Experts have proven that as environmental conditions keep rising, there are higher risks of outbreaks of public health emergencies all around the world. Unfortunately, the outbreaks of Ebola Virus Disease and Lassa Virus Disease in West Africa between 2014 and 2015/2016 respectively have once again confirmed these proofs. However, Lassa fever does not seem to be the last of these risks as Zika presently ravages the South of the Americas; posing the fear of a spread to vulnerable Africa and other parts of the world.

Zika Virus Disease (ZVD)

The wake of May 2015 announced the first confirmed Zika virus infection in Brazil by the Pan American Health Organization (PAHO) that issued an alert. This worrisome news kick started another health threat, but this time, not in Africa but in Brazil. The WHO on February 1, 2016 declared the outbreak a public health emergency after thousands of cases had been recorded. Just like the Ebola virus, Zika spread sporadically within a short time in affected countries because as of now, no treatment or vaccine is available unlike the Lassa virus, which can be curbed with a retroviral drug. Although the best prevention is to avoid mosquito bites, infected patients can however take fluids and treat symptoms.

First discovered in Rhesus Monkeys 1947 in Uganda, the Zika virus was later found in 1952 in humans in Uganda and the United Republic of Tanzania. It has since then spread from Africa to the Americas (2015), Asia, and the Pacific regions (2007 & 2013) with the first sporadic human case in 2007 (31 cases). Unlike the Ebola and Lassa viruses, the Zika virus comes from the Flavivirus family and the carrier/vector is the Aedes Mosquitoes that also causes the deadly Yellow Fever, which already has vaccine. About 80% of people infected usually have no symptoms, which makes it difficult to detect when people have it; only 1 in 5 infected get to develop the virus. However, possible symptoms are: mild fever, rash, joint pain, conjunctivitis, headache, and malaise, which could last 2–7 days. Virus may remain in the blood less than 28 days but rarely results in death. The major recorded effect/health threat of the virus is ‘Microcephaly’ in pregnant women, a case of an unusually small size of a baby’s head, resulting from the failure of the brain to develop properly and also causes brain development-related problems as the child grows. Another recorded effect is ‘Guillain Barre Syndrome’, an acute illness of the nervous system that causes one’s immune system to damage one’s nerve cells which can result in muscle weakness, breathing problems, and paralysis in some cases.

The virus is contacted from bites from the Aedes Mosquito and majorly transmitted when a mosquito bites an infected person and proceeds to bite another person. It can also be transmitted via a pregnant woman to her foetus during the 2nd and 3rd trimester of pregnancy, which makes it a major threat to pregnant women and new borns. WHO records evidence of sexual transmission in just 2 cases *(CNN News February 24, 2016–14 new cases linked) and in semen in 1 case so far.

Situation Summary as at February 19, 2016

Between January 1, 2007 and February 17, 2016, local cases recorded in 48 countries and territories. Zika virus cases reappeared in April 2015 in Brazil, then Columbia, and now transmission has been recorded in about 33 countries; Americas: 29, Oceania/Pacific Islands: 3, Africa: 1 (Cape Verde) (WHO) though a case of travel related case was reported in South Africa on February 19, 2016 (Sunday Guardian, February 21, 2016 pg. 62). Source: WHO

Public Health Threats as effects of Climate Change

Ebola, Lassa, and Zika were all discovered in Africa and two reemerged on the continent after several decades. One cannot but ask why now? Why a reemergence after decades? Why the rapid outburst of these diseases? Some of these answers lie in changing times; changing climate. Researchers have provided evidences of the links between changes in the climate and the outburst of public health threats.

The effects of a changing climate such as droughts, heat waves, flood, changed rainfall patterns, to mention a few naturally drive wildlife such as the Ebola reservoirs; bats, chimpanzees, from their natural habitats to human environments which can be a plausible reason for the high rate of the Ebola virus in these past months. Furthermore, rodents have been studied to reproduce faster under influences of climate change as they respond quickly to changes in the environment, giving credibility to the present reemergence of the Lassa fever. Moreover, climate change means that hot/dry seasons will be hotter, drier, and longer; and it has been established that pests such as Mosquitoes (Zika carriers) thrive in hot environment because Larvae complete their life circles in hot weathers. 2014 was declared the hottest year in record, the year the first of these diseases reemerged (Ebola).

Though the rise of these three (3) life-threatening diseases raises some concern but what should be of uttermost concern is the possibility of more diseases — both old and new — rising in coming years. As environmental conditions keep heightening, there are higher risks and even more public health emergencies all around the world. WHO warns that a global temperature rise above 2degrees spells an increase in the number of people at the risk of malaria and this indirectly include Zika, Dengue, Chikungunya, and Yellow Fever, all from deadly Mosquitoes. More worrisome, in 2008, Wildlife Conservation Society (WCS) released a report on twelve (12) disease threats likely to worsen with climate change, with Ebola and Yellow Fever amongst; we can conveniently add the reoccurring and growing Lassa, Zika, and even the Dengue and Chikungunya, to the list.

What should be of concern to all and sundry in times like this is the fact that the reappearance of these life threatening diseases could just be a tip of iceberg to what public health threats that could surface if the changes in the climate get to risky levels.


Centre for Disease Control and Prevention (CDC) fact sheet

European Centre for Disease Control and Prevention (ECDC) 2016, Communicable Disease Threat Report, January 23, 2016

WHO (2016), Zika Virus: Microcephaly and Guillain Barre Syndrome Situation Report, February 19, 2016

World Health Organization (WHO) website


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