Aberrant DNA methylation is associated with aggressive clinicopathological features and poor survival in cutaneous melanoma.

BACKGROUND: Promoter methylation of tumour suppressor genes (TSGs) has recently been implicated in the pathogenesis of several types of cancer. Regarding melanoma, over 100 genes that contribute to its pathogenesis have been identified to be aberrantly hypermethylated. OBJECTIVES: This is a retrospective observational study that aims to analyse the prevalence of CpG island methylation in a series of primary melanomas, to identify the associations with the main clinicopathological features, and to explore the prognostic significance of methylation in melanoma survival. MATERIALS AND METHODS: DNA methylation was analysed using methylation-specific multiplex ligation-dependent probe amplification in a series of 170 melanoma formalin-fixed paraffin-embedded tumour samples. The relationship between the methylation status, known somatic mutations and clinicopathological features was evaluated. Disease-free survival (DFS) and overall survival (OS) were displayed by the Kaplan-Meier method. RESULTS: In the entire cohort, one or more genes were detected to be methylated in 55% of the patients. The most prevalent methylated genes were RARB 31%, PTEN 24%, APC 16%, CDH13 16%, ESR1 14%, CDKN2A 6% and RASSF1 5%. An association between aberrant methylation and aggressive clinicopathological features was observed (older age, increased Breslow thickness, presence of mitosis and ulceration, fast-growing melanomas, advancing stage and TERT mutations). Furthermore, Kaplan-Meier survival analysis showed a correlation of methylation and poorer DFS and OS. CONCLUSIONS: Aberrant methylation of TSGs is a frequent event in melanoma. It is associated with aggressive clinicopathological features and poorer survival. Epigenetic alterations may represent a significant prognostic marker with utility in routine practice.

Use of universal 16S rRNA gene PCR as a diagnostic tool for venous access port-related bloodstream infections.

Amplification of the universal 16S rRNA gene using PCR has improved the diagnostic yield of microbiological samples. However, no data have been reported on the reliability of this technique with venous access ports (VAPs). We assessed the utility of 16S rRNA PCR for the prediction of VAP-related bloodstream infection (VAP-RBSI). During a 2-year period, we prospectively received all VAPs removed by interventional radiologists. PCR and conventional cultures were performed using samples from the different VAP sites. We compared the results of PCR with those of conventional culture for patients with confirmed VAP-RBSI. We collected 219 VAPs from 219 patients. Conventional VAP culture revealed 15 episodes of VAP-RBSI. PCR revealed a further 4 episodes in patients undergoing antibiotic therapy which would have gone undetected using conventional culture. Moreover, it had a negative predictive value of 97.8% for the prediction of VAP-RBSI when it was performed using biofilm from the internal surface of the port. In conclusion, universal 16S rRNA PCR performed with samples from the inside of VAPs proved to be a useful tool for the diagnosis of VAP-RBSI. It increased detection of VAP-RBSI episodes by 21.1% in patients undergoing antibiotic therapy whose episodes would have gone undetected using conventional culture. Therefore, we propose a new application of 16S rRNA PCR as a useful tool for the diagnosis of VAP-RBSI in patients receiving antibiotic therapy.

Value of superficial cultures for prediction of catheter-related bloodstream infection in long-term catheters: a prospective study.

