Perceptions of the COVID-19 Vaccine and Willingness to Receive Vaccination among Health Workers in Nigeria: A Cross-sectional Study.

BACKGROUND: COVID-19 vaccine hesitancy is a major barrier to vaccine uptake, and the achievement of herd immunity is required to reduce morbidity and mortality and protect the most vulnerable populations. In Nigeria, COVID-19 vaccine hesitancy has been high, and uptake remains very low. Healthcare workers (HCWs) in Nigeria can help support public health efforts to increase vaccine uptake. AIM: This study evaluates Nigerian HCWs' acceptance and intent to recommend the COVID-19 vaccine. SUBJECTS AND METHODS: Cross-sectional survey among 1,852 HCWs in primary, secondary, and tertiary care settings across Nigeria. Respondents included doctors, nurses, pharmacy workers, and clinical laboratory professionals who have direct clinical contact with patients in various healthcare settings. A 33-item questionnaire was used in the study, with two of the questions focused on the COVID-19 vaccine. The responses to the two questions were analyzed using Chi-square (c2) tests and independent t-tests to determine the acceptance of the vaccine. RESULTS: The majority of respondents were younger than 34 years (n = 1,227; 69.2%) and primarily worked in hospitals (n = 1,278; 72.0%). Among the respondents, 79.2% (n = 1,467) endorsed the COVID-19 vaccine as a critical tool in reducing the impact of the disease, and 76.2% (n = 1,412) will accept and recommend the vaccine to their patients. The younger HCWs were more likely to endorse and recommend the vaccine to their patients. CONCLUSION: There is a moderately high COVID-19 vaccine acceptance rate among HCWs surveyed in our study. The confidence of HCWs in its use and their willingness to recommend it to their patients can provide a potentially useful element in increasing acceptance by the larger population in Nigeria.

Plasma magnesium in adult asthmatics at the Lagos University Teaching Hospital, Nigeria.

OBJECTIVE: To determine the plasma magnesium levels in adult asthmatics. DESIGN: Case control study. SETTING: Lagos University Teaching Hospital, Lagos, Nigeria. SUBJECTS: Forty stable asthmatics and thirty five apparently healthy controls. METHODS: Detailed history including drug history was obtained from patients and controls. Fasting venous blood was collected into heparinized tubes from both patients and controls. Plasma magnesium, albumin, calcium and phosphorus were measured using spectrophotometric end point methods. RESULTS: Mean (SD) plasma magnesium concentration of 0.93(0.24) mmol/L in the asthmatics was significantly lower compared to the controls which was 1.15(0.28) mmol/L, p<0.001. There was no significant difference in the plasma albumin, calcium and phosphorus levels between the patients and controls. Plasma magnesium levels correlated with the plasma albumin level (r=0.62) but did not correlate with the duration of disease, peak flow rate and age of patients. There was no gender difference in plasma magnesium levels in the asthmatics. CONCLUSION: Adult Nigerian asthmatics have lower plasma magnesium concentrations compared to healthy controls. This may be of use in future therapeutic management of asthma. A large scale multi-centre study needs to be carried out since this study was done in one hospital.

Trypanocidal resistance in Trypanosoma evansi in vitro: effects of verapamil, cyproheptidine, desipramine and chlorpromazine alone and in combination with trypanocides.

A study was conducted in vitro to assess the ability of calcium antagonists to reverse trypanocidal resistance in Trypanosoma evansi. Susceptibility patterns of sensitive and resistant parasites were evaluated against calcium antagonists of several chemical classes (verapamil, cyproheptidine, desipramine and chlopromazine), alone and in combination with suramin, diminazene aceturate or melarsen oxide cyteamine. The putative resistance modulators were intrinsically antitrypanosomal, but were unable to reverse resistance to any of the trypanocides tested. It was thus concluded that resistance to these trypanocides in T. evansi may differ from drug resistance mechanisms occurring in cancer cells, malaria or in South American trypanosomosis, where calcium antagonists have successfully reversed resistance.

Anatomical sex conversion in a 21-year-old--case report and review of literature.

