Dengue-malaria co-infection reports are scarce. Of 1,723 consecutive febrile patients in Cayenne Hospital, 238 had dengue (174 early dengue fever cases) and 393 had malaria (371 acute malaria); 17 had both. Diagnosis of 1 of these 2 infections should not rule out testing for the other infection.

In South America, dengue is the arbovirus-transmitted disease with the highest incidence. Unlike other arboviruses, wild mammals have no confirmed role in the cycle of dengue in the neotropics, although serological studies have suggested a possible secondary amplification cycle involving mammals other than nonhuman primates. In French Guiana, where all four serotypes (DENV-1, DENV-2, DENV-3, DENV-4) are present, the disease is endemic with outbreak events. To determine whether wild mammals can be infected by DENV, rodents, marsupials, and bats were captured over several periods, from 2001 to 2007, at two sites. The first location is a secondary forest surrounded by an urban area where dengue is endemic. The second location is a forest edge site where the disease has not yet emerged. A total of 10,000 trap-nights were performed and 616 mammals were captured. RNAs representing the four DENV serotypes were detected at both sites by reverse-transcriptase polymerase chain reaction in the livers and/or sera of 92 mammals belonging to 14 out of 32 species distributed among all the orders investigated: Rodentia (33 positive/146 tested), Marsupialia (40/318), and Chiroptera (19/152). Sequence analyses of a portion of the capsid and premembrane junction revealed that mammal strains of DENV-1, DENV-2, DENV-3, and DENV-4 had only 92.6%, 89%, 95%, and 95.8% identity, respectively, with strains circulating in the human population during the same periods. Regarding DENV-2, strains related (99% identity) to those responsible for an epidemic event in humans in French Guiana concurrent to the capture sessions were also evidenced, suggesting that wild mammals in edge habitats can be infected by circulating human strains. Our results demonstrate, for the first time, that neotropical wild mammals can be infected with dengue virus. The question of whether mammals maintain DENV in enzootic cycles and can play a role in its reemergence in human populations remains to be answered.

Background: A dengue fever outbreak occured in French Guiana in 2006. The objectives were to study the value of a syndromic surveillance system set up within the armed forces, compared to the traditional clinical surveillance system during this outbreak, to highlight issues involved in comparing military and civilian surveillance systems and to discuss the interest of syndromic surveillance for public health response.Methods: Military syndromic surveillance allows the surveillance of suspected dengue fever cases among the 3,000 armed forces personnel. Within the same population, clinical surveillance uses several definition criteria for dengue fever cases, depending on the epidemiological situation. Civilian laboratory surveillance allows the surveillance of biologically confirmed cases, within the 200,000 inhabitants.Results: It was shown that syndromic surveillance detected the dengue fever outbreak several weeks before clinical surveillance, allowing quick and effective enhancement of vector control within the armed forces. Syndromic surveillance was also found to have detected the outbreak before civilian laboratory surveillance.Conclusion: Military syndromic surveillance allowed an early warning for this outbreak to be issued, enabling a quicker public health response by the armed forces. Civilian surveillance system has since introduced syndromic surveillance as part of its surveillance strategy. This should enable quicker public health responses in the future.

ABSTRACT We evaluated the use of capillary blood samples stored on filter papers for diagnosis of dengue virus infection. Venous and capillary blood samples were collected from 130 patients suspected of having dengue fever. We compared the performances of standard reference methods using capillary blood samples absorbed onto filter papers versus venous blood samples. The resulting sensitivity, specificity, and positive predictive value of tests performed on filter paper compared to those performed on venous blood samples were 81.6% (62/76; 95% confidence interval [CI], 74.9% to 88.3%), 90.7% (49/54; 95% CI, 85.7% to 95.7%), and 92.5% (62/67; 95% CI, 86.2% to 98.8%), respectively. During the acute phase of dengue virus infection (day 1 to day 4), the tests performed on capillary blood samples had a sensitivity of 88.5% (95% CI, 82.0% to 95.0%) and a specificity of 93.8% (95% CI, 88.9% to 98.7%). During the convalescent phase of infection, this method allowed the viral serotype to be determined for 4 of 15 (27%) dengue virus-infected patients for whom virological diagnosis using venous samples was negative. Capillary blood samples could therefore be a good alternative for the diagnosis of dengue virus infection in tropical areas. Indeed, these samples are convenient for storage and transport without the need for a cold chain and simplify the collection of samples from children. Moreover, our results suggest that viral particles persist longer in capillary blood than in peripheral blood. Analysis of the viability of viral particles under these conditions may give new insights into the physiopathology of dengue virus infection and the transmission of dengue virus during outbreaks.

