Novel Covid–19: Outbreaks Status in Two Main Regions of Nigeria and the Public Health Implication of Bats Population Dynamics in Urban Settlements

The novel coronaviruses 2019 (COVID-19) cannot be talked about in isolation of bats who serve as reservoir host and are present in urban settlements. The outbreak of COVID-19 in Nigeria has called for concern and a concise review of many facets of development in Nigeria. Compliance to regulations for siting and building settlements all over the country have not always been top priority in the past hence standard protocols may have often been compromised. This review focused on how the spread of COVID-19 pandemic was aided by urban settlement in Northern and Southern regions of Nigeria. All the 37 states in Nigeria confirmed cases in which it was higher in the southern region (67%) than the northern region (33%). Thus, this may imply that the COVID-19 strain in Nigeria may possibly be of two types since one region was more infected than the other. Also, it could be due to the variation in the settlement patterns between the two regions. Residents in crowded and congested settlements tend to have extreme difficulty to maintain social/physical distancing as recommended by WHO and NCDC. There is very crucial need for partnership between policy makers, academics, and representatives of those who live in slums so that such knowledge can grow in tandem with eﬀorts to improve health and wellbeing.in order to control and or reduce similar outbreaks in the nearest future. Bats adaptability to urban landscapes occurs more during dry season than wet season. Despite bats services in the ecosystem their population is being threatened by anthropogenic activities. Hence, more fruiting trees should be planted in urban settlements so as to provide roosting sites for bats in order to prevent them from roosting in ceilings of houses since they are known as zoonotic reservoir host of diseases of public health importance.


Introduction
The novel coronaviruses 2019 (nCoV-2019 or COVID- 19) cannot be talked about in isolation of bats who serve as reservoir host [1] and are present in urban settlements [2,3]. The  which is caused by the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARs-CoV-2) had been declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO) on 30 th January 2020 and was subsequently declared a global pandemic by the WHO on 11 th March 2020 [4,5]. The risk of emergence of a novel bat-Coronaviruses disease was predicted much earlier by various studies [6][7][8] prior to its occurrence in Wuhan, Hubei Province, China, in December 2019 and January 2020 [9,10]. Though a report by Cyranoski [11] identified the pangolin as the potential source of nCoV-2019 on the basis of their genetic sequences being 99% similar in relation to coronaviruses taken from animals and infected humans during the outbreak and other findings. Also, Xiao et al. [12] isolated coronavirus from pangolins that is closely related to the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-  which suggests them such as potential intermediate host of SARS- The rise in global human population growth has pushed man to seek for protein from bushmeat [13][14][15] in which some

are intermediate host of zoonotic diseases such as Middle East
Respiratory Syndrome (MERS-Cov) and SARS-CoV-2 which is the current enormous price the general public is paying back today for such association with wild animals [16,17]. As a matter of urgency an open letter was written to World Health Organization (WHO) and United Nations Environment Programme (UNEP) in April 2020 on the need to secure a better future to not only humans but also for nature, which supports the health and well-being of all humanity.
This can be achieved via holistic and equitable solutions which will reduce zoonotic pandemic risks. The Chinese government threw its weight by vowing to keep wildlife off the menu, though this may be a tough promise to keep [18]. Cohen [19] pointed out that a WHO-led mission was set up to investigate the pandemic's origin based on the global public health challenge at hand. The yearly increase of about 70 million people in the world's urban population as projected by United Nations [20] clearly points to the fact that there will be an eminent demand for housing, employment, and services. If the governments in developing countries fail to meet the needs of the masses then they will be forces to rely on or create their own informal infrastructure. Also, informal housing, informal employment, and self-employment are some of the survival activities adapted by these urban dwellers that are somewhat within their own power to implement [21].
The historic United Nations Millennium Declaration in the year 2000 formally recognized the existence and need to improve the lives of at least 100 million slum dwellers by the year 2020" [22] are likely to become central to this century's most expensive health crisis. The prediction by Riley et al. [21] seems to come true with the outbreak of the unprecedented COVID-19 that is ravaging more lives in the urban settings in especially those dwelling in urban informal settlements. Nigeria like many other countries in the world is being ravaged by COVID-19. After the index case of an Italian citizen who flew into Lagos an urbanized city from Milan on 25 th February, the next dozen cases were all linked to travel history from endemic countries [23] after which the spread of infection was by human to human transmission with the local community. Personto-person transmission has been established between people who are in close contact with one another (within about 2 metres/6 feet), primarily via respiratory droplets. Droplet transmission occurs when respiratory droplets generated via coughing, sneezing or talking contact susceptible mucosal surfaces, such as the eyes, nose or mouth while it may also occur indirectly via contact with contaminated fomites with hands and then mucosal surfaces [24].
Respiratory droplets are large and are not able to remain suspended in the air thus they are usually dispersed over short distances.
Though the rate of infection in Africa has been relatively lower when compared to advanced nations, one hypothesis suggest that the lower mortality rate in African settlements maybe due to regular exposure to other coronaviruses, malaria or many other infections in the past which could have primed the immune system against the novel coronavirus for some early defense response [25,26].
Alternatively, another hypothesis attributes resistance to genetic factors which have not yet been identified [25]. It is important to note that the situation in African countries stating their COVID-19 status could be worse than what is reported because of inadequate preparation for disease outbreak due to poor surveillance and lack of adequate testing facilities such as laboratories [27]. Settlements worldwide are located on the earth's surface with people living in them. Settlements are known to change spatially with time, but the pattern of such change varies according to certain factors such as transportation and socio-economic activities; political fragmentation; population density; infrastructural distribution and social amenities; economic development; industrialization and urbanization; social networks; topographical conditions; religious and cultural factors [28]. Inhabitants of Urban settlements around the world have been affected by the pandemic because one-half of the world's population resides there and because lifestyle demands inhabitants will travel to domestic or international locations for various reasons [29] which has led to the spread of the disease across different locations around the world [30]. Lilford et al. [31] sounded an alarm that the time is ripe to revisit the Urban Agenda with a strong emphasis on slum health and slum upgrading and on strengthening the capacities of urban governments to work with people who live in slums to act on these. They posited that this will go a long way in securing commitments in ensuring that policies are backed up with adequate finance.
The supposed neighbourhood effect in slums is like a coin with two sides. It has both a problem and an opportunity. It is a problem because it is likely to amplify health hazards and it is an opportuni-ty because one intervention can simultaneously improve so many lives in one densely packed community [31]. Hence, this review compared the relative level of COVID-19 outbreak in urban centers in relation to settlement patterns that could explain the variations in COVID-19 burden in Northern and Southern Nigeria and well as the public health implication of bats population dynamics in urban settlement.

