The Importance of Lassa Fever and Its Disease Management in West Africa.

Lassa virus (LASV) is a zoonotic pathogen endemic throughout western Africa and is responsible for a human disease known as Lassa fever (LF). Historically, LASV has been emphasized as one of the greatest public health threats in West Africa, with up to 300,000 cases and 5000 associated deaths per year. This, and the fact that the disease has been reported in travelers, has driven a rapid production of various vaccine candidates. Several of these vaccines are currently in clinical development, despite limitations in understanding the immune response to infection. Alarmingly, the host immune response has been implicated in the induction of sensorineural hearing loss in LF survivors, legitimately raising safety questions about any future vaccines as well as efficacy in preventing potential hearing loss. The objective of this article is to revisit the importance and prevalence of LF in West Africa, with focus on Nigeria, and discuss current therapeutic approaches and ongoing vaccine development. In addition, we aim to emphasize the need for more scientific studies relating to LF-associated hearing loss, and to promote critical discussion about potential risks and benefits of vaccinating the population in endemic regions of West Africa.

Clinical profile and Predictors of Outcomes of Hospitalized Patients with Laboratory-Confirmed Severe Acute Respiratory Syndrome Coronavirus 2 in Nigeria: A Retrospective Analysis of 13 High Burden States in Nigeria.

Background: The majority of global COVID deaths have occurred in developed countries. Not much is known about the clinical outcomes for the patients admitted with COVID in Nigeria. We thus described the clinical characteristics, outcomes, and predictors of outcomes of hospitalized Nigerian COVID-19 patients. Methodology: We performed multilevel and mixed effects regression, Kaplan-Meir survival, and Cox proportionate hazards analyses to evaluate factors associated with death in patients admitted for COVID-19 in 13 high-burden states of Nigeria between 25th February 2020 and 30th August 2021. Results: Of the 3462 patients (median age, 40 years (interquartile range 28 years 54 years), 2,990(60.6%) were male and, 213(6.15%) of them died while on admission. Male sex (adjusted odds ratio [aOR], 1.78 [95% confidence interval {CI}, 1.23-2.56]), age group 45-65 years (OR, 3.93 [95% CI, 1.29-12.02]), age group 66-75 years (aOR, 5.37 [95% CI, 1.68-17.14]), age group > 75 years (aOR, 6.81 [95% CI, 2.04-22.82]), chronic cardiac disease (aOR, 3.07 [95% CI, 1.20-7.86]), being diabetic (aOR, 2.16 [95% CI, 1.41-3.31]), and having chronic kidney disease (OR, 11.01 [95% CI, 2.74-44.24]),were strongly associated with increased odds of death. Having concurrent malaria (aOR, 0.45 [95% CI, 0.16-1.28]), use of Azithromycin for treatment (aOR, 0.33 [95% CI, 0.19-0.54]), and use of Chloroquine/Hydroxychloroquine for treatment (aOR, 0.07 [95% CI, 0.03-0.14]) were significantly associated with decreased odds of death. Conclusions: The cumulative probability of death of male patients, diabetics, hypertensives, and patients with CKD was higher than that of female patients and those without those comorbidities while concurrent malaria and use of chloroquine/hydroxychloroquine in the treatment regimen were associated with a decreased risk of dying in patients treated in our isolation centers.

Incident Kaposi sarcoma during the expansion of antiretroviral therapy eligibility in Nigeria: a retrospective cohort study.

