Epidemiological investigations on Trypanosoma evansi infection in dromedary camels in the South of Algeria

An epidemiological study of Trypanosoma evansi (T. evansi) infection in dromedaries was conducted in four wilayate (localities) of Southern Algeria: Béchar, El Bayadh, Ouargla, Tamanrasset. Between February 2014 and April 2016, 1056 camels of different ages and both sexes from 84 herds were sampled. The prevalence was determined through parasitological examination (Giemsa stained thin smear, GST), serological tests (CATT/T. evansi, ELISA/VSG RoTat 1.2, immune trypanolysis), and molecular tests (T. evansi type A specific RoTat 1.2 PCR and T. evansi type B specific EVAB PCR). The overall prevalence was 2.4 % with GST, 32.4% with CATT/T. evansi, 23.1% with ELISA/VSG RoTat 1.2, 21.0% with immune trypanolysis (TL), 11.2 % with RoTat 1.2 PCR and 0% with EVAB PCR. El Bayadh was the most affected wilaya with 11.8% positives in GST, 74.9% in CATT/T. evansi, 70.1% in ELISA/VSG RoTat 1.2 and 62.2% in immune trypanolysis. Only in Béchar, a non-significantly higher prevalence (13.6%) was observed with RoTat1.2 PCR than in El Bayadh (13.0%). We didn't find any evidence of the presence of T. evansi type B in the study area.

Fortuitous Detection of cmy-2 and dha-1 from ESBL-producing Escherichia coli in Senegal

Cephalosporinases, which are naturally present in some enterobacterial species, can be mobilized by transposons, migrate to plasmids, and spread into other species such as Escherichia coli. The aim of this study was to characterize genes responsible for the production of extended-spectrum β-lactamases (ESBL) in E. coli isolates from urinary origin isolated in two hospitals in Senegal. Thus, a fortuitous discovery of plasmidic cephalosporinase in two isolates was noted. One of the isolates produced dha-1 associated with ESBL CTX-M-14, the other produced cmy-2, ESBL CTXM-15, tem-1 penicillinase, and oxa-1. This confirms the circulation of multidrug-resistant bacteria producing plasmidic cephalosporinase in Senegal. However, a large study is needed to better understand the prevalence and the nature of the genes involved.

Molecular detection of CTX-M-15-type β-lactamases in Escherichia coli strains from Senegal

We aimed to detect the extended-spectrum β-lactamases (ESBLs) secreted by clinical strains of Escherichia coli at Fann University Hospital in Dakar and to characterize them molecularly. We identified 32 isolates producing ESBLs. The CTX-M-15 gene was the most frequently detected ESBL gene, detected in 90.63% of the isolates studied.

Urinary tract infection with Corynebacterium aurimucosum after urethroplasty stricture of the urethra: a case report

Introduction

Corynebacteria have an important place among the commensal flora of the skin and mucous membranes. Except for Corynebacterium diphtheriae, they were once considered contaminants of mucosa. Recent publications in medical bacteriology have highlighted the importance of several species, such as C. aurimucosum. To the best of our knowledge, we report the first isolation of this strain from urine.

Case presentation

We report a case of a patient with a urinary tract infection with C. aurimucosum. We isolated this bacterium from a 52-year-old man of Wolof ethniticity (an ethnic group in Senegal, West Africa) at the regional hospital of Saint Louis, Senegal. Microscopic examination of his total urine sample showed coryneform Gram-positive bacilli associated with a high leukocyte reaction. After repeated isolation of the corynebacteria in three samples from the patient’s urine, it was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The strain was susceptible to antibiotics, except for penicillin and co-trimoxazole. The potential infectious role of these commensal species in several infections should be taken into consideration.

Conclusions

This case highlights the significant proportion of species in the genus Corynebacterium other than dyphteriae in the infectious process. The use of mass spectrometry for identification highlights the originality of this work and the importance of these new diagnostic tools that are unavailable in most health facilities of countries with limited resources. We share the results of our method of identification of the isolated bacteria. This case should prompt attention to these rare bacteria, which can cause severe infections.

