Characterization of anti-Cryptosporidium IgA antibodies in sera from immunocompetent individuals and HIV-infected patients.

Human antibody response to Cryptosporidium parvum has been previously shown as involving immunoglobulin (Ig)M and IgG isotypes. The interest in anti-cryptosporidial IgA antibody response has been recently stimulated by studies on the therapeutic effects of secretory IgA antibodies to Cryptosporidium in animal models and in patients. In the present study, isotypes of serum anti-Cryptosporidium antibodies have been characterized in donors of the following categories: (a) healthy adults, (b) healthy children, (c) immunocompetent children with transient cryptosporidial diarrhea, (d) HIV-infected patients without clinical and parasitological evidence of Cryptosporidium infection and (e) AIDS patients with cryptosporidial diarrhea. Antibodies were detected using C. parvum oocysts purified by density gradient centrifugation from bovine faeces. The IgA antibodies were revealed using alpha-chain specific antibodies. Indirect immunofluorescence analysis with oocysts was used as control. Although high levels of serum antibodies of the IgA class were detected in some donors in the group of healthy adults, elevated values were consistently found in HIV-infected patients. Higher values were found in HIV patients with clinical cryptosporidiosis. The presence of a secretory component in serum IgA antibodies in these patients has been documented. Data indicate that IgA serum antibodies are produced as well as IgM and IgG antibodies upon contact with the parasite, and suggest that elevated IgA serum antibodies to Cryptosporidium are not associated with protection in HIV patients.     

Laboratory and field evaluation of different formulations of Metarhizium anisopliae var. acridum submerged spores and aerial conidia for the control of locusts and grasshoppers

Two emulsions and two water-based-formulations of freeze dried submerged spores of Metarhiziumanisopliae var. acridum (Metch.) Sorokin(isolate IMI 330189) were compared with aerialconidia (GREEN MUSCLE^TM) for their efficacyagainst Hieroglyphus daganensis (Krauss)and Locusta migratoria (R. & F.). Thefield experiments were conducted in East Nigeron H. daganensis whereas the laboratoryinvestigations were carried out in Germanyusing L. migratoria. In the fields, allformulations were applied on one hectare plotsusing ULV application techniques. Direct andresidual spray effects were assessed. In allcases there were highly significant (p < 0.001) differences between formulations asregards to total mortalities and mediansurvival times (MST). In both direct and sprayresidue effect assessments, aerial conidiaformulated in diesel oil showed over 95%mortality with significantly shorter MST (3 to8 days) under field conditions. These werefollowed by emulsions of submerged spores,which resulted in a mortality ranging from 56to 92% (MST = 8 to 16 days) for the directspray and 90 to 97% (MST = 7 to 12 days) forspray residue effect assessments. Experimentsin the laboratory positively confirmed theseresults. There were no apparent differencesbetween water-based formulations and thecontrol with respect to mortality and MST.These results emphasize the importance ofemploying oil carriers to protect spores fromenvironmental stress and thus enhance efficacy.The study also demonstrated the importance ofsecondary spore pick up from the sprayresidues. Spores in all formulations persistedover five days and caused mortalities rangingfrom 62 to 100% on healthy grasshoppersexposed to the spray residue from treatedvegetation. The results of this researchsuggest that emulsions may be an effectiveoption to improve efficacy of submerged sporesfor ultra low volume application under Sahelianconditions.     

Evaluation of conventional and four real-time PCR methods for the detection of Leishmania on field-collected samples in Ethiopia

In most low-resource settings, microscopy still is the standard method for diagnosis of cutaneous leishmaniasis, despite its limited sensitivity. In Ethiopia, the more sensitive molecular methods are not yet routinely used. This study compared five PCR methods with microscopy on two sample types collected from patients with a suspected lesion to advise on optimal diagnosis of Leishmania aethiopica. Between May and July 2018, skin scrapings (SS) and blood exudate from the lesion spotted on filter paper (dry blood spot, DBS) were collected for PCR from 111 patients of four zones in Southern Ethiopia. DNA and RNA were simultaneously extracted from both sample types. DNA was evaluated by a conventional PCR targeting ITS-1 and three probe-based real-time PCRs: one targeting the SSU 18S rRNA and two targeting the kDNA minicircle sequence (the ‘Mary kDNA PCR’ and a newly designed ‘LC kDNA PCR’ for improved L. aethiopica detection). RNAs were tested with a SYBR Green-based RT-PCR targeting spliced leader (SL) RNA. Giemsa-stained SS smears were examined by microscopy. Of the 111 SS, 100 were positive with at least two methods. Sensitivity of microscopy, ITS PCR, SSU PCR, Mary kDNA PCR, LC kDNA PCR and SL RNA PCR were respectively 52%, 22%, 64%, 99%, 100% and 94%. Microscopy-based parasite load correlated well with real-time PCR Ct-values. Despite suboptimal sample storage for RNA detection, the SL RNA PCR resulted in congruent results with low Ct-values. DBS collected from the same lesion showed lower PCR positivity rates compared to SS. The kDNA PCRs showed excellent performance for diagnosis of L. aethiopica on SS. Lower-cost SL RNA detection can be a complementary high-throughput tool. DBS can be used for PCR in case microscopy is negative, the SS sample can be sent to the referral health facility where kDNA PCR method is available.     

Miltefosine for the treatment of cutaneous leishmaniasis—A pilot study from Ethiopia

BackgroundCutaneous leishmaniasis (CL) in Ethiopia, caused by Leishmania aethiopica, is often severe and hard to treat compared to CL caused by other species elsewhere. Miltefosine is the only oral anti-leishmanial drug, with a favorable side-effect profile compared to routinely available sodium stibogluconate (SSG), but evidence about its use for L. aethiopica is lacking.Methodology and principal findingsIn an observational cohort study, treatment outcomes, safety and adherence among CL patients who required systemic treatment and received miltefosine for 28 days in Boru Meda Hospital and University of Gondar Hospital were studied. Patient cure was defined as 100% flattening for non-ulcerated lesions and 100% flattening and 100% re-epithelization for ulcerated lesions. Outcomes were documented for day 28, 90 and 180, both per site, and pooled, adjusting for site as a fixed effect with effect coding. Among 94 included patients (32 in Gondar, 62 in Boru Meda), median lesion duration was 12 months, median size six cm, and mucosal involvement (46.8%) and diffuse (30.9%) lesions were common. Adherence to miltefosine was good, and side-effects were tolerable. Initial outcomes at day 28 were promising, with 68.8% and 94.0% of patients having good improvement or cure in Gondar and Boru Meda respectively. In Boru Meda, outcomes were good with 72.7% and 72.9% cure at day 90 and day 180 respectively. In Gondar, results were less promising, with only 12.5% and 26.7% cure at day 90 and day 180, although confidence intervals were wide. In pooled estimates, 48.7% of patients reached cure at day 180, and 32.3% relapsed. Outcomes were better in Boru Meda Hospital, for smaller lesions and for mucosal lesions.Conclusions/SignificanceBased on miltefosine’s good initial response, tolerable side-effects, tablet-form, we propose to include miltefosine for future clinical trials using extended treatment schedules, combination therapy, or targeting specific subgroups.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT04004754","term_id":"NCT04004754"}}NCT04004754.