Lassa Fever: Patients Profile and Treatment Outcomes at Benue State University Teaching Hospital Makurdi, North-Central Nigeria

Lassa fever is a viral haemorrhagic fever found mostly in West Africa where it is endemic but generates periodic outbreaks in the dry seasons. The virus is spread by the rat species named mastomys natalensis. While the illness is minor in most cases, the mortality is significant in hospitalized patients. Few completely equipped treatment centers existed in Nigeria previous to current increase in frequency requiring demand for new treatment centers without the full complement of essential capabilities. Aim: To analyze the profile and treatment outcome in patients hospitalized in one of such new resource-constrained centers at the Benue State University Teaching Hospital Makurdi, Nigeria. Methodology: This was a retrospective, descriptive hospital-based research encompassing January 2020 to March 2023. Medical records of those admitted to the isolation center were reviewed. The relevant data was coded and analyzed using IBM SPSS version 23. Results: One hundred and ten (110) individuals were hospitalized for probable or suspected Lassa fever throughout the research period. A total of 35 confirmed patients satisfied the inclusion criteria and were included as the study subjects. There were 23 (65.7%) men and 12 (34.3%) females. Their mean age was 35.36 ± 12.21 years (range 15-61 years). The treatment outcome showed that 24 (75%) survived and were discharged, 5 (15.6%) were referred out of the facility for dialysis and 3 died, providing a mortality of 8.6%. The causes of mortality in study patients were acute kidney injury and encephalopathy. Conclusion: Lassa fever is endemic in Benue state with all types of individuals afflicted. The outcome of treatment was good despite resource difficulties. Lassa fever can be successfully managed even in resource-challenged situations typically encountered in developing countries.

Clinical Presentations of Lassa Fever in Non-Endemic Parts of the World: A Systematic Review

Background: Lassa fever cases outside Africa are seen as imported cases of Lassa fever. Timely diagnosis of imported Lassa fever is important for timely intervention necessary to reduce the morbidity and mortality associated with Lassa fever, and this requires the knowledge of the clinical manifestations of Lassa fever. Purpose: This review was done to see how clinical diagnosis of imported Lassa fever can be facilitated based on the clinical presentations of imported cases of Lassa fever in Lassa fever non-endemic region. Methods: The relevant articles for the review were obtained from the databases of PubMed and Google Scholar. Results: The clinical presentations of the imported Lassa fever cases consisted of multisystem involvement and were similar to those of Lassa fever patients who were treated in the Lassa fever endemic region. Conclusions: History of recent travel to, or residence in, Lassa fever endemic region is an important clue for clinical diagnosis of Lassa fever. The 2011 CDC surveillance case definition and the modified Khan case definition for Lassa fever may aid clinical diagnosis of Lassa fever. Any clinically suspected case of Lassa fever should have a laboratory confirmation.

Lassa Fever Case Report: Challenges in Making Early Diagnosis

Introduction: Lassa fever is a disease of public health importance because of the associated morbidity and high case fatality rate among hospitalized patients. Even after recovery, there may be residual problems such as sensorineural hearing loss. The initial presentation of Lassa fever may be with non-specific symptoms similar to what is seen in the more common febrile illnesses such as malaria or typhoid fever. In such a setting therefore, timely diagnosis of Lassa fever may be difficult. Case Report: We report a case of Lassa fever that presented to our institution. She was a middle aged woman who had non-specific symptoms of febrile illness and who died in less than 48 hours of admission. She had a subtle bleeding on the lip just before death which was what raised the suspicion for Lassa fever. Laboratory confirmation of Lassa fever was made retrospectively. Conclusion: When the presenting symptoms are non-specific, a high index of suspicion is required for timely recognition of Lassa fever. Early diagnosis is important for prompt therapeutic intervention as well as for limiting the spread of the disease. This is the second case of Lassa fever presenting to our hospital, but the first published case of Lassa fever from our hospital.

Hearing Loss in Lassa Fever: A Systematic Review

Background: Lassa fever is a viral haemorrhagic fever associated with several complications which include hearing loss. Hearing loss in Lassa fever may become residual with its negative impact on the quality of life. Purpose: This paper is a review of various studies on Lassa fever related hearing loss. Methods: Systematic literature review was done on articles on Lassa fever patients and Lassa fever survivors. Relevant articles published in English between 1969 and 2021 were searched for using Google Scholar and PubMed databases. Eight studies which met the inclusion criteria were finally selected and included in the review. The variables of interest were extracted from the full-text articles. Results: Lassa fever related hearing loss occurs in both sexes and in all age groups. The incidence of self-reported hearing loss ranged from 12.5% to 30% with a mean of 17.6%. The incidence of audiometrically determined sensorineural hearing loss ranged from 13.5% to 29% with a mean of 22.1%. Hearing loss persisted in 64% of those that were followed up. Cases of hearing loss varied in severity, ranging from mild to profound. No successful specific treatment for Lassa fever related hearing loss was reported apart from hearing rehabilitation. Conclusion: Hearing loss among Lassa fever patients remains a major challenge. Lack of effective treatment for Lassa fever related hearing loss is a serious gap in the management of Lassa fever patients which should be addressed in future research.