[Parasitic and bacterial etiologies of diarrhea among people living with HIV hospitalized in Fann hospital (Senegal)]

Diarrhea is the most common opportunistic infection in AIDS. We conducted at the Fann National University Hospital in Dakar, a study of all patients living with HIV, hospitalized in the the Clinical service of Infectious Diseases from 1 January 2003 to December 31, 2006, with diarrhea and having received an bacteriological and / or a parasitological examination of stools. The aim of this study was to identify the various pathogens isolated in the laboratory and responsible for those diarrhea. In total, 351 patients were collected, their average age was 39.93 years and the extreme ages 15 and 72 years. HIV1 serological profile was found in 90.77% of patients; 34.42% of patients received a dosage of CD4 count, among them 21.09% had a rate <200/mm3. Fifteen stool cultures were positive with the following breakdown: - Shigella (10 strains): 7 strains of Shigella flexneri, 2 of Shigella sp, one of Shigella sonnei; antibiotics most active on the Shigella strains were third generation cephalosporins and quinolones. - Salmonella (5 strains) with Salmonella Typhimurium and Salmonella Enteritidis, strains sensitive to an association of amoxicillin + clavulanic acid, to cephalosporins and to ciprofloxacin. 289 patients received a parasitological examination of the stools (KOP) and the positive number of KOP was 90 a 30,14% rate. The parasites most frequently found were: Cryptosporidium parvum, representing 10.38% of positive KOP, Isospora belli 6.23%, and Entamoeba coli 5.19%. These parasites were found predominantly in patients infected with HIV1 (61 cases/90). Cases of cobacterial and parasitic co-infections were also found. Diarrhea is one of the leading causes of death among people living with HIV. The etiologies of diarrhea, multiple, are yet to be identified and this should go through an improvement of the technical capacity and quality of our laboratories.

[Nontyphoidal Salmonella bacteremia cases in AIDS patients in a Dakar University Hospital (Senegal)]

OBJECTIVES

This study had for aim to describe epidemiological, clinical and bacteriological aspects of nontyphoidal Salmonella bacteremia in patients with AIDS in the Dakar University Hospital Infectious Diseases Clinic.

METHOD

This study was made on data recorded between 1January1996 and 31December2005. The strains were identified according to biochemical (API 20E, BioMérieux) and antigenic features. Their susceptibility to antibiotic drugs was tested by antibiogram. Screening for strains secreting of an extended-spectrum betalactamase was performed.

RESULTS

Sixty-two cases of nontyphoidal Salmonella bacteremia were recorded in AIDS patients as follows: Salmonellaenteritidis bacteremia (32 cases), Salmonellatyphimurium bacteremia (11 cases), and Salmonella spp bacteremia (11 cases). The strains were susceptible to ciprofloxacin, ceftriaxone, aztreonam, amoxicillin plus clavulanic acid in at least 92% of the cases. Only 79% of them were susceptible to cotrimoxazole. The lethality rate was 55%.

DISCUSSION

This lethality rate of nontyphoidal Salmonella bacteremia is high in AIDS patients. Therefore, the priority should be put on prevention and, in patients with AIDS, on food hygiene measures, antiretroviral treatment and efficient chemoprophylaxis. This should prove efficient to reduce incidence of nontyphoidal Salmonella bacteremia.

[Hand washing at Fann hospital: investigation among health workers]

INTRODUCTION

Handwashing is usually neglected in hospital settings. The objective of this study was to draw attention of health workers in Fann hospital as part of the prevention of hospital-acquired infections.

MATERIALS AND METHODS

This study was carried out prospectively from April 26h to May 25th. An anonymous questionnaire was administered by 20 formed investigators to health workers, along with an inventory of available resources for hand washing in the study site allowing to collect the data by interview.

RESULTS

A total of 256 health workers were investigated. The mean age was 35.3 +/- 9.4 years [range = 20-71] with a sex ratio of 0.62. As for the education level, the secondary and university predominated. The concept of Manu carrying was ignored by 59.3% of the personnel. This proportion was higher among people with low education level. Possibility of resident and transitional floras in the hand was ignored by most of the investigated personnel. The hand washing technique to be applied while putting vesicle probe was ignored by 59% of the personnel, and 34% declared using hand towel to dry hands. Half of the personnel ignored that bread soap was not recommended. The availability of hydro alcoholic solutions was variable according to the hospital wards. The lavabo/bed ratio was 1/7 and was unacceptable.

CONCLUSION

In Fann hospital, the importance and the techniques of hand washing are not well known, that's why a training of the hospital's Personnel and an improvement of resources for handwashing are necessary for a good hospital's hygiene.

