Module Eighteen, Activity Four

Current Issues in Central Africa

This activity will address health and environment, two of the major contemporary issues confronting the central Africa region.

I. Health

Remember when we studied activity II, we mentioned that there were numbers of problems that prevented accessibility to some remote areas in Central Africa and consequently prevented the colonies from generating enough tax money for a better governance. Sleeping sickness (encephalitis lethargica) continues to be one of these problems. In the first part of this activity we will detail this important health concern.  However, sleeping sickness is not the only health related issues that threatens the region. Three times in the past decade a more terrible epidemic added to the problem faced by the population of central Africa: Ebola Disease

Case Studies:

*Sleeping Sickness

Insects, bugs, and other small animals are part of the fauna of tropical forests.  Mosquitoes, flies, worms and others small species can be seen in the equatorial forests/zone of central Africa. Many of these insects and small animals are unfortunately not always friendly to humans. Quite often, they are carriers of parasites that cause serious diseases such as malaria, sleeping sickness, elephantiasis, river blindness, and yellow fever.

In activity II of this module we discussed the fact that Central Africa is under populated, compared to other parts of the continent. One of the explanations for the region’s under-population is the prevalence of endemic tropical diseases such as sleeping sickness.  This section will detail the impact and manifestation of this disease on both human beings and animals.

The tsetse fly is responsible for this epidemic disease-sleeping sickness-which has infected and killed thousands and thousands of people in Central Africa over the past century. With the nickname ‘King of Africa,’ at mid twentieth century the tsetse fly spread over an area of 4,500,000 sq miles from the southern limit of the Sahara desert to South Africa and from the Atlantic Ocean to the Indian Ocean.

Tsetse Fly Belt

 

This is the area some refer to as the tsetse fly belt. The number of tsetse flies (glossina) species varies between twenty four (24) and thirty four (34). But not all of these species are infectious to humans or animals. Only two species of trypanosome are found to cause the sleeping sickness to humans. Other species affect domestic animals by inducing a disease called ‘nagana.’

The process of infection or transmission of the disease to a victim is quite simple. The tsetse fly bites a person who is already infected and parasite is transferred into the fly as it drinks from human host’s stream. These parasites will be later on transmitted to a healthy person on the occasion of the next feeding bite of the insect.

Sick Subject

Discovering a sick subject

What is sleeping sickness?

The sleeping sickness or trypanosomiasis as it is called, is a parasite infection caused by the bite of the tsetse fly or glossina. After the bite of the insect, the trypanosomes injected in the body of the subject quickly develop, multiplying before disseminating in the blood and the nervous system (the covering of the brain and spinal cord).

Tsetse Fly

The tsetse fly (glossina)

After the dissemination of the trypanosomes in the body and the nervous system, the disease develops slowly and if the treatment is delayed, the patient may not have the chance to recover, and death will follow unavoidably.

Causes of the disease:

Sleeping sickness is caused by a parasite, a flagellate virus (organism with a propulsive tail) scientifically called ‘Trypanosoma brucei’, that lives in the body of the individual host. There are two (sub)species that are infectious: Trypanosoma gambiense and Trypanosoma rhodiesense. Each of these two is found respectively in the western and the eastern part of Africa.

The parasite reproduces in the blood. The symptom of the disease will increase with the development of the parasite followed by the increase in its harmful effect. The disease becomes more noticeable and persistent when the parasite migrates to the nervous system including the spinal cord.  The infection is slow in developing and it may take several years before the infected person falls into a coma from which they cannot be  woken; hence the name ‘sleeping sickness’.

Evolution:

Sleeping sickness evolves in two stages:

  • The first, usually less alarming stage shows the infection of the subject’s blood and lymph nodes with the parasite that cause the disease. The patient shows symptoms like intense fever, enlarged cervical nodes and a few spot on the skin. At this point, parasites are found easily in patients’ lymph nodes and blood stream.
  • Following this clinical symptom, the patient (if untreated) develops most serious neurological symptoms. This is marked by neurological disorders  that may result in what is called the “Kérandel symptom” (named for the colonial physician who described it first hand when he himself was suffering from the disease).  The “Kérandel symptom” shows paralysis, convulsions and sensory disorders that may make a simple daily act, such as using a key, a very difficult task. The worse part is when the mental disorders reach a point where the patient has an irrepressible need to sleep.  If untreated the patient will fall into an irreversible coma.

