[The ethical approach of small humanitarian medical non-governmental organisations (NGOs) - the example of Biology Without Borders]. / L'approche éthique des petites organisations non gouvernementales (ONG) médicales humanitaires ­ l'exemple de Biologie Sans Frontières.

In France, more than 400 non-governmental organisations (NGOs) work in the field of health; they differ in their missions and means. Nevertheless, their actions question common ethical principles, which include respect for populations and political or financial non-interference. Biologie Sans Frontières has considered these ethical aspects and has formalised a charter on the principles it defends in its actions. The creation of an ethics committee with a single charter would be unifying for all NGOs; it would also be a guarantee of respectability for international bodies such as the World Health Organisation (WHO).

[Epidemiological specificities of COVID-19 in Africa: Current or future public health concern?] / Spécificités épidémiologiques de la COVID-19 en Afrique : préoccupation de santé publique actuelle ou future ?

OBJECTIVES: Africa is the continent which is the least equipped to fight the COVID-19 epidemic. However, Africa, which represents 17 % of the world's population, is estimated to have only 5 % of global cases (source: WHO on 2020/08/04). In this work, the authors try to identify and understand the reasons for these epidemiological data. METHOD: Some follow-up indicators have been carried out, mainly through WHO reports. These data were compared with the literature and the field expertise of the association "Biologie sans frontières" in Africa. RESULTS: The following points mark the particularity of COVID-19 in Africa: (1) insufficient diagnostic capacity (linked to gross national product), (2) a younger population limiting the population at risk and the number of deaths, (3) a favourable climate (hot and humid) which is decreasing viral transmission, (4) some socio-cultural factors that can reduce cases reporting. CONCLUSION: Today, this health crisis is omnipresent while the number of deaths remains limited in Africa. Simultaneously, actions concerning African public health priorities (malaria, diarrhoea, AIDS…) are interrupted or slowed down.

Evaluation of the Aspergillus Western blot IgG kit for diagnosis of chronic aspergillosis.

Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method.

Inefficacy of alcohol-based hand rub on mites in a patient with hyperkeratotic scabies.

BACKGROUND: The World Health Organization is strongly promoting alcohol-based hand rubs to interrupt transmission of pathogens within the healthcare environment, and in some hospitals they are being recommended in cases of scabies. However, there are no studies that demonstrate the efficacy of such hand rubs against scabies. AIM: To evaluate the viability of Sarcoptes scabiei after the application of various topical antiseptics used for hand hygiene, and the effect of hand washing on the number of parasites present on the skin surface of a patient with scabies. METHODS: We applied three different topical antiseptics (two alcohol-based and one povidone-iodine-based) to the skin of one hand that was affected by scabies, and took a skin scraping of each area to evaluate the viability of the mites over time. A skin scraping of a control area without antiseptic application was also taken. We also tested the antiseptics directly on the mites. Statistical comparison between the percentages of vital mites in the different samples was assessed using the χ(2) test. We also captured a dermoscopic image of the other hand before and after hand washing to count the number of parasites on the skin surface. RESULTS: Topical antiseptics did not reduce the number of living mites compared with control skin, and hand washing did not reduce the number of parasites on the skin surface. CONCLUSIONS: Application of topical antiseptics does not reduce the viability of S. scabiei, and is therefore unable to prevent the transmission of scabies. The usefulness of hand washing in preventing transmission of scabies to new subjects remains to be investigated.

Development of high-throughput methods to quantify cysts of Toxoplasma gondii.

Toxplasma is a protozoan parasite, which forms persistent cysts in tissues of chronically infected animals and humans. Cysts can reactivate leading to severe pathologies. They also contribute to the transmission of Toxoplasma infection in humans by ingestion of undercooked meat. Classically, the quantification of cyst burden in tissues uses microscopy methods, which are laborious and time consuming. Here, we have developed automated protocols to quantify cysts, based on flow cytometry or high-throughput microscopy. Brains of rodents infected with cysts of Prugniaud strain were incubated with the FITC-Dolichos biflorus lectin and analyzed by flow cytometry and high-throughput epifluorescence microscopy. The comparison of cyst counts by manual epifluorescence microscopy to flow cytometry or to high-throughput epifluorescence microscopy revealed a good correlation (r = 0.934, r = 0.993, P < 0.001 respectively). High-throughput epifluorescence microscopy was found to be more specific and sensitive than flow cytometry and easier to use for large series of samples. This reliable and easy protocol allow the specific detection of Toxoplasma cysts in brain, even at low concentrations; it could be a new way to detect them in water and in contaminate food.