Mayaro (MAY) virus is a member of the genus Alphavirus in the family Togaviridae. Alphaviruses are distributed throughout the world and cause a wide range of diseases in humans and animals. Here, we determined the complete nucleotide sequence of MAY from a viral strain isolated from a French Guianese patient. The deduced MAY genome was 11,429 nucleotides in length, excluding the 5′ cap nucleotide and 3′ poly(A) tail. Nucleotide and amino acid homologies, as well as phylogenetic analyses of the obtained sequence confirmed that MAY is not a recombinant virus and belongs to the Semliki Forest complex according to the antigenic complex classification. Furthermore, analyses based on the E1 region revealed that MAY is closely related to Una virus, the only other South American virus clustering with the Old World viruses. On the basis of our results and of the alphaviruses diversity and pathogenicity, we suggest that alphaviruses may have an Old World origin.

After 10 years of absence, dengue virus type 4 (DENV-4) has recently reemerged in Martinique, Guadeloupe, and French Guiana. Phylogenetic analyses of strains isolated from 2004 to 2005 showed that they belong to DENV-4 genotype II, but to a different cluster than strains isolated from 1993 to 1995.

ABSTRACT We evaluated a one-step sandwich-format microplate enzyme immunoassay for detecting dengue virus NS1 antigen (Ag) in human serum by use of Platelia Dengue NS1 Ag kits (Bio-Rad Laboratories, Marnes La Coquette, France). We collected 299 serum samples from patients with dengue disease and 50 serum samples from patients not infected with dengue virus. For the 239 serum samples from patients with acute infections testing positive by reverse transcription-PCR and/or virus isolation for one of the four dengue virus serotypes, the sensitivity of the Platelia Dengue NS1 Ag kit was 88.7% (95% confidence interval, 84.0% to 92.4%). None of the serum samples from patients not infected with dengue virus tested positive with the Platelia Dengue NS1 Ag kit. A diagnostic strategy combining the Platelia Dengue NS1 Ag test for acute-phase sera and immunoglobulin M capture enzyme-linked immunosorbent assay for early-convalescent-phase sera increased sensitivity only from 88.7% to 91.9%. Thus, NS1 antigen detection with the Platelia Dengue NS1 Ag kit could be used for first-line testing for acute dengue virus infection in clinical diagnostic laboratories.