Cultures taken from the skin and from the hubs of short-term central venous catheters can help us to predict catheter-related bloodstream infections (C-RBSIs). The value of these cultures for such predictions has not been assessed in long-term catheters. Our objective was to assess the value of superficial cultures for the prediction of C-RBSI among patients with long-term catheters. Over a 2-year period, we prospectively obtained cultures from the skin overlying reservoir ports (group A) and from the skin insertion site and hubs of all tunneled catheters (group B). This routine was performed by vascular and interventional radiologists immediately before catheter removal (irrespective of the reason for withdrawal). Swabs were processed semiquantitatively. Catheter tips from both groups were cultured using Maki's semiquantitative technique and sonication. We also performed cultures of the reservoir ports at different sites. C-RBSI was defined as the isolation of the same species of microorganism(s) both in the colonized catheter and in at least 1 peripheral blood culture. We included 372 catheters (group A, 223; group B, 149) during the study period. The catheter colonization rate was 23.4% (87/372), and 28 patients had C-RBSI. Validity index values for the capacity of surface cultures to predict C-RBSI in groups A and B were, respectively, as follows: sensitivity, 23.5% and 45.5%; specificity, 59.7% and 63.0%; positive predictive value, 4.6% and 8.9%; and negative predictive value, 90.4% and 93.5%. Superficial cultures of patients with long-term catheters could help us to rule out the catheter as the portal of entry of bloodstream infections. Superficial cultures (from skin and hubs) proved to be a useful conservative diagnostic tool for ruling out C-RBSI among patients with long-term tunneled catheters and totally implantable venous access ports.

How should long-term tunneled central venous catheters be managed in microbiology laboratories in order to provide an accurate diagnosis of colonization?

Guidelines recommend the roll-plate technique for short-term central venous catheter (CVC) tip cultures. However, the issue of whether the roll-plate technique is better than the sonication method for long-term CVCs remains unresolved. In addition, no data are available for predicting the value of direct Gram staining in anticipating catheter colonization or catheter-related bloodstream infection (CRBSI) in these long-term CVCs. Our objectives were to compare the roll-plate technique and the sonication method and to define the validity values of Gram staining for the prediction of colonization and CRBSI in patients with long-term tunneled CVCs. During the study period, all tunneled CVCs removed at our institution were prospectively and routinely sent to the microbiology laboratory for Gram staining (first) and tip culture (the Maki technique and sonication, in a random order). We received 149 tunneled CVCs, 39 (26.2%) of which were colonized and 11 (7.4%) of which were associated with CRBSI. Overall, the roll-plate method detected 94.9% of the colonized catheters, whereas sonication detected only 43.6% (P < 0.001). The validity values of Gram staining for the detection of colonization and CRBSI were as follows: a sensitivity of 35.9% to 60.0%, a specificity of 100% to 94.2%, a positive predictive value of 100% to 42.9%, and a negative predictive value of 81.5% to 97.0%. The roll-plate technique proved to be better than sonication for the detection of bacteria in long-term tunneled CVCs. Gram staining of the tips of tunneled CVCs can anticipate a positive culture and rule out CRBSI. In our opinion, direct Gram staining should be incorporated into routine microbiological assessments of long-term catheter tips.

International variations in infrainguinal bypass surgery - a VASCUNET report.

OBJECTIVES: To compare practice in lower limb bypass surgery in nine countries. DESIGN: A prospective study amalgamating and analysing data from national and regional vascular registries. METHODS: A table of data fields and definitions was agreed by all member countries of the Vascunet Collaboration. Data from January 2005 to December 2009 was submitted to a central database. RESULTS: 32,084 cases of infrainguinal bypass (IIB) in nine countries were analysed. Procedures per 100,000 population varied between 2.3 in the UK and 24.6 in Finland. The proportion of women varied from 25% to 43.5%. The median age for all countries was 70 for men and 76 for women. Hungary treated the youngest patients. IIB was performed for claudication for between 15.7% and 40.8% of all procedures. Vein grafts were used in patients operated on for claudication (52.9%), for rest pain (66.7%) and tissue loss (74.1%). Italy had the highest use of synthetic grafts. Among claudicants 45% of bypasses were performed to the below knee popliteal artery or more distally. Graft patency at 30 days varied between 86% and 99%. CONCLUSIONS: Significant variations in practice between countries were demonstrated. These results should be interpreted alongside the known limitations of such registry data with respect to quality and completeness of the data. Variation in data completeness and data validation between countries needs to be improved for useful international comparison of outcomes.

Traumatic rupture of horseshoe kidney.

