Cardiovascular Risk Prediction Models in People Living with HIV in Colombia.

BACKGROUND: People living with HIV are at increased risk of cardiovascular disease. Cardiovascular risk (CVR) prediction scores are powerful tools for individualized assessment that inform decision-making about follow-up frequency, hypolipemiant treatment intensification, and choice antiretroviral therapy. OBJECTIVES: The objectives of the study were to evaluate the performance of multiple cardiovascular assessment scores in predicting major adverse cardiovascular events (MACE) at 5 and 10 years. Framingham (2004, 2008, and Colombia-adjusted), SCORE, PROCAM, ASCVD, and D:A:D scores were included in the analysis. METHODS: Data were obtained from a medical registry of adults living with HIV attended by a teaching hospital in Colombia. All patients with complete information necessary for risk score calculations and determination of MACE at 5 and 10 years were included in the study. Receiver operating characteristic curves (ROC) were generated using calculations with all the aforementioned models for every individual. Differences between curves were compared with De- Long's test. RESULTS: A total of 808 patients were included in the analysis. Mean age was 35 years, and 12% were female. The majority of subjects had low and very low CVR. Eight MACE occurred during follow-up. Area under ROC curves were: Framingham (0.90), Framingham ATP3 (0.92), Framingham calibrated for Colombia (0.90), SCORE (0.92), PROCAM (0.92), ASCVD (0.89), and D:A:D (0.92), with no statistically significant differences. CONCLUSIONS: The evaluated scores had an acceptable performance for HIV-infected patients in the studied cohort, especially for those in low and very low risk categories.

Consistent prevalence of asymptomatic infections in malaria endemic populations in Colombia over time.

BACKGROUND: Malaria control programmes rely on confirmation of parasite presence in patients' blood prior to treatment administration. Plasmodium parasites are detected mostly by microscopy or rapid diagnostic test (RDT). Although these methods contribute significantly to malaria control/elimination, they are not suitable for detecting the significant proportion of asymptomatic subjects harbouring low levels of parasitaemia, which endure untreated as potential reservoirs for transmission. Malaria prevalence was assessed in endemic regions of Colombia over a 4-year follow-up. METHODS: A series of cross-sectional surveys were conducted between 2011 and 2014 in low to moderate malaria transmission sentinel sites (SS) of Tumaco, Buenaventura and Tierralta municipalities of Colombia. A census was performed and a random sample of houses was selected from each SS prior to each survey. Inhabitants were asked to answer a questionnaire on clinical, epidemiological and demographic aspects, and to provide a blood sample for malaria diagnosis using microscopy and quantitative real time polymerase chain reaction (qPCR). RESULTS: A total of 3059 blood samples were obtained from all SS, 58.5 % of which were from women and displayed a malaria prevalence ranging from 4 % (95 % CI 3-5 %) to 10 % (95 % CI 8-12 %) in the 4 years' study period. Almost all malaria cases (n = 220, 97 %) were sub-microscopic and only detectable by qPCR; 90 % of the cases were asymptomatic at the time of blood collection. While Buenaventura and Tierralta had a decreasing tendency during the follow-up, Tumaco had a rise in 2013 and then a decrease in 2014. Plasmodium vivax accounted for the majority (66-100 %) of cases in Tierralta and Buenaventura and for 25-50 % of the cases in Tumaco. CONCLUSIONS: This study demonstrates an important prevalence of asymptomatic malaria cases not detectable by microscopy, which therefore remain untreated representing a parasite pool for malaria transmission. This demands the introduction of alternative strategies for diagnosis and treatment, especially for areas of low transmission to reduce it to appropriate levels for malaria pre-elimination efforts to start.

Profiling the antibody response of humans protected by immunization with Plasmodium vivax radiation-attenuated sporozoites.

Malaria sterile immunity has been reproducibly induced by immunization with Plasmodium radiation-attenuated sporozoites (RAS). Analyses of sera from RAS-immunized individuals allowed the identification of P. falciparum antigens, such as the circumsporozoite protein (CSP), the basis for the RTS, S and R21Matrix-M vaccines. Similar advances in P. vivax (Pv) vaccination have been elusive. We previously reported 42% (5/12) of sterile protection in malaria-unexposed, Duffy-positive (Fy +) volunteers immunized with PvRAS followed by a controlled human malaria infection (CHMI). Using a custom protein microarray displaying 515 Pv antigens, we found a significantly higher reactivity to PvCSP and one hypothetical protein (PVX_089630) in volunteers protected against P. vivax infection. In mock-vaccinated Fy + volunteers, a strong antibody response to CHMI was also observed. Although the Fy- volunteers immunized with non-irradiated Pv-infected mosquitoes (live sporozoites) did not develop malaria after CHMI, they recognized a high number of antigens, indicating the temporary presence of asexual parasites in peripheral blood. Together, our findings contribute to the understanding of the antibody response to P. vivax infection and allow the identification of novel parasite antigens as vaccine candidates.Trial registration: ClinicalTrials.gov number: NCT01082341.

Fever of unknown origin: A 12-year case series in Colombia.