To the Editor: Hantaviruses are etiologic agents for hemorrhagic fever with renal syndrome in Europe and Asia and for hantavirus pulmonary syndrome (HPS) in the Americas. These viruses belong to the family Bunyaviridae, genus Hantavirus. The natural reservoir of these viruses is wild or domestic rodents. HPS was first described in 1993 in the Four Corners region of the United States (1). It is a respiratory illness associated with the inhalation of aerosolized rodent excreta (urine and feces) contaminated with hantavirus particles. Sin Nombre virus (SNV) was the first etiologic agent of this syndrome. Since 1993, HPS has also been reported and confirmed in 6 countries in South America: Argentina, Bolivia, Brazil, Chile, Paraguay, Uruguay (2,3). Several distinct hantaviruses have been associated with HPS, including Juquituba virus in Brazil (4), Andes virus in Southern Argentina (5), and Laguna Negra virus in Paraguay (6). French Guiana, an overseas French Administrative Unit in the Amazonian forest complex, is located on the northeastern coast of the South America between Brazil and Suriname. Ninety percent of its surface is tropical rain forest; the remaining 10% is a coastal plain, where 90% of the 200,000 inhabitants live. Cayenne and 2 adjacent towns, Remire and Matoury, constitute the main urban centers, with 80,000 inhabitants, ≈40% of the population. People live mainly in individual houses and small buildings. Many houses are built near forests, except those in the center of Cayenne. The outskirts of Remire and Matoury are surrounded by secondary rain forest, and those of Cayenne by wooded hills, where wild mammals such as rodents live in large numbers. The prevalence of antibodies to New World hantavirus is unknown in French Guiana. Several cases of atypical pneumonia not linked to other etiologic agents (Coxiella burnetii, Histoplasma boydii), combined with identification of hantavirus rodent reservoirs in neighboring countries, prompted us to determine the seroprevalence of hantavirus in this area (7,8). To estimate the prevalence of antibodies to New World hantavirus, we conducted a retrospective serologic survey of patients with symptoms compatible with HPS. Patients were from all areas of French Guiana: 64% from the urban centers, 7% from rural regions, and 30% from unspecified regions. From April 2002 through April 2004, a total of 420 serum samples were collected from patients with acute-phase febrile illness, unexplained acute respiratory syndrome, or bilateral interstitial pulmonary infiltrates. Diagnosis of Q fever was excluded by negative serologic results for immunoglobulin M (IgM), IgG, or both to C. burnetii (bioMerieux, Marcy-l'Etoile, France). To detect patients with IgG antibodies to SNV, the ELISA described by Feldmann et al. was used (9). Briefly, an SNV-positive serum provided by the Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA) was used as a positive control. Negative controls were obtained by random sampling of all previously negative samples. A sample was considered positive if the net absorbance values (after subtraction of absorbance values with and without antigen) were >0.2 for dilutions of 1:100 and 1:400 and the sum of 4 net absorbance values was >0.95. Seropositive samples were confirmed at CDC. Antibodies reactive with SNV antigen indicate infection with a New World hantaviruses. However, because SNV is broadly cross-reactive with most New World hantavirus, the specific hantavirus cannot be identified. The seroprevalence of IgG antibody to hantavirus was 1.42% (6/420) in the selected population. Three other samples showed borderline positivity. Antibody prevalence was not significantly different among the 7 age classes used (0–9, 10–19, 20–29, 30–39, 40–49, 50–59, and >60 years of age, p = 0.36, degrees of freedom = 6, by χ2 test) or by sex (p = 0.22, by Fisher exact test). All patients with seropositive samples lived in the urban centers. The mean age of the 6 patients was 36.0 years (range 24–56 years), and 83% were men. Test results for IgM antibodies to SNV conducted on samples in parallel were negative. The seroprevalence found in this study was caused by patient exposure to hantavirus. However, in the absence of IgM to SNV, we cannot link the respiratory symptoms observed to recent infection with hantavirus. Lack of information about the patients, especially their clinical history and details of travel to bordering countries, did not permit an association of infection with hantavirus contact in French Guiana. The seroprevalence observed is similar to that in Venezuela, where hantaviruses were isolated from rodents in 1999, but is lower than that observed in regions of Brazil (10). The presence of hantaviruses in neighboring countries, as well as frequent travel by people in and out of French Guiana, has encouraged us to continue studying these viruses. We plan to conduct a study to systematically evaluate hantaviruses by serologic analysis and genomic amplification in persons with suggestive pathology. This study will be carried out in parallel with an investigation of rodent reservoirs of hantaviruses.