Epidemiological Pattern of Lassa Fever Outbreak in Ondo State, Southwest Nigeria, 2014 to 2019

Introduction: Annual outbreak of Lassa Fever (LF) has been reported in Ondo State over the years. We analyzed LF surveillance data from January 2014 to December 2019 to describe the epidemiological pattern of the outbreak. Method: Lassa fever dataset from January 2014 to December 2019 was obtained from the State Ministry of Health. Variables analyzed include date of onset of symptom, age, gender, place (Local Government Area, LGA) and outcome of laboratory test. Data were summarized using frequencies, proportions, chart and maps. Results: From January 2014 and December 2019, 2141 suspected LF cases were reported. Of these, 551 cases were laboratory confirmed with 134 deaths recorded. The LF cases (suspected vs. confirmed) reported increased in 2016 (73 vs. 19), 2017 (207 vs. 76), 2018 (452 vs. 159) and 2019 (856 vs. 285) respectively. Most of the confirmed cases (89.5%) were ≥15 years while more than half (53.7%) were males. Prior to 2016, only two LGAs (Owo and Ose) recorded continued transmission of the disease. However, between 2016 and 2019, the disease had spread to 8 neighboring LGAs (P < 0.001) with the CFR declining from 67% in 2015 to 20% in 2019. Conclusion: We found an unusual increase in the suspected LF cases reported between January 2016 and December 2019 with a corresponding increase in the confirmed cases and high annual case fatality rates. Hence, we recommend intensified surveillance activities to enhance timely reporting of cases and laboratory confirmation to ensure early commencement of treatment to reduce the case fatality rate.

Understanding the transmission pathways of Lassa fever:A mathematical modeling approach

The spread of Lassa fever infection is increasing in West Africa over the last decade.The impact of this can better be understood when considering the various possible transmission routes.We designed a mathematical model for the epidemiology of Lassa Fever using a system of nonlinear ordinary differential equations to determine the effect of transmission pathways toward the infection progression in humans and rodents including those usually neglected such as the environmental surface and aerosol routes.We analyzed the model and carried out numerical simulations to determine the impact of each transmission routes.Our results showed that the burden of Lassa fever infection is increased when all the transmission routes are incorporated and most single transmission routes are less harmful,but when in combination with other transmission routes,they increase the Lassa fever burden.It is therefore important to consider multiple transmission routes to better estimate the Lassa fever burden optimally and in turn determine control strategies targeted at the transmission pathways.

Screening of Rodents from Rural Communities of Lagos and Ogun State Nigeria of Lassa Virus RNA

Background: In recent times, there has been an increase in the number of Lassa fever cases resulting from the several episodes of Lassa fever epidemics ravaging Nigeria and other West African countries. The presence of Lassa virus in rodents other than the major reservoir (Mastomys natalensis) has been a public health concern as to the actual burden of the disease. It is therefore of a public health necessity to explore the LASV RNA habouring potential of several species of rodents in endemic as well as non-endemic areas for proper prevention of emergence of outbreaks in non-endemic areas. Objectives: The aim of this study was to detect the presence of LASV RNA in different species of rodents in Ikorodu, Lagos state and Abeokuta, Ogun state. Methods: A total of ninety one (91) rodents were captured from Ikorodu, Lagos State (61 rodents) and Abeokuta, Ogun State (30 rodents), euthanized, bled, and plasma obtained for the detection of LASV RNA by Reverse Transcriptase Polymerase Chain Reaction. Results: A total of 91 rodents consisting of 77 Rattus rattus and 14 Crocidura spp. The S segment of LASV RNA was not in any of the 91 rodents’ plasma samples. Conclusion: The rodents captured within the rural communities of Ikorodu, Lagos State and Abeokuta, Ogun State were found not to habour the LASV RNA. This study is limited by the relatively small sample size. Similar studies should be encouraged both in endemic and non-endemic areas in order to understand the actual burden of Lassa fever as well as put into check future epidemics.