Types of Settlements in Nigeria
The urban settlement is known as a non-agricultural area which has various building types and populations who earn high, medium and low incomes. Upper income earners residential areas is characterized by a low population density while the medium and low income earners residential areas have a moderate and very high population density respectively who are individuals of urban labour force office and factory workers. The location of the medium and low income individuals is in outskirts of towns whose buildings are contiguous and filled beyond capacity with the official occupier and his family, also job seeking relatives and friends visiting from the rural areas. On the other hand, high income earners have spacious houses which are not congested. The township is comprised of the following settlement types: nucleated, compact, isolated, linear, and dispersed settlements [32]. In the year 2020, the estimated population of Nigeria was over 206.14 million, ranking 7th in the world, which suggests that the entire population of Nigeria accounts for about 2.35% of the entire earth's population [33,34]. This means that about 1 out of every 43 people in the world is a Nigerian. Nigeria's pattern of settlement in both northern and southern regions is generally characterized by buildings built close to one another of varying degrees, some of which are without the appropriate approved town planning features which ultimately defy social/physical distancing in the event of any outbreak of any pandemic.
The settlement patterns common to both regions are usually characterized as congested/compact, mostly high population density or overpopulated settlements called shanty/squatter, ghetto, face me I face you, bacha where facilities such as kitchens, bathrooms and toilets are grossly inadequate, and the few available are shared [35]. Furthermore, many living conditions in such settlements violate social distancing due to congestion, grubby environment usually lacking hygiene and water supply. Such shared facilities easily result in contaminating surfaces with the novel virus thus infecting new victims.

COVID-19 Status in Nigeria
The status in Nigeria reveals that all 37 states in the 6 geopolitical zones (North-West, North-Central, North-East, South-West, South-South and South-East) reported at least a confirmed case with 6 states (Lagos, FCT, Oyo, Edo, Rivers and recently Plateau) accounting for more than 60% of cumulative cases [36,37].
Ihekweazu [36] 34,199 (64%) and 19,528 (36%) in females [37]. Interestingly, the most affected age group is 31 -40 years (25%) but the distribution and burden of mortality from COVID-19 has varied from the Northern and  The outbreak status between the northern and southern region of Nigeria shows a high variation as shown in (Figure 1) [37]. The southern region was more affected in terms of states with higher number of cases from 1,001-10,000 (7 states, 64%) and those >10,000 (1 state [Lagos], 100%) while the lower number of cases was predominant in the northern region from 1-100 (5 states, 83%) and 101-1000 cases (11 states, 58%). (Table 1) showed that the total number of confirmed cases in Nigeria was higher in the southern region 36,263 (67%) than the northern region 17,464 (33%) [37]. This may imply that the COVID-19 strain in Nigeria may possibly be of two types since one region was more infected than the other. Also, it could be due to the variation in the settlement patterns between the two regions. Furthermore, it may be due to variation in climatic conditions across the two regions.