To determine which pathogens are responsible for bloodstream infections in Bangui and to which antibiotics these pathogens are resistant, we conducted a prospective study of the bacteria isolated from the blood of febrile patients hospitalized in the department of medicine of the Bangui Community Hospital after the failure of antimalarial treatment. One hundred and thirty-one patients were included in this study. Bacteria were identified in 49 blood cultures (37.4%). Eleven different species were identified. Bacteremia was more frequent in HIV-positive patients than in HIV-negative patients. Salmonella typhimurium, Mycobacterium tuberculosis and Streptococcus pneumoniae were the most frequently isolated pathogens. Eighty percent of enterobacteria were resistant to amoxicillin and 85% to trimethoprim-sulfamethoxazole. Ciprofloxacin and ceftriaxone were the most efficient antibiotics for the enterobacteria, but chloramphenicol and gentamicin were efficient in most cases. Some strains of S. pneumoniae displayed reduced susceptibility to penicillin G, but all strains were susceptible to erythromycin.

A serologic survey for Mayaro virus (Alphavirus, Togaviridae) in 28 wild nonflying forest mammal species in French Guiana showed a prevalence ranging from 0% to 52% and increasing with age. Species active during the day and those who spent time in trees were significantly more infected, results consistent with transmission implicating diurnal mosquitoes and continuous infectious pressure.

A serologic survey for Mayaro virus (Alphavirus, Togaviridae) in 28 wild nonflying forest mammal species in French Guiana showed a prevalence ranging from 0% to 52% and increasing with age. Species active during the day and those who spent time in trees were significantly more infected, results consistent with transmission implicating diurnal mosquitoes and continuous infectious pressure.

ABSTRACT In contrast to humans, several primate species are believed to have harbored simian immunodeficiency viruses (SIVs) since ancient times. In particular, the geographically dispersed species of African green monkeys (AGMs) are all infected with highly diversified SIVagm viruses at high prevalences (greater than 50% of sexually mature individuals) without evident diseases, implying that the progenitor monkeys were infected prior to their dispersal. If this is correct, AGMs would be expected to have accumulated frequent resistance-conferring polymorphisms in host genes that are important for SIV replication. Accordingly, we analyzed the coding sequences of the CCR5 coreceptors from 26 AGMs (52 alleles) in distinct populations of the four species. These samples contained 29 nonsynonymous coding changes and only 15 synonymous nucleotide substitutions, implying intense functional selection. Moreover, 24 of the resulting amino acid substitutions were tightly clustered in the CCR5 amino terminus (D13N in the vervets and Y14N in the tantalus species) or in the first extracellular loop (Q93R and Q93K in all species). The Y14N substitution was extremely frequent in the 12 wild-born African tantalus, with 7 monkeys being homozygous for this substitution and 4 being heterozygous. Although two of these heterozygotes and the only wild-type homozygote were naturally infected with SIVagm, none of the Y14N homozygotes were naturally infected. A focal infectivity assay for SIVagm indicated that all five tested SIVagms efficiently use CCR5 as a coreceptor and that they also use CXCR6 (STRL33/Bonzo) and GPR15 (BOB) with lower efficiencies but not CXCR4. Interestingly, the D13N, Y14N, Q93R, and Q93K substitutions in AGM CCR5 all strongly inhibited infections by the SIVagm isolates in vitro. The Y14N substitution eliminates a tyrosine sulfation site that is important for infections and results in partial N-linked glycosylation (i.e., 60% efficiency) at this position. Nevertheless, the CCR5(Y14N) component that lacks an N-linked oligosaccharide binds the chemokine MIP-lβ with a normal affinity and is fully active in signal transduction. Similarly, D13N and Q93R substitutions did not interfere with signal transduction. Thus, the common substitution polymorphisms in AGM CCR5 strongly inhibit SIVagm infections while substantially preserving chemokine signaling. In contrast, polymorphisms of human CCR5 are relatively infrequent, and the amino acid substitutions are randomly situated and generally without effects on coreceptor function. These results support an ancient coevolution of AGMs and SIVagm viruses and establish AGMs as a highly informative model for learning about host proteins that play critical roles in immunodeficiency virus infections.