Re-emerging Lassa fever outbreaks in Nigeria:Re-enforcing“One Health”community surveillance and emergency response practice

We evaluated the impact of man-made conflict events and climate change impact in guiding evidence-based community“One Health”epidemiology and emergency response practice against re-/emerging epidemics.Increasing evidence of emerging and re-emerging zoonotic diseases including recent Lassa fever outbreaks in almost 20 states in Nigeria led to 101 deaths and 175 suspected and confirmed cases since August 2015.Of the 75 laboratory confirmed cases,90 deaths occurred representing 120%laboratory-confirmed case fatality.The outbreak has been imported into neighbouring country such as Benin,where 23 deaths out of 68 cases has also been reported.This study assesses the current trends in re-emerging Lassa fever outbreak in understanding spatiogeographical reservoir(s),risk factors pattern and Lassa virus incidence mapping,inherent gaps and raising challenges in health systems.It is shown that Lassa fever peak endemicity incidence and prevalence overlap the dry season(within January to March)and reduced during the wet season(of May to November)annually in Sierra Leone,Senegal to Eastern Nigeria.We documented a scarcity of consistent data on rodent(reservoirs)-linked Lassa fever outbreak,weak culturally and socio-behavioural effective prevention and control measures integration,weak or limited community knowledge and awareness to inadequate preparedness capacity and access to affordable case management in affected countries.Hence,robust sub/regional leadership commitment and investment in Lassa fever is urgently needed in building integrated and effective community“One Health”surveillance and rapid response approach practice coupled with pest management and phytosanitation measures against Lassa fever epidemic.This offers new opportunities in understanding human-animal interactions in strengthening Lassa fever outbreak early detection and surveillance,warning alerts and rapid response implementation in vulnerable settings.Leveraging on Africa CDC centre,advances in cloud-sourcing and social media tools and solutions is core in developing and integrating evidence-based and timely risk communication,and reporting systems in improving contextual community-based immunization and control decision making policy to effectively defeat Lassa fever outbreak and other emerging pandemics public health emergencies in Africa and worldwide.

From Social Determinants of Health Actions to Fight against the Lassa Virus Hemorrhagic Fever Epidemic in Tchaourou Commune in Benin, 2018

Background: Lassa Hemorrhagic Fever (LHF) is endemo-epidemic in West Africa with seasonal outbreaks raising a major public health issue. Nigeria borders Benin by the Tchaourou Commune. Since 2016, Tchaourou commune has been affected every year by this epidemic. Objective: To study how an action on the health social determinants can contribute to ending this epidemic in Tchaourou commune, Benin. Methods: This cross-sectional study was conducted in Tchaourou commune. All of the cases of LHF occurring in 2016-2018 were retrospectively tracked throughout the commune. The health workers and 172 participants of the general population of villages of the cases were enrolled. We used absolute frequency to describe the LHF cases because of their small number. The descriptive analyses were performed using EPI-INFO 7.1.14. Results: Overall, 27 cases of LHF occurred in Tchaourou. In these 27 cases, 12 were Laboratory-Confirmed. All 4 probable cases died while 42% and 18% died in the confirmed and suspected cases, respectively. Most (75%) of the cases were female. By direct observations, the commune had a weak health-promoting environment for fighting against LHF outbreak. According to the health care staff in the commune, the interventions were for controlling the outbreak and not the promoting interventions to preventing further outbreaks. Conclusion: To fight effectively against the Lassa fever, it is necessary to act on different social determinants of health with community participation, empowerment and health control. The fight against Lassa fever remains a major challenge facing developing countries like Benin.

Seasonal Changes in Vegetation and Land Use in Lassa-Fever-Prone Areas (Kenema and Kailahun Districts) in Eastern Sierra Leone

Lassa Fever is endemic to the eastern region of Sierra Leone. It is a haemorrhagic disease that is often transmitted from rats to humans and then human to humans. Ecological disturbances such as changes in land use involving conversion of natural ecosystems to agriculture, mining or for urban expansion are reported to bring humans into close contact with animals such as the Mastomys rat that carries the Lassa Fever virus thereby posing health problems.The nature and extent of such ecological disturbances or land use changes within areas known to be endemic to Lassa Fever are not clearly understood from a research context in Sierra Leone. This study was therefore undertaken to identify the pattern of changes in land use and cropping practices and their potential to bring humans into close interactions with the Mastomys rat that is the host for the Lassa Fever virus. Four communities were chosen for the study, two rural (Lalehun and Majihun) and two urban (Lambayama section in Kenema City and Largo Square section in Segbwema Town). Different vegetation and land use/cropping practices were identified and observations were made on the pattern of changes at different times in the cropping year. There were four common vegetation and cropping practices found in all communities: upland rice intercropping, old fallow, young fallow, and swamp rice cultivation. The study revealed the variations in land use patterns and cropping practices between urban and rural settlements. Agro-forestry practices such as perennial cash crops cacao and rubber plantations were more common in rural communities. The study also revealed that while fallow vegetation persisted in rural areas there had been expansion of settlements into old fallow vegetation indicating a greater threat to the persistence of natural ecosystem in urban than in rural settlements. These disturbances resulted in habitat fragmentation and increased the likelihood of contact between humans and animal species (e.g. Mastomys rat) associated with various habitats.

