Political instability and violence have massive impacts on the health of affected populations. Studies show that more people die of treatable diseases during conflict than die from conflict-related injuries. This is because the already poor state of healthcare facilities is often further degraded, to the point where diseases that require only basic interventions such as malaria or diarrhoea cannot be cured. Human African trypanosomiasis (HAT) or Sleeping Sickness, as it is more commonly known is a particularly problematic disease. It tends to surge during conflict, unlike malaria or diarrhoea it demands difficult diagnostics and treatment and it is 100% fatal if left untreated.
Sleeping Sickness: scale and symptoms
Sleeping Sickness ravaged Africa in the last century, with severe epidemics in Kenya, Tanzania, Uganda, Nigeria and the Democratic Republic of Congo (DRC). By the 1960s the disease had been bought under control, only to re-emerge in the mid-1970s. The disease is transmitted to humans by the tsetse fly. It comes in two human forms: Trypanosoma brucei (T.b.) gambiense (in west and central Africa) and T.b. rhodesiense (in east Africa). It is estimated that 50,00070,000 people are affected by the disease each year in Sub-Saharan Africa, with seven countries accounting for 97% of all reported cases. Most cases are due to T.b. gambiense. Surveillance is however poor in many areas; affected areas tend to be remote, neglected or affected by insecurity or conflict, and the true size of the problem is unknown.
Stage 1 symptoms begin with fever, headaches and joint pains. If untreated, the disease slowly overcomes the defences of the infected person, and the parasite passes through the blood-brain barrier. The symptoms of stage 2, which give the disease its misleadingly gentle common name, include confusion, motor disorders, reduced coordination, sleep disturbances and psychiatric problems. The manifestation of these advanced symptoms is frightening and causes household upheaval. It is common to see victims tied up to control them. Even if treated the damage caused in the neurological phase is largely irreversible.
Sleeping Sickness is problematic because significant laboratory capacity is required to diagnose the disease. A lumbar puncture is also needed to differentiate between stages 1 and 2. Treatment is less complicated and still effective for patients at stage 1. However, most cases present at stage 2, which is when treatment becomes very difficult. One option is to use a drug, melarsoprol, but this is extremely toxic and kills between 3% and 10% of patients, with limited effectiveness in many endemic areas. The other option, eflornithine, only works for the T.b. gambiense form of the disease, and needs 56 intravenous infusions over 14 days. This requires specialised staff and infrastructure. Vector control can also be used, but it is very cumbersome to implement on a large scale.
There has been little in the way of research and development to produce more efficient diagnostics and safer treatments Sleeping Sickness is one of the cluster of diseases that fall into the most neglected tropical disease basket (NTD), along with Chagas disease and Kala-azar. A new treatment developed by MSF, Epicentre, the Drugs for Neglected Diseases Initiative (DNDi) and other partners, called Nifurtimox-Eflornithine Combination Therapy (NECT), was approved as an essential medicine by the World Health Organisation in May 2009, and is being rolled out to the field. However, NECT only works for T.b. gambiense and still requires seven days of intravenous infusions and ten days of oral tablets. Although research is ongoing, there is as yet no magic bullet: a medicine that is oral, has limited side-effects, can treat both forms of the disease and is effective in both stages.
In general, there are two approaches to medical programmes: horizontal, meaning a clinic giving full services, and vertical, meaning radical targeted programmes that focus only on one disease, such as HIV/AIDS. There is also a hybrid approach, whereby services are integrated but specifically supported to manage a given disease with a passive case-finding approach. However, as Sleeping Sickness mimics other diseases in its early phase, most cases will not present until the point where difficult treatment is needed, and many affected people will die. The best method in heavily affected zones is therefore a radical vertical approach: teams are sent into remote areas to do initial diagnostics, and patients are treated either on site or referred to specialised services. This method makes a big difference in establishing the true size of the problem (see Figure 1), and is the only really effective way of cleansing an area that has a heavy rate of infection. This is nonetheless a long process: an MSF project in the West Nile region of Uganda, started in 1987, took 16 years before the disease was brought down to a level (less than 0.3% prevalence) that did not pose a public health threat.