A longitudinal epidemiological survey of bovine trypanosomosis and its vectors in the White Volta river basin of Northern Ghana

A longitudinal epidemiological survey of bovine trypanosomosis and its vectors was carried out in the Volta river basin of Northern Ghana to determine the relationship between cattle management and the incidence of bovine trypanosomosis. Two groups of sentinel cattle under different systems of management, classified as "fully-sedentary" and "partially-sedentary" (depending on the type of management) were followed over a 1-year period starting from March 2003 onwards. Cattle were screened at intervals of 3 months using the buffy coat technique (BCT). Buffy coat specimen from animals that were positive for the BCT and those that were negative, but with a packed cell volume (PCV) of less than 21% were further tested using the polymerase chain reaction (PCR). Plasma from all animals were tested for antibody using the indirect antibody enzyme-linked immunosorbent assay (ELISA). Trypanosomosis challenge was determined in tandem with the epidemiological survey with watering sites of sentinel cattle being the foci of interest. The parasitological prevalence at the start of the survey was higher in the fully-sedentary group (9%) than in the partially-sedentary group (3%). In subsequent visits, however, the parasitological incidence was consistently higher in the partially-sedentary group than in the fully-sedentary group. The mean seroprevalence (ELISA) of both groups increased from 3% in March to 54% in December. Statistical analysis of the serological results using a random effect logistic regression, showed a significant difference in incidence of bovine trypanosomosis between the two groups. There was also a significant effect of time. The influence of cattle herding on host-vector-parasite interface and its consequence on the incidence of trypanosomosis are discussed.

A cross-sectional epidemiological survey of bovine trypanosomosis and its vectors in the Savelugu and West Mamprusi districts of northern Ghana

The epidemiology of bovine trypanosomosis was investigated in two districts (Savelugu and West Mamprusi) of Northern Ghana with different land use and environmental characteristics. The land use intensity and environmental change was suspected to be higher in the Savelugu District. A cross-sectional entomological survey conducted along the White Volta river and its tributaries confirmed the presence of only Glossina palpalis gambiensis and G. tachinoides. The challenge index as measured by the product of tsetse density and tsetse infection rate was much higher in the West Mamprusi (19.6) than in the Savelugu district (4.7). A total of 1013 cattle (508 in Savelugu and 505 in West Mamprusi) were bled from a random selection of 16 villages in the Savelugu District and 13 villages in the West Mamprusi District. Blood samples were examined for trypanosomes by the buffy coat technique (BCT). Blood samples that were positive in the BCT or negative in the BCT but with packed cell volume (PCV) values below 21 were further tested with a polymerase chain reaction for trypanosomal DNA. Plasma samples of all cattle were serologically tested with an indirect ELISA for trypanosomal antibodies. The parasitological and serological prevalence of bovine trypanosomoses was significantly higher in West Mamprusi (16 and 53%, respectively) than in Savelugu District (8 and 24%, respectively). An evaluation of animal health at the village herd level, using PCV as an index of anaemia, provided various epidemiological scenarios prevalent in the entire study area.

Mechanical transmission of Trypanosoma vivax in cattle by the African tabanid Atylotus fuscipes

An experiment was carried out in Burkina Faso to evaluate the potential for mechanical transmission of Trypanosoma vivax by the African tabanid Atylotus fuscipes. The experiment was carried out in a corral (10 m x 10 m) completely covered by a mosquito net (12 m x 12 m and 2.5m high). Eight heifers (cross-bred Zebu X Baoulé), free of trypanosome infection, were kept together with two heifers experimentally infected with a local stock of T. vivax. An average of 539 A. fuscipes per day, freshly captured with two Nzi traps, were introduced into the mosquito net from Day 1 to 20, to allow mechanical transmission of the parasites among cattle. Daily parasitological examinations (BCM) of cattle blood samples indicated that six of the eight receiver heifers were positive from days 9, 10, 15, 16, 19 and 29. Mechanical transmission of T. vivax by A. fuscipes was demonstrated unequivocally in close to natural conditions, at a high rate (75% incidence over a 20-day period) under a mean challenge of 54 insects per heifer per day. These results, in addition to previous demonstration of mechanical transmission of T. vivax by Atylotus agrestis, confirm that mechanical transmission can be a significant route of infection.

Mechanical transmission of Trypanosoma congolense in cattle by the African tabanid Atylotus agrestis

