[Epidemiology of primary lung cancer among non-smokers in Senegal]. / Épidémiologie des cancers bronchopulmonaires primitifs des non-fumeurs au Sénégal.

INTRODUCTION: According to global data for 2002, one quarter of new cases of primary bronchopulmonary cancer were non-smokers. We undertook this study with the aim of describing the epidemiological characteristics of non-smokers with primary bronchopulmonary cancer in the Dakar region of Senegal. METHODS: A multicenter descriptive study that included all non-smokers who presented with primary bronchopulmonary cancer between January 1st 2014 and December 31st 2015. The data were captured on an Excel file and then transferred to Epi InfoTM 7 software for analysis. RESULTS: The rate of diagnosis for primary bronchopulmonary cancers was 72.1 %. The prevalence of non-smokers was 33.3 %. The sex ratio was 1.27. The average age was 54.6 years. More than a third of the sample were housewives. Carpenters and craftsmen exposed to metals predominated. Exposure to cooking oils was reported in one case. Three patients presented sequelae of pulmonary tuberculosis. Adenocarcinoma was the most common histological type and predominated in young subjects. CONCLUSION: The proportion of primary bronchopulmonary cancers diagnosed among non-smokers is increasing in Dakar. An analytical study of suspected risk factors would be helpful for prevention.

Discovery and validation of serum biomarkers expressed over the first twelve weeks of Fasciola hepatica infection in sheep.

Serum biomarkers associated with Fasciola hepatica infection of Corriedale sheep were analysed during the first 12 weeks of infection using surface-enhanced laser desorption ionisation time of flight mass spectrometry (SELDI-TOF MS). In the discovery phase of analysis, pooled sera collected at week 0 and at each week p.i. to week 12 were fractionated by anion-exchange chromatography and the protein mass fingerprints obtained in individual fractions were in the M/z range 1.5-150 kDa. A total of 2302 protein clusters (peaks) were identified that varied between time-points following infection with peaks increasing or decreasing in intensity, or showing transient variation in intensity, during the 12 weeks of parasite challenge. In the validation phase, candidate biomarkers in sera of individual sheep at weeks 3 and 9 p.i. were analysed, identifying 100 protein peaks, many of which are small peptides <10 kDa in size: 54% of these peaks were up-regulated in intensity at week 3 or 9 p.i. Twenty-six biomarkers were chosen for further study, ranging in size from 1832 to 89,823 Da: six biomarkers were up-regulated at weeks 3 and 9 p.i., 16 biomarkers were up-regulated only at week 9 p.i. and four biomarkers were down-regulated at week 9 p.i. Two biomarkers up-regulated at week 9 were identified as transferrin (77.2 kDa) and Apolipoprotein A-IV (44.3 kDa), respectively. The results show that the interaction between the host and F. hepatica is complex, with changes in biomarker patterns beginning within 3 weeks of infection and either persisting to weeks 9-12 or showing transient changes during infection. Identification of biomarkers expressed during ovine fasciolosis may provide insights into mechanisms of pathogenesis and immunity to Fasciola and may assist in the rational development and delivery of vaccines.

High-yield amplification of Cryptosporidium parvum in interferon gamma receptor knockout mice.

To date, large-scale production of Cryptosporidium parvum oocysts has only been achieved by amplification in neonatal calves and sheep. Many laboratories currently depend on supplies from external sources and store oocysts for prolonged periods which results in progressive loss of viability. Six to 8-week-old interferon gamma receptor knockout (IFN gamma R-KO) mice on a C57BL/6 background were inoculated by gavage (2000 oocysts/animal). Fecal pellets were collected daily from 7 days post-infection (p.i.) up to 2 weeks p.i. Intestinal oocyst yield was assessed at days 11, 12 and 14 p.i. by homogenization of intestinal tissues. Ether extraction and one or more NaCl flotations were used to purify oocysts. Total recoveries averaged 2.6 x 10(6) oocysts/mouse from fecal material and 3.8 x 10(7) oocysts/mouse from intestinal tissues. Overall, 2.3 x 10(9) purified oocysts were obtained from 60 mice. Recovered oocysts were capable of sporulation and were shown to be infectious both in vitro and in vivo. Oocyst amplification was achieved in only 11-14 days with minimal expense. The simplicity of this method presents a practical alternative for the routine passage, maintenance and storage of C. parvum in biomedical laboratories.

