Abstract. Successful establishment of a Plasmodium vivax sporozoite challenge model in humans is described. Eighteen healthy adult, malaria-naïve volunteers were randomly allocated to Groups A-C and exposed to 3 ± 1, 6 ± 1, and 9 ± 1 bites of Anopheles albimanus mosquitoes infected with P. vivax , respectively. Seventeen volunteers developed signs and symptoms consistent with malaria, and geometric mean prepatent periods of 11.1 days (9.3-11) for Group A; 10.8 days (9.8-11.9) for Group B; and 10.6 days (8.7-12.4) for Group C, with no statistically significant difference among groups (Kruskal-Wallis, P = 0.70). One volunteer exposed to eight mosquito bites did not develop a parasitemia. No differences in parasite density were observed and all individuals successfully recovered after anti-malarial treatment. None of the volunteers developed parasite relapses within an 18-month follow-up. In conclusion, malaria-naive volunteers can be safely and reproducibly infected with bites of 2-10 An. albimanus mosquitoes carrying P. vivax sporozoites. This challenge method is suitable for vaccine and anti-malarial drug testing.

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Introduction. The surgical management of cholesteatoma. You can opt for a closed technique (mastoidectomy simple) or open surgery (radical mastoidectomy). The open mastoidectomy with reconstruction of the posterior wall of the middle ear reconstruction in one surgery combines the advantages of both techniques as adequate surgical exposure, eradication of cholesteatoma and anatomical reconstruction of the middle ear structures. Objective. To evaluate the surgical results in the management of cholesteatoma with the technique of open mastoidectomy with reconstruction of the posterior wall and the middle ear in one surgery. Methods. Prospective analytical observational study conducted between 2009-2012 with patients undergoing this surgical technique in the Hospital Universitario del Valle, performing preoperative clinical monitoring and quarterly postoperative tomography and previous assessments of hearing and pre -and postoperative audiometry. Results. 45 patients were studied. Mean Postoperative follow-up was 28 months. Surgical success was achieved in 93.3% of patients as measured by clinical and radiological follow. Hearing preservation was found after reconstruction of the hearing mechanism, based on measured audiometry auditory tone average (PTA) by the statistical test for paired samples between preoperative and postoperative PTA. (95% CI -1.47 to 12.15). Residual cholesteatoma was presented in 6.6%, three to four times lower than that reported in the literature. Conclusions. This type of surgery can be considered a successful technique in the treatment of cholesteatoma in selected cases.

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Abstract. Chikungunya fever, an acute and often chronic arthralgic disease caused by the mosquito-borne alphavirus, chikungunya virus (CHIKV), spread into the Americas in late 2013. Since then it has caused epidemics in nearly all New World countries, the second largest being Colombia with over 450,000 suspected cases beginning in September, 2014, and focused in Bolivar Department in the north. We examined 32 human sera from suspected cases, including diverse age groups and both genders, and sequenced the CHIKV envelope glycoprotein genes, known determinants of vector host range. As expected for Asian lineage CHIKV strains, these isolates lacked known Aedes albopictus-adaptive mutations. All the Colombian strains were closely related to those from the Virgin Islands, Saint Lucia, Mexico, Puerto Rico, and Brazil, consistent with a single, point-source introduction from the southeast Asia/Pacific region. Two substitutions in the E2 and E1 envelope glycoprotein genes were found in the Colombian strains, especially E1-K211E involving a residue shown previously to affect epistatically the penetrance of the E1-A226V A. albopictus-adaptive substitution. We also identified two amino acid substitutions unique to all American CHIKV sequences: E2-V368A and 6K-L20M. Only one codon, 6K-47, had a high nonsynonymous substitution rate suggesting positive selection.