Changes in epidemiology of leptospirosis in 2003--2004, a two El Niño Southern Oscillation period, Guadeloupe archipelago, French West Indies.

Our study aimed at analysing the changes in epidemiological features of leptospirosis cases from the hospital of Pointe à Pitre in Guadeloupe in 2003--2004 compared to reliable data in 1994--2001. Leptospirosis incidence increased fourfold during 2002--2004, a period with two El Niño events. Whereas the main risk factors were unchanged (male gender, occupational exposure, contact with cattle or pigs) a major role of rodent exposure emerged (52%, P=0.02, multivariate analysis). Interestingly, mean age of cases shifted to the older population (51.7 years vs. 43 years, P<0.05). Moreover, the Ballum serogroup rose dramatically (36% of incidence) competing with the Icterohaemorragiae serogroup (62%). However, severe forms were less recorded. Our data suggest that the changes in leptospirosis features could be related to exceptional meteorological events and their consequences on rodent populations. We propose the monitoring of rodent population and climatic data as a tool of management of leptospirosis in Guadeloupe.

Lyme borreliosis incidence in two French departments: correlation with infection of Ixodes ricinus ticks by Borrelia burgdorferi sensu lato.

We conducted a prospective study to estimate the Lyme borreliosis incidence in two rural French departments, Meuse and Puy-de-Dôme. Concurrently, we investigated the prevalence of ticks infected with Borrelia burgdorferi sensu lato (sl) and Anaplasma phagocytophilum. The incidence of Lyme borreliosis decreased from 156 to 109/100,000 inhabitants in Meuse and from 117 to 76/100,000 inhabitants in Puy-de-Dôme in 2004 and 2005, respectively, corresponding to a decrease in the density of Ixodes ricinus nymphs infected with B. burgdorferi sl. During the same period, the density of adult ticks increased. Interestingly, B. valaisiana, a nonpathogenic species, infected adult ticks more often than nymphs. These results confirmed the correlation between the Lyme borreliosis incidence and the density of infected nymphs, a stage preferentially infected with B. afzelii. In contrast, we found a low rate of infection by A. phagocytophilum, ranging from 0% to 0.4% in Puy-de-Dôme and from 0.8% to 1.4% in Meuse, suggesting a low risk for humans.

[Retrospective study of Lyme borreliosis positive serologies in 2003]. / Etude rétrospective des sérologies de borréliose de Lyme positives en 2003.

PURPOSES OF THE STUDY: To estimate the percentage of positive sera for Lyme borreliosis antibodies, to precise the characteristics of clinical cases diagnosed from serological data and to determine their geographical distribution in France. MATERIALS AND METHODS: Studied sera were those received by the Pasteur-Cerba laboratory in 2003. IgG and IgM isotypes were detected using the Dade Behring kits. Antibody specificity was analysed with the Meridian's western blot. RESULTS: 1504/16 176 (9%) sera were positive for IgG isotype, and 978/3298 (29%) for IgM. The specificity was confirmed by western blot in 49% cases for IgG and in 54% for IgM. The highest positive serology rates were found in eastern and centre regions and in Aquitaine. Forty-two cases have been investigated leading to the identification of 16 borreliosis cases, each suffering of an erythema migrans. Five of them had neurological signs. Patient mean age was 40 years. 87% of patients had risk factors and 69% reported previous tick bites, mainly on lower limbs. CONCLUSION: A low rate of positive borreliosis sera was found, suggesting that serology prescription should be limited to patients suffering of compatible clinical signs, as recommended by the EUCALB. Erythema migrans was the most frequent clinical manifestation and neurological signs were present in 30% of cases. Finally, the geographical case distribution was similar to that provided by the study of the Sentinelle network in 1999-2000.

Retrospective review of leptospirosis in Guadeloupe, French West Indies 1994-2001.

Demographic, clinical, biological and personal data were obtained from patients hospitalized with symptoms of leptospirosis in the Hospital of Pointe a Pitre, Guadeloupe, French West Indies from 1994 to 2001. Of the 897 screened patients, 212 were acute cases, 607 were non-infected and 78 were undetermined cases. There was no predominant age group. Leptospirosis transmission followed the rainfall cycle and was greater in rural areas. Jaundice and conjunctival suffusion were significantly more frequent in cases than non-cases. Males, professions considered to be at risk and contact with swine or bovine were associated with infection. Serogroups Icterohaemorrhagiae, Cynopteri, Australis, Sejroe, Pomona and Ballum were serovars presumed responsible for acute cases.