A case of anatomical sex conversion in a 21-year-old genotypic male Nigerian with ambiguous genitalia but who was reared as a girl is presented. The clinical features observed in this particular case and the result obtained after surgery, adjuvant hormone therapy and supportive psychotherapy are discussed. The relevant literature pertaining to the clinical entity is reviewed.

Differentiation of Brucella abortus and Yersinia enterocolitica serotype 09 infections in cattle: the use of specific lymphocyte transformation and brucellin skin tests.

The lymphocyte transformation test (using an in vitro whole-blood lymphocyte stimulation procedure) and the Brucellin skin test were applied to five heifers infected with virulent Brucella abortus strain 544, five cows inoculated with Yersinia enterocolitica serotype 09, and four non-exposed cows. Lymphocytes from Brucella-inoculated animals persistently gave very high blastogenic reactions indicative of active Brucella infection. The test was persistently negative in Yersinia-infected and non-exposed cattle. Four of the five cows infected with Yersinia enterocolitica type 09 and all four control cattle were persistently negative to the delayed hypersensitivity skin reaction with brucellin. All cattle infected with Yersinia enterocolitica type 09 were strongly positive to the Rose Bengal, Serum agglutination, Complement fixation and Antibovine globulin tests using Brucella abortus antigens. One lactating cow infected with Yersinia enterocolitica type 09 was positive to Brucella milk ring test. These results indicate that standard Brucella serological tests are unreliable in differentiating the two infections in cattle and that both the Lymphocyte transformation and brucellin skin tests could be used to differentiate bovine brucellosis from yersiniosis.

Comparison of the brucellin skin test with the lymphocyte transformation test in bovine brucellosis.

The brucellin skin test and the lymphocyte transformation test were compared in heifers infected with virulent Brucella abortus strain 544, heifers vaccinated against brucellosis and unexposed cattle. Results of the in vitro lymphocyte transformation test were consistently positive for all 9 Brucella-infected heifers while the skin test was consistently positive for 6 of the 9 heifers. In 7 heifers repeatedly vaccinated with B. abortus strain-19 vaccine the in vitro test classified 3 animals as positive whereas the skin test identified all the animals as infected during most of the experimental period. Four heifers injected with a single dose of B. abortus strain 19 were consistently negative to the lymphocyte transformation test while the skin test classified all the animals as infected during most of the experimental period. The skin test gave strong reactions indicative of Brucella infection in heifers vaccinated with 'Duphavac' and 'Abortox' vaccines whereas the lymphocyte transformation test was consistently negative with these vaccines. The two tests were negative in unexposed cattle. It was concluded that the in vitro test correlated better with Brucella isolation than the in vivo test did and that the lack of agreement between the results of the two tests is likely to be due to the different antigens used in the assays.

Prevalence of fleas on dogs in Anambra State of Nigeria.

An examination of 338 dogs for fleas in Anambra State revealed that 28.7% of the dogs were infested. While 2.1% of the dogs harboured the poultry flea Echidnophaga gallinacea, 26.3% harboured the dog flea Ctenocephalides canis. It was considered that Ctenocephalides canis could be of great public health significance in this area in view of the high population of the flea. Elimination of the flea was therefore recommended. The populations of fleas on dogs in other areas and the distribution of Ctenocephalides species of veterinary importance in Nigeria are briefly discussed.

Serological response of cattle following Brucella abortus strain 19 vaccination and simultaneous administration of levamisole.

The serological response of heifers to injection with Brucella abortus strain 19 vaccine and simultaneous administration of levamisole hydrochloride were compared with those of heifers inoculated with Brucella abortus strain 19 vaccine alone. The Rose Bengal, serum agglutination, complement fixation and Coombs' antibovine globulin tests were used to measure the humoral responses for a period of sixteen weeks after vaccination. The results indicated that antibody titres in the heifers injected with levamisole and the vaccine were moderately elevated. It was suggested that the heightened antibody titres were possibly mediated through helper T-cells and macrophages. The significance of using levamisole as an adjuvant with Brucella abortus strain 19 vaccine in cattle is briefly discussed.

The instability of Brucella abortus strain 45/20 and a note on significance of using an unstable rough strain in the diagnosis of bovine brucellosis.