Use of ProteinChip technology for identifying biomarkers of parasitic diseases: the example of porcine cysticercosis (Taenia solium).

Taenia solium cysticercosis is a significant public health problem in endemic countries. The current serodiagnostic techniques are not able to differentiate between infections with viable cysts and infections with degenerated cysts. The objectives of this study were to identify specific novel biomarkers of these different disease stages in the serum of experimentally infected pigs using ProteinChip technology (Bio-Rad) and to validate these biomarkers by analyzing serum samples from naturally infected pigs. In the experimental sample set 30 discriminating biomarkers (p<0.05) were found, 13 specific for the viable phenotype, 9 specific for the degenerated phenotype and 8 specific for the infected phenotype (either viable or degenerated cysts). Only 3 of these biomarkers were also significant in the field samples; however, the peak profiles were not consistent among the two sample sets. Five biomarkers discovered in the sera from experimentally infected pigs were identified as clusterin, lecithin-cholesterol acyltransferase, vitronectin, haptoglobin and apolipoprotein A-I.

Point-of-care and point-of-'can': leveraging reference-laboratory capacity for integrated diagnosis of fever syndromes in the tropics.

BACKGROUND: There is an urgent need for integrated diagnosis of febrile syndromes able to account for multiple pathogens and to inform decisions for clinical care and public health. AIMS: To reflect on the evolving roles of laboratory-based testing for non-malarial febrile illnesses (NMFIs) in low-resource settings, and to consider how advances in diagnostics, in connectivity and transport, and in implementation of quality systems may substantially enhance the capacity of reference laboratories to bridge the current gap between remote passive surveillance and clinically meaningful integrated fever diagnosis. SOURCES: Iterative search of PubMed databases, organizational reports, and expert consultation. CONTENT: Implementation of new technologies-such as very broad molecular panels for surveillance and mass spectrometry-may considerably diminish capability gaps in reference laboratories in low-resource settings. Although the need for clinical bacteriology diagnostics is now recognized, the lack of new simple and rapid phenotypic tests for antimicrobial resistance remains a key deficiency. Several initiatives to strengthen diagnostic preparedness for infectious disease outbreaks have highlighted the need for functional tiered laboratory networks. Recently, dramatic headway in connectivity-such as combining automated readers with the image processing and data transmission capabilities of smartphones-now allows for more complex testing and interfacing with distant laboratory information systems while reducing workload and errors. Together with connectivity to transmit and receive results, new approaches to specimen collection and transport-such as the validation of rectal swabs and the use of aerial drones to transport specimens to distant laboratories-now make remote testing feasible. The above innovations also open up the possibility of implementing quality systems through community-level diagnostic stewardship. Finally, strengthened laboratory networks actively support the feasibility of implementing quality-assured point-of-care testing where it is needed. IMPLICATIONS: Recent advances offer the present-day possibility of innovations to re-invent the relationship between distant reference laboratories and end-users for integrated diagnosis of NMFIs.

Foxes (Vulpes vulpes) as sentinels for parasitic zoonoses, Toxoplasma gondii and Trichinella nativa, in the northeastern Canadian Arctic.

