Clinical characteristics and treatment outcome of patients with visceral leishmaniasis and HIV co‐infection in northwest Ethiopia

Objectives To describe the clinical presentation of patients with visceral leishmaniasis (VL) with and without human immunodeficiency virus (HIV) co‐infection and factors associated with poor outcome in northwest Ethiopia. Method Retrospective review of 241 patients with VL (92 with and 149 without HIV co‐infection). Results HIV co‐infection was present in 92 (38%) of the patients. Clinical presentation of VL was indistinguishable between patients with and without HIV co‐infection. Co‐infected patients had a poorer outcome i.e. either death or treatment failure (31.5%vs. 5.6%, P < 0.001). The presence of tuberculosis or sepsis syndrome among patients with VL and HIV co‐infected independently predicted death or treatment failure [odds ratio 4.5 (95% CI 1.47–13.92, P = 0.009) and 9.1 (95% CI 2.16–37.97, P = 0.003), respectively]. Despite having similar clinical presentation at the time of diagnosis, VL and HIV co‐infected patients had a higher mortality and treatment failure than immunocompetent patients. Conclusion The frequency of HIV co‐infection among patients with VL is high in the study area, and this co‐infection was associated with death or treatment failure. The clinical management of VL in HIV co‐infected patients is a major challenge that requires new treatment approaches to improve its outcome.     

Plasmodium vivax Duffy binding protein: baseline antibody responses and parasite polymorphisms in a well‐consolidated settlement of the Amazon Region

Objective  To investigate risk factors associated with the acquisition of antibodies against Plasmodium vivax Duffy binding protein (PvDBP) – a leading malaria vaccine candidate – in a well‐consolidated agricultural settlement of the Brazilian Amazon Region and to determine the sequence diversity of the PvDBP ligand domain (DBP_II) within the local malaria parasite population. Methods  Demographic, epidemiological and clinical data were collected from 541 volunteers using a structured questionnaire. Malaria parasites were detected by conventional microscopy and PCR, and blood collection was used for antibody assays and molecular characterisation of DBP_II. Results  The frequency of malaria infection was 7% (6% for P. vivax and 1% for P. falciparum), with malaria cases clustered near mosquito breeding sites. Nearly 50% of settlers had anti‐PvDBP IgG antibodies, as detected by enzyme‐linked immunosorbent assay (ELISA) with subject’s age being the only strong predictor of seropositivity to PvDBP. Unexpectedly, low levels of DBP_II diversity were found within the local malaria parasites, suggesting the existence of low gene flow between P. vivax populations, probably due to the relative isolation of the studied settlement. Conclusion  The recognition of PvDBP by a significant proportion of the community, associated with low levels of DBP_II diversity among local P. vivax, reinforces the variety of malaria transmission patterns in communities from frontier settlements. Such studies should provide baseline information for antimalarial vaccines now in development.