Children of Calamity
In early 2012, an explosive documentary about Ugandan “warlord” Joseph Kony, was unleashed on the Internet. Within a short time the video (detailing Kony’s supplemental children’s army – crudely trained child assassins) made him an infamous global village villain, garnering a quick 150 million views.
Although not much justice can be meted out to Kony based solely on the film, the glaring spotlight of truth has been shone upon him. This viral video, Kony 2012, though perhaps ineffective in stopping Kony guerilla insurgency, has, however, collaterally brought some other issues to the fore in Uganda.
One of these is the mysterious nodding disease of Uganda. The disease was first observed in the 1960s; it was only in the early months of 2012, though, that the world at large, including the United States Center for Disease Control, became noticeably aware of the disease.
Nodding disease’s causes are unknown but hypothesized. It is also an incredibly ironic twist of history that a well-intentioned video documentary exposing a mercenary monster may hold the key to curing a decades’ old mystery disease by drawing international attention.
The casualties are myriad – the economy is almost non-existent, the common people are starving, and they live in terror of roaming death squads that indiscriminately torture and murder. All of these man-made atrocities divert resources and intelligence away from a more sinister problem, and that is the fact that hundreds of Uganda’s children have died from a strange sickness that, because of its characteristic symptom of uncontrolled head movement, has been dubbed “nodding disease”.
It has a high mortality rate, and it is also mentally and physically disabling. It mysteriously only affects children between the ages of 5 and 15 (those most vulnerable whose immune systems are probably compromised by poor diet and parasite infestation in an impoverished country). It appears to be restricted to small regions in South Sudan (drained by the Upper Nile), Tanzania, and northern Uganda.
Credit: Reuter's, 2012
The disease was first described in 1962 – it was completely segregated to a secluded mountainous region of Tanzania then. It was a little considered problem, and it wasn’t until the more recent years brought outbreaks in South Sudan that virologists and other people of medicine began looking at the Sudanese cases of nodding disease as the same thing noted in the early, unresolved 1960’s Tanzania cases.
A child under the influence of the disease, which is chronic (long-term) will have his or her growth stunted permanently. The brain’s growth is stunted as well, leaving the victim mentally retarded.
The disease was given its name for a pathological nodding seizure, continuous head movements in the Western version of a silent “affirmative”. Triggers for the nodding seizure are unusual in pathology – the seizure often begins when a child begins to eat or when the child feels cold. The oddness of these environmental and physical conditions causes other strange occurrences – the nodding seizures are brief, and stop after the child stops eating. For those that are cold, the warming of the body stops the seizure. More strangely the child’s nodding seizure does not stop when he or she is offered food with which he or she is unfamiliar (a wrapped, Western-style, chocolate bar, for example).
A neurotoxicologist studying the disease recently reported that the nodding sensation in the presence of food can spread among other nearby infected children. When shown food, one or two children will start the tell-tale nodding; another child nearby may suddenly go into a grand-mal seizure, others will freeze (meaning to feel cold). The more severe seizures can cause collapse in which a child may physically injure himself or herself. Clinical scans during the seizure process produce visible deviations in expected brain activity. MRI (magnetic resonance imaging) scans show the brains of these children atrophy and are damaged in specific areas.
The disease was first thought to be neurological – one of its more coldly diabolical side effects is leaving its victims, if they survive, mentally retarded. Birth defects were considered as a source of the disease. Environmental factors were taken up as causes as well, International relief efforts to starving nations many times include large shipments of seeds (such as wheat or corn) are sent to the starving nation as stock for growing crops. Sometimes, this act is misinterpreted by the recipients – they eat the seed stock instead of planting it. Other times this is done willfully – starving and with no energy or wherewithal to plant and wait for crops to fruit, the natives go for the more short-term relief for their hunger.
Most crop seeds are treated with chemicals – antifungal, insecticides, etc., as preservatives and to ward off infestation. Toxic substances were initially considered in 2002 (including eating tainted monkey meat) and rightfully rejected as sources of the ailment. Since the disease is very focused in its targets, and seeds and monkey meat were eaten by as many people as could get them, then a larger, more diversified demographic would present with symptoms and not just children between certain ages.