中国首例拉沙热病例报道

拉沙热(Lassa fever)是一种由拉沙病毒(Lassa virus,LASV)引起的发热性传染病。该疾病于1969年在尼日利亚首次被报告,后在西非地区流行。LASV主要通过大鼠的尿液或粪便传播给人类,也可能通过接触感染者的血液、粪便或其他身体分泌物在人与人之间传播。拉沙热常见症状包括发热、头痛、呕吐、腹痛和咳嗽。本文报道了中国首例确诊拉沙热病例,该病例发病前曾在西非几内亚工作,发病后LASV血清荧光定量PCR检测和IgG抗体检测均为阳性,确诊拉沙热。确诊后,患者接受了利巴韦林联合对症支持治疗,病情逐渐好转。本研究全面回顾了该病例的流行病学史、临床症状、诊断过程、治疗措施及转归,以提高医务人员对拉沙热的认识和防治水平。通过对本病例的深入分析,为未来类似病例的快速识别与有效应对提供科学依据,促进公共卫生体系对输入性传染病防控能力的提升。

Prognosis and Evolution of Lassa Virus Infected Persons during the 2017 Epidemic in Togo

Introduction: Lassa viral hemorrhagic fever is common in West Africa. Almost 300,000 persons are affected each year with 5000 deaths. The mice of the genus mastomys is the wild tank. Objective: The aim of our study is to describe clinic, therapeutic and evolution of the affected patients during February-March 2017 epidemic that occurred in the north of Togo. Methodology: Our study is a record review study from patients’ record, who were hospitalized from February, 1st to March, 31st 2017 at Mango hospital. Lassa diagnosis was performed by PCR. They patients have received Ribavirin and blood transfusion when necessary. Results: We have reported 5 clinical observations of Lassa viral hemorrhagic fever. Patients came from Benin (03 cases), from Burkina-Faso (1 case), from Togo (1 case) and were 25, 34, 60, 52 years old and a premature baby of 13 days. External hemorrhage and abdominal pains were the main symptoms. Fever was observed for all the cases. Complications were marked by hemorrhages and shocks. Only 3 patients had benefitted of Antiviral therapy with Ribavirin. The other 2 patients did not benefit from the treatment because the diagnosis of Lassa fever was done the day they dead before the treatment started. Lethality was 80% (4 cases) with a highly secured burial. Effective management of contacts was done. Conclusion: Diagnostic and therapeutic delays of patients are responsible of the bad prognosis of the disease.

The Lassa Virus Epidemic in Mango, Togo: Therapeutic Route of the First 4 Cases

Introduction: Lassa viral hemorrhagic fever is caused by the Lassa virus. The aim of our study is to describe the therapeutic itinerary of the 4 cases of Lassa virus hemorrhagic of February-March 2017 epidemic that occurred in Mango. Methodology: Our study is a transverse retro-prospective and descriptive study from February, 1st to March, 31st 2017 that dealt with 4 confirmed Lassa fever cases declared positive on the PCR basis;hospitalized or deceased at the hospital “Esperance” of Mango;support center of Lassa viral hemorrhagic fever. Results: we reported 4 clinical observations of Lassa viral hemorrhagic fever diagnosed on the PCR basis during the Lassa fever epidemic. Patients came from Benin (2 cases) or from Burkina-Faso (1 case) and were 25, 60, 52 years old and a premature baby of 13 days. The reasons for admission were external hemorrhage, a pultated tonsillitis and abdominal pains. Fever was observed for all the cases. Complications were marked by hemorrhages and shocks. Only two patients benefitted from Antiviral therapy with Ribavirin and were declared healed. The other two patients did not benefit from the treatment due to diagnostic and therapeutic delays. Lethality was 75% (3 cases) with a highly secured burial. Effective management of contacts was established. Conclusion: Diagnostic and therapeutic delays of patients are responsible of the Dark Prognosis of Lassa fever during the epidemic.