Outbreaks of Toxoplasma gondii and Trichinella spp. have been recurring for decades among Inuit of Nunavik, northeastern Canada. Contact with wildlife has been identified as a risk factor for Inuit exposure to T. gondii, but reservoirs have yet to be confirmed based on direct detection of DNA or organism. Similarly, little is known about the occurrence of Trichinella spp. in wildlife species of Nunavik other than walrus (Odobenus rosmarus) and bears (Ursus americanus, Ursus maritimus). Foxes (Vulpes vulpes) were targeted as possible sentinels for T. gondii and Trichinella spp. because of their high trophic position within the Arctic food chain as carnivorous scavengers. A total of 39 red foxes were sampled from four communities in southern and western Nunavik between November 2015 and September 2016. For the first time in wildlife, a novel magnetic capture DNA extraction and real-time PCR technique was used to isolate and detect T. gondii DNA from the heart and brain of foxes. A double separatory funnel digestion method followed by multiplex PCR was used to recover and genotype larvae of Trichinella spp. from tongues of foxes. Seroprevalence based on detection of antibodies to T. gondii was 41% (95% CI: 27-57%) using a commercially available modified agglutination test (MAT). Detection of DNA of T. gondii and larvae of Trichinella nativa (T2) occurred in 44% (95% CI: 28-60%) and 36% (95% CI: 21-51%) of foxes, respectively. Coinfection with both T. nativa and T. gondii occurred among 23% (95%CI: 13-38%) of foxes which can be attributed to co-transmission from prey and scavenged species in their diet. There was only moderate agreement between T. gondii serology and direct detection of T. gondii DNA using the MC-PCR technique (Kappa test statistic: 0.321), suggesting that using both methods in tandem can increase the sensitivity of detection for this parasite. These findings show that foxes are good sentinels for circulation of parasitic zoonoses in terrestrial northern ecosystems since they are highly exposed, show measurable indicators of infection and do not serve as exposure sources for humans.

Hepatic cytolysis and bicytopenia after 15 days of four-drug tuberculosis treatment in Senegal.

We report the case of a 31-year-old immunocompetent woman residing in Senegal, with localized microscopy-proved pulmonary tuberculosis, complicated by macrophage activation syndrome and associated with viral hepatitis B, identified due to hepatic cytolysis and a bicytopenia.

The interaction of Trypanosoma congolense and Haemonchus contortus in Djallonké sheep.

The interaction between Trypanosoma congolense and Haemonchus contortus was studied in 5 groups of 8 Djallonké sheep. Two groups received a single infection with either H. contortus or T. congolense, and 2 groups were infected with T. congolense followed by H. contortus (TH) or vice versa (HT). One group was kept as uninfected controls. Mortality due to infection was observed only in the dual infection groups. In the TH group, the effects were more acute whereas in the HT group they were more chronic. No significant differences in weight gain could be demonstrated between infected and control groups. Djallonké sheep are able to withstand a single infection with either T. congolense or H. contortus, which confirms their trypanotolerant nature and provides preliminary indication of resistance against helminth infections. However, when exposed to successive infections with both parasites, some of the animals lose this tolerance.

Diagnostic evaluation of PCR in goats experimentally infected with Trypanosoma vivax.

Six goats were experimentally infected with a stock of Trypanosoma vivax. Parasitaemia was weekly monitored by buffy coat and wet blood film examination during a period of 15 weeks and another 3 weeks following drug-treatment. Dried blood samples were tested by the polymerase chain reaction (PCR), using an extraction method with Chelex 100 (BioRad). PCR proved consistently more sensitive than the parasitological techniques.

Diagnostic evaluation of PCR on dried blood samples from goats experimentally infected with Trypanosoma brucei brucei.

In seven goats experimentally infected with a pleomorphic clone of Trypanosoma brucei brucei, parasitaemia was monitored weekly for 6 weeks by wet blood film and microhaematocrit buffy coat examination. Dried blood samples on filter paper were concomitantly collected and tested by PCR using three different primer sets, putatively specific for Trypanozoon, T. vivax and T. congolense. With the originally designed ORPHON5J Trypanozoon primers, PCR tests became positive after 1 week (six animals) or 2 weeks (one animal) of infection and remained consistently positive until the end of the experiments, thus yielding an overall positivity rate of 97%, as compared with 74% for all parasitological tests together. The T. vivax and T. congolense primers yielded no positive PCR results.

Extension of the prophylactic effect of isometamidium against trypanosome infections in cattle using a biodegradable copolymer.

