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Tsetse fly saliva biases the immune response to Th2 and induces anti-vector antibodies that are a useful tool for exposure assessment
No full textTsetse flies (Glossina sp.) are blood-feeding dipteran insects that transmit African trypanosomes, parasites that are responsible for human sleeping sickness and veterinary infections. Increasing attention is being paid to the effects of tsetse fly saliva deposited at the feeding site, which enables the blood-feeding process and putatively promotes parasite transmission. Here we demonstrate that saliva induces strong humoral responses against the major 43-45 kDa protein fraction (tsetse salivary gland proteins 1 and 2 - Tsal1 and Tsal2) in mice and humans and suppresses murine T and B cell responses to heterologous antigen. The saliva-induced immune response is associated with a Th2-biased cytokine profile and the production of mainly IgG1 and IgE antibody isotypes. Functionally, the antibodies raised in mice exposed to tsetse fly bites or induced after experimental saliva immunisation do not affect the fly's blood-feeding efficiency nor its survival. We propose that anti-saliva as well as anti-Tsal1/2 antibody responses can be used in epidemiological studies as a tool to analyze human exposure to tsetse flies
In-vitro susceptibility of Plasmodium falciparum to monodesethylamodiaquine, dihydroartemisinin and quinine in an area of high chloroquine resistance in Rwanda
No full textPlasmodium falciparum in-vitro susceptibility to chloroquine (CQ), monodesethylamodiaquine, quinine and dihydroartemisinin was investigated in Rwandan patients with a parasitaemia of at least >or=4000/microl. The study was carried out in November-December 2003. Dihydroartemisinin was the most potent (GM IC(50)=2.6nmol/l, 95% CI 2.2-3.2) among the drugs tested. Resistance to chloroquine was 45% (33/74) and that to monodesethylamodiaquine 7% (5/74). All the tested isolates were susceptible to quinine. The mean IC(50) of monodesethylamodiaquine, quinine and dihydroartemisinin was significantly higher for chloroquine-resistant than for chloroquine-sensitive strains (P<0.05). The IC(50) of each drug was significantly and positively correlated to that of the other three drugs (P<0.005), and this correlation was higher between CQ and monodesethylamodiaquine (r=0.8). In-vitro CQ resistance is linked to that of the other drugs tested. Most worrying is the positive correlation between the IC(50) of dihydroartemisinin and the other drugs, more particularly with CQ, suggesting an increased tolerance of the parasites to all drugs
Prevalence and risk factors of intestinal parasites in Cuban children
No full textThe definitive version is available at www3.interscience.wiley.comOBJECTIVES: To determine the prevalence of intestinal parasite infections and their risk factors in children in urban and rural settings in two Cuban municipalities. METHODS: A total of 1320 Cuban schoolchildren aged 4-14 were tested by stool examination for intestinal parasite infections and evaluated by parental questionnaire for a number of common environmental, sanitary, socioeconomic and behavioural risk factors. Multivariate regression was applied to examine the relationship between the respective parasite infections and the risk factors. RESULTS: Prevalences of intestinal parasite infections were 58% in Fomento and 45% in San Juan y Martínez; for helminth infections, these were 18% and 24% and for protozoa infections, 50% and 29%, respectively. Helminth infections were associated with high parental education (maternal: OR 0.68, CI 0.50-0.93; paternal: OR 0.71, CI 0.52-0.96), absence of toilet (OR 1.57, CI 1.12-2.19), consumption of water from a well or river (OR 0.56, CI 0.41-0.77) and eating unpeeled/unwashed fruit (OR 1.37, CI 1.01-1.87); protozoa infections were only associated with high maternal education (OR 0.72, CI 0.57-0.91). CONCLUSIONS: Paediatric intestinal parasite infections are still prevalent in certain areas in Cuba and associated with a number of common environmental, socioeconomic and sanitary risk factors
Reciprocal antibody and complement responses of two chicken breeds to vaccine strains of Newcastle disease virus, infectious bursal disease virus and infectious bronchitis virus
No full textSerum antibody responses and haemolytic complement activity were evaluated in White Leghorn (WLH) and Rhode Island Red (RIR) chickens that were vaccinated with live-attenuated vaccines of Newcastle disease virus, or infectious bronchitis virus, or infectious bursal disease virus by means of ocular challenge at 10 times the normal vaccination dose. Complement titres in non-vaccinated birds were significantly higher in WLH birds compared to RIR birds. The lentogenic viral infection resulted in an immediate stimulation of complement activity, followed by a decrease to initial complement levels within 2 weeks post vaccination, when the antibody response took over immune defence. As compared to WLH chickens, RIR birds mounted a faster and significantly higher antibody response to the vaccine viruses used. In WLH hens, significantly higher haemolytic complement activity post vaccination was found as compared to RIR hens. Possible consequences of the observed differences in immune responsiveness of the two breeds to viral vaccines are discussed