Impacts/Consequences:

Currently the situation of the tsetse fly is not as serious as it was during the colonial era when it was among the first causes of human and animal death in many Central Africa countries. Indeed at that time,  sleeping sickness affected the level of the population posing a major challenge to efforts to develop sustainable economies in infected countries.  By the early 1960’s, just after independence, with the help of modern medicine, the sleeping sickness epidemic in Central Africa was under control.  The number of cases has drastically dropped even though the population living in that area is still under the constant threat of the fly.  According to the World Health Organization, there has been a resurgence of new cases of sleeping sickness in the region beginning in the late 1990s. About 40000 new cases were reported in 1998. By the early 21st century this number had grown to between 300,000 and 500,000 new cases.  Health experts blame the economic recession for the resurgence of sleeping sickness in the region.

Treatment/Prevention:

Thanks to medical research effective treatment for trypanosomiasis is now available.   However, given financial constraints brought about by a severe recession, Central African governments do not have the capacity to treat all infected individuals.  Moreover, the medical infrastructure (hospitals, rural health centers and clinics) have deteriorated significantly in the past two decades, greatly restricting the ability of the health system to treat citizens infected with sleeping sickness, or other serious diseases.

Governments have also attempted to reduce the impact and spread of the disease by eliminating or controlling the spread of the tsetse population. The main objective is actually to prevent the development of the disease by reducing and eliminating completely if possible its vectors (the flies). These techniques include the use of chemicals in controlling tsetse populations; the use of traps and targets [that are mechanical devices used to kill or weaken tsetse flies through insecticides or various trapping methods] and also through clearing the bush which host the tsetse fly. One of the environment friendly methods is the Sterile Insect techniques. It mainly consists in mating the wild female tsetse with the sterile male.

Ariel Chemical Spray

Ariel spraying of chemicals to control tsetse

NG2G at Nguruman in 1996 with Swiss film crew when Maasai herded animals near traps set at pipeline road

A tsetse trap, developed in 1987, to fight against the sleeping sickness vector

*Ebola Disease

Have you seen the movie Outbreak, which presents a fictional account of the transfer of the Ebola virus from a country in Central Africa to the U.S?  This scary movie helped raise concerns about the disease and its possible impact on Americans. Fortunately there have been no outbreaks of the dreaded disease in the U.S. However, outbreaks of Ebola hemorrhagic fever have occurred in Central Africa a number of times in recent decades  Ebola is caused by several different viruses, however medical scientists to date have not been able to isolate the source of the virus that infects humans but rodents, arthropods and monkeys are the suspected hosts of the viruses  Ebola belongs to a family of diseases that is called “VIRAL HEMORRHAGIC FEVERS”. These fevers range from mild to fatal. They become fatal when the individual becomes so ill with breathing problems, severe bleeding (hemorrhage), kidney problems, and shock.

Ebola was originally discovered in 1976 and was named after a river in Zaire (current Democratic Republic of Congo) where the disease was first identified.

Risk of Contagion:

When it comes to contagion, Ebola is not very different from other form of epidemic disease like the common flu.  People are infected by direct contact with virus-infected blood and other bodily fluids..

Part of the contagion risk is the handling of ill or dead chimpanzees.  Beside the transmission through bodily fluids, Ebola can also be transmitted through respiratory routes particularly in the case of nonhuman primates who run a higher risk of airborne transmission than human beings.

Therefore Ebola, like many other contagious diseases, spread mainly through close, person-to-person contact with a severely ill patient. Health care professionals dealing with patients ill from the virus and the patients’ family members need to be extremely careful.

Another source of transmission (contagion) is the re-use of (hypodermic) needles, a practice common in areas where the health care system is unfinanced. Reusing needles in the treatment of patients increases the risk of transmission.

Last but not least, like AIDS, Ebola can be transmitted through sexual contact.