Two trials were carried out in order to compare the prophylactic effect of a subcutaneously implanted sustained release device (SRD) containing a mixture of a biodegradable copolymer, poly(caprolactone-co-L-lactide), and isometamidium (ISMM) with that obtained after intramuscular injection of the drug. In a first experiment under controlled conditions, two groups of cattle were treated with 0.5 mg/kg isometamidium either as a SRD or intramuscularly (i.m.), and exposed at monthly intervals to Glossina morsitans morsitans infected with Trypanosoma congolense. The average protection period was at least 24 months in the SRD treated against 5.7 months in the i.m. treated group. Using an ISMM enzyme-linked immunosorbent assay, the drug could be detected until 140 days post-treatment in the latter group, whereas in the former group, traces of the drug were detectable until 330 days after treatment. Furthermore, a field trial was carried out at the Madina Diassa ranch in Mali involving three groups of N'Dama cattle, each containing 23 or 24 animals. Two groups were treated with 1 mg/kg ISMM either as a SRD or i.m. and a third group served as untreated control. Twelve months after treatment, the cumulative infection rates were 56.5, 87.8 and 91.6% in the SRD implanted, the i.m. treated and the control groups, respectively. The ISMM concentrations were slightly lower than in the laboratory trial, but the overall pattern of drug disappearance from the sera of the SRD treated cattle was very similar in both trials. Statistical analysis showed that the incidence of trypanosomiasis was significantly lower in the SRD treated than in the i.m. treated group.

Seasonal prevalence of gastrointestinal nematodes in communal land goats from the highveld of Zimbabwe.

On six occasions during a 1 year period, goats run on communal pastures by small-scale farmers, were purchased, housed indoors for 3 weeks and autopsied for examination of their gastrointestinal nematode burden. All of the 32 goats examined were infected. The four dominant species, Haemonchus contortus, Trichostrongylus axei, Trichostrongylus colubriformis and Oesophagostomum columbianum, were present in 88-97% of the animals. Three other nematodes, Strongyloides papillosus, Bunostomum spp. and Trichuris spp. occurred respectively in 9%, 3% and 21% of the goats. The total nematode burden was least at the end of the dry season in November and increased gradually through the rainy season to reach a peak at the end of the rains in April. The population of H. contortus followed the same trend as that of the total worm burden. Trichostrongylus colubriformis showed a peak in April and T. axei in June. The fourth stage larvae (L4) of H. contortus accounted for 0-6.8% of the total H. contortus population during most of the year except in August, when they comprised 46.1% of the burden. It can be concluded that there is a direct relationship between rainfall and intensity of infection with gastrointestinal nematodes.

Haematological changes and antibody response in trypanotolerant sheep and goats following experimental Trypanosoma congolense infection.

Ten West African Dwarf (WAD) female goats and twelve Djallonké ewes were artificially infected with a West African strain of Trypanosoma congolense and monitored during 36 weeks over an acute phase (weeks 0-12) and chronic phase (weeks 13-36) to evaluate their haematological and immunological response. Parasitaemia, packed cell volume, red blood cells, haemoglobin, white blood cells and trypanosomal antibodies were assessed. Mean corpuscular volume and mean corpuscular haemoglobin concentration were calculated. The infected animals showed a persistent parasitaemia together with a chronic anaemia and significantly lower packed cell volume, red blood cell count and haemoglobin. The infected sheep developed a macrocytic, hypochromic anaemia during the acute phase changing to normocytic, hypochromic during the chronic phase, whereas, the infected goats developed a normocytic, normochromic anaemia during the acute phase and normocytic, hypochromic during the chronic phase. A significant increase in WBC counts was observed only in the infected sheep during the chronic phase. Trypanosomal antibody titres were significantly higher in the infected sheep than in the infected goats. Both species are regarded as trypanotolerant but Djallonké sheep mount a better haematopoietic and immunological response to infection with T. congolense than WAD goats.

Helminth parasites and hypobiosis of nematodes in N'Dama cattle during the dry season in The Gambia.

