Understanding the influence of the COVID-19 pandemic on hospital-based mortality in Burundi: a cross-sectional study comparing two time periods

This study used hospital records from two time periods to understand the implication of COVID-19 on hospital-based deaths in Burundi. The place of COVID-19 symptoms was sought among deaths that occurred from January to May 2020 (during the pandemic) vs. January to May 2019 (before the pandemic). First, death proportions were tested to seize differences between mortality rates for each month in 2020 vs. 2019. In the second time, we compared mean time-to-death between the two periods using the Kaplan-Meier survival curve. Finally, a logistic regression was fitted to assess the likelihood of dying from COVID-19 symptoms between the two periods. We found statistical evidence of a higher death rate in May 2020 as compared to May 2019. Moreover, death occurred faster in 2020 (mean = 6.7 days, s.d. = 8.9) than in 2019 (mean = 7.8 days, s.d. = 10.9). Unlike in 2019, being a male was significantly associated with a much lower likelihood of dying with one or more COVID-19 symptom(s) in 2020 (odds ratio 0.35, 95% confidence interval 0.14-0.87). This study yielded some evidence for a possible COVID-19-related hospital-based mortality trend for May 2020. However, considering the time-constraint of the study, further similar studies over a longer period of time need to be conducted to trace a clearer picture on COVID-19 implication on hospital-based deaths in Burundi.

Analysis of Xanthomonas oryzae pv. oryzicola population in Mali and Burkina Faso reveals a high level of genetic and pathogenic diversity

Bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola was first reported in Africa in the 1980s. Recently, a substantial reemergence of this disease was observed in West Africa. Samples were collected at various sites in five and three different rice-growing regions of Burkina Faso and Mali, respectively. Sixty-seven X. oryzae pv. oryzicola strains were isolated from cultivated and wild rice varieties and from weeds showing BLS symptoms. X. oryzae pv. oryzicola strains were evaluated for virulence on rice and showed high variation in lesion length on a susceptible cultivar. X. oryzae pv. oryzicola strains were further characterized by multilocus sequence analysis (MLSA) using six housekeeping genes. Inferred dendrograms clearly indicated different groups among X. oryzae pv. oryzicola strains. Restriction fragment length polymorphism analysis using the transcriptional activator like effector avrXa7 as probe resulted in the identification of 18 haplotypes. Polymerase chain reaction-based analyses of two conserved type III effector (T3E) genes (xopAJ and xopW) differentiated the strains into distinct groups, with xopAJ not detected in most African X. oryzae pv. oryzicola strains. XopAJ functionality was confirmed by leaf infiltration on 'Kitaake' rice Rxo1 lines. Sequence analysis of xopW revealed four groups among X. oryzae pv. oryzicola strains. Distribution of 43 T3E genes shows variation in a subset of X. oryzae pv. oryzicola strains. Together, our results show that African X. oryzae pv. oryzicola strains are diverse and rapidly evolving, with a group endemic to Africa and another one that may have evolved from an Asian strain.

First Report of Xanthomonas citri pv. citri Causing Asiatic Citrus Canker in Burkina Faso