INTRODUCTION: The expansion of antiretroviral therapy (ART) eligibility could lead to earlier initiation of Human Immunodeficiency Virus (HIV) treatment and consequently reduce the risk of HIV-associated Kaposi Sarcoma (KS). We investigated the impact of changes in the Nigerian HIV treatment guidelines on KS incidence among adults enrolled in HIV care in Nigeria. METHODS: We analyzed data of adults who enrolled for HIV care from January 2006 to December 2016 at one of Nigeria's largest HIV treatment centers. Based on changes in HIV treatment guidelines, we classified 2006-2009 as the pre-expansion period and 2010-2016 as the post-expansion period. We used Kaplan Meier curves to compare the incidence of KS in the pre-expansion to the post-expansion period. We used Cox regression models to assess the hazard for incident KS between the two periods after adjusting for potential confounders. RESULTS: Among 14,479 patients with HIV, the overall KS incidence was 2.35; 95% CI 2.01-2.74/1,000 person-years. The incidence of KS decreased from 2.53 to 1.58 per 1,000 person-years from 2006 to 2009 to 2010-2016. In models adjusting for age, sex, CD4-T cell count, and ART use, the risk for KS remained lower in 2010-2016 compared to 2006-2009. In analyses restricted to time on ART, there was no significant difference in KS incidence between HIV patients who enrolled in 2006-2009 and 2010-2016 after adjusting for age, sex, and CD4 T-cell count. CONCLUSION: The expansion of ART eligibility was associated with a reduced incidence of HIV-associated KS among adults initiating HIV care in Jos, Nigeria. The reduction was likely driven by earlier enrollment for HIV care and ART initiation.

Analysis of sensorineural hearing loss in patients attending an otolaryngology clinic in North Central Nigeria.

Hearing loss is the third leading cause of years lived with disability. Approximately 1.4 billion people have hearing loss, of which 80% reside in low- and middle-income countries with limited audiology and otolaryngology care available to them. The objective of this study was to estimate period prevalence of hearing loss and audiogram patterns of patients attending an otolaryngology clinic in North Central Nigeria. A 10-year retrospective cohort study was carried out analyzing 1507 patient records of pure tone audiograms of patients at the otolaryngology clinic at Jos University Teaching Hospital, Plateau State, Nigeria. Prevalence of hearing loss of moderate or higher grade increased significantly and steadily after age 60. Compared to other studies, there was a higher prevalence of overall sensorineural hearing loss (24-28% in our study compared to 1.7-8.4% globally) and higher proportions of the flat audiogram configuration among the younger age patients (40% in younger patients compared to 20% in patients older than 60 years). The higher prevalence of the flat audiogram configuration compared to other parts of the world may be suggestive of an etiology specific to this region, such as the endemic Lassa Fever and Lassa virus infection in addition to cytomegalovirus or other viral infections associated with hearing loss.

A multicenter survey of asymptomatic cryptococcal antigenemia among patients with advanced HIV disease in Nigeria.

As of 2018, cryptococcal antigen (CrAg) screening in patients with advanced human immunodeficiency virus (HIV) disease (AHD) was not routinely implemented in Nigeria despite being recommended in the national HIV treatment guidelines. Our aim was to determine the prevalence and risk factors for asymptomatic cryptococcal antigenemia in adult people living with HIV (PLHIV) in Nigeria to advocate for the implementation of routine CrAg screening. A descriptive cross-sectional study and CrAg screening of consecutive adult PLHIV with CD4 counts ≤200 cells/µL was conducted from April 2018 to April 2019 at HIV clinics in eleven tertiary hospitals spread across Nigeria's six geopolitical regions. Prevalence of asymptomatic cryptococcal antigenemia was estimated by facility and geopolitical zone. Logistic regression was conducted to identify risk factors for cryptococcal antigenemia. In total, 1,114 patients with AHD were screened. The overall prevalence of asymptomatic cryptococcal antigenemia was 3.9% with wide variation across facilities (range: 0/75 [0%]- 15/122 [12.3%]) and geopolitical zones (range: 0/75 [0%]-19/279 [6.8%]). Prevalence of antigenemia was highest in the South-West (19/279 [6.8%]) and lowest in the North-East (0/75 [0%]). Prevalence was 5.2% (26/512) and 3.2% (18/561) in patients with CD4<100 and CD4 of 101-200, respectively. Of all patients with antigenemia, 50% were on antiretroviral therapy (ART) at the time of having a positive CrAg test. In adjusted analysis, cryptococcal antigenemia was significantly less in patients on ART and patients who had completed any formal education. The survey showed a high overall burden of cryptococcal antigenemia in Nigeria, with variable prevalence across geopolitical regions. We provided valuable evidence for implementing routine CrAg screening of AHD patients in Nigeria which has commenced in selected centres.

