Search

Abstract: Despite the common occurrence of ascariasis in southwestern Uganda, helminth control in the region has been limited. To gain further insights into the genetic diversity of Ascaris in this area, a parasitological survey in mothers (n=41) and children (n=74) living in two villages, Habutobere and Musezero, was carried out. Adult Ascaris worms were collected from infected individuals by chemo-expulsion using pyrantel pamoate treatment. Genetic diversity within these worms was assessed by inspection of DNA sequence variation in a mitochondrial marker and length polymorphism at microsatellite loci. Overall prevalence of ascariasis was 42.5% in mothers and 30.4% in their children and a total of 98 worms was examined from 18 hosts. Sequence analysis of a portion of the mitochondrial cytochrome c oxidase subunit 1 gene revealed 19 different haplotypes, 13 of which had not been previously encountered. Microsatellite analysis using eight loci provided evidence for high gene flow between worm populations from the two villages but comparing these worms with others obtained in a prior study on Unguja, Zanzibar, confirmed little genetic exchange and mixing of worm populations between the two areas. By adding to our understanding of the genetic diversity of Ascaris in Africa, this study provides useful information for monitoring changes in parasite population structure in the face of ongoing and future control. [Copyright &y& Elsevier]

Background: Combination therapies are now recommended to treat uncomplicated malaria. We used a longitudinal design to assess the incidence of malaria and compare the efficacies of 3 combination regimens in Kampala, Uganda. Methodology/Principal Findings: Children aged 1-10 years were enrolled from randomly selected households in 2004-05 and 2007, and were followed at least monthly through 2008. Insecticide-treated bednets (ITNs) were provided in 2006. Children were randomized upon their first episode, and then treated for all episodes of uncomplicated malaria with amodiaquine/sulfadoxine-pyrimethamine (AQ/SP), artesunate/amodiaquine (AS/AQ), or artemether/lumefantrine (AL). Risks of parasitological failure were determined for each episode of uncomplicated malaria and clinical parameters were followed. A total of 690 children experienced 1464 episodes of malaria. 96% of these episodes were uncomplicated malaria and treated with study drugs; 94% were due to Plasmodium falciparum. The rank order of treatment efficacy was AL > AS/AQ > AQ/SP. Failure rates increased over time for AQ/SP, but not the artemisinin-based regimens. Over the 4-year course of the study the prevalence of asymptomatic parasitemia decreased from 11.8% to 1.4%, the incidence of malaria decreased from 1.55 to 0.32 per person year, and the prevalence of anemia (hemoglobin <10 gm/dL) decreased from 5.9% to 1.0%. No episodes of severe malaria (based on WHO criteria) and no deaths were seen. Conclusions/Significance: With ready access to combination therapies and distribution of ITNs, responses were excellent for artemisinin-containing regimens, severe malaria was not seen, and the incidence of malaria and prevalence of parasitemia and anemia decreased steadily over time. [ABSTRACT FROM AUTHOR]

Abstract  The Mansonella perstans microfilarial (mf) periodicity in peripheral blood was analysed in a group of 32 healthy individuals from an endemic community in Uganda. The majority of individuals had maximum mf intensity during the first and minimum during the last 12 h of the day. Mean mf ratios (i.e. time-specific counts in relation to mean count for the individual) indicated a weak but significant diurnal periodicity with peak intensity around 0800 h. Trigonometric analysis of the ratios, assuming a harmonic wave pattern of periodicity, gave a periodicity index of 11.1 and a peak time of 0645 h. The higher mf intensities in the early morning appeared to coincide with the preferred biting hour of the vectors. The observed weak pattern of mf periodicity indicates that the sampling time of blood specimens for diagnosis will have only minor effect on diagnostic sensitivity. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates on the host, macrohabitat and microhabitat specificity in the gill parasite Afrodiplozoon polycotyleus or Monogenea. The occurences of four species of the parasite were compared. The study was conducted in and around Kibale National Park in western Uganda.

Objective To determine, through the use of molecular diagnostic tools, whether the two species of parasite that cause human African trypanosomiasis have become sympatric. Design Blood sampling of all available patients between June 2001 and June 2005 in central Uganda and between July and September 2003 in northwest Uganda and analysis of subcounty sleeping sickness records in Uganda between 1985 and 2005. Setting Sleeping sickness treatment centres in central and northwest Uganda and in south Sudan. Participants Patients presenting at the treatment centres and diagnosed as having sleeping sickness. Main outcome measure Classification of parasites from patients from each disease focus as either Trypanosoma brucei rhodesiense (acute form) or T b gambiense (chronic form). Results Blood from 231 patients with sleeping sickness in central Uganda and from 91 patients with sleeping sickness in northwest Uganda and south Sudan were screened for T b rhodesiense (detection of SRA gene) and T b gambiense (detection of TgsGP gene). All samples from central Uganda were classified as T b rhodesiense, and all samples from northwest Uganda and south Sudan were identified as T b gambiense. Conclusions The two focuses of human African trypanosomiasis remain discrete, but the area of Uganda affected by the acute form of human sleeping sickness has increased 2.5-fold since 1985, spreading to three new districts within the past five years through movement of infected livestock. Without preventive action targeted at the livestock reservoir of this zoonotic disease, it is likely that the two disease focuses will converge. This will have a major impact on diagnosis and treatment of this neglected disease. Real time monitoring is recommended, using molecular diagnostic tools (at a regional surveillance centre, for example) targeted at both livestock and human patients. [ABSTRACT FROM AUTHOR]

Investigates the gastrointestinal parasites of the Colobus monkeys of Uganda. Collection of samples; Determination of the prevalence of gastro-intestinal parasites; Detection of nematodes.

Intestinal schistosomiasis caused by infection with Schistosoma mansoni is a widespread public health problem in Uganda. Although long known to be endemic, its current distribution within the country requires updating of parasitological data to help guide planned control. We report such data collected between 1998 and 2002 from 201 schools and 68 communities across Uganda. In accordance with epidemiological expectation, prevalence and intensity increased with age, peaking at 10-20 years and thereafter declined moderately with age, whereas intensity declined more rapidly with age, and the prevalence of infection in a school was non-linearly related to the mean intensity of infection. We used geographical information systems to map the distribution of infection and to overlay parasitological data with interpolated environmental surfaces. The derived maps indicate both a widespread occurrence of infection and a marked variability in infection prevalence, with prevalence typically highest near the lakeshore and along large rivers. No transmission occurred at altitudes >1400 m or where total annual rainfall was <900 mm; limits which can help estimate the population at risk of schistosomiasis. The results are discussed in reference to the ecology of infection and provide an epidemiological framework for the design and implementation of control efforts underway in Uganda. [ABSTRACT FROM AUTHOR]