The effect of essential oils from Thymus broussonetii Boiss on transmission of Toxoplasma gondii cysts in mice.

In this study, we have evaluated the effect of essential oils of Thymus broussonetii Boiss, an endemic plant of Morocco in experimental transmission of Toxoplasma gondii cysts in mice. These oils were obtained by hydrodistillation and were administered to mice at 20 microg/animal orally at the time of infection and for several days thereafter. This resulted in total absence of intracerebral cysts in mice who received the essential oils signifying that these essential oils of thyme have a blocking effect on the appearance of the cysts. In addition, no abnormality was observed in the control mice who received the essential oils of thyme.

Fatal aspergillosis complicating severe SARS-CoV-2 infection: A case report.

As aspergillosis is a well-known complication of severe influenza, we suggest that SARS-CoV-2 might be a risk factor for invasive aspergillosis (IA). We report the case of an 87 year-old woman, with no history of immune deficit, admitted in our emergency room for severe respiratory distress. Coronavirus disease 2019 (COVID-19) diagnosis was confirmed by a SARS-CoV-2 reverse transcriptase polymerase chain reaction (PCR) on nasal swab. On day 14, pulmonary examination deteriorated with haemoptysis and a major increase of inflammatory response. A computed tomography (CT) scan revealed nodules highly suggestive of IA. Aspergillus antigen was found highly positive in sputum and blood, as was Aspergillusspp PCR on serum. Sputum cultures remained negative for Aspergillus. This patient died rapidly from severe respiratory failure, despite the addition of voriconazole. Considering SARS-CoV-2 acute respiratory distress syndrome (ARDS) as an acquired immunodeficiency, we report here a new case of "probable" IA based on clinical and biological arguments, in accordance with the last consensus definition of invasive fungal disease. On a routine basis, we have detected 30% of aspergillosis carriage (positive culture and antigen in tracheal secretions) in critically ill patients with COVID-19 in our centre. Further studies will have to determine whether sputum or tracheal secretions should be systematically screened for fungal investigations in intensive care unit (ICU) COVID-19 patients to early diagnose and treat aspergillosis.

[Toxoplasma gondii serology in pregnant woman: characteristics and pitfalls]. / Sérologie de la toxoplasmose chez la femme enceinte : caractéristiques et pièges.

Screening program of congenital toxoplasmosis depends principally on serological testing and follow-up of pregnant women with negative serology from the onset of pregnancy. This program is particularly efficient because the majority of cases of obstetrical seroconversion are diagnosed and followed up. Serological techniques have evolved with time and are many on the market. The "IgG" tests are more and more specific at the detriment of their sensitivity. The latter is variable from one technique to the other. In 2008, despite the presence of an international standard, serological titrations are particularly variable making interpretation of the kinetics impossible between two different series, two techniques or two laboratories. In cases of interpretation discordance or borderline values, it is useful to do a confirmatory technique. The dye test or the western blot are useful in these cases and prevent up to 2 to 8% of unnecessary obstetric follow up. IgM tests are becoming more and more sensitive and precocious. These tests frequently detect "non specific IgM" as well as "residual IgM" (associated with a stable positive IgG titre). In such cases and in the absence of a preceding positive result, a complementary test done by specialized laboratories (such as ISAgA IgM or IgA, IgG avidity test, differential agglutination, etc.) is indispensable in order to prevent any error of interpretation. These complementary tests as well as the serological evolution (control done in 15 days) permit, in a large number of cases, to reassure the patient with full confidence.

A technique for dating toxoplasmosis in pregnancy and comparison with the Vidas anti-toxoplasma IgG avidity test.