We present the case of a 25-year-old male who came to the emergency room for pain and abdominal distension following trauma to the mesogastrium. A CT scan was performed, revealing a voluminous retroperitoneal hematoma with laceration of both inferior renal poles with regard to rupture of the isthmus of a horseshoe kidney. The patient presented anemization and increased pain, requiring selective embolization by means of arteriography of a branch of the right renal artery and placement of a double J stent due to urinary extravasation in the lower left kidney pole. Following 1 year of monitoring, the patient has maintained normal renal function. Renal affection in blunt abdominal trauma is frequent, occurring in 7% of previously pathological kidneys. The traumatic rupture of horseshoe kidney is facilitated by its particular anatomical characteristics, constituting an infrequent entity, knowledge of which is necessary to achieve conservative management that renders it possible to preserve renal function.

Stent-assisted remote iliac artery endarterectomy: an alternative approach to treating combined external iliac and common femoral artery disease.

OBJECTIVE: Stent-assisted remote iliac endarterectomy (SA-RIEA) is a hybrid minimally invasive technique for treating patients with combined external iliac and common femoral disease, when the only alternative would be conventional open revascularisation. DESIGN: This was a retrospective, single-centre study. MATERIALS AND METHODS: From January 2004 to April 2010, 155 SA-RIEA procedures were performed. The patients' mean age was 62 (range, 43-86) years. Indications for surgery were: severe claudication in 79 (51%), rest pain in 43 (28%) and gangrene in 33 (21%) cases. The mean length of follow-up was 21 months. RESULT: Initial technical success was achieved in 145 (93.5%) procedures. Ten patients required conversion to a conventional iliofemoral reconstructive procedure. The 1-, 3- and 5-year primary, primary-assisted and secondary patency rates were 80.2%, 74.7% and 69.3%; 84.8%, 82.4% and 78.2%; and 86.8%, 84.2% and 79.6%, respectively. Within the first 30 days, there were no early reocclusions, one (0.6%) perioperative death due to myocardial infarction, five (3.4%) minor wound complications and two (1.3%) limb losses. During follow-up, seven patients underwent open reconstruction due to symptomatic reocclusion, and four were re-operated on due to symptomatic restenosis (three percutaneous transluminal angioplasties (PTAs), one reendarterectomy). CONCLUSION: In patients with combined common femoral and external iliac disease, SA-RIEA appears to offer a safe and effective alternative to conventional open surgery.

Treatment of abdominal aortic aneurysm in nine countries 2005-2009: a vascunet report.

OBJECTIVES: To study contemporary treatment and outcome of abdominal aortic aneurysm (AAA) repair in nine countries. DESIGN AND METHODS: Data on primary AAA repairs 2005-2009 were amalgamated from national and regional vascular registries in Australia, Denmark, Finland, Hungary, Italy, Norway, Sweden, Switzerland and the UK. Primary outcome was in-hospital or 30-day mortality. Multivariate logistic regression was used to assess case-mix. RESULTS: 31,427 intact AAA repairs were identified, mean age 72.6 years (95% CI 72.5-72.7). The rate of octogenarians and use of endovascular repair (EVAR) increased over time (p < 0.001). EVAR varied between countries from 14.7% (Finland) to 56.0% (Australia). Overall perioperative mortality after intact AAA repair was 2.8% (2.6-3.0) and was stable over time. The perioperative mortality rate varied from 1.6% (1.3-1.8) in Italy to 4.1% (2.4-7.0) in Finland. Increasing age, open repair and presence of comorbidities were associated with outcome. 7040 ruptured AAA repairs were identified, mean age 73.8 (73.6-74.0). The overall perioperative mortality was 31.6% (30.6-32.8), and decreased over time (p = 0.004). CONCLUSIONS: The rate of AAA repair in octogenarians as well as EVAR increased over time. Perioperative outcome after intact AAA repair was stable over time, but improved after ruptured repair. Geographical differences in treatment of AAA remain.