Treatment for this disease, whose cause is unknown, has been based on observation and trial-and-error. There is no known cure. Mostly, health care workers have done their best to treat the symptoms – anticonvulsants, such as Phenobarbital, have been used to control the nodding and grand mal seizures. Anti-malarial drugs have also been experimentally administered ad hoc to no known harm or good.
In 2003, there were roughly 300 cases of the disease reported in one area of Sudan. In 2009, the first cases were found in Uganda, and more than 2,000 cases were reported there quickly enough. In the latter half of 2011, over 1,000 new cases of the disease were reported in the region; 2012 opened with more cases reported. As of March 4, 2012, there were 4,000 known cases of the sickness in northern Uganda alone – over 200 deaths are known (probably more that went unreported).
Credit: Mar 10, 2012
The prognosis for someone with nodding disease is not good. If the child survives, he or she will be mentally retarded and physically disabled in some way. A few children have survived the disease; however, many succumb from the consequences of their physical disabilities and brain atrophy. Others, while in the throes of a seizure, may inadvertently injure themselves (pitching forward into an open fire, or falling down, for example).
Researchers have no reason to suppose the disease will spread beyond the Yeri River watershed. However, there are those who issue that as a qualified and cautious caveat: no one has forgotten the dismal lack of attention to a certain West African fatal illness called “slim disease” received when it was first observed in the late 1970s to early 1980s. Slim disease was the beginnings of what is now infamously known as AIDS.
Because the disease is enigmatic, doctors are helpless to do much except ease the discomfort of excessive nodding (which affects a child’s ability to eat properly, leading to malnutrition and further debility). A Vitamin B deficiency was cited as a possible cause due to malnutrition, but that link seems unlikely, since more of the population would suffer as well.
River blindness (onchocerciasisis) is a condition of the tropics, and it may present the closest link to the nodding illness. River blindness is caused by a parasitic nematode, Onchocerca volvulus. The nematode is carried by black flies (who ingest the earliest larval stage from an infected host). A bite on a new human host transfers the microscopic organism into the victim. The larvae embed in the subcutaneous tissues and form protective nodules (defenses against the body’s immune system). Mature worms emerge from the nodules after 6 to 12 months. They mate; the females produce anywhere from 1,000 to 3,000 new microscopic parasites daily.
Adults can live up to fifteen years – the earliest larval stage of the worm can last up to two years. This means an infected person carries millions of these nematodes in different stages of their life-cycles at all times.Credit: bbc.co.uk The nematodes that settle in the cornea cause long-term corneal inflammation; this leads to blindness. The eyes of a person suffering from river blindness are characteristically filmy, oozing and milky in appearance.
An enterprising researcher with the World Health Organizations noted that the majority of victims of nodding sickness dwelled in the immediate environs of the Yeri River. Additionally, the number of nodding sickness victims who were parasitically infested with the river blindness nematode was ridiculously high, higher than mere chance would allow. The infestation percentages ranged from 70% to 100% by region (in Uganda, there a Credit: Reuter's, 2012pockets of nodding disease victims where 100% of them also carry Onchocerca volvulus.)
With a 93% average incidence of nematode infestation among all nodding sickness sufferers, a connection was thought to have been made. The black flies are abundant in the area of the Yeri River; thus the nematode has a continual system of transport and transfer. But the river blindness worm alone cannot account for the nodding sickness – many people with full blown river blindness do not have nodding sickness.
Researchers are convinced, though, there is a link to the nematode and the nodding sickness. One candidate is a bacteria carried by the nematode, but that, too, may be a blind alley.