First chronic wasting disease (CWD) surveillance of roe deer (Capreolus capreolus) in the northern part of Belgium
No full textCases of chronic wasting disease (CWD) in wild cervids have yet not been reported in Europe, whereas the disease is considered enzootic in free-ranging mule deer, Rocky mountain elk and white-tailed deer in the area of Colorado, Wyoming, and Nebraska. New foci of CWD continue to be detected in other parts of the United States. However, no large-scale active epidemiosurveillance of European wild cervids is yet installed in Europe. In accordance with the opinion of the European Scientific Steering Committee, a preliminary (active) surveillance scheme was installed, in order to improve the knowledge of the CWD status of wild cervids (roe deer) in the Northern part of Belgium. Spleen samples (n=206) and brain samples (n=222) of roe deer collected in the Northern part of Belgium, were examined for CWD using the antigen-capture enzyme-linked immunoassay (EIA) of IDEXX. Afterwards, the EIA was systematically confirmed by immunohistochemistry using three antibodies, namely R524, 2G11 and 12F10. There were no indications on the occurrence of TSE in any of the samples. A Bayesian framework was used for the estimation of the true prevalence of CWD in the Northern part of Belgium that was estimated to have a median value of zero with a 95th percentile value of 0.0049 and 0.0045 for spleen and brain samples respectively
Comparison of the transmissibility of Trypanosoma congolense strains, isolated in a trypanosomiasis endemic area of eastern Zambia, by Glossina morsitans morsitans
No full textTransmission experiments were conducted to compare the transmissibility of genetically different Trypanosoma congolense (Savannah subgroup) strains isolated from cattle in a trypanosomiasis endemic area of eastern Zambia. A total of 17 strains were compared. Three strains were extremely virulent with a short pre-patent period, high parasitaemia and a short median survival time (between 5 and 9 days) in mice. The remainder of the strains belonged to the moderate (6 strains) or low (8 strains) virulence categories with median survival times between 10 and 30 days and >30 days, respectively. Batches of 40 teneral Glossina morsitans morsitans (Diptera: Glossinidae) were offered a single bloodmeal on mice infected with one of those strains. Flies were dissected to determine their infection status 21 days later. The proportion of flies with procyclic and metacyclic infections differed significantly between trypanosome strains and were significantly higher in flies infected with extremely virulent strains (P=0.033 and P=0.016 for the differences in the procyclic infection rate of strains with moderate and low virulence, respectively and P=0.005 and P=0.019 for the differences in the metacyclic infection rate of strains with moderate and low virulence, respectively). On the other hand, moderately virulent strains had, in general, higher procyclic and metacyclic infection rates compared to low virulent strains. But the differences were not significant (P>0.05). The outcome of those experiments shows clear differences in transmissibility of trypanosome strains associated with their virulence. This observation confirms the theory for the evolution and maintenance of virulence in a parasite population and may explain the persistence of virulent trypanosome strains in a susceptible host population
Mefloquine-induced pneumonitis
No full textThe definitive version is available at www3.interscience.wiley.comMefloquine is indicated as oral treatment and as prophylaxis for malaria in areas where chloroquine-resistant malaria is present. Gastrointestinal and neuropsychiatric side effects of mefloquine are well known. More severe neuropsychiatric disorders such as psychosis, depression, hallucinations, and seizures are also reported in the literature. We are reporting a case of drug-induced pneumonia due to mefloquine. This diagnosis was confirmed 4 months after the adverse event, after restarting the same malaria prophylaxis, which could be considered as an unintentional provocation test. This is the third case report in the literature of acute lung injury caused by mefloquine
Demographic and clinical characteristics of HIV-infected inpatients and outpatients at a Cambodian hospital