A new transmission risk index for human African trypanosomiasis and its application in the identification of sites of high transmission of sleeping sickness in the Fontem focus of southwest Cameroon.

A new index for the risk for transmission of human African trypanosomiasis was developed from an earlier index by adding terms for the proportion of tsetse infected with Trypanosoma brucei gambiense group 1 and the contribution of animals to tsetse diet. The validity of the new index was then assessed in the Fontem focus of southwest Cameroon. Averages of 0.66 and 4.85 Glossina palpalis palpalis (Diptera: Glossinidae) were caught per trap/day at the end of one rainy season (November) and the start of the next (April), respectively. Of 1596 tsetse flies examined, 4.7% were positive for Trypanosoma brucei s.l. midgut infections and 0.6% for T. b. gambiense group 1. Among 184 bloodmeals identified, 55.1% were from pigs, 25.2% from humans, 17.6% from wild animals and 1.2% from goats. Of the meals taken from humans, 81.5% were taken at sites distant from pigsties. At the end of the rainy season, catches were low and similar between biotopes distant from and close to pigsties, but the risk for transmission was greatest at sites distant from the sties, suggesting that the presence of pigs reduced the risk to humans. At the beginning of the rainy season, catches of tsetse and risk for transmission were greatest close to the sties. In all seasons, there was a strong correlation between the old and new indices, suggesting that both can be used to estimate the level of transmission, but as the new index is the more comprehensive, it may be more accurate.

Trypanosoma vivax, T. congolense "forest type" and T. simiae: prevalence in domestic animals of sleeping sickness foci of Cameroon.

In order to better understand the epidemiology of Human and Animal trypanosomiasis that occur together in sleeping sickness foci, a study of prevalences of animal parasites (Trypanosoma vivax, T. congolense "forest type", and T. simiae) infections was conducted on domestic animals to complete the previous work carried on T. brucei gambiense prevalence using the same animal sample. 875 domestic animals, including 307 pigs, 264 goats, 267 sheep and 37 dogs were sampled in the sleeping sickness foci of Bipindi, Campo, Doumé and Fontem in Cameroon. The polymerase chain reaction (PCR) based method was used to identify these trypanosome species. A total of 237 (27.08%) domestic animals were infected by at least one trypanosome species. The prevalence of T. vivax, T. congolense "forest type" and T. simiae were 20.91%, 11.42% and 0.34% respectively. The prevalences of 7 vivax and T. congolense "forest type" differed significantly between the animal species and between the foci (p < 0.0001); however, these two trypanosomes were found in all animal species as well as in all the foci subjected to the study. The high prevalences of 7 vivax and T congolense "forest type" in Bipindi and Fontem-Center indicate their intense transmission in these foci.

Domestic animals as potential reservoir hosts of Trypanosoma brucei gambiense in sleeping sickness foci in Cameroon.

An explanation of the endemic nature and/or the resurgence of Human African Trypanosomiasis (HAT) in the historic foci in West and Central Africa may be the existence of an animal reservoir. In some HAT foci, pigs were found infected by Trypanosoma brucei gambiense but the implication of the other domestic animals was not quite evaluated. This study aims to determine the prevalence of T. b. gambiense in domestic animal species (goat, sheep, pig and dog) commonly found in the four active HAT foci in Cameroon (Bipindi, Fontem, Campo and Doumé). Blood samples were collected from 307 pigs, 264 goats, 267 sheep and 37 dogs and used for parasitological (QBC), immunological (LiTat 1.3 CATT) and molecular (PCR) analyses. QBC detected trypanosomes in 3.88% domestic animals while 22.7% were sero-positive with LiTat 1.3 CATT tests. Of the 875 animals analysed, 174 (19.88%) harboured T. brucei s.l. DNA, found in each of the four types of animal and in the four localities. The infection rate significantly differed among the animal species (p < 0.0001) and localities (p < 0.0001). The PCR also revealed T. b. gambiense group 1 DNA in 27 (3.08 %) domestic animals. The specific infection rates were as follows: sheep (6.74%), goats (3.08%), pigs (0.32%) and dogs (O%). T. b. gambiense was found in 8 (3.92%) animals from Bipindi, 15 (4.83%) from Campo, 4 (2.59%) from FontemCenter and none from Doumé. The infection rates significantly differed between the localities, and correlated with the intensity of HAT transmission in the foci.

