Risk factors of visceral leishmaniasis: a case control study in north-western Ethiopia

Background Visceral leishmaniasis (VL, also called “kala-azar”), is a life threatening neglected tropical infectious disease which mainly affects the poorest of the poor. VL is prevalent in Ethiopia particularly in the northwest of the country. Understanding the risk factors of VL infection helps in its prevention and control. The aim of the present study was to identify the factors associated with VL. Methods A case–control study was carried out during the period of January-July 2013 in northwest Ethiopia. Cases and controls were diagnosed using clinical presentation, the rk39 rapid diagnostic test and Direct Agglutination Test (DAT). A total of 283 (84.8% males versus 15.2% females) participants were interviewed. 90 cases and 193 controls were involved, matched by age, sex and geographical location with a ratio of 1:2 (case: controls). Univariate and backward multivariate conditional logistic regression were used to identify risk factors of VL. Results Elevated odds of VL was associated with goat ownership (OR = 6.4; 95%: confidence interval [Cl]: 1.5-28.4), living in houses with cracked wall (OR = 6.4; 95% Cl: 1.6-25.6), increased family size (OR = 1.3; 95% Cl: 1.0-1.8) and the number of days spent in the farm field (OR = 1.1; 95% Cl: 1.0-1.2). However, daily individual activities around the home and farm fields, mainly sleeping on a bed (OR = 0.2; 95%: Cl 0.03-0.9), sleeping outside the house under a bed net (OR = 0.1; 95% Cl: 0.02-0.36)] and smoking plant parts in the house during the night time (OR = 0.1; 95% Cl: 0.01-0.6) were associated with decreased odds of being VL case. Conclusion Our findings showed that use of bed net and smoke could be helpful for the prevention of VL in the area particularly among individuals who spend most of their time in the farm. VL control effort could be focused on improving housing conditions, such as sealing cracks and crevices inside and outside houses. Further research is warranted to elucidate the role of goats in the transmission of L. donovani, assess the impact of bed nets and the role of the traditional practice of smoking plants

Peritrophic matrix of Phlebotomus duboscqi and its kinetics during Leishmania major development

Light microscopy of native preparations, histology, and electron microscopy have revealed that Phlebotomus duboscqi belongs to a class of sand fly species with prompt development of the peritrophic matrix (PM). Secretion of electron-lucent fibrils, presumably chitin, starts immediately after the ingestion of a blood meal and, about 6 h later, is followed by secretion of amorphous electron-dense components, presumably proteins and glycoproteins. The PM matures in less than 12 h and consists of a thin laminar outer layer and a thick amorphous inner layer. No differences have been found in the timing of the disintegration of the PM in females infected with Leishmania major. In both groups of females (infected and uninfected), the disintegration of the PM is initiated at the posterior end. Although parasites are present at high densities in the anterior part of the blood meal bolus, they escape from the PM at the posterior end only. These results suggest that L. major chitinase does not have an important role in parasite escape from the PM. Promastigotes remain in the intraperitrophic space until the PM is broken down by sand-fly-derived chitinases and only then migrate anteriorly. Disintegration of the PM occurs simultaneously with the morphological transformation of parasites from procyclic forms to long nectomonads. A novel role is ascribed to the anterior plug, a component of the PM secreted by the thoracic midgut; this plug functions as a temporary barrier to stop the forward migration of nectomonads to the thoracic midgut

A description of the female of

Description is given for the previously unknown female of Phlebotomus (Larroussius) fantalensis from Ethiopia. Supplementary descriptive notes are also given on its male and the related P.(L.) gibiensis with illustrations of their spermathecae/ducts and aedeagi which show morphological and size variation between the two species

Detection of Plasmodium falciparum sporozoites in naturally infected anopheline species using a fluorescein-labelled DNA probe

A dot blot hybridization method was developed to detect Plasmodium falciparum sporozoites in naturally infected mosquitoes. A fluorescein-labelled oligomer was used as a probe. Initial non-specific hybridization was found to correlate with the presence of blood in the mosquitoes. This was eliminated by allowing digestion of the engorged blood by keeping the mosquitoes in cages for 48 h before processing. The limit of detection of the hybridization assay was estimated to be about 500 sporozoites. The assay was evaluated on 198 indoor resting blood fed female Anopheles gambiae s.l mosquitoes collected from three malaria hypo- and meso-endemic areas in Ethiopia. An application of the polymerase chain reaction (PCR) amplifying a fragment of the K1-14 gene of P. falciparum was used as a reference method. P. falciparum sporozoites were detected in four specimens (2%) by hybridization assay and by PCR alike. The results of this study indicate that the hybridization method can be potentially valuable in large scale epidemiological studies for detection of P. falciparum sporozoites in naturally infected anopheline species

Control of Schistosoma Mansoni by the Soapberry Endod (Phytolacca Dodecandra) in Wollo, North eastern Ethiopia: Post-intervention prevalence

Objectives: To record the effect of Endod soap and spraying of soaked Endod suspension on the prevalence of human schistosomiasis. Design: A cross-sectional epidemiological study in which pre- and post-intervention parasitological results were compared. Setting: Kemise, Bati and Harbu towns in northeastern Ethiopia. Subjects: The study subjects included all members of the five per cent households systematically selected from the three towns. Results: In Kemise town, where suspension of ground Endod was sprayed on the stream containing infected snails, the prevalence of the disease was reduced from 59% to 53% and the mean intensity of infection was reduced from 239 eggs per gram (EPG) of faeces to 99 EPG (p < 0.05). In Bati town where Endod soap approach was used, the respective reduction in the prevalence and intensity of infection was from 51% to 43% and from 195 EPG to 162 EPG (