Three series of necropsies of cattle were performed, corresponding to early dry season, approximately 1 month after the last rains (November, n = 6), mid dry season (February, n = 6) and end dry season (April, n = 3). Eggs per gram of faeces (epg) were determined just before necropsy. Three trematodes (Fasciola gigantica, Schistosoma spp. and Paramphistomatids) and 11 nematodes were identified from cattle, with the prevalence rate varying from 6.7% to 100%. Haemonchus contortus was the most abundant nematode species, constituting from 81% (February) to 34.8% (April) of the total nematode burden. The proportion of L4 (indicating hypobiosis) of H. contortus was 85-99%. During the dry season, 44-67% of Oesophagostomum radiatum and 8-34% of Cooperia spp. population occurred as L4. There was no correlation between the number of worms found at necropsy and the epg. H. contortus survives almost exclusively as larvae in the abomasal mucosae, whereas Cooperia spp. and O. radiatum survive partly as larvae in the lumen, and also in nodules in the case of O. radiatum, and partly as hypometabolic adults with highly reduced fecundity. Trichostrongylus axei, T. colubriformis, Bunostomum phlebotomum, Strongyloides papillosus, Nematodirus spp. and Setaria labiatopapillosa occurred in small numbers.

The susceptibility of Djallonké and Djallonké-Sahelian crossbred sheep to Trypanosoma congolense and helminth infection under different diet levels.

Forty two Djallonké and 27 Djallonké-Sahelian crossbred sheep were compared during 34 weeks for their disease resistance and productivity in a multifactorial experiment including trypanosome infection, helminth infections and dietary level. Eight treatment combinations were formed in which the two breeds were balanced. Pyrexia was observed following trypanosome infection and was not different between the two breeds. However, a significant higher parasitaemia level, a shorter prepatent period and a lower antibody response in the crossbreds following infection, indicated a significant reduction of the trypanotolerance and confirmed the genetic origin of the trait. Neither helminth infection nor dietary level influenced the onset and level of parasitaemia or the level of antibody response following trypanosome infection. Trypanosome infection, helminth infection and low supplementary feeding caused independently significant reductions in PCV level and weight gain but these declines were not worse in crossbreds as compared to Djallonké. Independently, of the studied factors, crossbreds were generally heavier than Djallonké and also grew faster, especially during the second phase of the study. Crossbreds had significantly higher mean nematode egg output (epg) compared to Djallonké sheep but reduction of epg following deworming was similar in both breeds. The lower epg in the Djallonké breed indicated an innate resistance to helminths and/or more efficient immune response. Trypanosome infection tended to increase epg, confirming the immunosuppressive effect of the former. The higher body temperature in the Djallonké compared to crossbreds suggested a better heat tolerance in the former breed. From this study it was concluded that Djallonké-Sahelian crossbred sheep inspite of a reduced trypanotolerance and lower resistance to helminth infection, posses a higher potential to intensify mutton production as compared to the pure Djallonké. However, appropriate measures should be taken to limit disease and stress factors in order to optimise production environment for this crossbred sheep.

PCR primer evaluation for the detection of trypanosome DNA in naturally infected goats.

The buffy coat of 76 roaming goats from the Bansang and Missira regions in Gambia, was examined for the presence of trypanosomes. From these animals, extractions from dry blood samples on filter paper were subjected to PCR using three different primer sets, ORPHON5J, GOL and TVW, specific for Trypanosoma brucei/Trypanosoma evansi, Trypanosoma congolense and Trypanosoma vivax, respectively. PCR results for T. congolense were 100% concordant with buffy coat examination. Besides the three T. vivax buffy coat-positive samples, another 15 yielded positive with the TVW primers. The ORPHON5J primers yielded no positive results. Analyses with the GOL primers of putatively negative samples, yielded aberrant band patterns whose diagnostic significance still remains to be determined.

Prevalence and incidence of trypanosomosis in horses and donkeys in the Gambia.

In a study of the prevalence and incidence of trypanosomosis in horses and donkeys in two regions of the Gambia, surveys were carried out at Niamina east and Bansang south with a high and low to moderate tsetse challenge, respectively. Eleven horses and 67 donkeys were sampled monthly from August 1997 to September 1998. Blood samples were examined for trypanosomes using the buffy-coat (BC) method and polymerase chain reaction (PCR). Three primer sets were used, specific for either Trypanosoma vivax (TVW), Trypanosoma congolense (GOL) or Trypanosoma brucei (ORPHON5J). The BC results showed that the prevalence (August 1997) and the average monthly incidence (September 1997-1998) of trypanosome infections in horses (45.5 and 16%, respectively) were significantly higher than in donkeys (6.2 and 9%, respectively). Using PCR, the number of detected cases was seven times higher than using the BC. T. congolense was the most frequently observed species, followed by T. vivax and T. brucei. This study confirms earlier observations by other authors that donkeys, which are exposed to a similar tsetse challenge as horses, are significantly less infected with trypanosomes than the latter.