Analyses of Kaposi Sarcoma trends among adults establishing initial outpatient HIV care in Nigeria: 2006-2017.

BACKGROUND: The incidence of Human Immunodeficiency Virus (HIV)-associated Kaposi Sarcoma (KS) in the pre-antiretroviral therapy (ART) population remains high in several countries in sub-Saharan Africa. We examined trends of KS prevalence in adults, establishing initial outpatient HIV care from 2006 to 2017 in Nigeria. METHODS: We analyzed data of 16,431 adults (age ≥ 18 years) enrolled for HIV care from January 1, 2006, to December 31, 2017, in a large clinic in Jos, Nigeria. KS at enrollment was defined as KS recorded in the electronic health record within 30 days of clinic enrollment. Time trends were compared among four periods: 2006-2008, 2009-2011, 2012-2014, and 2015-2017 using logistic regression models. Annual trends were analyzed using join point regression and restricted splines. RESULTS: The study population had a mean age 35.1 (standard deviation, SD 9.5) years, and were 65.7% female (n = 10,788). The mean CD4 cell count was 220 (95% CI 117-223). The overall KS prevalence at entry was 0.59% (95% CI 0.48-0.72). Compared to 2006-2008, KS prevalence was significantly higher in 2009-2011 (adjusted odds ratio 5.07 (95% CI 3.12-8.24), p < 0.001), but remained unchanged in subsequent periods. Male sex and low CD4 T-cell count independently increased odds for KS. CONCLUSIONS: Despite ART expansion, KS at enrollment showed no significant decline. The low CD4 cell count, across all periods, indicates delay in enrollment for HIV care, which increases KS risk. Interventions aimed at early HIV diagnosis and linkage to ART is critical to KS risk reduction in this population.

A standardised Phase III clinical trial framework to assess therapeutic interventions for Lassa fever.

BACKGROUND: Only one recommendation currently exists for the treatment of Lassa fever (LF), which is ribavirin administered in conjunction with supportive care. This recommendation is primarily based on evidence generated from a single clinical trial that was conducted more than 30 years ago-the methodology and results of which have recently come under scrutiny. The requirement for novel therapeutics and reassessment of ribavirin is therefore urgent. However, a significant amount of work now needs to be undertaken to ensure that future trials for LF can be conducted consistently and reliably to facilitate the efficient generation of evidence. METHODOLOGY: We convened a consultation group to establish the position of clinicians and researchers on the core components of future trials. A Core Eligibility Criteria (CEC), Core Case Definition (CCD), Core Outcome Set (COS) and Core Data Variables (CDV) were developed through the process of a multi-stakeholder consultation that took place using a modified-Delphi methodology. RESULTS: A consensus position was achieved for each aspect of the framework, which accounts for the inclusion of pregnant women and children in future LF clinical trials. The framework consists of 8 core criteria, as well as additional considerations for trial protocols. CONCLUSIONS: This project represents the first step towards delineating the clinical development pathway for new Lassa fever therapeutics, following a period of 40 years without advancement. Future planned projects will bolster the work initiated here to continue the advancement of LF clinical research through a regionally-centred, collaborative methodology, with the aim of delineating a clear pathway through which LF clinical trials can progress efficiently and ensure sustainable investments are made in research capacity at a regional level.

Epidemiological review of confirmed Lassa fever cases during 2016-2018, in Plateau State, North Central Nigeria.

Lassa fever (LF) is endemic in West Africa and constitutes a significant public health concern due to its potential for epidemics and associated high mortality. The first reported case and management of Lassa fever in Plateau State occurred more than 50 years ago. We set out to undertake a three-year epidemiological review of LF cases in Plateau State, North Central Nigeria. This is a retrospective study of all confirmed LF cases in Plateau State between 2016 and 2018. Plateau state Lassa fever- Line list and patient case records were used to extract relevant data. Lassa PCR was carried out at the NCDC accredited Laboratory network. Data analysis was done using STATA version SE14.1. Forty-four persons (44) had confirmed LF over the examined period, 18 (41%) in 2016, 15 (34%) in 2017 and 11 (25%) in 2018. The mean age was 29.7±14.6 years and 53% were males. Sixty-six percent (66%) of the patients resided in rural areas. It affected all local government areas (LGA) in the state except Pankshin, Jos East and Kanke LGAs. Twenty-five percent (25%) of the cases occurred among underprivileged communities of Jos North and another 25% in rural dwellers of Langtang North. Fifty-nine percent (59%) of cases occurred during the 1st quarter, 27% the 2nd quarter and 18% the 3rd quarter of the year. The case fatality rate was 57%. LF is endemic in Plateau State. Prevention strategies must be sustained year round and target the youth, urban and rural underprivileged communities. There is also need for case management improvement to reduce mortality.