Level of Adherence to COVID-19 Precautionary Measures in Northern and Southern Settlements of Nigeria
Residents in crowded and congested settlements as shown in tend to have extreme difficulty to maintain social/physical distancing as recommended by WHO and NCDC. Shared corridors, rooms, cooking areas, wells and the presence of large number of family dependents as well as dependents all contribute to the violation. Though some residents in some of the settlements were aware, some others were forgetful, not willing or express disbelief while some were completely ignorant especially in some northern settlements [35]. Though predictive models indicate that in Lagos 55% of the inhabitants comply with social distancing, use of nose masks, contact tracing and testing [38], it is possible that such measures were not done properly hence Lagos alone accounting for 18,000 confirmed cases in Nigeria [36,37]. According to the studies as shown in (Table 2)

Population Dynamics of Bats in Urban Settlements in Nigeria
The order Chiroptera is the second most diverse and abundant order of mammals with great physiological and ecological diversity.
They play important ecological roles as prey and predator, arthropod suppression, seed dispersal, pollination, material and nutrient distribution, and recycle. They have great advantage and disadvantage in economic terms [40]. Bats represent an order of great evolutionary success, with elevated geographical diffusion and species diversity [2]. They form one of the largest nonhuman aggregations and the most abundant groups of mammals when measured in numbers of individuals. They are diversified into more than 1,232 extant species [41]. They are small, with adult masses ranging from 2g to 1kg; although most living bats weigh less than 50g as adults [42]. They have evolved into an incredibly rich diversity of roosting and feeding habits. Many species of bats roost during the day time in foliage, caves, rock, crevices, hollow soft trees, beneath exfoliating bark, and different manmade structures [43]. During night, they become active and forage on diverse food items like insects, nectar, fruits, seeds, frogs, fish, small mammals, and even blood [41]. Fahr et al. [44] opined that straw-coloured fruit bats (Eidolon helvum) migrate over vast distances across the African continent due to seasonal bursts of resource availability. Thus, causing enormous fluctuations in population size as shown in (Figure 2), which in turn may influence the bats' impact on local ecosystems.
According to the study by Fahr et al. [44] in Accra city which is an urban center in Ghana had bat population in wet season that was low with about 4000 individuals during the months of May to September and the distance covered to forage locally was 3.5-36.7km and their main food source is introduced trees. But during dry season foraging distance almost tripled (24.1-87.9km) and population size between January and February was thirty eight times (150,000 individuals) more than the wet season period ( Figure 3). With respect to urban footprint and tree cover, dry season foraging was random and they exclusively fed on nectar and pollen of native trees. Similarly, Thomas [45] reported that the straw- conservation is mandatory [41,49]. It is however sad but true that bats rank amongst the least known of any mammalian group; little information available on their diversity, distribution and ecological requirements [50][51][52][53]. More importantly, information is sparse on bats in Nigeria.
As observed by Adeyanju et al. [54], bat species diversity and abundance decreased with increase in density of trees and that diversity decreased with increase in the amounts of litter cover.
Similarly, Tibbels et al. [55] and Owen et al. [56] showed that higher abundance of forest dwelling bats have been connected with greater availability of roosting sites. More bat species occur in plantations due to availability of fruiting trees compared to the forest [57]. The increase in number of trees and litter cover causes a decrease in bats diversity [57]. Among the taxa capable of adapting to urban landscapes, bats are particularly ubiquitous. They play important roles in the maintenance of biodiversity by providing many substantial services to the ecosystems (e.g. seed dispersal and pollination) and to human economic activities (e.g. biological pest control) [41,58,59]. There is a growing body of knowledge on bat's sensitivity to urban environments, showing that they present a species-specific response to this process [60][61][62]. A reduction in bat richness and in the abundance of certain species in urban areas indicates that this process has negative effects on most bat species. These effects are being increased exponentially as a result of an increasing anthropogenic pressure, which causes habitat loss, fragmentation and biodiversity decline [49,63,64].
The abundance of bat populations could depend on the availability of suitable roosting sites [65]. In Nigeria, bats natural roosting sites appear to be declining in numbers, presumably due to urbanization resulting in change in their natural habitat [66]. economic and aesthetic benefits [67]. However, given the wrong set of circumstances, bat species can become a nuisance. Besides being providers of many ecosystem services such as control of insect populations, pollination, and seed dispersal [49,68]. Bats are often unwanted visitors in the urban landscape. Aside their destructive roosting activities, they are mostly regarded as causative agent of perilous diseases. Also, locals believe them to be of spiritual significance [65].

Conclusion
To successfully eliminate or reduce the infection rate of COVID-19 by agencies of government or non-governmental organizations, priority should also be given to the nature of settlement which will determine the most effective strategy in relation to other demographic structure and associated risk factors.
For settlements that are established contrary to the approved standards, the right steps must be taken to correct such anomalies no matter the challenges. This will ensure that in the future, the effect of outbreaks can be minimized to the barest minimum. There