Identification of variable-number tandem-repeat loci in Leptospira interrogans sensu stricto.

Leptospira interrogans sensu stricto is responsible for the most frequent and severe cases of human leptospirosis. The epidemiology and clinical features of leptospirosis are usually associated with the serovars and serogroups of Leptospira. Because of the difficulties associated with serological identification of Leptospira strains, we evaluated a novel PCR-based method for typing L. interrogans serovars. Based upon the genome sequence of L. interrogans serovar Lai type strain 5660, 44 loci were analyzed by PCR for their variability in size due to the presence of variable-number tandem repeats (VNTR). Seven VNTR loci were found to be powerful markers for serovar identification, epidemiology, and phylogenetic studies of L. interrogans. This rapid and easy method should greatly contribute to a better knowledge of the epidemiology of Leptospira.

Retrospective review of leptospirosis in Guadeloupe, French West Indies 1994-2001 / Revisión retrospectiva de la leptospirosis en Guadalupe, Indias Occidentales Francesas 1994­2001

Demographic, clinical, biological and personal data were obtained from patients hospitalized with symptoms of leptospirosis in the Hospital of Pointe a Pitre, Guadeloupe, French West Indies from 1994 to 2001. Of the 897 screened patients, 212 were acute cases, 607 were non-infected and 78 were undetermined cases. There was no predominant age group. Leptospirosis transmission followed the rainfall cycle and was greater in rural areas. Jaundice and conjunctival suffusion were significantly more frequent in cases than non-cases. Males, professions considered to be at risk and contact with swine or bovine were associated with infection. Serogroups Icterohaemorrhagiae, Cynopteri, Australis, Sejroe, Pomona and Ballum were serovars presumed responsible for acute cases

Se obtuvieron los datos demográficos, clínicos, biológicos y personales de pacientes hospitalizados con síntomas de leptospirosis en el Hospital de Pointe à Pitre, Guadalupe, Indias Orientales Francesas, en el período comprendido de 1994 a 2001. De los 897 pacientes investigados, 212 eran casos graves, 607 eran no infectados y 78 eran casos indeterminados. No hubo grupo etario predominante. La transmisión de la leptospirosis seguía el ciclo hidrológico y era mayor en las áreas rurales. La ictericia y sufusión conjuntival fueron significativamente más frecuentes en los casos que en los no casos. Los varones, las profesiones consideradas en riesgo, y el contacto con cerdos o bovinos estuvieron asociados con la infección. Los serogrupos Icterohemorragia, Cynopteri, Australis, Sejroe, Pomona y Ballum fueron serovares presumiblemente responsables de los casos graves

Guidelines for the diagnosis of tick-borne bacterial diseases in Europe.

Ticks are obligate haematophagous acarines that parasitise every class of vertebrate (including man) and have a worldwide distribution. An increasing awareness of tick-borne diseases among clinicians and scientific researchers has led to the recent description of a number of emerging tick-borne bacterial diseases. Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 11 tick-borne human bacterial pathogens have been described in Europe. Aetiological diagnosis of tick-transmitted diseases is often difficult and relies on specialised laboratories using very specific tools. Interpretation of laboratory data is very important in order to establish the diagnosis. These guidelines aim to help clinicians and microbiologists in diagnosing infection transmitted by tick bites and to provide the scientific and medical community with a better understanding of these infectious diseases.

[Lyme borreliosis situation in North Africa]. / Situation de la borreliose de Lyme au Maghreb.

Many epidemiological studies were conducted for studying Lyme borreliosis (LB) which represents a new global public health problem. It is now the most common vector-borne disease in Europe and North America. The causative agent Borrelia burgdorferi sl is a bacterial species complex comprising 12 delineated and named species. In North Africa, few studies based on clinical and serological features, have suggested that LB could occur. Indeed, recent studies conducted in Tunisia, Algeria and Morocco have showm that Ixodes ricinus is present in cooler and humid area of these regions. These studies also revealed that this species is a vector of B. burgdorferi sl with high prevalence of infection. Using IFI and PCR tests, the mean rate of Borrelia-infection ranged from 50 to 60% in I. ricinus adult collected in Tunisia and Morocco and from 30 to 40% in nymphs; in contrast, the prevalence in larvae is less than 2.5%. Several strains of B. burgdorfer were isolated from adult and nymph I ricinus collected in Tunisia and Morocco. The identification of these strains and DNAs directly extracted from Ixodes was done by PCR-RFLP and sequence analysis. The results showed that B. lusitaniae (genotypes Poti B2 and Poti B3) is the predominant species circulating in I. ricinus in Tunisia and Morocco, B. garinii and B. burgdorferi ss and B lusitaniae were also present but very rare. These results provide the evidence for the existence of B. burgdorferi sl in North Africa; however, the impact of LB in the human population seem to be negligible and the seroprevalence of Borrelia in forest workers (considered as population at high risk) in Tunisia is less than 4%.