No full textA retrospective cross-sectional survey of 299 HIV-infected inpatients and outpatients was conducted between March 1999 and June 2000 in Phnom Penh, Cambodia, to define patient demographics and risk factors for HIV-1 infection, and to compare whether symptoms and opportunistic infections (OIs) differ by gender and site of patient care. The population represented one third of HIV-infected patients regularly receiving care at the Sihanouk Hospital Center of HOPE. Over one quarter (26%) of the men were soldiers and 27% were farmers or laborers. Eighty-nine percent of the men had visited sex workers, 29% of men and women had unsafe injections in the past, and 18% of women reported a spouse who was HIV-positive. Eighty percent of patients presented with weight loss more than 10% from baseline. Seventy-two percent of patients were diagnosed with two or more concurrent OIs or conditions. Oral candidiasis (p = <0.001), abdominal lymphadenitis (p = 0.03), and two or more concurrent OIs (p = <0.001) were diagnosed more often among men than women. Multivariate logistic regression shows that patients who presented with weight loss more than 10% from baseline are more likely to have one or more OIs or conditions. The results of this survey suggest that the primary risk factor for HIV-infected men presenting to this care facility was visiting sex workers. The pattern of OIs and other HIV-associated conditions indicated that the majority of patients delayed seeking care at the hospital. HIV physicians in Cambodia should be aware of the likelihood for multiple OIs or conditions when patients present weight loss more than 10% from baseline
Validité, coût et faisabilité de la mAECT et CTC comme tests de confirmation dans la détection de la Trypanosomiase Humaine Africaine
No full textThe definitive version is available at www3.interscience.wiley.comOBJECTIVES: To evaluate the validity, cost and feasibility of two parasitological tests for the confirmation of Human African Trypanosomiasis (HAT): the mini Anion-exchange Centrifugation Technique (mAECT) and Capillary Tube Centrifugation (CTC). METHODS: During a sleeping sickness screening campaign in 2004 we screened 6502 people in Kwamouth, DRC. Those with a positive result in the Card Agglutination Test for Trypanosomiasis (CATT) had a gland puncture, fresh blood examination, stained thick blood film, mAECT, CTC and CATT titration. Sensitivity and specificity of the confirmation tests were calculated using the combination of all parasitological tests as a reference standard. Each method was costed and its feasibility was assessed with structured interviews of the technicians. RESULTS: Sensitivity of classical parasitological methods was 44.8% (36.8-53.0), of CTC 56.5% (48.3-64.5) and of mAECT 75.3% (95% CI: 67.7-81.9). Cost per test was 2.82 Euro for mAECT and 0.76 Euro for CTC. Time per test was 29.78 min for mAECT and 18.25 min for CTC. These two tests were judged feasible in field conditions. CONCLUSION: CTC and mAECT used alone or in combination would bring a considerable improvement to HAT active case finding when used as confirmation tests in CATT-whole blood-positive persons. They proved feasible in operational conditions if a 220 V power supply can be guaranteed. As mAECT is more sensitive but also considerably more expensive, efficiency as well as feasibility considerations will have to guide the choice of the best algorithm
Integrating refugee and host health services in West Nile districts, Uganda
No full textThis is a pre-copy-editing, author-produced PDF of an article accepted for publication in Health Policy and Planning following peer review. The definitive publisher-authenticated version Orach CG, De Brouwere V. Health Policy Plan. 2006 Jan;21(1):53-64 is available online at: http://heapol.oxfordjournals.org/cgi/content/full/21/1/53.Refugees are a common feature in Africa and Uganda is no exception. However, Uganda does not have the resources to provide health care to all its own citizens, let alone to refugees. Refugee health services are therefore usually set up and provided separately by international organizations such as the United Nations High Commissioner for Refugees (UNHCR). However, such services often end up being the only available or reliable services in a particular location for both host and refugee populations. Yet the host populations are often denied access to these services because, in theory, other services are being provided by their government. The case study in the West Nile region of Uganda describes how host and refugee services were integrated in an attempt to address the concerns of inequity of access to care for host populations, when reasonably good health services were available to nearby refugee populations. The paper identifies and discusses the challenges encountered and those remaining