COVID-19 Subclinical Infection and Immunity: A Review.

The aetiologic agent of COVID-19 is a novel coronavirus, SARS-CoV-2. Like other coronaviruses, it generally induces enteric and respiratory diseases in animals and humans. COVID-19 may be subclinical, and symptomatic, ranging from mild-to-severe disease. The spectrum of presentation is the result of several factors ranging from the inoculum size, inherent host susceptibility, possible cross-reacting circulating antibodies. Subclinical viral infections are associated with widespread community transmission and in some cases like Polio, herd immunity. An understanding of the biology and immune behavior in subclinical coronavirus disease 2019 (COVID-19) might be useful in the quest for vaccine development as well as the current control efforts against the COVID-19 pandemic. We carried out a narrative review of the available literature on the biology, etiopathogenesis, clinical manifestation of SARS-CoV-2 viral infection, focusing on our current understanding of the disease mechanisms and its clinical manifestation, and the host immune response to the infection. We also highlighted some of the research gaps regarding subclinical infection in COVID-19 and its potential application for vaccine development and other preventive efforts toward containing the current COVID-19 pandemic.

At-birth vaccination timeliness: An analysis of inborns in the highlands of Jos, North-Central Nigeria.

INTRODUCTION: Immunisation and vaccination programmes are preventive and cost-effective child health interventions for reducing childhood mortality and disability from infectious diseases. Timely administration of these vaccines is important to ensure their effectiveness in disease prevention. AIM: The aim was to determine the timeliness, barriers and predictors of at-birth vaccinations. MATERIALS AND METHODS: This was a cross-sectional study of 355 mother-newborn pairs using simple random sampling technique by balloting. SPSS version 23.0 was used for data analysis. Crude and adjusted odds ratios (AORs) were used as point estimates in the binary logistic regression model, while 95% confidence interval (CI) was used as the interval estimate. A P < 0.05 was considered statistically significant for the study. RESULTS: The mean age of the mothers was 31.0 ± 6 years. The median age of newborns at vaccination was 18 h (IQR = 1 - 17) h. About 185 (52.1%) of the newborns studied were males. Only 191 (53.8%) newborns received at-birth vaccination within 24 h of life. Weekend delivery, birth outside vaccination days, delivery during public holidays and vaccine stock-outs were barriers to timely vaccinations. Private hospital delivery was an independent predictor of delayed at-birth vaccinations (AOR = 2.616; 95% CI = 1.382-4.951). CONCLUSIONS: Our study has identified weekend delivery, preterm birth, delivery outside vaccination days and vaccines stock-outs as barriers to timely at-birth vaccinations. Private hospital delivery is a significant predictor of delayed at-birth vaccinations.

Sensorineural hearing loss (SNHL) as an adverse event following immunization (AEFI): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data.

This is a Brighton Collaboration case definition of the term "Sensorineural Hearing Loss" to be utilized in the evaluation of adverse events following immunization. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for Lassa Fever and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and define levels of diagnostic certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network.

Assessment of hand hygiene facilities and staff compliance in a large tertiary health care facility in northern Nigeria: a cross sectional study.

