Climate change at the global scale
Most modeling of the effect of climate change has focused on malaria (Marten and Lefebvre, 1995; Rogers and Randolph, 2002). A recent paper has estimated the potential impact on the global distribution of dengue (Hales et al.,2002). But the potential impact of climate change on other vector borne diseases have been neglected due to the lack of appropriate models and reliable high resolution surveillance data to refine and validate them. Several assessments have been published using previous version of the MIASMA model (Jetten et al., 1996; Martens et al., 1999).
Global malaria out breaks have been regularly linked for example heavy rains associated with El-Nino events in the Unites States, hotter and more humid weather conditions were factors in local outbreaks of malaria; a case at Michigan camp site in 1999. These warmer weather conditions can increase the survival of the mosquito and reduce the required length of the sporogenic cycle sufficiently to allow the parasite develop and the mosquito to become infectious where it will otherwise would not (Zucker, 1996).
Predictions of global climate change have led to expensive research interest into its potential impacts on malaria incidence, but low climate change may affect the incidence and distribution of malaria which is much debated. Some researchers have predicted significant global or region spread base on biological models that incorporates some climates driven variables that directly affects the basic reproductive number of malaria (Ro).
Effects of climate change and malaria in Africa
The majority of research that had been done concerning how climate change would affect human health in Africa has focused on the livelihood of it causing an increase number of malaria outbreak. Annually, there are between 300-500million cases of malaria world-wide, a highly proportion of these occurring within Africa. There are between 1.5-2.7million deaths resulting from malaria per year, with more than 90% of these being children under age of five (WGCCD, 2005). Climate change and its consequences have threatened to undo the progress made in this area in two ways:
By causing higher temperature and
Through the occurrence of natural disasters which leave large amounts of stagnant water in their wake.
In 1987, one highland area of Rwanda experienced a 37% increase in cases of malaria and 80% of this increase could be accounted by changes in temperature, rainfall and humidity levels, resulting from climate change (WGCCD, 2005). Malaria epidemics in Zimbabwe have been found to be closely linked to climatic variability caused by events like El-Nino (WHO, 2003). Hartmen et al. (2002) also assessed climate suitability for stable malaria transmission in Zimbabwe under different scenarios.
Effects of climate change and malaria in Nigeria
There are numbers of indirect impacts of climate change on human health in Nigeria. As Nigerias inhabitants have already suffered from mal-nutritional imbalances (poor nutrition and mal-nutrition) climate change will only have a deleterious effect on food security. A shift could occur in the location of some vector borne diseases like malaria (mosquito) and sleeping sickness (tse-tse fly). In response to shift in patterns of rainfall, humidity and temperature; mosquitoes currently thrive in locations where water logging due to climate in eco zones hitherto unassociated with malaria will enhance the breeding of mosquitoes and thus the spread of malaria. Malaria will also increase due to stagnant pools of water resulting from sea level rise related flooding. New evidence with respect to micro climate change due to land use changes such as swamp reclamation and deforestation suggest an increase spread of malaria to new areas (Munga et al., 2006; IPCC, 2007).
Effects of climate change and malaria in Plateau state
The malaria parasite requires a temperature of at least 15oc to complete its development within the mosquito, while the mosquito vector requires a temperature of at least 16oc and prefers a relative humidity above 60%. The parasitic agent develops more quickly with elevated temperatures at 30oc; if reproduction rate is more than twice at 20oc. This abundance of both the agent and the vector could increase considerably under warmer condition (Jeshurun, 2013). A prediction of future climate scenarios has the potential for creating numerous new breeding grounds. From the above conditions, a critical assessment of Plateau state will show some important related features that helps the spread of malaria starting with height of Plateau being about 1200m above sea level, this altitude is known to help the breeding of mosquitoes.
Secondly, the irrigation farming that is carried out in Plateau state such as the FADAMA project and ASTC leads to the breeding of mosquitoes. Thirdly, the temperature of Jos hardly falls below 15oc which is a good breeding temperature for both mosquitoes and the malaria parasite. Lastly, Plateau state is the 12th largest city in Nigeria and because of the population size, there will be little space for people and therefore, the spread of mosquito is enhanced according to traditional rulers.
Plateau State is known to be the 2nd highest in the incidence of HIV/AIDS in Nigeria. The HIV causes low immunity and therefore predisposes the individuals to opportunistic infections such as malaria.
Effects of climate change and malaria in Jos north
A close look at the areas in Jos North L.G.A has shown that no research work on effect of climate change on malaria has been specifically undertaken in this area and these has given the reasons to observe malaria cases in Jos North and their cause being as result of climate change.
Jos North is the central area of Jos capital of Plateau state; for this reason, it is the most populated of all local governments. It is the most industrialize and the most polluted due to waste matter produced by the industries and the populace together with gases released by automobiles, these factors together bring about an increase in the temperature of Jos North. It can be observed that Jos is not as cold as it were some decades ago due to the increase in atmospheric temperature and since a little increase in temperature could bring a great burst of malaria spread; Jos North therefore is generally an endemic area of malaria.
In areas such as Angwan Rogo, Farin Gada, Yan Gongoni, Angwan Rukuba, Gada Biu, Abattoir and Apata which are all along streams and also places such as lamingo dam (which could serve as a breeding ground and subsequent spread source) are likely at risk of malaria due to the collection of water in these areas that serves as good breeding grounds for mosquitoes. There is also a wide spread resistance of malaria to common drugs use for its treatment such as chloroquine and fansider; this is due to the fact that almost everyone is a doctor since a little fever will cause people to buy anti-malaria drugs which may not be properly taken and has now lead to the resistance to these drugs.
In conclusion, the flooding of the year 2012 in which areas around the streams were over flooded, enhanced the breeding and spread of malaria in Jos North, hence, even with the campaign against malaria such as giving out of mosquito nets to pregnant women at the hospitals, little efforts or non are achieved due to the above factors that out-weighs the control measures.