Is the COVID-19 pandemic masking the deadlier Lassa fever epidemic in Nigeria?

From Wuhan city in China, the coronavirus disease (COVID-19) caused by the novel SARS-CoV-2 virus spread to other cities within China and the world over [¹] with the World Health Organization (WHO) declaring the COVID-19 outbreak a pandemic on March 11, 2020. As of May 8, 2020, the world has recorded 3,726,292 confirmed cases and 257,405 deaths due to COVID-19 across 215 countries and territories [²]. In Nigeria, from the 23,835 samples tested across the 36 states including the Federal capital territory (FCT), there had been 3,526 confirmed cases and 107 deaths as of May 8, 2020 [³]. Being the 7 ^{most populous country in the world with over 200 million people, Nigeria is at grave danger for a collapse of its convulsive healthcare system and to a large extend social life. Like with COVID-19, Nigeria has been battling with Lassa fever (LF), a more severe, zoonotic and viral haemorrhagic fever caused by Lassa virus, a single-stranded RNA virus first isolated from Lassa, a town in north-eastern Nigeria [4}]. Transmission of Lassa virus to human occurs primarily through contact with contaminated urine, excreta, body fluids or saliva of Multimammate rat, Mastomys natalensis (known to be the virus natural reservoir) or secondarily through the person-to-person spread and nosocomially via contact with infected body secretions, excretions and blood [⁴5].

From the first LF outbreak in Nigeria in 1969, the disease has continuously occurred annually and had long been declared endemic in Nigeria, affecting over 26 states including the FCT. Outbreaks of LF mostly occurred during the dry season in Nigeria with the highest incidence around (November-April) [²]. All ages and gender can be infected with LF. In West Africa, approximately 300,000–500,000 cases of LF occur annually with over 5000 deaths [⁶]. Currently, Nigeria has recorded 4,622 suspected cases of LF with 991 confirmed cases and 191 deaths as of May 8, 2020. These cases spread across 128 Local Government Areas from 27 States with the case fatality ratio (CFR) of 19.3% lower than 22.7% reported for the same period last year [⁷].

While Nigeria's government alongside the NCDC focuses on COVID-19 with a far lower CFR of 3.0%, the increasing cases of LF with 19.3% CFR across the country are overlooked and not given the urgent and needed attention. Prior to the emergence of COVID-19, the WHO posited that Nigeria’s capacity to manage LF remains suboptimal at the sub-national levels with weakened infection prevention and control (IPC) measures [²]. Nigeria's healthcare system has inadequately managed the recurring LF outbreaks in previous years with grossly inadequate diagnostic kits and referral centres, high mortality involving health professionals and poor surveillance and management. Since the management of COVID-19 and LF cases in Nigeria demands shared clinical and laboratory facilities, confronting COVID-19 and LF simultaneously will add severe diagnostic difficulties to the poor and inadequate facilities available. Although a majority of LF infected persons are asymptomatic, severe cases are characterized by febrile illness associated with severe diarrhoea, haemorrhage and multiple organ dysfunction [⁵] with patients in dare need of healthcare facilities alongside COVID-19 patients. Furthermore, due to the inadequate molecular diagnostics for the detection and confirmation of COVID-19 using reverse transcription polymerase chain reaction (RT-PCR) [⁸], the possibility of misdiagnosis of these 2 viral infections is high in Nigeria. Pseudo-serological results for COVID-19 in LF patients and vice versa cannot be overruled. Most importantly, although no cases of COVID-19 and LF coinfection has been reported among patients, the possibility of such occurrence cannot be precluded. With the simultaneously increasing cases of COVID-19 and LF across Nigeria, both outbreaks will be catastrophic.

The blueprint for mitigating LF lies primarily with the control of rodents’ infestation of homes and the promotion of good community hygiene. Farm produce especially grains and other foodstuffs in homes should be effectively stored in rodent-proof bags while household garbage should be disposed far from residential areas. Also, contact with secretions, excretions and blood from infected persons should be avoided. For robust and effective containment of these 2 outbreaks, Nigeria needs to adequately equip its health centres with available, contemporary and functional diagnostic facilities and kits. Additionally, due to wild misconceptions regarding COVID-19 and LF, urgent public health enlightenment campaigns across Nigeria are needed for both control and minimization of the outbreaks.