Need for preventive and control measures for Lassa fever through the One Health strategic approach

Abstract

Lassa virus (LASV) has increasingly been recognised as a significant public-health pathogen transmitted by rodents. LASV infection leads to life-threatening Lassa fever, which has high potential for severe morbidity and mortality. There have been several scientific efforts to understand the genomics and ecological epidemiology of Lassa. However, very limited studies have focused on the short- and long-term impacts of environmental factors, human behaviours and rodent activities on LASV transmission dynamics and control. Recently, a very plausible and ideal way to address the Lassa epidemic has been considered through the One Health approach. The One Health system of intervention is capable of providing better and comprehensive information necessary to address the complex interplay between human, ecological, and environmental determinants of LASV transmission, persistence and re-emergence. Thus, the aim of this article was to review critically the impacts of various environmental factors on rodent infestations, LASV transmission and how human activities contribute to the persistence of Lassa with regard to exploring how they could be harnessed for better understanding of Lassa prevention and control through a concerted One Health approach.

Lassa fever in Nigeria: Social and Ecological Risk Factors Exacerbating Transmission and Sustainable Management Strategies

“…This rodent is synanthropic in nature and prevalent in sub-Saharan Africa [14,22,23] with a life span of about 2 years. Hansen, et al [24] and Abdullahi, et al [25], stated that other rodent species such as Hylomyscus pamfi, Rattus rattus, Praomys daltoni, Mus minutoides, Crocidura spp., and Mastomys erthrocyclus may likely be carriers of Lassa virus although their impact in the spread of the virus. M. natalensis is a widespread rodent in urban and semi-urban settlements in Nigeria: where it was discovered and Sierra Leone, Liberia, and Guinea [26], the rodent has been reported in Mali, Ghana, Benin, Togo, and Ivory Coast [27][28][29].…”

“…It has been widely speculated that LASV is airborne and can be transmitted through aerosols. Hansen, et al [24]; Adebimpe, et al [12]; Abdullahi, et al [25]; Gibb, et al [26]; Ogbu, et al [61] include aerosol inhalation as a route of transmission but this disagrees with Brosh-Nissimov [62] that there is a little epidemiological report showing significant levels. environmental exposure rather than direct human contact [16].…”

“…Temperature, humidity, and seasonality are other environmental predictors of Lassa fever transmission, Abdullahi, et al [25] and Hansen, et al [24] noted that the dry season is usually the peak of Lassa fever cases in endemic areas in Nigeria and this could be as a result of the varying interaction between humans and rodents during the rainy and dry season which can impact Lassa fever transmission, and can be used to predict outbreaks in the future and identify areas suitable for interventions in public health. Furthermore, Akhmetzhanov [16] observed that LASV shows seasonality in its incidence rate as there is more often a rise in reported cases during the first few months of the year which exceeds that of the remaining months of the year, although Ogbu, et al [61] noted that it is possible to transport the virus from one endemic region to a non-endemic one during the period of incubation, hence an outbreak of LASV can occur during the year at any time irrespective of the season.…”

“…Zhao, et al [77] in their study noted that in Nigeria, LASV outbreaks have been known to occur during the dry season between November and May, and a positive association between rainfall and the transmission of LASV was ascertained. Nchom, et al [73] also observed that there was a hike in cases during the dry season when rainfall has significantly reduced The primary transmission of LASV has not been fully comprehended [25] as several environmental factors play a major role in determining the rate of transmission; as common with all emerging diseases, any increase in cases both suspected and confirmed across an endemic region must be closely monitored to establish a pattern, hence the need to study environmental factors that considerably contribute to the spread and sustenance of LASV in endemic areas. Another consideration is hygiene practices, food packaging, food storage and waste disposal practices, which have the potential to increase the disease incidence [63][64][65][66][67][68][69][70].…”

The deuce-ace of Lassa Fever, Ebola virus disease and COVID-19 simultaneous infections and epidemics in West Africa: clinical and public health implications

“…The exploitation of wildlife and the growth of wet markets to feed the bushmeat and bird consumption culture have increased interaction with livestock, allowing animal illnesses to spread to humans [ 68 ]. Bush burning for subsistence farming has also driven animal populations from their habitats in several West African and East African countries, resulting in seasonal surges in the frequency of zoonotic illnesses [ 72 ].…”