The serum agglutinin titres of six heifers experimentally inoculated with live Br. abortus strain 45/20 were similar to those produced in six bullocks inoculated with virulent Br. abortus strain 544. However, the agglutinin response appeared slowly and disappeared earlier in the heifers than in the bullocks. It is concluded that Br. abortus strain 45/20 is an unstable strain, could revert to the smooth form and become highly agglutinogenic in non-pregnant heifers. The significance of using an unstable rough strain of Br. abortus vaccine in the diagnosis of bovine brucellosis is briefly discussed.

Differentiation of Brucella abortus and Yersinia enterocolitica serotype 09 infections: use of lymphocyte transformation test.

Cell-mediated immune responses in cattle infected with Brucella abortus Strain 544, cattle infected with Yersinia enterocolitica serotype 09 and non exposed cattle were studied by an in vitro whole-blood lymphocyte stimulation procedure. A soluble Brucella polypeptide containing some lipopolysaccharide prepared from Brucella abortus strain 99 was used as antigen while Concanavalin A was used as mitogen. Results were assayed for (6-3H) thymidine incorporation into deoxyribonucleic acid. All the cattle from which Brucella abortus was recovered developed very high lymphocyte transformation responses while cattle infected with Yersinia enterocolitica 09 and non exposed cattle did not develop high lymphocyte stimulation reactions. The animals infected with Yersinia enterocolitica 09 were strongly positive to the Rose Bengal, serum agglutination, Complement fixation and Coombs' antibovine globulin tests. One lactating cow infected with Yersinia enterocolitica 09 was positive to the Brucella milk ring test. It was concluded that the lymphocyte stimulation assay could be used to differentiate bovine brucellosis from yersiniosis.

Serological investigation on cattle vaccinated with a killed Brucella abortus strain 45/20 adjuvant vaccine.

Serum antibody reactions were monitored for a period of 18 months in 18 heifers which had been vaccinated with Brucella abortus Killed 45/20 adjuvant vaccine, using four standard serological procedures: the Rose Bengal, Serum agglutination, Complement fixation and Coombs antibovine globulin tests. The Rose Bengal and Serum agglutination tests were persistently negative during the experiment. Titres to the complement fixation test rose sharply for only four weeks after the second dose of the vaccine. Thereafter the titres fluctuated to positive levels at unpredictable intervals. One out of 14 heifers tested 12 months after vaccination was strongly positive to the complement fixation test but all the animals were absolutely negative at the end of the experiment. The Coombs test became strongly positive after the second dose of the vaccine for up to 34 weeks after primary vaccination. The animals were negative to the test at the end of the experimental period but some still retained suspicious titres. It was concluded that the Brucella abortus killed 45/20 adjuvant vaccine did not interfer stall with the Rose Bengal and Serum agglutination tests, that the fluctuations of the Complement fixation titres to positive levels at unpredictable intervals were undesirable and that the Coombs test showed little promise as an assay which would be used to differentiate antibody titres due to Brucella abortus Killed 45/20 adjuvant vaccine from those of natural infection. It would appear that the Complement fixation test and the Coombs antibovine globulin test could be safely used 12 and 18 months respectively, after immunization of cattle with the vaccine.

Evaluation of brucellin skin test for bovine brucellosis.

The diagnostic efficiency of the Brucellin skin test for bovine brucellosis was evaluated using cattle of known history. The test was negative in six out of 14 heifers (42.9%) infected with virulent Brucella abortus (Br. abortus) strain 544. In four cattle vaccinated with a reduced dose of Br. abortus strain 19 vaccine (5 X 10(9) live organisms) the skin test became positive in all the animals but two weeks after immunization. However, all the vaccinates became negative 14 weeks after vaccination, whereas nine out of 14 heifers (64.3%) vaccinated with killed Br. abortus 45/20 adjuvant vaccine (Duphavac vaccine) were still positive 18 months post immunization. Four control cattle were persistently negative. It was considered that the procedure would be most useful for testing non-exposed cattle and should be used as a screen test. It is not useful as a diagnostic test for cattle immunized with Duphavac vaccine. A recommendation is made for interpreting the Brucellin skin test for the diagnosis of bovine brucellosis in non-exposed herds.