Dengue fever in Dar es Salaam, Tanzania: clinical features and outcome in populations of black and non-black racial category.

BACKGROUND: Although the incidence of dengue across Africa is high, severe dengue is reported infrequently. We describe the clinical features and the outcome of dengue according to raceduring an outbreak in Dar es Salaam, Tanzania that occurred in both native and expatriate populations. METHODS: Adults with confirmed dengue (NS1 and/or IgM on rapid diagnostic test and/or PCR positive) were included between December 2013 and July 2014 in outpatient clinics. Seven-day outcome was assessed by a visit or a call. Association between black race and clinical presentation, including warning signs, was assessed by logistic regression adjusted for age, malaria coinfection, secondary dengue and duration of symptoms at inclusion. The independent association between demographic and comorbidities characteristics of the patients and severe dengue was evaluated by multivariate logistic regression that included potential confounders. RESULTS: After exclusion of 3 patients of mixed race, 431 patients with dengue (serotype 2, genotype Cosmopolitan) were included: 241 of black and 190 of non-black race. Black patients were younger (median age 30 versus 41 years; p < 0.001) and attended care after a slightly longer duration of symptoms (median of 2.9 versus 2.7 days; p = 0.01). Malaria coinfection was not significantly different between black (5%) and non-black (1.6%) patients (p = 0.06). The same proportion of patients in both group had secondary dengue (13 and 14%; p = 0.78). Among warning signs, only mucosal bleed was associated with race, black race being protective (adjusted OR 0.44; 95% CI 0.21-0.92). Overall, 20 patients (4.7%) presented with severe dengue. Non-black race (adjusted OR 3.9; 95% CI 1.3-12) and previously known diabetes (adjusted OR 43; 95% CI 5.2-361) were independently associated with severe dengue. CONCLUSIONS: Although all patients were infected with the same dengue virus genotype, black race was independently protective against a severe course of dengue, suggesting the presence of protective genetic or environmental host factors among people of African ancestry. The milder clinical presentation of dengue in black patients might partly explain why dengue outbreaks are under-reported in Africa and often mistaken for malaria. These results highlight the need to introduce point-of-care tests, beside the one for malaria, to detect outbreaks and orientate diagnosis. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01947075 , retrospectively registered on the 13 of September 2014.

Diagnóstico microbiológico de arbovirosis y robovirosis emergentes / Microbiological diagnosis of emerging arboviral and rodent borne diseases

Los virus transmitidos por artrópodos (arbovirus) y los transmitidos por roedores (robovirus) o por otros animales se engloban en el epígrafe «virus transmitidos por vector» (VTV). En nuestro entorno son 3 los principales VTV autóctonos que causan enfermedad: los virus Toscana, West Nile y de la coriomeningitis linfocitaria; además, se diagnostican enfermedades por VTV importados (virus dengue, chikungunya) que actualmente suponen un riesgo de asentamiento por la circulación de vectores competentes de transmisión en nuestro territorio, como es el mosquito Aedes albopictus. La Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica se ha hecho eco de la emergencia de las enfermedades por VTV y ha redactado un procedimiento sobre diagnóstico microbiológico de arbovirosis y robovirosis emergentes que supone una actualización sobre los VTV con mayor sospecha diagnóstica en nuestro entorno y los métodos de detección disponibles para el diagnóstico de las enfermedades que producen

Vector borne viruses (VBV) include viruses transmitted by arthropods, rodents and other animals. In Spain the three main autochthonous VBVs causing human diseases are: Toscana, West Nile and Lymphocytic Choriomeningitis viruses. There are also other imported viruses that are potential threats to our public health, due to the presence of competent transmission vectors (dengue and chikungunya viruses in areas infested with Aedes albopictus), or due to the potential person-to-person transmission (Lassa and other viruses causing haemorrhagic fever). The Spanish Society for Infectious Diseases and Clinical Microbiology has responded to the emergence of VBVs by publishing a special issue of Microbiological Proceedings focused on the diagnosis of those emerging vector borne viruses of major concern in our country

[Microbiological diagnosis of emerging arboviral and rodent borne diseases]. / Diagnóstico microbiológico de arbovirosis y robovirosis emergentes.

Vector borne viruses (VBV) include viruses transmitted by arthropods, rodents and other animals. In Spain the three main autochthonous VBVs causing human diseases are: Toscana, West Nile and Lymphocytic Choriomeningitis viruses. There are also other imported viruses that are potential threats to our public health, due to the presence of competent transmission vectors (dengue and chikungunya viruses in areas infested with Aedes albopictus), or due to the potential person-to-person transmission (Lassa and other viruses causing haemorrhagic fever). The Spanish Society for Infectious Diseases and Clinical Microbiology has responded to the emergence of VBVs by publishing a special issue of Microbiological Proceedings focused on the diagnosis of those emerging vector borne viruses of major concern in our country.