A comparative evaluation of 384 selected sera was performed using the Beckman Coulter Access and Abbott Axsym Toxo-IgG assays. The Axsym assay yields positive early results following infection, while the Access assay gives higher titres during chronic infection. The ratio between the two complementary tests, Axsym Toxo-IgG/Access Toxo-IgG (Ax/Ac), was compared with the Vidas anti-Toxoplasma IgG avidity index (AI). The Ax/Ac ratio decreased progressively as the time between infection and sampling increased. The mean Ax/Ac values (+/-SE) were 2.50 (+/-0.26), 2.14 (+/-0.13), 2.33 (+/-0.22), 1.34 (+/-0.09), 1.32 (+/-0.10), 0.92 (+/-0.08) and 0.74 (+/-0.07) for groups of sera sampled at 1, 2, 3, 4-5, 6-8, 9-12 and 13-24 months, respectively, after infection in pregnant women. These values were much smaller for cases with chronic infection (>24 months), i.e., 0.56 (+/-0.03), 0.44 (+/-0.04) and 0.53 (+/-0.04), respectively, for pregnant women and immunodepressed patients with and without reactivation. Taking a ratio of 1 as a threshold for recent infection, the patients in the groups sampled at 1, 2 and 3 months had Ax/Ac ratios >1 in 49/50 (98%), 53/55 (96.4%) and 36/36 (100%) cases, respectively. Thus, an Ax/Ac ratio of <1 in serum from a pregnant woman allows a recent infection (<3 months) to be excluded. This technique has the advantage of yielding positive results that develop much more rapidly than the AI, thereby helping to reassure large numbers of pregnant women and avoiding costly and unnecessary prophylactic treatment and follow-up.

Seroprevalence of T. gondii in sheep from Marrakech, Morocco.

Toxoplasma gondii is a ubiquitous intracellular protozoan parasite transmitted by food. Concerning this parasite, there are few studies done in Morocco. In this study, 261 sera from sheep intended for consumption in Marrakech were subjected to the Toxoplasma ELISA based serology test for the detection of anti-T. gondii specific IgG confirming a past infection. Of the total tested 72 (27.6%) sera were positive for IgG. This result shows that the seroprevalence approaches the world average and is similar to what is found in other cities of Morocco. This has prompted us to investigate other animal species in the region in order to evaluate the degree of contamination by this parasite as well as the potential risk incurred on consumption of their meat.

Efficacy comparison between anti-malarial drugs in Africans presenting with mild malaria in the Central Republic of Africa: a preliminary study.

Drug resistance to Plasmodium falciparum contributes to major health problems in central Africa and, as a consequence, poverty. We have analyzed the efficacy of three currently available antimalarial drugs to treat symptomatic, uncomplicated P. falciparum malaria in semi-immune adults living in Bangui, Central Republic of Africa. 210 consecutive individuals were enrolled in the survey, of which 45 were excluded. Those having received dihydroartemisin proved significantly less parasitemic than those having received quinine per os or sulfadoxin-pyrimethamin (chi2 = 16.93; p < 0.05), and 75% recovered in two days compared to 57 and 44%, respectively. The 25% who did not recover benefited from a second cure with dihydroartemisin, which proved 100% efficient. The most accurate protocol remains to be established by analyzing clinical and parasitological data and taking into account the economics of the country.

Interactive effects between trichloroethylene and pesticides at metabolic and genetic level in mice.

A combined cytogeneticurine metabolite analysis approach was used to assess potential interactive effects between Fenarimol (FN), a fungicide, and trichloroethylene (TRI), a halogenated solvent. FN was demonstrated to selectively induce P450-2B1 isoforms in different organs of treated mice. Since the rate of metabolism and the stereospecificity of metabolism are dependent on the types and amount of P450s available, FN might drastically alter the metabolic activation of a precarcinogen, such as TRI, and its toxicological consequences. Male CD1 mice were divided into untreated, vehicle control, and experimental groups. Animals of the latter groups were treated ip with 150 mg/kg bw FN in corn oil, 457 mg/kg bw TRI in corn oil, TRI plus FN separated by different time intervals. Bone marrow cells were harvested for determination of micronuclei (MN) frequencies in polychromatic erythrocytes (PCE). The presence of the known metabolite of TRI, trichloroethanol (TCE), was quantitated in collected urine by gas chromatography using an electron-capture detector. Linear regression analysis shows that MN frequency by TRI is correlated with TCE concentration in urine. Observed potentiation of genotoxicity of TRI by FN pretreatment (1 hr before TRI treatment) apparently reflects changes in the spectra of enzymes involved in TRI metabolism, and altered toxicokinetic, as witnessed by the 20% difference in TCE excretion from combined treated mice. However, no increased genetic or metabolic effects were observed when FN was administered 3 hr before TRI. No significant interactive effects were observed at a genetic level when FN was administered 1 hr and 3 hr after TRI whereas a 33 to 47% loss in TCE excretion was recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of PCR, capture ELISA and immunoblotting for detection of Toxoplasma gondii in infected mice.