BACKGROUND: The burden of healthcare-associated infection (HAI) is 2 to 18 times higher in developing countries. However, few data are available regarding infection prevention and control (IPC) process indicators in these countries. We evaluated hand hygiene (HH) facilities and compliance amongst healthcare workers (HCW) in a 600-bed healthcare facility in Northcentral Nigeria providing tertiary care service for a catchment population of about 20 million. METHODS: An in-house facility assessment tool and the World Health Organization (WHO) direct observation method were used to assess the HH facilities and compliance, respectively. Factors associated with good compliance were determined by multivariate analysis. RESULTS: The facility survey was carried out in all 46 clinical units of the hospital. 72% of the units had no poster or written policy on HH; 87% did not have alcohol-based hand rubs; 98% had at least one handwash sink; 28% had flowing tap water all day while 72% utilized cup and bucket; and 58% had no hand drying facilities. A total of 406 HH opportunities were observed among 175 HCWs. The overall compliance was 31%, ranging from 18% among ward attendants to 82% among medical students. Based on WHO "5 moments" for HH, average compliance was 21% before patient contact, 23% before aseptic procedure, 63% after body fluid exposure risk, 41% after patient contact and 40% after contact with patients' surrounding. Being a medical student was independently associated with high HH compliance, adjusted odds ratio: 13.87 (1.70-112.88). CONCLUSIONS: Availability of HH facilities and HCW compliance in a large tertiary hospital in Nigeria is poor. Our findings confirm that HCWs seem more sensitized to their risk of exposure to potential pathogens than to the prevention of HAI cross-transmission. Inadequate HH facilities probably contributed to the poor compliance. Specific measures such as improved facilities, training and monitoring are needed to improve HH compliance.

HIV-1 Central Nervous System Compartmentalization and Cytokine Interplay in Non-Subtype B HIV-1 Infections in Nigeria and Malawi.

HIV-1 compartmentalization in the central nervous system (CNS) and its contribution to neurological disease have been well documented. Previous studies were conducted among people infected with subtypes B or C where CNS compartmentalization has been observed when comparing viral sequences in the blood to virus in cerebrospinal fluid (CSF). However, little is known about CNS compartmentalization in other HIV-1 subtypes. Using a deep sequencing approach with Primer ID, we conducted a cross-sectional study among Nigerian and Malawian HIV-1 cohorts with or without fungal Cryptococcus infection diagnosed as cryptococcal meningitis (CM) to determine the extent of CSF/CNS compartmentalization with CM. Paired plasma and CSF samples from 45 participants were also analyzed for cytokine/chemokine levels. Viral populations comparing virus in the blood and the CSF ranged from compartmentalized to equilibrated, including minor or partial compartmentalization or clonal amplification of a single viral sequence. The frequency of compartmentalized viral populations in the blood and CSF was similar between the CM- and CM+ participants. We confirmed the potential to see compartmentalization with subtype C infection and have also documented CNS compartmentalization of an HIV-1 subtype G infection. Cytokine profiles indicated a proinflammatory environment, especially within the CSF/CNS. However, sCD163 was suppressed in the CSF in the presence of CM, perhaps due to elevated levels of IL-4, which were also a feature of the cytokine profile, showing a distinct cytokine profile with CM.

Current small animal models for LASV hearing loss.

Lassa virus (LASV) is endemic in West Africa, causing an estimated 100000-300000 new infections and up to 5000-10000 deaths yearly. There are no vaccines and therapeutics are extremely limited. Typical case fatality rates are ∼1%, although a recent 2018 Nigerian outbreak featured an unprecedented 25.4% case fatality rate. Survivors of infection suffer a lifetime of sequelae with sudden onset sensorineural hearing loss (SNHL) being the most prevalent. The cause of this hearing loss remains unknown, and there is a critical need for further research on its mechanisms and potential therapeutics. The objective of this review is to outline the only currently available small animal model for LASV-induced hearing loss and to identify potential surrogate models.

Head Circumference of Babies at Birth in Nigeria.