Hot spots: DRC and CAR
One very worrying Sleeping Sickness hot spot is in Haut-Uélé, in Province Orientale in the DRC. MSF had projects there to detect and treat Sleeping Sickness from July 2007 until March 2009. During this period, the agency found areas of high infection approximately 3.4% (n = 1,570) of the 46,601 people screened were positive and treated, with some small pockets as high as 10%. For this lethal disease, these rates are serious. Haut-Uélé borders the Central African Republic and Southern Sudan, is notoriously under-resourced and has been subject to sporadic conflict and political tension for many years. This insecurity and violence, exacerbated by military operations by Ugandan and DRC armed forces against the Lords Resistance Army (LRA), has caused almost all MSF activities to be shut down since March 2009.
The suspension of MSFs work will have a substantial impact on excess mortality owing to the conflict. UN estimates of deaths due to violence are around 1,200, with many more abducted. Based on the 3.4% estimate of infection, more than 3,000 people are estimated to be affected by stage 1 and over 2,000 with stage 2. Stage 2 kills within six to 12 months, and within two years stage 1 will progress to stage 2. Therefore, for the excess mortality linked to the conflict from infectious diseases, it is feared that around 1,000 more people may have died from Sleeping Sickness alone within six months, and several thousand more will die within 23 years if insecurity does not allow for the resumption of medical activities. These numbers do not include the estimated 510% of all stage 2 patients treated with eflornithine who will relapse within two years after completing treatment. What is even more troubling is that, during the period of active case-finding, the borders of the endemic focus (area of transmission) were never reached. This means that these figures are probably conservative, and that the true number of people at risk may be higher still.
The concern does not end there, because the population is on the move. Refugees and internally displaced people are entering previously affected areas, raising the risk of reactivating historically cleansed pockets or creating new foci. The tsetse fly is abundant across this region, and an uninfected fly biting an affected person will in turn infect another person. This kicks off the cycle of transmission once again. For example, Congolese refugees are crossing into Southern Sudan, an area with a history of serious Sleeping Sickness and where hot spots of the disease still exist.
The Central African Republic (CAR) is another area that is characterised by political insecurity and also has a serious HAT problem. MSF is working in two areas in the north-east. One area bordering Chad has revealed a very serious problem, with 14% of people screened during active and passive case-finding infected by Sleeping Sickness. The high proportion of stage 1 patients (approximately 67%) means that transmission is very intense. Approximately 40% of these cases have crossed the border from Chad, where MSF is launching an assessment with a view to intervening. Away from areas of conflict and insecurity there are other pockets of concern. Recently another assessment was done in the West Nile region of Uganda, and some preliminary data suggests that this previously cleaned up area may be at risk once again.
Although huge progress has been made to get Sleeping Sickness under control, it is not a disease that can be called a past public health problem. It has been suggested that elimination is feasible, and that the best approach is to integrate surveillance and control into existing services. Embarking on a HAT project requires firm commitment covering several years at a minimum, and substantial logistics as well as medical input. It takes many years to clean disease hot spots. Taking all of these factors into consideration, hopes that the disease can be eliminated in the near future are too optimistic. In many areas, the best outcome for now is containment and in Haut-Uélé, even this objective is impossible.
As with all public health problems, there has to be serious and committed collaboration between a variety of actors: national programmes, WHO, NGOs and donors. All actors involved must remain vigilant and active. MSF has been involved in Sleeping Sickness projects since 1987 in Uganda, Southern Sudan, the CAR, the DRC and Angola, treating over 48,000 patients. Several years ago MSFs input was scaled down in the mistaken belief that the disease was under control. This was an error, and the agency has had to bolster its efforts to assist in the control of Sleeping Sickness. If this disease and its victims are neglected once again, history may well repeat itself.
Dr François Chappuis is Medical Adviser for leishmaniasis and trypanosomiasis, Medical Department, MSF, Operational Centre Geneva, Switzerland. His email address is Francois.Chappuis@hcuge.ch. Bruno Jochum is Head of Department of Operations, MSF. His email address is Bruno.JOCHUM@geneva.msf.org.