BACKGROUND: Fever of unknown origin (FUO) is a diagnostic challenge with highly heterogeneous causes. Its etiology can change according to the studied regions, and the chance of reaching a diagnosis depends on available resources. The aim of this study is to describe the clinical characteristics, etiology and the usefulness of diagnostic aids in cases of FUO managed over 12 years in a Colombian reference center. METHODOLOGY: Single-institution retrospective case series. All cases of FUO between 2006 and 2017 were identified with the help of an electronic medical record search software. Cases of adults with fever for more than three weeks who remained undiagnosed after three days of hospitalization are described. RESULTS: Of 1,009 cases evaluated, 112 cases met the inclusion criteria (median age 43 years, 66% men). The etiologies identified were infectious (31.2%), inflammatory (20.5%), neoplastic (14.3%), and miscellaneous (2.7%) diseases. 31.2% remained without etiological diagnosis. The most frequent conditions were tuberculosis (17%), Hodgkin's lymphoma (7.1%), systemic lupus erythematosus (6.3%), disseminated histoplasmosis, and adult Still's disease. Contrast tomography and biopsies were the studies that most frequently supported or confirmed the final diagnosis. CONCLUSIONS: This series of contemporary Latin American cases suggests that the categories of FUO etiologies are similar to those reported in studies from developed countries, with tuberculosis being the most frequent cause in our setting. Our results highlight the importance of tomography-guided invasive studies in the diagnostic approach to FUO.

Protective Efficacy of Plasmodium vivax Radiation-Attenuated Sporozoites in Colombian Volunteers: A Randomized Controlled Trial.

BACKGROUND: Immunizing human volunteers by mosquito bite with radiation-attenuated Plasmodium falciparum sporozoites (RAS) results in high-level protection against infection. Only two volunteers have been similarly immunized with P. vivax (Pv) RAS, and both were protected. A phase 2 controlled clinical trial was conducted to assess the safety and protective efficacy of PvRAS immunization. METHODOLOGY/PRINCIPAL FINDINGS: A randomized, single-blinded trial was conducted. Duffy positive (Fy+; Pv susceptible) individuals were enrolled: 14 received bites from irradiated (150 ± 10 cGy) Pv-infected Anopheles mosquitoes (RAS) and 7 from non-irradiated non-infected mosquitoes (Ctl). An additional group of seven Fy- (Pv refractory) volunteers was immunized with bites from non-irradiated Pv-infected mosquitoes. A total of seven immunizations were carried out at mean intervals of nine weeks. Eight weeks after last immunization, a controlled human malaria infection (CHMI) with non-irradiated Pv-infected mosquitoes was performed. Nineteen volunteers completed seven immunizations (12 RAS, 2 Ctl, and 5 Fy-) and received a CHMI. Five of 12 (42%) RAS volunteers were protected (receiving a median of 434 infective bites) compared with 0/2 Ctl. None of the Fy- volunteers developed infection by the seventh immunization or after CHMI. All non-protected volunteers developed symptoms 8-13 days after CHMI with a mean pre-patent period of 12.8 days. No serious adverse events related to the immunizations were observed. Specific IgG1 anti-PvCS response was associated with protection. CONCLUSION: Immunization with PvRAS was safe, immunogenic, and induced sterile immunity in 42% of the Fy+ volunteers. Moreover, Fy- volunteers were refractory to Pv malaria. TRIAL REGISTRATION: Identifier: NCT01082341.

Tos ferina neonatal, una enfermedad emergente / Newborn pertussis: a re-emergent disease

La tos ferina es una enfermedad del tracto respiratorio superior que ha incrementado últimamente su incidencia. Se ha demostrado que los adultos son la principal fuente de transmisión para los niños susceptibles. En la actualidad, la enfermedad afecta con más frecuencia a los niños menores de 3 meses, entre los cuales, los menores de 1 mes tienen mayor riesgo de complicaciones y letalidad. Se presenta un caso autóctono de una recién nacida de 16 días con episodios de tos quintosa, cianosante y emetizante, cuadro hemático que evidencia leucocitosis y linfocitosis, que se originó en un área donde está implementada, como política de salud pública, la vacunación para tos ferina en niños. La paciente tuvo una evolución tórpida complicada con convulsiones y necesidad de ventilación mecánica. Se identificó en la paciente Bordetella pertussis por inmunofluorescencia, reacción en cadena de la polimerasa y cultivo. Se hace una breve revisión de la literatura, haciendo énfasis en el panorama actual de la vacunación en neonatos.

Neonatal pertussis is an upper respiratory tract infection whose incidence has recently increased. Adults have been demonstrated to be the main source for neonatal infection, accounting for the rising rates of disease in this later population group. Currently, the disease affects chiefly infants under three months of age, among which, those younger than one moth have the highest rates of complication and death. Here we present an indigenous case of a 16 days old newborn that arose in an area where pertussis vaccination during the first months of life is the rule and very few cases had been documented throughout the last years. The patient presented whooping cough with cyanosis and emesis episodes, whose complete blood count showed markedly and increasingly high leukocytosis and lymphocytosis. Her clinical course complicated with seizures and required mechanical ventilation. B. pertussis was demonstrated by means of immunofluorescence, polymerase chain reaction and culture. A brief literature review is made with emphasis on current landmarks on pertussis vaccination.