The trypanosomes pathogenic to livestock in Africa (Trypanosoma congolense, Trypanosoma vivax, and Trypanosoma brucei) are mainly cyclically transmitted by tsetse (Glossina). However, T. vivax, can also be mechanically transmitted by haematophagous insects. Laboratory studies have demonstrated the mechanical transmission of T. congolense, but confirmation of this under natural conditions was necessary. An experiment was therefore carried out in Lahirasso, Burkina Faso, in a corral completely covered by mosquito net, to avoid exposure to tsetse. Eight receiver heifers, free of trypanosome infection, were kept together with two donor heifers, experimentally infected with local stocks of T. congolense. On average, 291 Atylotus agrestis, freshly captured in Nzi traps, were introduced into the mosquito net daily for a period of 20 days to initiate mechanical transmission among cattle. Daily microscopical observation of their blood indicated that two of the eight receiver heifers became infected with T. congolense from days 42 and 53. Mechanical transmission of T. congolense by A. agrestis was demonstrated unequivocally with a 25% incidence over a 20-day period of exposure under a mean challenge of 29 insects/animal/day. These results, in addition to previous reports, demonstrate the ability of A. agrestis to transmit T. vivax and T. congolense to cattle in Africa by mechanical means. Efforts to eliminate cattle trypanosomosis should therefore consider the eventual persistence of disease as a result of mechanical transmission of trypanosomes by tabanids. Index descriptor and abbreviations: Trypanosoma congolense (Trypanosomatidae) is a pathogenic trypanosome found in wild and domestic herbivores, principally in cattle (Bos taurus, Bos indicus, and cross-breds), in Africa. It is cyclically transmitted by tsetse (Glossina, Diptera); however, mechanical transmission by biting insects may also occur. The present study demonstrates unequivocally the mechanical transmission of T. congolense to cattle by one of the most common African tabanids, A. agrestis. The main conclusion is that tabanids are able to transmit T. congolense; however, the incidence of transmission was lower than in studies carried out under the same conditions with T. vivax. Better models of mechanical transmission are required to understand why, on the one hand, epidemiological studies support the mechanical transmission of T. vivax but not T. congolense, and, on the other hand, experimental studies confirm that both species can be mechanically transmitted. Our studies suggest that the epidemiology of trypanosomosis in cattle involves tabanids, and hence, the eradication of tsetse-flies in Africa will not necessarily lead to the eradication of trypanosomosis in domestic livestock. ADT, apparent density of insects per trap per day (mean number of insects caught in one type of trap per 24h of trapping); D, day; NS, not statistically significant

Trypanosoma vivax: mechanical transmission in cattle by one of the most common African tabanids, Atylotus agrestis

The role of mechanical vectors in the transmission of African livestock trypanosomes has always been controversial relative to tsetse flies, their cyclical vectors. An experiment was carried out in Burkina Faso to demonstrate mechanical transmission of Trypanosoma vivax by one of the most common tabanids in Africa: Atylotus agrestis. Eight heifers (crossbred zebuxBaoulé), free of trypanosome infection, were kept in a corral covered by a mosquito net, together with two heifers infected experimentally with a local stock of T. vivax. On average, 324 A. agrestis, freshly captured with Nzi traps, were introduced daily over 20 days. Parasitological, PCR and serological examinations were carried out regularly to assess infections and levels of parasitaemia. Microscopic examination of buffy-coats indicated that five of the eight receiver-heifers were infected on days 8, 13, 32, 41, and 48. PCR results indicated that these five heifers were already infected by day 13. Mechanical transmission of T. vivax by A. agrestis was demonstrated unequivocally, at a high rate (63% in 13-20 days). Conditions of transmission in this experiment are discussed in terms of natural rates of challenge. The importance of tabanids as mechanical vectors of T. vivax should be re-considered, in light of these results. Creation of tsetse free zones in Africa will generally lead to the disappearance of T. congolense, T. brucei, and most often T. vivax as well; however, in areas where T. vivax can be mechanically transmitted, clearance of tsetse may not be sufficient to eradicate livestock trypanosomosis.

Ten years of research activities on tropical parasitology of dromedaries, cattle, and small ruminants in Mauritania

In the past, the essential part of the activity of the parasitology laboratory of the Centre National d'Elevage et de Recherches Vétérinaires (CNERV) was represented by diagnostic work that enabled the construction of an inventory of local parasitic fauna and a good collection of specimens. However, the small and irregular number of samples each year, led us to switch our activities in 1990 toward work that could better justify the existence of CNERV. We started work on applied research topics, such as tick-borne diseases, helminthology (nemathelminths and plathelminths), and trypanosomosis. These results were valorized through scientific publication and communication at international meetings. The most valuable information was conveyed to herders.

Some factors affecting the prevalence of Trypanosoma evansi in camels in Mauritania

A study was conducted on the epidemiology of camel trypanosomosis in Mauritania using 2073 camels of various ages in five regions (Trarza, Gorgol, Adrar, Hodh E1 Chargui, Nouakchott). The prevalence was determined through blood smear and serological tests: card agglutination test for trypanosomiasis (CATT) and immuno fluorescence antibody test (IFAT). The prevalence of the disease was 1.3% using blood smear examinations, 16.2% with CATT and 25.2% with IFAT. The following variations were observed: (1) Camels in Trarza had the highest prevalence; (2) Intraregion was a significant factor; (3) Animals that migrated to the south were more commonly infected than those in the north; and (4) Animals in the 5- to 10-yr age group had the highest prevalence. The study indicated that camel trypanosomosis was widespread in Mauritania, especially in the wooded areas near waterways in the south.

