This month's health bulletin focuses on:
- The ongoing Ebola outbreak in the Democratic Republic of Congo
- The evolving situation regarding Lassa fever in Nigeria and
- The increasing spread of infectious diseases in Venezuela
Democratic Republic of Congo (DRC)
The outbreak of the Ebola virus in eastern DRC, the second largest in history, continues unabated. Now over 900 cases of this serious illness have been reported, resulting in over almost 600 deaths. Starting mid-2018, this present outbreak continues to threaten DRC’s surrounding countries with the potential of spread across what are often porous borders. Many tens of thousands of workers and traders cross back and forth each day from countries such as Uganda, Rwanda, and Burundi. At these points of entry, as well as airports and ports, the basic health checks that are carried out in an attempt to screen those who are possibly infected with the Ebola virus, are so far seemingly effective: there have been no reports of transmission outside of the DRC.
As the health inspection at these entry-points initially comprises of just a simple temperature check, this is perhaps somewhat surprising. Since the Ebola virus manifests symptoms only after several days following infection, it is quite possible that someone unwittingly infected, feeling entirely well, could cross the border or get on a plane, not triggering concern at the screening points. This hasn’t yet occurred, however.
Whether this is because of the widespread use of the novel Ebola vaccines is unclear at present - an astonishing 80,000 people have so far been immunised. The particular method of vaccination that is being used has received widespread attention. When a case of Ebola is identified, those who have come into recent contact with the patient (and are therefore at highest risk of becoming infected) are sorted into the first ring of those to be immunised. In the second ring are put the recent contacts of those in the first ring. In this way, those at highest risk receive the vaccine, decreasing the chance that they will get the disease and also that they will pass on the virus to others.
The eastern region of the DRC has not only been plagued by Ebola, however, but also by the continued militia activity hindering the efforts of the WHO and partners. There have been several notable rebel attacks that have necessitated temporary halts of efforts to both contact trace and to deliver vaccine. Only last week, for example, it was the abduction and murder of a nurse from a health centre in Busongo that put pay to the surveillance activities in the Vuhovi health zone, an area between the Ebola affected areas of Beni and Butembo.
Further complications in controlling the epidemic include the coincidence of other outbreaks, including malaria, affecting the region. As the initial symptoms of Ebola are easily mistaken for malaria, several patients have presented themselves to malaria treatment centres only later to be diagnosed with Ebola, thus potentially exposing other patients in the treatment centre to the Ebola virus.
What will happen during this outbreak is still difficult to predict. Although there has been some decrease in the incidence of cases in previously affected areas, as the confounding issues of militia activity, community resistance, and a displaced population are set to continue, the epidemic is likely to be far from over.
Lassa fever shares several similarities with Ebola. Most significantly perhaps, Lassa is caused by a virus that in severe cases produces haemorrhage or uncontrolled bleeding, presaging death in many cases. Lassa is endemic in West African countries such as Nigeria, but for the past few years there has been a spike in the numbers of patients. 2018 saw around 3,500 cases, which resulted in 171 deaths - the death rate from Lassa is significantly less than that for the Ebola virus.
This year, however, has already seen 75 deaths, from almost 1,200 suspected cases, suggesting that an important epidemic might be evolving. In distinction to Ebola, which is harboured by the fruit bat, Lassa is spread by the rodent Mastomys natalensis. This small rat enters local homes and is able to infect humans by contaminating food, or by infecting cuts or sores on the individual’s body. Once infected, human to human transmission can occur following sustained contact.
At present the authorities are following up almost 3,000 people who are at high risk of Lassa fever infection. Healthcare measures to limit transmission usually concern educating the local population to make their houses unattractive to rodents. In healthcare settings, the correct use of personal protective equipment is strongly advocated when caring for any undiagnosed patients with fever. As there is no specific treatment for Lassa fever, prevention of transmission is particularly important if further causalities are to be avoided.
The political situation in Venezuela is rightly receiving increasing world attention as tensions escalate across neighbouring borders. What has received fewer press reports, however, are the widespread epidemics of several infectious diseases that have occurred hand-in-hand with the economic devastation. Diseases spread by mosquitoes have increased dramatically. This usually occurs when public health measures to control the propagation of mosquitoes are hindered. Diseases such as Zika and Dengue have increased, but it is the incidence of malaria that has spiralled out of control: a staggering 1.3 million cases are reported by some authorities.
Other diseases such as measles and diphtheria have also seen dramatic rises in cases as immunisation efforts have been hindered. As the upper levels of Venezuelan society have fled to other countries to escape the political and economic turmoil, medical staff too have also sought refuge in more certain regions of the globe. Thus, the increase in disease, and decrease in public health provision, has been mirrored by a depletion of those able to treat the population. For many reasons, the advice to avoid all non-essential travel to Venezuela is strongly advised.