Citrus canker, caused by Xanthomonas citri pv. citri, is a bacterial disease of economic importance in tropical and sub-tropical citrus-producing areas (EPPO-PQR online database). X. citri pv. citri causes severe infection in a wide range of citrus species, and induces erumpent, callus-like lesions with water-soaked margins leading to premature fruit drop and twig dieback. It has consequently been subjected to eradication efforts and international regulations. It was first described on the African continent in South Africa at the beginning of the 20th century, from which it was eventually eradicated. Since 2006, several outbreaks caused by phylogenetically diverse strains of X. citri pv. citri have been reported from several African countries (Ethiopia, Mali, Senegal, and Somalia). In July 2011, citrus canker in Burkina Faso was suspected in the area adjacent to the Sikassso Province of Mali where X. citri pv. citri has been confirmed. In November and December 2012, leaves of clementine (Citrus clementina), lemon (C. limon), Volkamer lemon (C. volkameriana), sweet orange (C. sinensis), tangelo (C. paradisi× C. reticulata), and mandarin (C. reticulata) were collected from orchards with trees showing symptoms of citrus canker in the Comoé, Houet, and Kénédougou provinces of Burkina Faso. Isolations performed using KC semi-selective medium (4) recovered 45 Xanthomonas-like strains. All Xanthomonas-like strains were tentatively identified as X. citri pv. citri by PCR (4/7 primers) using IAPAR 306 and sterile distilled water as the positive and negative controls, respectively (3). Among these, two strains (LK4-4 and LK4-5) produced a 'fuscans'-like brown diffusible pigment, a phenotype never reported previously for X. citri pv. citri. MultiLocus Sequence Analysis targeting six housekeeping genes (atpD, dnaK, efp, gltA, gyrB, and lepA) (1,2) fully identified seven strains from Burkina Faso (LJ301-1, LJ303-1, LK1-1, LK2-6, LK4-3, LK4-4, and LK4-5) as X. citri pv. citri (and not to any other Xanthomonas pathovars pathogenic to citrus or host range-restricted pathotypes of pathovar citri), and more specifically as sequence type ST2 which is composed mostly of pathotype A strains of X. citri pv. citri (2). The same seven strains were inoculated to at least four leaves of each of grapefruit cv. Henderson, Mexican lime SRA 140 (C. aurantifolia), Tahiti lime SRA 58 (C. latifolia), and sweet orange cv. Washington Navel, using a detached leaf assay (2). All strains developed typical erumpent, callus-like tissue at wound sites on all citrus species inoculated. No lesions developed on the negative control (sterile 10 mM tris buffer). Koch's postulate was fulfilled after reisolation of Xanthomonas-like yellow colonies from symptoms on Mexican lime produced by the seven strains. Boiled bacterial suspensions were assayed by PCR with 4/7 primers (3) and produced the expected 468-bp amplicon in contrast with the PCR negative control. To our knowledge, this is the first report of X. citri pv. citri in Burkina Faso. Citrus canker-free nurseries and grove sanitation should be implemented for reducing the prevalence of Asiatic canker in Burkina Faso and a thorough survey of citrus nurseries and groves in the region should be conducted. References: (1) N. F. Almeida et al. Phytopathology 100:208, 2010. (2) L. Bui Thi Ngoc et al. Int. J. Syst. Evol. Microbiol. 60:515, 2010. (3) J. S. Hartung et al. Phytopathology 86:95, 1996. (4) O. Pruvost et al. J. Appl. Microbiol. 99:803, 2005.

First Report of Bacterial Leaf Streak Caused by Xanthomonas oryzae pv. oryzicola on Rice in Burkina Faso

Bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola is prevalent in Asia where it can decrease yield by as much as 30%. In Africa, BLS has been reported in Madagascar, Nigeria, Senegal, and recently in Mali (1). The pathogen is seed transmitted and rice seeds can be a source of primary inoculum (3). In October 2009, leaf streak symptoms were observed on 3-month-old field rice grown in three regions of Burkina Faso (Haut-Bassin, Cascades, and East Center). Disease was found on cultivated Oryza sativa (varieties TS2, FKR19, and FKR56N), wild rice species (O. longistaminata and O. barthii), and weeds. Symptoms consisted of water-soaked lesions that developed into translucent, yellow streaks with visible exudates at the leaf surface. Yellow-pigmented Xanthomonas-like colonies were isolated on PSA semiselective medium (peptone 10 g, sucrose 10 g, bacto agar 16 g, distilled water 1,000 ml, actidione 50 mg liter^-1, cephalexin 40 mg liter^-1, and kasugamycin 20 mg liter^-1). A multiplex PCR developed for the identification of Xanthomonas oryzae pathovars (2) was used to check the identity of Xanthomonas-like isolates. X. oryzae pv. oryzicola strains BLS256 from the Philippines and CFBP 7331 from Mali were used as positive controls. Three expected DNA fragments (331, 691, and 945 bp) corresponding to X. oryzae pv. oryzicola were obtained from all isolates using the multiplex PCR. No fragment was observed for negative controls (distilled water as the template). Five X. oryzae pv. oryzicola isolates were further analyzed by sequence analysis using portions of the gyrB housekeeping gene together with reference strains. Two sequence types were identified among Burkinabe isolates differing by only one nucleotide. When compared with the nucleotide database with BLAST, three isolates (BAI6, BAI15, and BAI19) were 100% identical to the type culture strain X. oryzae pv. oryzicola BLS256 (gyrB sequence was obtained from GenBank AAQN01000001.1) while the other two (BAI5 and BAI20) demonstrated 99% sequence similarity. The nucleotide sequence of isolate BAI5 was submitted to GenBank (HQ112342). Pathogenicity tests were performed on greenhouse-grown 3-week-old rice plants cv. Nipponbare. Cultures were grown overnight in PSA medium and adjusted in sterile water to 1 × 10⁸ CFU/ml and inoculated into rice leaves with the blunt end of a 1-ml syringe. Four infiltrations were done per isolate per leaf and two leaves were inoculated per plant. Control plants were inoculated with sterile water. After 15 days of incubation in the greenhouse at 27 ± 1°C with a 12-h photoperiod, inoculated leaves exhibited water-soaked lesions with yellow exudates that were identical to symptoms seen in the field. Control plants remained symptomless. Colonies with morphology typical of Xanthomonas were recovered from the symptomatic leaves and typed using multiplex PCR to fulfill Koch's postulates. Three isolates have been deposited in the Collection Française de Bactéries Phytopathogènes (CFBP) and identified as X. oryzae pv. oryzicola strains CFBP7341-43. To our knowledge, this is the first report of X. oryzae pv. oryzicola in Burkina Faso. Further surveys and strain collection will be necessary to evaluate the geographic distribution and prevalence of BLS in Burkina Faso and neighboring countries. References: (1) C. Gonzalez et al. Mol. Plant-Microbe Interact. 20:534, 2007. (2) J. Lang et al. Plant Dis. 94:311, 2010. (3) G. Xie and T. Mew. Plant Dis. 82:1007, 1998.

[Retrospective study of urogenital fistula in Burkina Faso from 2001 to 2003]

The purpose of this study was to analyze aspects of obstetric urogenital fistulae to provide a foundation for implementation of a national control program in Burkina Faso. A cross-sectional study with quantitative and qualitative components was carried out in 47 hospitals in January 2004. The quantitative component consisted of analyzing available data for 2001, 2002 and 2003. The qualitative component consisted of interviewing women with fistulae to evaluate the impact of the disease on the quality of life and persons in charge of the health reference centers to identify the difficulties and needs of the facility. In the 3-year study period, 1,500,000 deliveries were attended and 347 fistulae were identified in the health reference centers. The incidence rate of obstetric fistulae was 23.1 per 100 000 deliveries (CI 95% 20.8-25.7). Women with fistulae were young and usually without paid employment. Many had a history of dystocia during the labor. Most fistulae were recent, small or average in size and located at the level of the vesico-vaginal septum. The failure rate of surgical treatment was about 17.5%. Four of the 12 women interviewed reported social alienation and ostrasization. Only 4 of the 47 hospitals studied had a personnel qualified to manage women with urogenital fistula on a daily basis. One NGO assisted women in obtaining care. Proposals for improvement of the situation were considered at a national validation workshop. These findings support the need to implement a national program that should be evaluated to see lessons learned from this study.

