Schistosomiasis mansoni and soil-transmitted helminthiasis in Bushulo village, southern Ethiopia

Background: Schistosomiasis mansoni and soil-transmitted helminthiasis (STHs) are considerable medical and public health problems in Ethiopia. However, information is limited on the epidemiology of these infections in different localities even though it is needed to plan effective prevention and control measures. Objective: This study was designed to determine the prevalence of Schistosoma mansoni and soil-transmitted helminth infections in school children and residents in Bushulo village near Lake Awassa (Hawassa), southern Ethiopia. Methods: Cross-sectional epidemiological and parasitological studies were conducted on schistosomiasis mansoni and STHs in Bushulo village in May and June 2007. A total of 419 participants (353 school children and 66 other residents) were included in the study. The principal investigator interviewed the study subjects about demographic status using structured questionnaires. Moreover, experienced nurse took history and conducted physical examination to assess symptoms and signs related to chronic S. mansoni infection. A single stool sample was collected from each participant and processed using the Kato-Katz technique. Experienced laboratory technician read all slides at Bushulo Health Center. Results: The overall infection rates of schistosomiasis mansoni, trichuriasis, ascariasis and hookworm infection were 73.7%, 41.5%, 37.2% and 28.4%, respectively. Other parasitic infections observed were caused by Hymenolepis nana (1.7%), Taenia species (1.4%), and Enterobius vermicularis (1.4%). Children in the age range 10-14 years and those attending at St. Paul’s School had higher rates of T. trichiura and S. mansoni, respectively. Intensity of infection was higher for A. lumbricoides in the age range 5-9 years. The overall prevalence of any STHs was 67.3%. The rates of single, dual, triple and quadruple infections were 29.6%, 32%, 20.3% and 7.4%, respectively. Conclusion: The high prevalence and intensity of schistosomiasis mansoni and soil-transmitted helminthiasis makes periodic deworming programme urgent to reduce morbidity and transmission of helminthiasis in the area. Provisions of sanitary facilities and clean water supply as well as health education are also critically needed to sustain the impact of chemotherapy

A bis-calixarene from olefin metathesis

A ring-closing olefin metathesis reaction of tetra­kis­(all­yl­oxy)calix[4]arene gave the bis­ calixarene, (15E,40E,60E)-65,74-bis­(prop-2-en-1-yl­oxy)-13,18,38,43,58,63-hexa­oxado­deca­cyclo­[28.26.8.720,36.111,45.151,55.05,57.07,12.019,24.026,64.032,37.044,49.168,72]tetra­hepta­conta-1,3,5(57),7,9,11,15,19(24),20,22,26,28,30(64),32,34,36,40,44(49),45,47,51,53,55(65),60,68,70,72(74)-hepta­cosa­ene, C74H68O8. It is a cage formed from two calix[4]arene units joined by butenyl groups at three of the O atoms on the narrow rim. The fourth O atom on each calixarene unit is joined with an allyl group. Each of the calix[4]arene units has a flattened cone conformation in which the all­yloxy-substituted aryl group and the opposite aryl group are close together and almost parallel [dihedral angle between planes = 1.09 (11)°], and the other two aryl groups are splayed outward [dihedral angle between planes = 79.53 (11)°]. No guest mol­ecule (e.g. solvent) was observed within the cage. The alkene C atoms of one of the links between the calixarene moieties are disordered over two orientations with occupancies of 0.533 (9) and 0.467 (9)

Crystal structure of a mono-bridged calix[4]arene

The title compound, 52-[(5-bromopentyl)oxy]-12,114,35,55-tetra-tert-butyl-17,18,19,110-tetrahydro-16H,116H-1(4,12)-dibenzo[b,e][1,7]dioxacyclododecina-3,5(1,3)-dibenzenacyclohexaphan-32-ol, C54H73BrO4, was synthesized from the reaction of tert-butylcalix[4]arene with 1,5-dibromopentane using K2CO3 in CH3CN. The structure consists of a calixarene unit with a five-carbon bridge connecting two proximal phenolic O atoms, and with a bromopentoxy chain on one of the remaining phenolic O atoms. The calixarene unit was found to have a flattened cone conformation with no solvent (or other guest) molecule observed in the cavity. Two of the opposite phenyl rings lean outwards with fold angles of 136.2 (1) and 133.0 (1)° between the rings and the plane of the bridging methylene C atoms, while the other two opposite rings form fold angles of 83.27 (9) and 105.46 (9)°. There is considerable disorder in this molecule. One of the tert-butyl groups is disordered over two conformations with occupancies of 0.527 (5) and 0.473 (5). The bromopentoxy chain is disordered over three configurations with occupancies of 0.418, 0.332 and 0.250. The five-carbon bridge connecting two proximal phenolic O atoms is disordered over two conformations with occupancies of 0.537 (7) and 0.463 (7)

Evaluation of Auramine O staining and conventional PCR for leprosy diagnosis: A comparative cross-sectional study from Ethiopia.

BACKGROUND:Diagnosis of leprosy mainly relies on clinical examination due to the inconsistent sensitivity and poor reproducibility of the current laboratory tests. Utilisation of alternative methods to the standard Ziehl Neelsen (ZN), Fite-Faraco (FF) and Haematoxylin and Eosin (H&E) staining procedures may eventually improve leprosy diagnosis. METHODOLOGY/PRINCIPAL FINDINGS:In this comparative study, the performance of the fluorescent Auramine O (AO) staining and polymerase chain reaction (PCR) was assessed with different skin samples using a combination of ZN, FF and H&E staining as the gold standard. AO, ZN, FF, H&E and PCR tests were performed on slit skin smears (SSS) and/or punch biopsies collected from 141 clinically confirmed leprosy cases and 28 non-leprosy skin samples. DNA was extracted from punch biopsies using two different methods with or without mechanical lysis. Sensitivities were 87.6%, 59.3% and 77% for H&E, ZN and FF, respectively, whereas it reached 65.5% and 77.9% for AO in SSS and tissue sections and 91.1% for PCR in tissue samples. Morover, samples with low bacillary index, sensitivity of AO staining (61.8%) was similar to FF (60%, p>0.05) and lower than PCR (86.6%, p<0.05). Sensitivity of PCR also increased (96.8%, p<0.05) when mechanical lysis was used during DNA extraction compared to enzymatic treatment alone (84.6%). CONCLUSIONS/SIGNIFICANCE:Our results showed that for diagnostic purposes, analysis of skin section is more sensitive than SSS, especially for samples with low bacillary load. AO staining on SSS and tissue sections was not significantly better than other routine diagnostic tests but considerably more user friendly. The sensitivity of PCR was higher than current standard methods and increased when combined with more efficient DNA extraction using mechanical and chemical lysis. Therefore, we recommend AO staining for the diagnosis of leprosy in lower health facilities such as health centres and district hospitals and PCR diagnosis at referral level and research centres