Background: Infection with human herpesvirus 8 (HHV8), also termed Kaposi's sarcoma (KS)-associated herpesvirus, is associated with all forms of KS, with primary effusion lymphoma (PEL), and with some forms of multicentric Castleman's disease (MCD), but the pathogenic role of HHV8 in these tumors and the clonal nature of KS are still unclear. The purpose of this study was to examine whether the number of terminal repeats (TRs) contained in the fused TR region of HHV8 could be used as a marker of clonality in HHV8-associated tumors. Methods: Pulsed-field gel electrophoresis (PFGE) and multiple-probe Southern blot analysis of the HHV8 TR region were performed on high-molecular-weight DNA obtained from tumoral KS, PEL, and MCD lesions. Results: These analysis showed that the fused TR region contains a large but variable number of TR units (ranging from 16 to 75) and that the viral genome is present as extrachromosomal circular DNA in these tumors in vivo, with occasional ladders of heterogeneous linear termini reflecting lytic replication. All PEL tumors and PEL-derived cell lines as well as some KS tumors contained monoclonal or oligoclonal fused TR fragments; however, the TR region appeared polyclonal in MCD tumors and in a few KS lesions. Conclusion: Several KS and PEL lesions are monoclonal expansions of a single infected cell, suggesting that HHV8 infection precedes tumor growth and thus supporting an etiologic role of latent HHV8 in these proliferations. Our finding that nodular KS lesions display all possible patterns of clonality supports the model according to which KS begins as a polyclonal disease with subsequent evolution to a monoclonal process.

An investigation was conducted between 1994 and 1997 in forested areas of the Central African Republic (CAR) to determine the seroprevalence of IgG antibodies against several haemorrhagic fever viruses present in the region. Sera were obtained from 1762 individuals in two groups (Pygmy and Bantu locuted populations) living in 4 forested areas in the south of the country. Sera were tested for IgG antibodies against Ebola, Marburg, Rift Valley fever (RVF), Yellow fever (YF) and Hantaviruses by enzyme immunoassay (EIA), and against Lassa virus by immunofluorescent assay. The prevalence of IgG antibodies was 5.9% for Ebola, 2% for Marburg, 6.9% pour RVF, 6.5% for YF, 2% for Hantaan. No antibodies were detected against Lassa, Seoul, Puumala and Thottapalayam viruses. No IgM antibodies were detected against RVF and YF viruses. The distribution of antibodies appears to be related to tropical rain forest areas. This study indicates that several haemorrhagic fever viruses are endemic in forested areas of the CAR and could emerge due to environmental modification.

The concomitant presence of five distinct HIV-1 subtypes and of unclassified HIV-1 was reported in Bangui, Central African Republic (C.A.R.) between 1990 and 1991. This previous study was conducted in individuals belonging to the C.A.R. Armed Forces (FACA) Cohort and in patients from the University Hospital of Baugui. To follow the HIV-1 subtype distribution in Bangui over time, we conducted a cross-sectional surveillance of HIV-1 subtypes between 1987 and 1997 in three groups of individuals in Bangui: 47 men belonging to the FACA Cohort, 38 patients from the CNHUB hospital, and 51 individuals consulting the sexually transmitted diseases (STD) clinic. One hundred and ten HIV-1 were subtyped by heteroduplex mobility assay (HMA) and/or sequencing of env regions encompassing the V3 domain. By comparing the HIV-1 distribution in two time periods (1987-1991 and 1991-1996) in the FACA cohort, we observed a significant increase of subtype A from 43.7% to 83.9%. This subtype distribution does not seem specific to the FACA cohort, in that subtype A accounted for 46.7% of the HIV-1 infections in CNHUB patients in the first time period studied and for 69.6% in the second time period. In STD patients, subtype A infections were predominant in 1995 (72.7%) and 1997 (89.7%). Subtype E viruses could be identified in the second time period, but represented only between 6.5% and 21.8% of the infections in the three groups of individuals studied. Other subtypes (B, C, H) and non-classified HIV-1 in C2-V3 were detected with only a 3.2% to 9.1% frequency for each in the second time period. Phylogenetic analysis excluded infection by a single source for the individuals included in the study. Our data demonstrate an increase in the proportion of HIV-1 subtype A infections in Bangui that raises the question of a preferential transmissibility of specific HIV-1 variants.