Imported Dengue Infection in a Spanish Hospital with a High Proportion of Travelers from Africa: A 9-Year Retrospective Study.

Epidemiological data on dengue in Africa are still scarce. We investigated imported dengue infection among travelers with a high proportion of subjects from Africa over a 9-year period. From January 2005 to December 2013, blood samples from travelers with clinical suspicion of dengue were analyzed. Dengue was diagnosed using serological, antigen detection, and molecular methods. Subjects were classified according to birthplace (Europeans versus non-Europeans) and last country visited. Overall, 10,307 serum samples corresponding to 8,295 patients were studied; 62% were European travelers, most of them from Spain, and 35.9% were non-Europeans, the majority of whom were born in Africa (mainly Equatorial Guinea) and Latin America (mainly Bolivia, Ecuador, and Colombia). A total of 492 cases of dengue were identified, the highest number of cases corresponding to subjects who had traveled from Africa (N = 189), followed by Latin America (N = 174) and Asia (N = 113). The rate of cases for Africa (4.5%) was inferior to Asia (9%) and Latin America (6.1%). Three peaks of dengue were found (2007, 2010, and 2013) which correlated with African cases. A total of 2,157 of past dengue infections were diagnosed. Non-Europeans who had traveled from Africa had the highest rate of past infection (67.8%), compared with non-Europeans traveling from Latin America (38.7%) or Asia (35%). Dengue infection in certain regions of Africa is underreported and the burden of the disease may have a magnitude similar to endemic countries in Latin America. It is necessary to consider dengue in the differential diagnosis of other febrile diseases in Africa.

Performance of a new gelled nested PCR test for the diagnosis of imported malaria: comparison with microscopy, rapid diagnostic test, and real-time PCR.

Microscopy and rapid diagnostic tests (RDTs) are the techniques commonly used for malaria diagnosis but they are usually insensitive at very low levels of parasitemia. Nested PCR is commonly used as a reference technique in the diagnosis of malaria due to its high sensitivity and specificity. However, it is a cumbersome assay only available in reference centers. We evaluated a new nested PCR-based assay, BIOMALAR kit (Biotools B&M Labs, Madrid, Spain) which employs ready-to-use gelled reagents and allows the identification of the main four species of Plasmodium. Blood samples were obtained from patients with clinical suspicion of malaria. A total of 94 subjects were studied. Fifty-two (55.3%) of them were malaria-infected subjects corresponding to 48 cases of Plasmodium falciparum, 1 Plasmodium malariae, 2 Plasmodium vivax, and 1 Plasmodium ovale. The performance of the BIOMALAR test was compared with microscopy, rapid diagnostic test (RDT) (BinaxNOW® Malaria) and real-time quantitative PCR (qPCR). The BIOMALAR test showed a sensitivity of 98.1% (95% confidence interval [CI], 89.7-100), superior to microscopy (82.7% [95% CI, 69.7-91.8]) and RDT (94.2% [95% CI, 84.1-98.8]) and similar to qPCR (100% [95% CI, 93.2-100]). In terms of specificity, the BIOMALAR assay showed the same value as microscopy and qPCR (100% [95% CI, 93.2-100]). Nine subjects were submicroscopic carriers of malaria. The BIOMALAR test identified almost all of them (8/9) in comparison with RDT (6/9) and microscopy (0/9). In conclusion, the BIOMALAR is a PCR-based assay easy to use with an excellent performance and especially useful for diagnosis submicroscopic malaria.