BACKGROUND AND OBJECTIVES: Measuring head circumference (HC) of newborns is an important tool for evaluating intra-uterine brain development. HC reference charts currently in use in Nigeria are not representative of the local population. We thus present locally derived HC reference data for Nigerian infants at birth. SUBJECTS AND METHODS: We reviewed birth records of all infants at the Jos University Teaching Hospital (JUTH) over a 10 year period from January 2006. JUTH is a tertiary care center offering obstetric services to a large population of women in Jos and its environs. All births with gestational age between 28 and 42 weeks were included in the study. STATA version 14 was used to calculate gestational age associated HC percentile measurements. RESULTS: We included 18 282 babies to generate the reference values. The mean HC value was 34.4 ± 2.1 cm (M = 34.6 ± 2.16 cm, F = 34.1 ± 2.02 cm, p < 0.001). Our HC reference values significantly differ from the USA and INTERGROWTH-21 charts currently in use in our country. Mean HC was higher in male infants compared with female infants. This difference was uniformly so across all gestational age groups. CONCLUSIONS: The use of our locally derived HC reference values could be more appropriate in defining normal head growth in Nigerian infant populations thereby improving newborn care.

Lassa Fever 2016 Outbreak in Plateau State, Nigeria-The Changing Epidemiology and Clinical Presentation.

Lassa fever (LF) outbreaks in Nigeria mostly occur in rural areas and during the dry season, peaking between December through February. Fever is a cardinal presenting feature among the myriad manifestations of LF. Thirty four patients with clinical diagnosis of LF were analyzed. However, only 11 (32%) LASV infections were confirmed by RT-PCR. The 2016 LF outbreak showed a preferential urban occurrence and a high case fatality. Fever (≥38°C) was not detected in over a fourth of the patients at the time of examination. Bleeding diathesis was the most common presentation while abdominal pain and headache were present in more than half of the confirmed cases. Changes in the geographical distribution and clinical presentation may have implications for disease control efforts and the risk of transmission, both locally and internationally. In order to guide interventions, public health authorities should be aware that the epidemic patterns may be changing.

Pathogenesis, diagnostic challenges and treatment of zika virus disease in resource-limited settings.

The association of Zika virus (ZIKV) infection with congenital malformation and neurological sequelae has brought significant global concern. Consequently, the World Health Organization (WHO) declared it "a public health emergency of International concern" on 1 February, 2016. A critical review of its pathogenesis would lead to a better understanding of the clinical features and the neurological complications. This review is based on literature search in PubMed/Medline, Google Scholar and the WHO, http://www.who.int. This include all relevant articles written in English published through June 2018, with subject heading and keywords such as Zika, ZIKV, Zika pathogenesis, diagnosis of Zika, Zika Nigeria, Zika Africa and Zika resource-limited settings. Following ZIKV infection, viraemia ensues targeting primarily the monocytes for both the Asian and African strains. ZIKV infection by an African strain appears to be more pathogenic, in early pregnancy tends to result in spontaneous abortion. Whereas an Asian strain tends to be less pathogenic and more chronic, this allows the pregnancy to continue, ultimately resulting in congenital malformations. There is no routine laboratory diagnosis of ZIKV infection in resource-constrained countries. Serologic tests should be interpreted with caution since there can be cross-reactivity with other flaviviruses, especially in Africa where the burden of infection with flaviviruses is comparatively high. There is a paucity of well-equipped laboratories for comprehensive ZIKV diagnosis. It is imperative to strengthen the health systems, improve health workforce and diagnostic capacity of such settings.

Low Zika virus seroprevalence among pregnant women in North Central Nigeria, 2016.

BACKGROUND: Zika virus (ZIKV) has been known for decades in Africa but contemporary data is lacking at large. OBJECTIVES: To describe the seroepidemiology of ZIKV in North Central Nigeria. STUDY DESIGN: We performed a cross-sectional study at six health care facilities in North Central Nigeria from January to December 2016. Detection of ZIKV antibodies was done using an anti-ZIKV recombinant non-structural protein 1 (NS1)-based ELISA. A colorimetric assay to detect ZIKV neutralizing antibodies was used on ELISA reactive and randomly selected ELISA non-reactive samples. ZIKV real-time RT-PCR was done on a subset of samples. RESULTS: A total of 468 individual samples were included with almost 60% from pregnant women. Using NS1-based ELISA, an anti-ZIKV positive rate of 6% for IgM and 4% for IgG was found. Pregnant women showed anti-ZIKV positive rates of 4% for IgM and 3% for IgG. None of the ZIKV antibody positive samples tested ZIKV RT-PCR positive. An association with male sex was found for anti-ZIKV IgG ELISA positivity (prevalence ratio 3.49; 95% confidence interval: 1.48-8.25; p = .004). No association with pregnancy, yellow fever vaccination or malaria was found for anti-ZIKV IgM or IgG positivity. ZIKV neutralizing antibodies were detected in 17/18 (94%) anti-ZIKV NS1 positive/borderline samples and in one sample without detectable ZIKV NS1 antibodies. Partial ZIKV E gene sequence was retrieved in one sample without ZIKV antibodies, which clustered within the West African ZIKV lineage. CONCLUSIONS: Our results show a largely ZIKV immunologically naïve population and reinforce the importance of ZIKV surveillance in Africa.