[The suicide conference. An instrument for support of involved teams after inpatient suicides]

This is a report on the authors' experience over two years in developing a new way to deal with patient suicides in a District Psychiatric Hospital. The main aim of the Suicide Counselling Session is to help the involved hospital ward teams to overcome the strain, doubt and psychological burden often caused by the suicide of a patient. The authors describe the institutional conditions and setting in which a Suicide Counselling Session takes place. The method is characterised by a special attitude and the ideas of "Reflecting Team" to bring the involved stress factors into the open.

Adaptation to arid environment: Haemonchus longistipes in dromedaries of Saharo-Sahelian areas of Mauritania

The adaptations of the trichostrongylid nematode Haemonchus longistipes of dromedaries (Camelus dromedarius) to the harsh environment of Saharo-Sahelian climate were assessed by means of (i) an epidemiological survey of dromedary infection in the south-west of Mauritania, (ii) an estimate over a 3 year period of parasite distribution within the host population and of prolificacy of H. longistipes females recovered from natural populations of infected dromedaries sampled at Nouakchott's slaughterhouse, and (iii) experimental infections of young dromedaries during three different periods of the year (end of the rainy season, middle and end of the dry season). Egg excretions (estimated by faecal egg counts), infective larvae derived from eggs as well as female prolificacy showed a marked seasonal pattern: high values in the rainy season and very low values in the dry season (especially March and April). Female prolificacy differed slightly between morphotypes: the knobbed type excreting over a longer period than the linguiform and smooth types. Following experimental infections in young dromedaries, arrest of larval development took place irrespective of the period. The survival strategy of H. longistipes in the dry season was based only on arrested larval development. Patent infections occurred from July to October, i.e. during the rainy season and was facilitated by the conjunction of high prevalence and intensity of adult worm burdens associated with high female prolificacy.

Dry areas: an example of seasonal evolution of helminth infection of sheep and goats in southern Mauritania

A total of 647 faecal egg counts and 53 necropsies were performed on sheep and goats originating from three sites of a Sahelian region of Mauritania (Gorgol) over a period of 2 years (1990-1992). Haemonchus contortus, Oesophagostomum columbianum and Stilesia globipunctata were the most prevalent species. The seasonal pattern was characterized by long survival of adults and high percentages of arrested fourth-stage larvae in the dry season, suggesting that two different strategies were used to survive from one rainy season to the next. Sheep and goats were equally infected, except for Stilesia globipunctata, which was found more often in sheep. The influence of age was limited, although kids and lambs born in the beginning of the dry season did not become infected until their first grazing in the rainy season.

[Trypanosomiasis caused by Trypanosoma evansi (Steel 1885), Balbiani 1888 in small ruminants in Mauritania: results of experimental inoculation and field surveys]

In order to define the eventual role of small ruminants in the epidemiology of T. evansi infection in Southern Mauritania, the following experiments were carried out: the intravenous inoculation of a ewe and a goat with a local strain of T. evansi isolated from a dairy camel; surveys of small ruminant flocks which graze with infected camels in the South of the Trarza region. The experimental inoculation allowed to show that local sheep and goats are receptive. Only the ewe showed a clinical episode with loss of weight and abortion. During 220 days after inoculation the blood of the goat remained constantly infectious for the mouse whereas in the same period the ewe's blood showed an alternation of infectious and non-infectious phases. However in the field, none of 381 blood smears of small ruminants (207 goats, 174 sheep) were positive and none of the 187 serums (109 goats, 78 sheep). Therefore, it seems that the small ruminants of the South Mauritania do not play any role in the epidemiology of T. evansi camel trypanosomosis even if they are receptive to experimental inoculation.

Helminths of sheep and goats in desert areas of south-west Mauritania (Trarza)

Faecal samples were obtained from sheep and goats before, during and after the rainy season at three locations in south-west Mauritania. Several animals were also necropsied at the same time. Haemonchus contortus was the most prevalent worm. Infection by digestive-tract strongyles and Strongyloides papillosus was always very light (prevalence less than 20%). Sheep were more heavily infected than goats but animals under 1 year of age were not infected by digestive-tract strongyles. It is likely that young small ruminants became infected during the rainy season and that the parasites so acquired are inhibited in their development and/or survive nearly one year as adults.