拉沙热疫苗研究进展

拉沙热是由拉沙病毒(Lassa virus,LASV)引起的一种急性传染病,主要由啮齿类动物传给人。西非是拉沙热最主要的流行区,该地区每年有几十万人患病,数千例死亡。由于LASV的高致病性,被列为潜在生物战剂,当前无获批的拉沙热疫苗。研究表明传统的灭活疫苗免疫保护效果不理想,LASV基因重组的复制增殖型病毒载体疫苗、复制缺陷型病毒载体疫苗和DNA疫苗等新型疫苗显示较好的发展前景。但是这几种新型疫苗仍处于临床预试验阶段或临床试验阶段。

2019年1-3月全球传染病疫情研判分析

2019年1-3月,全球共监测到传染病64种,涉及102个国家和地区,其中传染病数量位于前5位的为麻疹(44个)、登革热(44个)、基孔肯雅热(16个)、霍乱(12个)和疟疾(9个)。病死率位于前5位的传染病为埃博拉出血热(62.4%)、中东呼吸综合征(34.4%)、鼠疫(32.4%)、拉沙热(23.0%)和汉坦病毒肺综合征(18.6%)。死亡病例数位于前5位的传染病为麻疹、霍乱、埃博拉出血热、登革热和拉沙热。非洲流行的传染病主要为埃博拉出血热、霍乱、黄热病、拉沙热和麻疹;亚洲流行的传染病主要为中东呼吸综合征、登革热和麻疹;美洲流行的传染病主要为登革热和基孔肯雅热;欧洲流行的传染病主要为麻疹。

Diseases Associated with Stigma: A Review

Background: When a disease is associated with stigma, there may be attendant negative consequences. Purpose: This review was to show how stigma-associated diseases impact negatively on the psychological and social wellbeing of the affected persons. Methods: The relevant articles for the review were obtained through PubMed and Google Scholar search on the internet using relevant keywords. Results: Several infectious and non-infectious diseases are associated with stigma. The causes of stigma in these diseases include fear of contracting the disease and dying from it, disfiguring caused by the disease and ignorance and misconception concerning the cause, nature and infectivity of the disease. Those suffering from stigma-associated diseases are usually discriminated against and denied the privileges and opportunities available for those not suffering from stigma-associated diseases. This often leads to psychosocial or psychiatric complications such as social isolation, depression or even suicidal ideation. Conclusions: Stigma-associated diseases still remain a very important health problem with attendant psychosocial consequences. Multi-disciplinary and multi-level efforts are required for its effective mitigation.

塞拉利昂西区拉沙热血清流行病学调查

目的了解拉沙热在塞拉利昂西区流行和分布情况。方法用随机抽样的方式采集并检测了820份塞拉利昂西区人群血清中的拉沙热IgG抗体,并分析其分布特征。结果总体拉沙热IgG抗体阳性率为28.78%,95%可信区间(Confidence Interval,CI)为25.68%~31.88%。拉沙热阳性率西区郊区43.48%(80/184),高于西区城市24.82%(136/548)(χ2=23.06,P<0.05),差异有统计学意义;不同性别和不同年龄组之间拉沙热阳性率差异无统计学意义。结论塞拉利昂西区拉沙热总体阳性率较高,且郊区和城市差异明显,应加强环境卫生的改善,加大防鼠灭鼠工作。

《6种输入性传染病预防控制指南和临床诊疗方案》解读（二）黄热病；（三）拉沙热

本文就黄热病及拉沙热的病原学，流行病学，临床表现，诊断，治疗及预防进行扼要阐述。

2021年3—4月全球主要疫情回顾

本刊对2021年3—4月全球重点传染病疫情(截至4月25日)汇总如下。1全球新冠疫情4月份反弹,印度疫情急剧恶化2021年1月全球新型冠状病毒肺炎(新冠肺炎)每日新增病例数达到50万~60万例,2月以后增速放缓,每日新增病例数降到30万~40万例,但3月以后每日新增病例数又持续上升,4月中旬开始以每日新增70万~80万例的速度继续上升,达到了新型冠状病毒肺炎疫情(新冠疫情)发生以来的峰值。见图1。

2020年全球传染病重要疫情事件回顾

2020年,新型冠状病毒肺炎疫情全球大流行,导致8000万人患病,170万人死亡。脊髓灰质炎疫情继续扩大,阻碍了全球消灭脊髓灰质炎的目标。非洲埃博拉疫情被扑灭。登革热疫情较上一年明显缓解。年底欧洲和亚洲暴发H5N8禽间禽流感疫情。本文对2020年重要传染病疫情事件进行回顾。