Lassa fever-induced sensorineural hearing loss: A neglected public health and social burden.

Although an association between Lassa fever (LF) and sudden-onset sensorineural hearing loss (SNHL) was confirmed clinically in 1990, the prevalence of LF-induced SNHL in endemic countries is still underestimated. LF, a viral hemorrhagic fever disease caused by Lassa virus (LASV), is endemic in West Africa, causing an estimated 500,000 cases and 5,000 deaths per year. Sudden-onset SNHL, one complication of LF, occurs in approximately one-third of survivors and constitutes a neglected public health and social burden. In the endemic countries, where access to hearing aids is limited, SNHL results in a decline of the quality of life for those affected. In addition, hearing loss costs Nigeria approximately 43 million dollars per year. The epidemiology of LF-induced SNHL has not been characterized well. The complication of LF induced by SNHL is also an important consideration for vaccine development and treatments. However, research into the mechanism has been hindered by the lack of autopsy samples and relevant small animal models. Recently, the first animal model that mimics the symptoms of SNHL associated with LF was developed. Preliminary data from the new animal model as well as the clinical case studies support the mechanism of immune-mediated injury that causes SNHL in LF patients. This article summarizes clinical findings of hearing loss in LF patients highlighting the association between LASV infection and SNHL as well as the potential mechanism(s) for LF-induced SNHL. Further research is necessary to identify the mechanism and the epidemiology of LF-induced SNHL.

A cross sectional study of dengue virus infection in febrile patients presumptively diagnosed of malaria in Maiduguri and Jos plateau, Nigeria.

BACKGROUND: In Nigeria, where malaria is endemic, greater than 70% of febrile illnesses are treated presumptively as malaria, often without a laboratory evaluation for other possible causes of fever. This cross-sectional study evaluated the presence of dengue virus infection in febrile patients, presumptively diagnosed of malaria infections in the clinic. METHODOLOGY: Blood samples were collected from 529 febrile patients (246 in Jos and 283 in Maiduguri) attending the general outpatient clinics of the Jos University Teaching Hospital (JUTH) and the University of Maiduguri Teaching Hospital (UMTH) and tested for anti-dengue immunoglobulin M (IgM) and immunoglobulin G (IgG), as well as anti-non-structural protein (NS1) by ELISA. The samples were also evaluated for presence of P. falciparum malaria parasites by microscopic examination of Giemsa-stained blood smears. RESULTS: The prevalence of confirmed, highly suggestive and probable dengue virus infections categorized in relation to duration of illness since onset of fever were 2.3%, 5.5% and 1.5% respectively, while the prevalence of anti-flavivirus IgG and IgM seropositivity was 11.7%. In a total of 117 (22.1%) patients (32 in Jos, 85 in Maiduguri), malaria parasites were detected by blood smear microscopy, out of which 7 (6%) also had a positively confirmed, highly suggestive or probable dengue test result. CONCLUSION: Although the high cross-reactivity of anti-flavivirus antibodies should be taken into account in the interpretation of the seroprevalence data, our findings suggest a significant presence of dengue virus in this environment, some of which may otherwise be misdiagnosed as malaria. These findings are strong enough to recommend serological screening for anti-dengue virus titer and NS1 antigen for all febrile patients, as part of fever diagnostic protocols in tropical regions. Given the prevalence of dengue virus infections, there is also a need for a dengue control program and public education to prevent outbreaks and occurrence of severe dengue complications.