical area. We determined the phylogenetic group, the prevalence of the antibiotic resistance, the presence of integrons and the strain diversity in faecal isolates from 25 subjects originally from metropolitan France and expatriated to French Guyana. These characteristics were compared with those of 25 previously studied Wayampi Amerindian natives of French Guyana and from 25 metropolitan French residents. The three groups of subjects were matched for age and sex, had not taken antibiotics for at least 1 month, nor had been hospitalized within the past year. In all, the characteristics of intestinal E. coli from Expatriates were intermediate between those found in residents from metropolitan France and those found in natives of French Guyana. Prevalence of carriage of resistant Gram-negative bacteria in Expatriates was intermediate between French residents and Wayampi as were the prevalence of integrons in E. coli (12.3% versus 16.3% and 7.8% respectively), and the intra-host diversity of E. coli (2.3 strains/subject versus 1.9 and 3.1, respectively); lastly, in Expatriates, the prevalence of carriage of phylogenetic group B2 strains was lower than in French residents (16% versus 56%, P = 0.005), while carriage of phylogenetic group A strains was lower than in Wayampi (56% versus 88%, P = 0.03). Our results suggest that the composition of the commensal intestinal flora of humans is not static but changes dynamically in response to new environmental conditions.

Outbreak of malaria among policemen in French Guiana.

An outbreak of malaria occurred among 62 policemen following an operation against illegal gold panning in French Guiana. A retrospective cohort study was conducted. The objectives were to describe the outbreak and to identify factors related to the cases. The total number of initial cases was 37. Both Plasmodium falciparum and Plasmodium vivax were detected. Twenty-seven policemen presented with one to four recurrences. In bivariate analysis, factors related to malaria were a "medium to high" level of mosquito bites pollution at night, late washing in the evening and wearing a nonimpregnated Battle Dress Uniform (BDU). This investigation confirmed the low level of compliance with chemoprophylaxis among individuals on long-term assignment in French Guiana. Compliance with mosquito protection measures was satisfactory except for the use of impregnated BDU. Several recommendations were provided. Therefore, this outbreak reminds us that malaria remains a public health problem in French Guiana.