T-cell responses to MERS coronavirus infection in people with occupational exposure to dromedary camels in Nigeria: an observational cohort study.

BACKGROUND: Middle East respiratory syndrome (MERS) remains of global public health concern. Dromedary camels are the source of zoonotic infection. Over 70% of MERS coronavirus (MERS-CoV)-infected dromedaries are found in Africa but no zoonotic disease has been reported in Africa. We aimed to understand whether individuals with exposure to dromedaries in Africa had been infected by MERS-CoV. METHODS: Workers slaughtering dromedaries in an abattoir in Kano, Nigeria, were compared with abattoir workers without direct dromedary contact, non-abattoir workers from Kano, and controls from Guangzhou, China. Exposure to dromedaries was ascertained using a questionnaire. Serum and peripheral blood mononuclear cells (PBMCs) were tested for MERS-CoV specific neutralising antibody and T-cell responses. FINDINGS: None of the participants from Nigeria or Guangdong were MERS-CoV seropositive. 18 (30%) of 61 abattoir workers with exposure to dromedaries, but none of 20 abattoir workers without exposure (p=0·0042), ten non-abattoir workers or 24 controls from Guangzhou (p=0·0002) had evidence of MERS-CoV-specific CD4+ or CD8+ T cells in PBMC. T-cell responses to other endemic human coronaviruses (229E, OC43, HKU-1, and NL-63) were observed in all groups with no association with dromedary exposure. Drinking both unpasteurised camel milk and camel urine was significantly and negatively associated with T-cell positivity (odds ratio 0·07, 95% CI 0·01-0·54). INTERPRETATION: Zoonotic infection of dromedary-exposed individuals is taking place in Nigeria and suggests that the extent of MERS-CoV infections in Africa is underestimated. MERS-CoV could therefore adapt to human transmission in Africa rather than the Arabian Peninsula, where attention is currently focused. FUNDING: The National Science and Technology Major Project, National Institutes of Health.

Diversity of Dromedary Camel Coronavirus HKU23 in African Camels Revealed Multiple Recombination Events among Closely Related Betacoronaviruses of the Subgenus Embecovirus.

Genetic recombination has frequently been observed in coronaviruses. Here, we sequenced multiple complete genomes of dromedary camel coronavirus HKU23 (DcCoV-HKU23) from Nigeria, Morocco, and Ethiopia and identified several genomic positions indicative of cross-species virus recombination events among other betacoronaviruses of the subgenus Embecovirus (clade A beta-CoVs). Recombinant fragments of a rabbit coronavirus (RbCoV-HKU14) were identified at the hemagglutinin esterase gene position. Homolog fragments of a rodent CoV were also observed at 8.9-kDa open reading frame 4a at the 3' end of the spike gene. The patterns of recombination differed geographically across the African region, highlighting a mosaic structure of DcCoV-HKU23 genomes circulating in dromedaries. Our results highlighted active recombination of coronaviruses circulating in dromedaries and are also relevant to the emergence and evolution of other betacoronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV).IMPORTANCE Genetic recombination is often demonstrated in coronaviruses and can result in host range expansion or alteration in tissue tropism. Here, we showed interspecies events of recombination of an endemic dromedary camel coronavirus, HKU23, with other clade A betacoronaviruses. Our results supported the possibility that the zoonotic pathogen MERS-CoV, which also cocirculates in the same camel species, may have undergone similar recombination events facilitating its emergence or may do so in its future evolution.

Lack of serological evidence of Middle East respiratory syndrome coronavirus infection in virus exposed camel abattoir workers in Nigeria, 2016.

BackgroundMiddle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic threat of global public health concern and dromedary camels are the source of zoonotic infection. Although MERS-CoV is enzootic in dromedaries in Africa as well as the Middle East, zoonotic disease has not been reported in Africa. Methods: In an abattoir in Kano, Nigeria, we tested nasal swabs from camels and investigated 261 humans with repeated occupational exposure to camels, many of whom also reported drinking fresh camel milk (n = 138) or urine (n = 94) or using camel urine for medicinal purposes (n = 96). Results: Weekly MERS-CoV RNA detection in January-February 2016 ranged from 0-8.4% of camels sampled. None of the abattoir workers with exposure to camels had evidence of neutralising antibody to MERS-CoV. Conclusion: There is a need for more studies to investigate whether or not zoonotic transmission of MERS-CoV does take place in Africa.

MERS coronaviruses from camels in Africa exhibit region-dependent genetic diversity.

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal-human interface.

The impact of recycled neonatal incubators in Nigeria: a 6-year follow-up study.

Nigeria has a record of high newborn mortality as an estimated 778 babies die daily, accounting for a ratio of 48 deaths per 1000 live births. The aim of this paper was to show how a deteriorating neonatal delivery system in Nigeria may have, in part, been improved by the application of a novel recycled incubator technique (RIT). Retrospective assessment of clinical, technical, and human factors in 15 Nigerian neonatal centres was carried out to investigate how the application of RIT impacted these factors. Pre-RIT and post-RIT neonatal mortalities were compared by studying case files. Effect on neonatal nursing was studied through questionnaires that were completed by 79 nurses from 9 centres across the country. Technical performance was assessed based on 10-indices scores from clinicians and nurses. The results showed an increase in neonatal survival, nursing enthusiasm, and practice confidence. Appropriately recycled incubators are good substitutes to the less affordable modern incubators in boosting neonatal practice outcome in low-income countries.

Sonographic assessment of postvoid residual urine volumes in patients with benign prostatic hyperplasia.

OBJECTIVE: To derive a formula that defines the postvoid residual (PVR) urine volume more accurately in patients with prostatic gland enlargement. DESIGN: Prospective. SETTING: Department of Radiology, University of Ilorin Teaching Hospital, Ilorin. SUBJECT: Fifty-two consecutive patients with benign prostatic hyperplasia. The mean age was 64.98+/-9.57 years. METHOD: PVR urine was evaluated by ultrasonography. Each patient had two examinations, the first of which was with a full bladder and the second of which was immediately after voiding. Two orthogonal diameters were measured on each bladder section (longitudinal and transverse) in the supine position. Fifty-two paired sets of ultrasonic measurements were thus obtained. Catheterized postvoid urine residue was regarded as the gold standard. RESULTS: Using these measurements, an equation--[PVR(CUBIC)=374.057+(-196.94+V1)+(32.5539+V1(2))+(-1.1480+V1(3)) where V1=average of the length (L), width (T), and the anteroposterior distance on transverse section (Dt) of the postvoid urinary bladder]--more accurate than previously existing ones was obtained by cubic regression analysis. Mean ultrasound estimated volume was 220.51 ml as against 220.76 ml after catheterization. The mean difference was 0.25 ml (not significant, p<0.01) with 95% confidence interval of +/-10 ml. With this equation, the ultrasonographic residual urine volume showed a higher correlation coefficient with the catheterized volume at p<0.01 (Pearson r=0.982, r2=0.96) than previously defined formulas. The standard error of the mean was 5.11 ml (mean=220.5+/-190.4 ml). CONCLUSION: With the above equation, we consider conventional transabdominal ultrasonography a reliable method for assessing the residual urine volume in patients with benign prostatic hyperplasia. This equation, though complex when compared to some of the pre-existing formulas, can be integrated into the memory of modern ultrasound machines for easy and faster computation.