(1) Background: Only a few studies on histoplasmosis in immunocompetent patients have been reported in French Guiana. Therefore, we conducted a detailed clinical description of hospitalized patients suffering with histoplasmosis among non-HIV patients. (2) Methods: This is a single-center, retrospective study conducted at Cayenne Hospital Center between 2008 and 2022. (3) Results: Our cohort was composed of 31 (91%) adults (>18 years of age) and 3 (9%) children, with a sex ratio, M:F, of 1:2. The median age was higher among the women than among the men (70 versus 54 years). The collection of respiratory samples constituted the majority of the performed examinations (38%). Fever (>37 °C) was found in 56% of patients. Surprisingly, the histoplasmosis was disseminated in 82% of patients with an overall case fatality rate of 14.7%. However, immunosuppressive conditions were found in 52% (16/31) of the adult patients, including lymphoid hemopathies, diabetes and immunosuppressive drugs. Conclusions: This disease, though rare and usually considered a mostly benign disease in non-HIV patients, presented a relatively high mortality rate in our cohort. Thus, histoplasmosis should be suspected, screened and investigated as a first line of defense in highly endemic areas, even in immunocompetent and non-HIV patients, especially those with fever or chronic respiratory symptoms.

BACKGROUND: Tick- and louse-borne relapsing fever are highly-neglected, vector-borne diseases caused by diverse Borrelia species. Presently, there are no data available on the endemicity of tick- and louse-borne relapsing fever spirochetes in Kenya. Here, we present data of a retrospective study on the seroprevalence of louse-borne relapsing fever (LBRF) in northern Kenya.
METHODS: A novel immunoassay, recently established for the diagnosis of LBRF was utilized to screen 2005 blood samples collected from individuals with fever without a source in Turkana County, Kenya between May 2009 and November 2010 for anti-LBRF antibodies.
RESULTS: Out of the 2005 sera analyzed, 287 samples (14.3 %) were considered anti-LBRF IgG positive. Subsequent analyses revealed that 87 out of 152 sera randomly selected from these 2005 samples were tested positive (57.2 %) for anti-LBRF IgM antibodies. Most of the IgG and IgM positive samples were from individuals living in northern regions of Turkana County.
CONCLUSIONS: Our serological finding provides strong evidence for the occurrence of LBRF in Kenya.

Emerging and emergent infectious diseases (EIDs) represent a significant and growing cause of morbidity and mortality with increased potential for pandemics due to globalization and international trade. Challenges remain to the approach toward vaccine development for EIDs. This Special Feature explores areas related to vaccine development and testing, including unique challenges posed in the developing world. Vaccines against multiple pathogens spanning a number of viral families are explored with respect to past activities through to future commercialization. Cost drivers balanced against clinical need are discussed and unique challenges posed by rare diseases are considered.