Risk associations for intestinal parasites in symptomatic and asymptomatic schoolchildren in central Mozambique.

OBJECTIVES: Chronic infections by enteric parasites including protist and helminthic species produce long-term sequelae on the health status of infected children. This study assesses potential associations linked with enteric parasite infections in symptomatic and asymptomatic children in Zambézia province, Mozambique. METHODS: In this prospective cross-sectional study, stool samples and epidemiological questionnaires on demographics and risk associations were collected from symptomatic children (n = 286) from clinical settings and asymptomatic (n = 807) children from 17 schools and creches aged 3‒14 years. We detected enteric parasites using PCR-based methods. We calculated prevalence (adjusted for age, sex, house construction, drinking water, and latrine use) and odds ratios (ORs) for risk associations with logistic regression, after adjusting for district, neighbourhood and symptoms. RESULTS: Numbers and adjusted prevalence (95% confidence intervals in parentheses) for the symptomatic and asymptomatic populations were Giardia duodenalis 120, 52% (22-82), 339, 42% (25-59); followed by Strongyloides stercoralis 52, 14% (9‒20), 180, 20% (15-25). Risk associations for G. duodenalis included drinking untreated river/spring water, OR 2.91 (1.80-4.70); contact with ducks, OR 14.96 (2.93‒76.31); dogs, OR 1.92 (1.04-3.52); cats, OR 1.73 (1.16-2.59), and a relative with diarrhoea, OR 2.59 (1.54‒4.37). Risk associations for S. stercoralis included having no latrine, OR 2.41 (1.44-4.02); drinking well water, OR 1.82 (1.02-3.25), and increasing age, OR 1.11 (1.04-1.20). CONCLUSIONS: We found a high prevalence of intestinal parasites regardless of the children's symptoms. Drinking well or river water, domestic animals, and latrine absence were contributing factors of human infections.

Parasitological versus molecular diagnosis of strongyloidiasis in serial stool samples: how many?

Strongyloidiasis is usually an asymptomatic disease in immunocompetent patients, caused by Strongyloides stercoralis. However, in immunocompromised patients it can produce a severe clinical profile. Therefore, a correct diagnosis is necessary in these cases and in those chronic asymptomatic patients. The low sensitivity of classical parasitological techniques requires the analysis of multiple serial stool samples. Molecular diagnostic techniques represent an improvement in the detection of the parasite. The objective of this study was to evaluate the minimum number of samples necessary to achieve maximum sensitivity by real-time polymerase chain reaction (PCR). A total of 116 stool samples from 39 patients were analysed by direct microscopic observation, agar culture, Harada-Mori and real-time PCR, in one, two, three and four or more consecutive samples. After two serial samples, 6 out of 39 patients were positive by parasitological and molecular techniques, while 16 of them were real-time PCR positive, and all the patients detected by parasitology were also detected by the molecular technique, reaching 100.00% sensitivity versus 83.00% when analysing a single sample. These data also reflect apparently low specificity (51.52%) and positive predictive value (PPV) (27.27 %) values, due to the high number of cases detected by real-time PCR and not by parasitological techniques. These cases were confirmed as true positives when analysing three, four or more samples from the same patient. In conclusion, the application of molecular techniques decreases the number of serial stool samples necessary to give a diagnosis with the maximum sensitivity.

Cryptosporidium hominis genotypes involved in increased incidence and clusters of cases, Navarra, Spain, 2012.

SUMMARY Two clusters of confirmed cryptosporidiosis infections were detected in Navarra, Spain, in the summer of 2012, in the context of an increased incidence in the region. Molecular subtyping of Cryptosporidium hominis determined that one cluster, occurring in an urban area, was due to the predominant circulating subtype IbA10G2R2 and the other cluster, with cases occurring in a rural area, was due to a rare subtype IaA18R3. No single exposure was associated with infection, although exposure to certain children's pools was reported by a majority of patients interviewed in each cluster. Genotyping tools were useful in the investigation and could aid investigation of cryptosporidiosis outbreaks in Spain in the future.

In vitro activity of CA(1-8)M(1-18), a synthetic cecropin A-melittin hybrid peptide, against multiresistant Acinetobacter baumannii strains.

The in vitro antibiotic activity of CA(1-8)M(1-18), a synthetic cecropin A-melittin hybrid peptide, was determined by broth microdilution on 20 clinical Acinetobacter baumannii isolates with different resistance profiles. The MIC(50), MIC(90) and ranges were 4 mg/l, 4 mg/l and 2-8 mg/l, respectively, and were independent of resistance pattern. Different assay parameters such as microplate plastic (polystyrene or polypropylene), addition of supplements (5-10% fetal calf serum or 5% horse blood), inoculum size (10(5), 10(6), 10(7) and 10(8) CFU/ml) or incubation period (24 or 48 h) were studied. MIC was independent of the first two parameters, although the MIC values increased both with inoculum size or incubation period. Killing curves were obtained both for a standard strain and a multiresistant isolate over a 45.7-2.8 mg/l (16-1 mM) peptide range, using an initial inoculum of 10(5)-10(6) CFU/ml and 10(9)-10(10) CFU/ml. A concentration of 45.7 mg/l was required for complete killing. Accordingly, CA(1-8)M(1-18) showed good in vitro activity against the A. baumannii strains tested irrespective of the resistance to classical antibiotics, and could be a future candidate for multiresistant A. baumannii infections, although further cytotoxicity and pharmacological studies will be needed.

Actividad in vitro de CA(1-8)M(1-18), un péptido sintético híbrido cecropina A-melitina, frente a aislamientos clínicos multirresistentes de Acinetobacter baumannii / In vitro activity of CA(1-8)M(1-18), a synthetic cecropin A-melittin hybrid peptide, against multiresistant Acinetobacter baumannii strains

El objetivo de este estudio fue determinar la actividad in vitro de CA(1-8)M(1-18), un péptido sintético híbrido cecropina A-melitina, frente a aislamientos clínicos multirresistentes de Acinetobacter baumannii. Se estudió la CMI en 20 aislamientos clínicos de A. baumannii con diferente perfil de resistencia, mediante microdilución en caldo, obteniéndose CMI50 = 4 mg/l, CMI90 = 4 mg/l e intervalo de 2 a 8 mg/l. En la cepa control se ensayó el efecto de diferentes factores, como el material de la placa de microdilución (poliestireno o polipropileno), el suplemento (5 por ciento o 10 por ciento de suero fetal bovino o 5 por ciento de sangre de caballo), el tamaño del inóculo (105, 106, 107 y 108 UFC/ml) y el periodo de incubación (24 o 48 h). La CMI fue similar en los dos tipos de placas de microdilución utilizadas e independiente del suplemento con suero fetal bovino o sangre de caballo; sin embargo, se observó un aumento del valor al utilizar un inóculo elevado o incubación prolongada. La actividad se determinó mediante curvas de muerte a diluciones dobles seriadas del péptido de 45,7 mg/l a 2,8 mg/l (16 a 1 mM) de CA(1-8)M(1-18) en la cepa control y en una cepa multirresistente, con un inóculo inicial de 105-106 UFC/ml y de 109-1010 UFC/ml. Se observó muerte completa de todos los microorganismos a una concentración de 45,7 mg/l. CA(1-8)M(1-18) mostró buena actividad in vitro frente a los aislamientos de A. baumannii probados independientemente del patrón de resistencia a los antimicrobianos clásicos, y podría ser un futuro candidato para tratar infecciones por A. baumannii multirresistente, aunque serán necesarios estudios farmacológicos y de toxicidad (AU)