Telomerase Expression in a Series of Melanocytic Neoplasms. / Estudio de la expresión de telomerasa en una serie de neoplasias melanocíticas.

BACKGROUND AND OBJECTIVES: Telomerase is an enzyme involved in maintaining the length of telomeres and cell senescence. Numerous studies have shown that in more than 90% of malignant tumors telomerase activity is detected. MATERIAL AND METHODS: Retrospective observational study in a series of 85 cases of primary melanomas, 12 metastatic melanomas, and 22 melanocytic nevi. We used the monoclonal antibody hTERT (human telomerase reverse transcriptase, Rockland) to assess telomerase activity. The SPSS software package was used to analyze data. RESULTS: Telomerase expression was present in all the melanocytic neoplasms analyzed. Expression was heterogenous and moderate or high in the melanomas. In contrast, expression was homogeneous and lower in the nevi. Heterogeneous expression was associated with rapid melanoma growth (P=.028), a Breslow thickness of more than 4 mm (P=.004), mitosis (P=.032), and mutations in the TERT gene (P=.002). Activity was less intense in intradermal nevi, and more intense in compound and dysplastic nevi (P=.054). CONCLUSIONS: Telomerase expression is found in all melanocytic neoplasms but is higher in melanomas than in nevi. A heterogeneous pattern of expression in melanomas is associated with more aggressive tumors.

Tsetse fly host preference from sleeping sickness foci in Cameroon: epidemiological implications.

To determine the tsetse fly host preferences in two sleeping sickness foci of southern Cameroon, four entomological surveys (two in each focus) were carried out. For the whole study, 4929 tsetse flies were caught: 3933 (79.8%) Glossina palpalis palpalis, 626 (12.7%) Glossina pallicera pallicera, 276 (5.6%) Glossina nigrofusca and 94 (1.9%) Glossina caliginea. One hundred and thirty-eight blood meals were collected and the origin of 118 (85.5%) meals was successfully identified: 38.4% from man, 23.9% from pig, 20.3% from sitatunga (Tragelaphus spekeii), 2.2% from sheep and 0.7% from golden cat (Profilis aurata). The number of Glossina palpalis palpalis with man blood meals is more important in the Human African Trypanosomiasis (HAT) focus showing endemic evolution (Campo) than in the focus (Bipindi) presenting a flare up of the disease. The consideration of both results of the prevalence of Trypanosoma brucei gambiense in vertebrate hosts and those of the tsetse fly host preferences indicates a wild animal reservoir of Gambian sleeping sickness and three transmission cycles (human, domestic and wild animals' cycles) in southern Cameroon HAT foci.

[Ecology of stomoxyine fulies (Diptera: Muscidae) in Gabon. II. Blood meals analysis a nd epidemiologic consequences]. / Ecologie des stomoxes (Diptera: Muscidae) au Gabon. II. Origine des repas de sang et conséquences epidémiologiques.