Molecular characterization of Leptospira spp. strains isolated from small rodents in Croatia.

We report the isolation and characterization of 16 Leptospira spp. strains isolated from small rodents captured in 11 different regions of inland Croatia. Large NotI and SgrAI restriction fragment allowed us to assign 10 isolates to the serovar istrica, 5 isolates to the serovar tsaratsovo and 1 isolate to the serovar lora. The phylogenetic analysis conducted from the sequences of the first 330 bp from the 16S rDNA gene revealed that the strains belonged to three different species, L. borgpetersenii, L. kirschneri and L. interrogans. Carrier rates in eight rodent species varied from 0 to 71.4%. Mus musculus showed the highest infection level and confirmed its role as a major reservoir of the serogroup Sejroë. For the first time we reported the occurrence of serovars tsaratsovo and lora in Croatia.

Clustered cases of leptospirosis in Rochefort, France, June 2001.

Five clustered cases of leptospirosis were diagnosed in the area of Rochefort, France, in June 2001, among teenagers who had swum in the Genouillé canal. The symptoms included fever, headache, abdominal pain and vomiting, chills and myalgia. Three cases were confirmed by PCR and serology. The mean cumulative duration of bathing was significantly higher in cases (23.8 hours) compared to controls (14.4 hours). No other particular risk factor was observed. The environmental investigation revealed the presence of rodents excreting of leptospires near the bathing area. For all antigens considered, the occurence of seropositive rodents was 30.8%, L. icterohaemorrhagiae being the predominant serogroup (23,1%).

[The first isolation of Borrelia burgdorferi sensu stricto in Russia]. / Pervaia izoliatsiia Borrelia burgdorferi sensu stricto v Rossii.

18 Borrelia isolates obtained from adult ticks of the Ixodes ricinus species, collected from different plants in April 2000 in the Khostinsk region of the Krasnodar Territory in the vicinity of the health resort of Matsesta not far from Sochi, were identified by means of PCR and the analysis of polymorphism of the restriction fragments of ribosomal rrf-rrl spacer amplicon. Among them, in addition to Borrelia species, found in Russia earlier (B. garinii, B. afzelii, B. valaisiana and B. lusitaniae), the classical causative agent of Lyme borreliosis (B. burgdorferi sensu stricto) was detected for the first time. The isolated strain (lr-4721) is now kept in the collection of the Borreliosis Center of the Ministry of Health of Russia (the Laboratory of Infections Vectors at the Gamaleya Research Institute of Epidemiology and Microbiology). The probable role of this infective agent in infectious pathology in Russia is discussed.

High prevalence of Borrelia lusitaniae in Ixodes ricinus ticks in Tunisia.

To investigate whether ticks of the genus Ixodes are infected by Borrelia burgdorferi complex, 490 unfed Ixodes ricinus ticks were collected by flagging in three different areas of Tunisia in 1998. DNAs extracted from 81 adults, 60 nymphs and 38 larvae were analysed after genic amplification of the non-coding spacer between the two copies of the rrl-rrf genes of B. burgdorferi sl. The prevalence of B. burgdorferi sl. in adults, nymphs and larvae was found to be 34, 33.3 and 2.6%, respectively. All DNAs (n = 61) but one were identified as belonging to different genotypes of B. lusitaniae by analysis of the restriction fragment length polymorphism of amplification products. In addition, 290 adults, 14 nymphs and 7 larvae were used to inoculate BSK-H medium to isolate spirochetes. Fifteen strains were isolated from adult ticks in the humid areas of Tunisia, whereas only one was obtained from larvae. Isolates were identified as B. lusitaniae (15/16) and B. garinii (1/16). These results provide new evidence for the existence of Lyme borreliosis in North Africa.

First evidence for a restriction-modification system in Leptospira sp.