Parasites, despite their simplicity (in many cases microscopic flatworms, single-celled organisms, up to more complex multi-cellular creatures), many times have the ability to affect their host organisms’ behaviors. This is seen in nature many times, and it is a function of biology and evolution. Many parasites need separate environments to complete their life cycles. For example, an egg may be laid in soil; a snail eats the egg along with compost, and a larva hatches inside the snail. This second stage thrives inside the snail until a bird eats the snail. This final host may be where the parasite matures. It may live then in the bird, which deposits the parasite’s eggs in its feces, and the process begins anew.
Some parasites (without intelligence, just chemical and biological cues) can alter an animal’s behavior so that the host does what the parasite needs at certain points in its life cycle. There is a certain parasite that affects a specific breed of fresh water lake fish. When this fish is parasitized, it behaves in ways not conducive to its survival. It seemingly, and randomly, swims too near the surface of the lake water. It spends time nearer the shores in shallow waters instead of in safer depths. Furthermore, considering its coloration is protective, the fish many times roll onto their backs near the surface, exposing the silvery-white flesh as a sure beacon to predatory birds. The bird swoops down, eats the fish, and is itself parasitized. The parasite moves through its next stage of development, and the cycle begins anew.
The fish’s behaviors – lurking in shallow waters, advertising its presence near the surface by exposing its white belly – is counter-intuitive to the fish’s survival. A leading parasitologist has determined that the parasite itself is causing the fish to behave in this way so that it will get eaten, allowing the parasite to continue its life-cycle.
Similarly, the nodding disease of Uganda produces odd, counter-intuitive behaviors in its victims. Parasites generally may weaken their hosts, but it is not in their interest to kill their hosts. If the host dies before the parasite completes its life stages, it dies, too.
The connection between nodding and food presentation seems almost classically Pavlovian. Beginning in about 1877, Ivan Pavlov, a Russian physiologist was engaged in studying digestive processes. His test subjects were dogs. In one classic experiment he had hoses attached (with staples) to his dogs’ mouths, and after presenting them with food, he measured the amount of saliva excreted. The anticipatory nature of feeding them was then explored – Pavlov rang a bell, then gave his dogs their suppers. The dogs salivated as expected upon receiving the food. He did the ringing of the bell followed by food (a reward) for many more trials. Finally, he rang the bell without presenting the dogs with food – he found, in trial after trial, the dogs salivated upon hearing the bell just as copiously as if they had been given food. This behavior came to be known in psychology as a “conditioned response”.
The nodding symptom of the affected children may be a function of a parasite. The parasite is affecting the brain chemistry in such a way that the host acts to achieve an end. Since it has Credit: Mike Goldwater/Alamybeen noted that nodding can be triggered by the presence of food, and the seizure ceases after eating, it may seem the parasite is scheduling its meals. Nodding equals food. In support of this is the particular failure to recognize “foreign” comestibles as food (to a Ugandan child a packaged, unopened candy bar, for example, may hold the same appeal as a stone or a tree branch). The child in Uganda, like Pavlov’s dogs, senses its familiar foods. This sets off a chain reaction in both the child’s brain and body; he or she is preparing to eat. This bodily change, subtle though it may be, may prompt (through biochemical signals) the unknown parasite into forcing the nodding behavior which is relieved by eating.
The same can be said of children who are chilled, and seize. When warmed they stop. It seems possible the parasite “likes” its host’s body temperature to be at a steady, and warmer, state. Hosts need to be kept alive – the one irony is the nodding that is relieved by eating actually makes eating difficult.
There is a last, unexplored question as well to discuss in the search for a solution: “What do Ugandan, Sudanese, and Tanzanian children roughly between the ages of five and fifteen years old do that people outside that age range do not?”
Within that broad question are many subtexts. Is there some division of labor relegated to school-age children that their older siblings and adults don’t perform? Is there a cultural dietary restriction on youngsters? Is there some task considered “children’s work” that is exposing them to a risk factor for nodding disease?
The symbiotic parasite angle could be explored, but for now it is almost certain the Yeri River, river blindness, and a mysterious unknown quantity (perhaps another parasite) are connected to nodding disease.
CDC response to Ugandan nodding disease
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