To determine the origin of stomoxyine fly bloodmeals (Diptera: Muscidae) in Gabon, 1,021 flies belonging to seven different species of Stomoxys were captured and dissected in the area of Makokou. In total, 798 were not blood-fed and 223 bloodmeals could be gathered on filter paper. The identification of the origin of these meals was made by amplification of mitochondrial Cytb gene, then heteroduplex technique by using the Gambian rat (Cricetomys gambianus) as driver. Samples of fauna, collected on the local market, consisted of 24 mammal and two reptile blood and muscle samples, to which it is necessary to add human samples (27 potential hosts). 19 meals could not be amplified for technical reasons, 65 were amplified, but the acquired patterns corresponded to none of the tested potential hosts. On the 139 identified meals, 55% were taken on the black-fronted duiker (Cephalophus nigrifrons) and 19% on pig. Stomoxys transvittatus, the most abundant species in Makokou, is very opportunistic: 68 % of meals were taken on six different hosts, among whom 48% on the black-fronted duiker and 32% were not identified using the panel of tested hosts. S. xanthomelas took 50% of its meals on the moustached monkey (Cercopithecus cephus) and 7% on human beings. S. calcitrans, species of anthropised areas, took 33% of its meals on human beings. These three species can therefore take bloodmeals on wild fauna and human beings. They could potentially play an important role in the emergence of zoonotic diseases. The four other species took their bloodmeals only on wild fauna and pig, the only example of domestic fauna in this study. This preliminary study must be followed up using a larger number of specimens and by increasing the diversity of the tested potential hosts.

Trends in Nutrient Content of Children's Menu Items in U.S. Chain Restaurants.

INTRODUCTION: Restaurant food is widely consumed by children and is associated with poor diet quality. Although many restaurants have made voluntary commitments to improve the nutritional quality of children's menus, it is unclear whether this has led to meaningful changes. METHODS: Nutrients in children's menu items (n=4,016) from 45 chain restaurants were extracted from the nutrition information database MenuStat. Bootstrapped mixed linear models estimated changes in mean calories, saturated fat, and sodium in children's menu items between 2012 and 2013, 2014, and 2015. Changes in nutrient content of these items over time were compared among restaurants participating in the Kids LiveWell initiative and non-participating restaurants. Types of available children's beverages were also examined. Data were analyzed in 2016. RESULTS: There was a significant increase in mean beverage calories from 2012 to 2013 (6, 95% CI=0.8, 10.6) and from 2012 to 2014 (11, 95% CI=3.7, 18.3), but no change between 2012 and 2015, and no differences in nutrient content of other items over time. Restaurants participating in Kids LiveWell reduced entrée calories between 2012 and 2013 (-24, 95% CI= -40.4, -7.2) and between 2012 and 2014 (-40, 95% CI= -68.1, -11.4) and increased side dish calories between 2012 and 2015 (49, 95% CI=4.6, 92.7) versus non-participating restaurants. Sugar-sweetened beverages consistently constituted 80% of children's beverages, with soda declining and flavored milks increasing between 2012 and 2015. CONCLUSIONS: Results suggest little progress toward improving nutrition in children's menu items. Efforts are needed to engage restaurants in offering healthful children's meals.

Wild fauna as a probable animal reservoir for Trypanosoma brucei gambiense in Cameroon.

In order to study the existence of a wild animal reservoir for Trypanosoma brucei gambiense in South Cameroon, blood was collected from wild animals in three human African trypanosomiasis foci and from a nonendemic control area. The 1142 wild animals sampled belonged to 36 different species pertaining to eight orders (407 primates, 347 artiodactyls, 265 rodents, 54 pangolins, 53 carnivores, 11 saurians and crocodilians, and five hyraxes). QBC and KIVI tests detected trypanosomes on 1.7% (13/762) and 18.4% (43/234) of animals examined, respectively. Using specific primers, T. brucei non-gambiense group 1 DNA was detected on 56 animals (4.9%). This infection rate was 5.3% in the endemic zone and 3.8% in the control zone. Of the 832 animals of the endemic zone, PCR revealed T. b. gambiense group 1 DNA in 18 (2.2%). These hosts included two rodents, two artiodactyls, two carnivores and two primates. T. b. gambiense group 1 was absent from animals from the nonendemic zone. A decrease in the prevalence of T. b. gambiense group 1 was observed in wild animals from the Bipindi sleeping sickness focus after a medical survey and vector control in this area. The epidemiological implications of these findings remain to be determined with further investigations.

High prevalence of Trypanosoma brucei gambiense group 1 in pigs from the Fontem sleeping sickness focus in Cameroon.

