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- Thomas, HS, et al.
(author)
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- 2019
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swepub:Mat__t
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- Akande, OW, et al.
(author)
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Epidemiological comparison of the first and second waves of the COVID-19 pandemic in Nigeria, February 2020-April 2021
- 2021
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In: BMJ global health. - : BMJ. - 2059-7908. ; 6:11
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Journal article (peer-reviewed)abstract
- With reports of surges in COVID-19 case numbers across over 50 countries, country-level epidemiological analysis is required to inform context-appropriate response strategies for containment and mitigation of the outbreak. We aimed to compare the epidemiological features of the first and second waves of COVID-19 in Nigeria.MethodsWe conducted a retrospective analysis of the Surveillance Outbreak Response Management and Analysis System data of the first and second epidemiological waves, which were between 27 February and 24 October 2020, and 25 October 2020 to 3 April 2021, respectively. Descriptive statistical measures including frequencies and percentages, test positivity rate (TPR), cumulative incidence (CI) and case fatality rates (CFRs) were compared. A p value of <0.05 was considered statistically significant. All statistical analyses were carried out in STATA V.13.ResultsThere were 802 143 tests recorded during the study period (362 550 and 439 593 in the first and second waves, respectively). Of these, 66 121 (18.2%) and 91 644 (20.8%) tested positive in the first and second waves, respectively. There was a 21.3% increase in the number of tests conducted in the second wave with TPR increasing by 14.3%. CI during the first and second waves were 30.3/100 000 and 42.0/100 000 respectively. During the second wave, confirmed COVID-19 cases increased among females and people 30 years old or younger and decreased among urban residents and individuals with travel history within 14 days of sample collection (p value <0.001). Most confirmed cases were asymptomatic at diagnosis during both waves: 74.9% in the first wave; 79.7% in the second wave. CFR decreased during the second wave (0.7%) compared with the first wave (1.8%).ConclusionNigeria experienced a larger but less severe second wave of COVID-19. Continued implementation of public health and social measures is needed to mitigate the resurgence of another wave.
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- Balogun, Halima A., et al.
(author)
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Immunogenicity and antigenic properties of Pf332-C231, a fragment of a non-repeat region of the Plasmodium falciparum antigen Pf332
- 2009
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In: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 28:1, s. 90-97
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Journal article (peer-reviewed)abstract
- Antigen Pf332, a megadalton protein has been shown to be associated with the membrane of infected erythrocytes. Detailed functional studies on the antigen have remained hampered by the cross-reactive nature of antibodies generated to Pf332. Pf332-C231, identified in the C-terminal region of Pf332 was cloned and antibodies against the C231 fragment were shown to react with intact Pf332 antigen by both immunofluorescence and immunoblotting analyses. Antibodies to C231 inhibited in vitro Plasmodium falciparum growth efficiently. In addition, human sera from malaria-exposed individuals reacted with recombinant C231. We show that Pf332-C231 represents a functional domain and is expected to facilitate further studies on Pf332 as a potential target for protective immune responses and the function of the antigen.
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- Nasr, Amre, et al.
(author)
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Fc gamma receptor IIa (CD32) polymorphism and antibody responses to asexual blood-stage antigens of Plasmodium falciparum malaria in Sudanese patients
- 2007
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In: Scandinavian Journal of Immunology. - Oxford : Blackwell Science. - 0300-9475 .- 1365-3083. ; 66:1, s. 87-96
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Journal article (peer-reviewed)abstract
- In a prospective clinical study in New Halfa Teaching Hospital, the possible association between FcRIIa-R/H131 polymorphism and anti-malarial antibody responses with clinical outcome of Plasmodium falciparum malaria among Sudanese patients was investigated. A total of 256 individuals were consecutively enrolled, comprising 115 patients with severe malaria, 85 with mild malaria and 56 malaria-free controls. Genotyping of FcRIIa-R/H131 dimorphism was performed using gene-specific polymerase chain reaction (PCR) amplification with allele-specific restriction enzyme digestion of the PCR product. The antibody responses to asexual blood-stage antigens were assessed by an enzyme-linked immunosorbent assay. The frequency of the FcRIIa-R/R131 genotype was significantly higher in those with severe malaria when compared with patients with mild malaria, while the FcRIIa-H/H131 genotype showed a significant association with mild malaria. A reduced risk of severe malaria with IgG3 antibodies in combination with the H/H131 genotype was observed. Furthermore, low levels of IgG2 antibodies reactive with the Pf332-C231 antigen were also associated with lower risk of severe malaria in individuals carrying the H131 allele. The levels of IgG1 and IgG3 antibodies were statistically significantly higher in the mild malaria patients when compared with the severe malaria patients. Taken together, our study revealed that the FcRIIa-R/R131 genotype is associated with the development of severe malaria, while the H/H131 genotype is more likely to be associated with mild malaria. Our results also revealed that the natural acquisition of immunity against clinical malaria appeared to be more associated with IgG1 and IgG3 antibodies, signifying their roles in parasite-neutralizing immune mechanisms.
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