The LE1 leptophage exhibited a host range restricted to the saprophytic Leptospira biflexa [Saint Girons et al., Res. Microbiol. 141 (1990) 1131-1133] and mainly to the Patoc 1 strain (hereafter called PFRA) kept in the Paris, France collection. Results of titration of LE1 lysates indicated the presence of a host-controlled modification and restriction system within PUSA (Patoc 1 strain maintained in the Morgantown, WV, USA collection) that was absent in PFRA. Because genomic DNA of PITAL (Patoc 1 strain maintained in Trieste, Italy) appeared smeared in pulsed field gel electrophoresis (PFGE), this strain is likely to contain nucleases that are activated upon DNA isolation. Moreover, comparative NotI digestions of PUSA and PFRA DNAs, as visualized by PFGE, indicated that PUSA belonged to a different serovar than PFRA. Finally, 16S ribosomal sequence analysis indicated that PUSA belonged to the saprophytic Leptospira meyeri species, while PITAL and PFRA appertained to L. biflexa. The evolutionary significance and the importance of the restriction and modification enzymes or non-specific nucleases within strains for genetic experiments are discussed.

Distinct levels of genetic diversity of Borrelia burgdorferi are associated with different aspects of pathogenicity.

Different species of pathogenic Borrelia show different symptoms and tick vector specificity. Even within regions where only one species is found, Lyme disease progresses very differently from one patient to another. Since Borrelia shows very little recombination either within or between species, alleles of a gene can be used to mark clones. The ospC gene is highly variable within each species and can be used to define groups of related clones. It has been previously shown that only four out of seventeen ospC groups of Borrelia burgdorferi sensu stricto cause invasive forms of the disease. Other groups cause erythema migrans, a skin rash at the site of the tick bite, but not invasive disease, while still other groups seem to be nonpathogenic to humans. In this study we extend the analysis of the ospC gene to the other pathogenic species, Borrelia garinii and Borrelia afzelii. Only two groups in B. afzelii and four groups in B. garinii cause invasive disease. Thus, only ten out of the 58 defined ospC groups cause invasive and presumably chronic Lyme disease.

Interest of partial 16S rDNA gene sequences to resolve heterogeneities between Leptospira collections: application to L. meyeri.

This paper describes the advantage of using the first 330 bp (positions 46 to 375, Escherichia coli numbering) of the 16S rDNA gene for comparison of Leptospira isolates. Phylogenetic analysis conducted from the whole 16S rDNA sequences available in databanks as well as that conducted from the partial sequences yielded quite similar results, in accordance with data inferred from previous DNA-DNA relatedness studies. This tool was used for the comparison of Leptospira strains from different reference collections. Consistent results were obtained from the analysis of the polymorphism generated by pulsed-field gel electrophoresis. The study focused on different serovars of L. meyeri species, the classification of which has been controversial. The results revealed large collection heterogeneities, and suggest that the classification of the L. meyeri species should be revised.

Antigenic variation of Borrelia turicatae Vsp surface lipoproteins occurs in vitro and generates novel serotypes.

As a means of avoiding the host immune response, the tick-borne relapsing fever spirochete Borrelia turicatae undergoes antigenic variation in its abundant surface lipoproteins. In this study, B. turicatae strain Oz1, serotype B, was subcultured in vitro and cloned by limited dilutions after 50 passages. Four different serotypes (serotypes A, B, E, and F) differing by their expressed Vsp lipoproteins were isolated. Using pulsed-field gel electrophoresis, we showed that the variability in surface-exposed proteins is correlated with rearrangement between different linear plasmids, defining serotype-specific plasmid profiles. Moreover, we determined the nucleotide sequence of genes encoding the VspE and VspF lipoproteins, corresponding to the two novel serotypes E and F, respectively. Our results showed that antigenic variation in B. turicatae occurs spontaneously in vitro, in the absence of immune selection.

Common ancestry of Borrelia burgdorferi sensu lato strains from North America and Europe.

Ten atypical European Borrelia burgdorferi sensu lato (Borrelia spp. ) strains were genetically characterized, and the diversity was compared to that encountered among related Borrelia spp. from North America. Phylogenetic analyses of a limited region of the genome and of the whole genome extend existing knowledge about borrelial diversity reported earlier in Europe and the United States. Our results accord with the evidence that North American and European strains may have a common ancestry.

[Borrelia species new to Russia--possible causative agents of ixodid tick-borne borreliosis]. / Novye dlia Rossii vidy borrelii--vozmozhnye vozbuditeli iksodovykh kleshchevykh borreliozov.

18 Borrelia isolates, obtained in 1996-1997 from adult Ixodes ricinus collected from plants in the environs of Stavropol', were identified with the use of the polymerase chain reaction and the analysis of the polymorphism of the length of restriction fragments. Among them, in addition to B. garinii and B. afzelii, widely spread in Eurasia, 2 recently described species, B. valaisiana and B. lusitaniae, were found in Russia for the first time. Their possible spread and their importance in infectious pathology are described.