To understand the importance of domestic pigs in the epidemiology of human trypanosomiasis, PCR was used to identify trypanosome populations in 133 pigs from the Fontem sleeping sickness focus of Cameroon. The results from this study show that 73.7% (98/133) of pigs from the Fontem area carry at least one trypanosome species. Trypanosoma vivax, T. brucei s.l. and T. congolense forest were found in 34.6% (46/133), 40.0% (53/133) and 46.0% (61/133) of the pigs respectively. T. simiae and T. congolense savannah were not identified in these animals. The use of repeated DNA sequences detected T. b. gambiense group 1 in 14.8% (15/101) of the pigs. Such pigs can be possible reservoir hosts for T. b. gambiense group 1 and contribute to the maintenance of the disease in the area. Mixed infections were revealed in 35.3% (47/133) of the pigs. Furthermore, we observed that under natural conditions, 52.4% (11/21) of the pigs from the Fontem focus carry mixed infections with T. b. gambiense group 1. No significant difference was observed between the percentage of T. b. gambiense group 1 single and mixed infections, and between the prevalence of this trypanosome in pigs from villages with and without sleeping sickness patients.

Spontaneous cure of domestic pigs experimentally infected by Trypanosoma brucei gambiense. Implications for the control of sleeping sickness.

The existence of a pig reservoir for human African trypanosomosis (HAT) due to Trypanosoma brucei gambiense complicates the fight against this disease. This study, reports results obtained from pigs, which were inoculated with the blood of a person, suffering from HAT in Cameroon. The pigs were reared and kept in the shelter from all contact with Glossina, and monitored for 188 days. The seroconversion was checked by agglutination assays for trypanosomosis (CATT 1.3 and LATEX/T.b.gambiense). The parasitemia was measured by quantitative buffy coat method (QBC) and by polymerase chain reaction method (PCR). In addition, growth was recorded as well as blood counting and blood formulas. The results showed that the pigs were trypanotolerant and cure themselves in less than 6 months. It is concluded that sterilisation of this reservoir could be achieved by tsetse-control measures in 1 year. It confirms the strategy to complement screening and treatment of HAT with tsetse fly control measures.

Diagnosis of human trypanosomiasis, due to Trypanosoma brucei gambiense in central Africa, by the polymerase chain reaction.

During a mass screening of sleeping sickness conducted in 1998 and 1999, and involving 27,932 persons in Cameroon and the Central African Republic, we tested the polymerase chain reaction (PCR) on whole blood for the diagnosis of human African trypanosomiasis due to Trypanosoma brucei gambiense. The 1858 samples obtained were from 4 groups: 155 infected patients, 1432 serological suspects detected by the card agglutination test for trypanosomiasis (CATT), 222 negative controls living in the prospected area (negative with the CATT and parasitological methods), and 49 negative controls (CATT and parasitological methods) and unexposed to the disease (Europeans). The technique of DNA extraction used made it possible to preserve the blood samples in the field. The primers used were specific for T. brucei s.l. Only 1 patient was PCR negative, and 3 of the negative controls, exposed to the disease, were PCR positive. Among the 1432 serological suspects, only 50 were PCR positive. During the 6-month follow-up after the surveys, the 3 negative controls, who were initially positive by PCR, were found to be negative. These initial positive PCR results are unlikely to have been due to a cross-reaction with T. brucei brucei, which is non-pathogenic for man, but are more likely to have resulted from a mislabelling of sample tubes. All control individuals, exposed or not to the disease, were negative by PCR. The PCR-negative patient was possibly a registration error. Among 50 PCR positive serological suspects, 39 of them were re-examined. Five were found to be positive by the kit for in-vitro isolation of trypanosomes, representing an increase in patients of almost 13%. At the end of the study, 160 patients were diagnosed, and the PCR was positive for 159 of them (99.4%). Moreover, the PCR made it possible to reduce the number of suspects to be re-examined (50 instead of 1432; a reduction of 96.5%).