PCR was compared with capture ELISA and immunoblotting for the detection of Toxoplasma gondii in sera of acutely infected mice. One hundred animals were inoculated intraperitoneally with 5000 trophozoites of RH strain and five of them were killed every 3 h from 3 h to 21 h post infection (p.i.), and every day from day 1 to day 7 p.i.. No assay detected the parasite from 3 h p.i. to 15 h p.i. PCR was the most sensitive assay and detected the T. gondii from 18 h p.i., whereas the other assays detected it only from day 1.

Experimental model of congenital toxoplasmosis in guinea-pigs: use of quantitative and qualitative PCR for the study of maternofetal transmission.

Maternofetal transmission of Toxoplasma gondii was assessed in pregnant guinea-pigs, with a gestational period of 65 +/- 5 days. A total of 56 female guinea pigs was infected by the intraperitoneal route (RH strain), by the oral or the intraperitoneal route (Prugniaud strain; PRU) or by the oral route (76K strain). Inoculation was performed 90 +/- 18 days or 30 +/- 9 days before the onset of gestation or 20 +/- 6 days or 40 +/- 6 days after. Gestational age was determined by a progesterone assay. Parasite loads (fetal brain and liver) were assessed by nested PCR and real-time PCR quantification on Light Cycler was performed with a SYBR Green I technique. The 76K strain appeared to be the most virulent in the model: the neonatal survival rate was 31%, in contrast to 53% and 68% for the PRU and RH strains, respectively. The percentage of survival of neonates for all strains taken together was lower after inoculation at 40 days' gestation (25%) than at 20 days' gestation (77%). Whatever the strain, maternofetal transmission determination was greater with nested PCR (54% for RH, 84% for PRU and 86% for 76K strains) than with real-time quantitative PCR (31% for RH, 66% for PRU and 76% for 76K strains). However, real-time quantitative PCR showed that neonatal parasite load was greater with the cystogenic strains (76K, PRU) and that high hepatic load (> 10000 parasites/g) was often associated with disease severity (11 of 12 cases). Therefore, this technique may provide an important element in understanding this congenital disease.

Influence of the quantity of nonspecific DNA and repeated freezing and thawing of samples on the quantification of DNA by the Light Cycler.

Quantification of DNA in real-time using the Light Cycler is increasingly being used for the detection and follow-up of various infectious and other diseases. We evaluated the effect of two parameters, namely the presence of nonspecific DNA and prior repeated freezing and thawing on the accurate quantification of DNA extracts from the RH strain of Toxoplasma gondii by the SYBR Green I and the Hybridization Probe techniques. For both parameters, a high copy number sample containing 5x10(5) parasites/extract and a low copy number sample containing 100 parasites/extract were tested. Reliable quantification was possible in the presence of up to 200 ng of nonspecific DNA by the SYBR Green I technique and up to 1000 ng by the Hybridization Probe technique as compared to the company threshold of 50 and 500 ng, respectively. As tissue samples usually contain more than 200 ng of nonspecific DNA, the ideal choice is the Hybridization Probe technique. The stability of DNA extracts after repeated freeze-thaw cycles was found to be dependent on the volume in which they were stored. Samples stored in 100-microl total volumes were not stable after 3 freeze-thaw cycles, whereas those stored in 1-ml total volumes were stable after 14 freeze-thaw cycles.