Even when a patient is treated, it is better to wait for about three months before considering it safe to approach him. People who have recovered from Ebola can still have the virus in their secretions for about 12 weeks and therefore are able to transmit it to others.

 Symptoms:

People who develop the disease after the infection with the Ebola virus show a certain numbers of external signs and symptoms. These signs are usually observed within two to twenty one days after infection. Symptoms include a sudden fever, and muscle pains. Victims also show signs of weakness, headaches and other forms of symptoms.

A list of signs and symptoms is shown below from a Stanford University website on Ebola:  http://virus.stanford.edu/filo/humandiseases.html

 

Signs and Symptoms of Ebola Hemorrhagic Fever:
Fever (90%-100%) (2)Headache (40%-90%) (2)Chills (3)Myalgia/arthralgia (40%-80%)

Malaise (75%-85%)

Pharyngitis (20%-40%)

Loss of appetite

Vomiting (59%)

Hematemesis (10%-40%)

Non-bloody diarrhea (81%)

Blood fails to clot (71%-78%)

Abdominal pain (60-80%)

Dry and sore throat (63%)

Chest pain (83% of EBO-S infected patients; uncommon in EBO-Z infected patients)

Hemorrhagic diathesis (71%-78%)Maculopapular rash (5%-20%)Hiccups (15 %)Hepatic damage

Renal failure

CNS involvement (infrequently)

Terminal shock

Lymphopenia

Severe thrombocytopenia

Transaminase elevation

Hyperamylasemia

During the convalescent stage:

Loss of memory

Central nervous system disorders

Loss of hair


History

Fortunately there have not been that many cases of Ebola outbreak. To this day only three major outbreaks occurred in 1976, 1979, and 1994-1995.

The two outbreaks of 1976 were in the Congo and Western Sudan; they resulted in 550 cases and 340 deaths. These outbreaks were followed by a third one in 1979 in Sudan with 34 cases and 22 deaths.  For the most part these cases occurred in hospitals with inadequate supplies, where basics instruments like needles and syringes were used on more than one patient. Fortunately medical professionals were able to control these outbreaks by isolating the sick patients and by taking safety measures like wearing masks, gowns, and gloves.  In addition hygienic precautions were also taken as sterilized needles and syringes were used and the wastes and the corpse of the victims of the disease were disposed of in a sanitary way.

In 1995, Kikwit (Congo) and the surrounding areas of Bandundu became the spotlight of  world media when 316 deaths were related to the outbreak of the Ebola. The outbreak was worsened by the infection of some among the staff members of a hospital. Their contagion resulted from poor nursing techniques. Other cases of outbreak occurred in rural Gabon (in 1994, 1996) and another part of Africa (Cote d’Ivoire) in 1995.

This overview of the Ebola forces us to ask who is really at risk with the disease?  The initial outbreak of the disease normally happens in isolated rural areas among resource poor people who are forced to hunt rodents and monkeys as source of protein. From there the highly contagious disease spreads to family members and neighbors and often to the medical professionals who treat infected patients.  Like so many other diseases and health issues in Africa, Ebola outbreaks most strongly impact the most economically vulnerable members of the community.

Ebola in Gabon

 

Ebola in Zaire and Sudan

Your turn:

  1. Why do you think the tsetse fly is considered the ‘King of Africa’?
  2. How many outbreaks of Ebola do we know of so far? Be specific about the year they happened. Do a Google search to find out if there have been more recent outbreaks of Ebola.
  3. Observe the picture from the lesson of the individual suffering from sleeping sickness. What did you notice on his body? What explanation can you suggest about his physical conditions?
  4. Seasons, climate, and environment determines how humans dress. If you were to go out in the winter, dressed in shorts, a t-shirt, and sandals, what would your parents say? Would they find your dress appropriate? Would you go out in the summer in snow boots, a warm hat, and mittens? Look closely at the below picture of Central African children. Do you think they are properly dressed against the tsetse fly? Justify your answer.