Receptors involved in the positive inotropic action induced by dopamine on the ventricle of a 7-day-old chick embryo heart

Earlier experiments only revealed involvement of sympathetic pre-synaptic dopaminergic receptors in dopamine induced inotropism in myocardium. We therefore used electrically stimulated (1 Hz) isolated 7-day-old chick embryo heart ventricles, thought to be devoid of functional sympathetic nerves, to re-investigate post-synaptic receptors involvement and particularly that of dopaminergic receptors in the positive inotropic effect of dopamine. The results showed that noradrenaline, isoprenaline and dopamine produced a positive inotropic effect with a similar efficacy and with an order of potency as follows: Isoprenaline = Noradrenaline > Dopamine. Tyramine induced no significant modification of the "initial tension" indicating that functional sympathetic innervation and/or releasable endogenous catecholamines were not demonstrable in the 7-day-old chick embryo heart ventricle. Propranolol (1 microM) competitively antagonized the positive inotropic response to isoprenaline, noradrenaline and dopamine, meanwhile phentolamine (3 microM) failed to significantly modify the effects of both noradrenaline and dopamine, indicating that these catecholamines induced their positive inotropic effects via stimulation of beta-adrenoceptors; involvement of alpha-adrenergic receptors stimulation was not demonstrable in these effects. Moreover, haloperidol (2 microM) antagonized the positive inotropic response to dopamine but had not any significant effect on the response to isoprenaline. The combined application of both propranolol and haloperidol antagonized the positive inotropic response to dopamine to a greater extent than when these two antagonists were given alone. Consequently, post-synaptic dopaminergic receptors were also involved in the positive inotropic effect of dopamine. Furthermore, in preparations in which sodium channels were inactivated by high potassium physiological salt solution, high concentrations of dopamine (0.1 mM to 1 mM) induced a slow developing electrical and positive inotropic responses which were also inhibited by propranolol and haloperidol, but not by phentolamine. These latter results indicated that like beta-adrenergic stimulation, the slow inward calcium current activated by stimulation of adenylate cyclase, was at least in part involved in the positive inotropic response to dopamine. In conclusion, dopamine induced its positive inotropism via stimulation of post-synaptic beta-adrenergic and dopaminergic receptors. The contribution of dopaminergic receptors in this positive inotropic effect might be of the DA-2 receptors since haloperidol used had been reported to be more DA-2 than DA-1 antagonist. These DA-2 receptors subtypes would mediate activation of adenylate cyclase.

[Inotropic effect of isoprenaline and noradrenaline on chick embryo heart]

Isolated ventricles of developing chick embryo heart, paced at 1 Hz, were used to assess the positive inotropic responses to isoprenaline and noradrenaline in order to characterize the adrenergic receptors involved in these effects. In 7 day-old-chick embryo heart ventricle, isoprenaline and noradrenaline exhibited similar potencies and efficacies. Moreover, propranolol (1 microM) inhibited the positive inotropic effect of isoprenaline and noradrenaline, while pentholamine (3 microM) failed to affect the latter response; in addition, phenylephrine (1 microM-1 mM) had no positive inotropic effect. It was therefore concluded that isoprenaline and noradrenaline induce their effect via stimulation of beta-adrenergic receptors. The efficacy of isoprenaline and noradrenaline and the potency of isoprenaline increased from the 7th to 10th day while the potency of noradrenaline decreased. The decrease in noradrenaline potency with age was attributed to its uptake, while the increase in isoprenaline potency was attributed to the increase in beta-adrenergic receptors. However, the increase in efficacy of both isoprenaline and noradrenaline with age might be due to the higher density and/or higher maturity of contractile proteins.

[Malaria morbidity in a hospital environment in Burkina Faso (West Africa)]

We carried out a study on malaria morbidity from November 1982 to October 1983 in the Pediatric Department of the Hospital of Bobo Dioulasso (Burkina Faso, West Africa). Malaria fever attacks were present in 21.4% of all febrile cases. The highest rate was observed in the 2-4 age group (42%). We observed 97.4% of all malaria fever attacks during the rainy season and the beginning of the dry season (June to December).