Atypical Mpox in a Nigerian Tertiary Health Facility.

BACKGROUND: We describe diverse clinical characteristics and course of confirmed mpox cases managed in a Nigerian tertiary health facility. METHODS: Clinical and epidemiologic data were analyzed, highlighting the unusual presentations of polymerase chain reaction (PCR)-confirmed mpox cases observed during the 2022 outbreak. RESULTS: Out of 17 suspected cases, 13 (76.4%) were PCR confirmed for mpox. The mean ± SD age for the participants was 28.62 ± 10.29 years (range, 2-55), of which 9 (64.3%) were male. Of the 13 PCR-confirmed cases, 5 (38.5%) had varicella zoster virus coinfection, 2 (15.4%) had HIV coinfection, and 1 (7.7%) had diabetes mellitus comorbidity. All patients experienced rash, with 6 (46.2%) having significant genital lesions and 1 (7.7%) having a severe perianal lesion. A lack of prodromal symptoms was reported in 3 (23.1%), and a prolonged prodrome (>1 week) occurred in 5 (38.5%). Skin lesions were polymorphic in 6 (46.2%), and solitary skin lesions occurred in 3 (23.1%), which persisted for >120 days in 7.7%. CONCLUSIONS: Clinical recognition, diagnosis, and prevention remain a concern in resource-limited settings. Our findings highlight the need to further evaluate unusual skin lesions and to include mpox screening for genital skin lesions that are presumed to be sexually transmitted infections. Revision of clinical case definition and enhanced surveillance are key to early recognition and prevention of spread.

Field evaluation of validity and feasibility of Pan-Lassa rapid diagnostic test for Lassa fever in Abakaliki, Nigeria: a prospective diagnostic accuracy study.

BACKGROUND: Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria. METHODS: We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity. FINDINGS: Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read. INTERPRETATION: The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings. FUNDING: Médecins Sans Frontières.

Immunological insights into COVID-19 in Southern Nigeria.

Introduction: One of the unexpected outcomes of the COVID-19 pandemic was the relatively low levels of morbidity and mortality in Africa compared to the rest of the world. Nigeria, Africa's most populous nation, accounted for less than 0.01% of the global COVID-19 fatalities. The factors responsible for Nigeria's relatively low loss of life due to COVID-19 are unknown. Also, the correlates of protective immunity to SARS-CoV-2 and the impact of pre-existing immunity on the outcome of the COVID-19 pandemic in Africa are yet to be elucidated. Here, we evaluated the natural and vaccine-induced immune responses from vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria throughout the three waves of the COVID-19 pandemic in Nigeria. We also examined the pre-existing immune responses to SARS-CoV-2 from samples collected prior to the COVID-19 pandemic. Methods: We used spike RBD and N- IgG antibody ELISA to measure binding antibody responses, SARS-CoV-2 pseudotype assay protocol expressing the spike protein of different variants (D614G, Delta, Beta, Omicron BA1) to measure neutralizing antibody responses and nucleoprotein (N) and spike (S1, S2) direct ex vivo interferon gamma (IFNγ) T cell ELISpot to measure T cell responses. Result: Our study demonstrated a similar magnitude of both binding (N-IgG (74% and 62%), S-RBD IgG (70% and 53%) and neutralizing (D614G (49% and 29%), Delta (56% and 47%), Beta (48% and 24%), Omicron BA1 (41% and 21%)) antibody responses from symptomatic and asymptomatic survivors in Nigeria. A similar magnitude was also seen among vaccinated participants. Interestingly, we revealed the presence of preexisting binding antibodies (N-IgG (60%) and S-RBD IgG (44%)) but no neutralizing antibodies from samples collected prior to the pandemic. Discussion: These findings revealed that both vaccinated, non-vaccinated and convalescent individuals in Southern Nigeria make similar magnitude of both binding and cross-reactive neutralizing antibody responses. It supported the presence of preexisting binding antibody responses among some Nigerians prior to the COVID-19 pandemic. Lastly, hybrid immunity and heterologous vaccine boosting induced the strongest binding and broadly neutralizing antibody responses compared to vaccine or infection-acquired immunity alone.