Kids tsetse fly

 

 

 

II. Environment

*Lake Overturn: Case of Lake Nyos (Cameroon)

Cameroon Map

 

In activity I of this unit we studied one of the rivers in the central part of Africa, the Congo. although the Congo River demonstrates how economically important rivers are to the economic and social life of Central Africa, the same assessment cannot be made about  Lake Nyos, in Cameroon.

Location of Lake Nyos:

Lake Nyos is located in the Cameroon, more specifically, in the western part of the country, adjacent to Nigeria, in what geologists call the Oku volcanic field. With an area of about 1.5 square km and more than 200 meters deep, Lake Nyos has, in normal circumstances, beautiful, deep-blue color water.

Lake Nyos occupies the crater of an extinct volcano known for its gaseous water springs, part of the volcanic chain of Cameroon.  The chain ends at far south-west at Mount Cameroon, a still active volcano of about 4000 m. elevation, which is among 34 recent craters in the Oku volcanic field.

Description of the Disaster: 

Lake  Nyos became a matter of international concern on the evening of August 12, 1986 when around 9:30pm local time, a cloudy mixture of carbon dioxide (CO2 ) and water (droplets) rose violently from the lake. Although that specific evening’s event was not unique, the level of casualties (number of human and animal victims) was unprecedented,  Within minutes about 1800 people lost their lives to the mixture of water and dioxide of carbon (CO2). They died by suffocation. Thankfully many individuals who lived on the shores of Lake Nyos survived the tragedy and were able to recount their experience of the event. One of those 300 lucky villagers, Joseph Nkwain a survivor from Subum, gives a vivid account of what happened that evening as follows:

I could not speak. I became unconscious. I could not open my mouth because then I smelled something terrible . . . I heard my daughter snoring in a terrible way, very abnormal . . . When crossing to my daughter’s bed . . . I collapsed and fell. I was there till nine o’clock in the (Friday) morning . . . until a friend of mine came and knocked at my door . . . I was surprised to see that my trousers were red, had some stains like honey. I saw some . . . starchy mess on my body. My arms had some wounds . . . I didn’t really know how I got these wounds . . .I opened the door . . . I wanted to speak, my breath would not come out . . . My daughter was already dead . . . I went into my daughter’s bed, thinking that she was still sleeping. I slept till it was 4:30 p.m. in the afternoon . . . on Friday. (Then) I managed to go over to my neighbors’ houses. They were all dead . . . I decided to leave . . . . (because) most of my family was in Wum . . . I got my motorcycle . . . A friend whose father had died left with me (for) Wum . . . As I rode . . . through Nyos I didn’t see any sign of any living thing . . . (When I got to Wum), I was unable to walk, even to talk . . . my body was completely weak.” — From A. Scarth (1999)

Lake Nyos before and After

Lake Nyos in normal conditions (left) and after the 1986 event (right)

Lake Nyos Before

Lake Nyos before the eruption

Lake Nyos After

Lake Nyos after the eruption

 

Causes: 

One of the explanations suggested and later on confirmed is that carbon dioxide springs on the floor of the lake pump carbon dioxide into the lake. The disaster was caused by a release of CO2. The major question here is what caused the sudden release of the carbon dioxide that evening?

Different possible explanations have been suggested. According to some Italian volcanologists, the blast that occurred in 1986 was produced by a sudden injection of hot fluids with a high CO2 content into the bottom of the lake. What sustains this argument is that if the gas release had directly come from the bottom of the lake, a reduction of the level of the lake would have been noted. Although there is little data on the change of the level of the lake, pilots who flew over the lake on august 21st reported a decrease of about 1 meter below the lake spillway. Non-confirmed evidence also suggested that the outflow of the lake has also stopped temporarily after the disaster

Solution Diagram

A diagram of one of the solutions suggested to rid the lake of the killer gas

Your Turn:

  1. Carefully reread Joseph Nkwain’s account of the Lake Nyos disaster. What details suggest how intense the disaster was?
  2. From what you have read about the lake and from Joseph Nkwain’s account, write a paragraph in which you will argue whether or not it is safe to settle in a town near the lake. Give at least two reasons to support your position.

This is the final activity in this module. Return to the curriculum, go on to Module Nineteen, or select one of the other activities in this module.