Trypanosoma cruzi infection of squirrel monkeys: comparison of blood smear examination, commercial enzyme-linked immunosorbent assay, and polymerase chain reaction analysis as screening tests for evaluation of monkey-related injuries.

BACKGROUND AND PURPOSE: Wild-caught New World monkeys (NWM) from Central or South America are often infected with Trypanosoma species, including T. cruzi. In humans, T. cruzi causes Chagas' disease. Even in closed monkey colonies, T. cruzi can be propagated by blood-to-blood exposure, sexual activity, and transplacental transmission. Animal handlers and laboratory staff who deal with blood and tissues from infected NWM are at riskfor acquiring Chagas' disease via accidental exposure. METHODS: We screened 162 blood samples from wild-caught Saimiri sp. monkeys for Trypanosoma species infections by use of blood smear examination, ELISA, and polymerase chain reaction (PCR) analysis. Blood samples from 19 employees with recent history of monkey-associated injuries also were tested. RESULTS: Six percent (10/162) of the monkey samples were T. cruzi positive on the basis of blood smear examination results, 10.4% (17/162) were positive by ELISA results, and 26.5% (43/162) were positive by PCR results. Other organisms identified by PCR analysis included T. rangeli in two animals, Plasmodium spp. in two animals (P. malariae confirmed by PCR results) and microfilariae in one animal (morphologically, Mansonella perstans). Evidence of trypanosome infection was not found in the 19 employee samples on the basis of results of any of the three aforementioned tests. CONCLUSIONS: Close attention must be paid to worker safety where wild-caught NWM are used. The PCR analysis has a clear advantage over conventional techniques (ELISA, blood smear) for screening NWM for trypanosome infections during quarantine and after employee injury.

Trypanosoma vivax: a simplified protocol for in vivo growth, isolation and cryopreservation.

A rodent adapted clone of Trypanosoma vivax was used to infect cyclophosphamide treated mice and rats. Fresh blood containing trypanosomes, was centrifuged in a density gradient of three Percoll solutions, 1.07, 1.06, 1.05 g/ml, respectively, carefully layered on top of each other. The yields of this simple procedure for trypanosome purification were about six times higher than those obtained with the conventional anion-exchange columns. Cryopreservation of trypanosomes using glycerol yielded 90% viable parasites, whereas using dimethylsulfoxide, a more commonly used cryoprotectant, the viability was only 35%.

Effect of a single dry season anthelmintic treatment of N'Dama cattle on communal pastures in The Gambia.

The effect of a single anthelmintic treatment of cattle during the early dry season was studied. One hundred and sixty-six N'Dama cattle, 1-3 years old, were selected from five herds. There were 65 males and 101 females divided into two groups of 83 animals each. One group was treated with fenbendazole at 7.5 mg/kg body weight by mouth in November 1992; the other group remained as the untreated control. At monthly intervals from November 1992 to April 1993, each animal was weighed and the number of eggs/g of faeces (epg) was determined. The infective larvae (L3) were examined following culture of pooled samples from each group of animals. In April 1993, 6 animals (3 treated and 3 controls) from the herds under study were necropsied. The difference in the weight gains (4.6 kg) of the two groups was highly significant (p < 0.0001). The difference in the weight gains and the epg between the treated and control groups was influenced by the age of the animals. Of the treated animals, one contained no nematodes, one contained only 25 Oesophagostomum radiatum, and the third contained 25 Cooperia L4. The three untreated animals were all infected. It was concluded that the treatment in early dry season, with an anthelmintic effective against both adults and larvae, led to a significant reduction in egg counts, to elimination of adults and hypobiotic larvae and, consequently, to an increase in the body weight gain by the treated animals.