An Epidemiological Investigation of Lassa Fever Outbreak in Ebonyi State South Eastern Nigeria Lessons Learnt (January to March 2018).

Background: We investigated an outbreak of Lassa fever that occurred in Ebonyi state, Southeast Nigeria from January to March 2018. Methodology: The Emergency operational centre (EOC) model was used for the outbreak coordination. Cases and deaths were identified through the routine surveillance system. Blood specimens collected from suspected cases were sent for confirmation at the Virology Centre, Alex Ekwueme Federal University Teaching Hospital, Abakaliki (AEFUTHA). Active case search was instituted, and identified contacts of confirmed cases were followed up for the maximum incubation period of the disease. Other public health responses included infection prevention and control, communication and advocacy as well as case management. Data collected were analysed using the Epi info statistical software package. Results: We identified 89 suspected Lassa Fever (LF) cases out of which 61 were confirmed. The mean age was 35±16.2 and the age group mostly affected was 30-39 years. More than half (59.7%) of the confirmed cases were females. The Case Fatality Rate (CFR) was 26.2% among the laboratory confirmed cases. Five of the deaths occurred among health care workers. Out of 325 contacts of the confirmed cases, 304(99.7%) completed the follow-up and only 1(0.3%) of them developed symptoms consistent with LF and was confirmed by the laboratory. Conclusions: The high CFR in those presenting late to the hospital underscores the need for intensive public enlightenment that encourages early presentation to hospital. Majority of the confirmed cases were primary cases, hence efforts should be intensified in breaking the chain of transmission in the animal-man interphase. Death of healthcare workers involved in management of Lassa fever raises the importance of providing life insurance for concerned healthcare workers.

Positivity Rate, Predictors, and Outcome of Paediatric Lassa Fever Disease (LFD) in a Lassa Fever Endemic State, South-East Nigeria.

Background: The pattern and case fatality rate of Paediatric Lassa fever disease (LFD) is not well documented even in Lassa fever endemic communities. Aim and Objective: This prospective observational study was aimed at determining the pattern and outcome of Paediatric LFD. Methodology: A total of 183 children that met the criteria for LFD suspects were subjected to the Lassa virus PCR test. The suspects that tested positive were recruited into the study and a structured questionnaire was used to collect information on socio-demographics. Results: Of the 183 LFD suspects that were tested, 24 of them were positive to Lassa virus PCR, giving a positivity rate of 13.1%. The mean duration of illness before hospital presentation was 8.54 ± 3.83 days. All the subjects had a history of fever. Abdominal pain and vomiting were the two highest presenting complaints after fever. Seven out of 24 children died during the study period, giving a case fatality rate (CFR) of 29.2%. Subjects who presented with convulsions and unconsciousness (OR =10.00, 95% CI= 1.2, 81.81, p=0.020), bleeding (OR =40.00, 95% CI= 12.96, 539.67, p=0.020), poor urine output (OR =40.00, 95% CI= 12.96, 539.67, p=0.020) were more likely to die of LFD compared to their colleagues without such symptoms. Conclusion: The positivity rate and case fatality rate of LFD in children were high. Public enlightenment on the common features of Lassa fever disease and the need to seek health care early for children with febrile illness is advocated.

Possible artemisinin-based combination therapy-resistant malaria in Nigeria: a report of three cases

Artemisinin-based combination therapy-resistant malaria is rare in Sub-Saharan Africa. The World Health Organization identifies monitoring and surveillance using day-3 parasitaemia post-treatment as the standard test for identifying suspected artemisinin resistance. We report three cases of early treatment failure due to possible artemisinin-based combination therapy-resistant Plasmodium falciparum malaria. All cases showed adequate clinical and parasitological responses to quinine. This study reveals a need to re-evaluate the quality and efficacy of artemisinin-based combination therapy agents in Nigeria and Sub-Saharan Africa.