The health zone of Rethy in Ituri province, the Democratic Republic of the Congo, has seen an upsurge of plague cases since June 2020. The first case, a 12-year-old girl, reported to a local health centre on 12 June experiencing a headache, fever, cough, and an enlarged lymph node. She died on the same day and further deaths from the community due to suspected cases of plague were subsequently reported.
From 11 June though 15 July, six out of 22 health areas have been affected within Rethy health zone (11 villages), with a total of 45 cases including nine deaths (case fatality rate: 20%). All nine (9) cases who died presented with signs of headache, high fever, and painful nodes; four (4) out of the nine (9) cases had cough.
The health zone team carried out an investigation resulting in five positive rapid diagnostic tests (RDTs). Nine additional samples were taken and shipped to the Institut National de Recherche Biomédicale (INRB) laboratory in Kinshasa. Of the 45 cases reported, two showed signs of septicemic plague; all the other cases were diagnosed as having bubonic plague. According to the available information, it is likely that all three types of plague clinical presentation (bubonic, septicemic and pneumonic) are present.
The distribution by sex shows 58% (26/45) are male and 93% (42/45) are greater than five years old. Of the 45 cases reported, nine including four who died, had cough among the symptoms – a sign indicating a potential progression from bubonic plague to pulmonary plague. This was specifically noticed among the deceased.
Plague is endemic in Ituri province. Since the beginning of 2020, Ituri Province has reported a total of 64 plague cases and 14 deaths (CFR:21.8%) in five health zones, namely Aungba, Linga, Rethy, Aru and Kambala health zones. This compares against 10 cases and 5 deaths (lethality 50.0%) during the same period in 2019, all in a single zone.
The current COVID-19 epidemic affects seven out of 26 provinces in the country. Ituri has also reported cases of COVID-191 that may further interrupt response activities due to lockdown. These are in addition to long standing public health response challenges identified in the region, including a lack of resources and insecurity. Although it has been reported that there is no significant impact of the COVID-19 context on activities taking place in this area, there is limited information available on the current access to health care. This includes whether or not there is a need for the population of Ituri to seek care in Uganda, as well as the availability of human resources, drugs, and personal protective equipment (PPE). Furthermore, the reference laboratory in Bunia, Ituri province is currently not functional, which might delay the confirmation of suspected cases and response efforts.
Public health response
- A national rapid response team (RRT) has been deployed to the affected health zone to conduct an outbreak investigation and implement initial response activities.
- UNICEF is on the ground responding to the humanitarian situation at Bunia, working on community engagement and safe and dignified burial practices.
- The WHO guideline for plague, including case definitions, has been disseminated to health facilities to improve the detection of cases.
- The WHO is supporting plague endemic areas with surveillance, investigation of cases, and training of health workers and community relays in the prevention, early detection and case management of plague.
- Doxycycline prophylaxis has been administrated to the listed contacts.
- Intra-household spraying with deltamethrin has been used in some villages.
- Safe and dignified burials (SDB) have been performed by the health district team.
- Sensitization of the population on plague prevention measures in the affected villages through local radio.
WHO risk assessment
Infection with plague can cause severe disease resulting in high mortality in humans, particularly if not identified early. Plague can exhibit in three forms: bubonic, septicemic and pneumonic. If untreated, bubonic plague can evolve to pneumonic plague. Early diagnosis and treatment are essential for survival and reduction of complications.
Rethy health zone is endemic for plague and regularly registers cases of enzootic variants of Yersinia pestis, in much of the wild rodent population. Its first outbreak was reported in February 2020 with cases imported from Linga health zone, based in the Godjoka health area.
On the security level, there are reports of atrocities and violence linked to the militia CODECO which continues to impact the population of this territory (Djugu and its surroundings). There have been mass population displacements within Djugu and Mahagi Territories. Currently, the Rethy Health Zone has received approximately 112 714 internally displaced persons (IDPs), most of whom have come from the Jiba and Linga Health Zone. The growing insecurity impacts traffic flow between the villages and the willingness of the population to either stay or work in that area. There has also been a deterioration of water, hygiene and sanitation conditions in the reception areas and in the IDP sites.
The early detection and reporting of the current outbreak by healthcare workers demonstrate that a functioning surveillance system is in place. Ituri province had a reference laboratory in Bunia which is no longer functional. The Institut National de la Recherce Biomedicale (INRB) laboratory based in Kinshasa/DRC has the ability to conduct laboratory testing for suspected cases. However, delays in shipping samples from Rethy to Bunia and then to Kinshasa, and delays in testing in Kinshasa INRB due to high workload and backload related to COVID-19 samples to be tested, might jeopardize the surveillance and response. Ongoing efforts are required to ensure that any other cases are promptly detected, isolated, and investigated to avoid the establishment of local transmission.
The risk at national level is considered to be moderate given: the evolution of the current situation is in danger of deteriorating rapidly (case fatality rate: 20%), the notification of cases of pulmonary plague, the challenges with the surveillance system and delays between sample collection and laboratory confirmation, and the volatile security situation and the existence of other epidemics in progress in the country which prevents the setting up of a more comprehensive response. Furthermore, the health zone currently does not have enough PPE, body bags and materials needed for decontamination. Malteser International, an NGO that supplies the health zone with drugs, has had difficulty getting the products into the zone because of insecurity on the RN27 road.
The principles of control are known and have been implemented (early treatment with the recommended antibiotics, isolation of the pneumonic cases, chemoprophylaxis given to the close contacts of the latest ones, rodent and flea control, safe and dignified burials, and the prevention of nosocomial transmission) but the means are limited and the health system is unable to manage the cases in the most appropriate way. The antibiotics used for the treatment of the cases are Doxycycline, Ciprofloxacin and Cotrimoxazole. For the pulmonary or septicemic form case, Gentamycin was administrated. The lack of laboratory confirmation is worrying but the use of rapid diagnostic tests (RDT) on the field ensures a minimum of confirmation among the suspected cases. The RDTs are especially reliable to confirm bubonic plague suspected forms.
The risk at regional level is considered low since the epidemic seems to be contained in the Rethy health zone and that it is an isolated region. The risk is considered low globally.
Bubonic plague is the most common form of plague and is caused by the bite of an infected flea. The plague bacillus, Y. pestis, enters at the bite site and travels through the lymphatic system to the nearest lymph node where it replicates. At advanced stages of the infection, the inflamed lymph nodes can turn into suppurating open sores. There is no inter-human transmission of bubonic plague.
Untreated, bubonic plague can advance and spread to the lungs, which is the more severe type of plague called pneumonic plague, the most virulent form of plague. Incubation period can be as short as 24 hours. Any person with pneumonic plague may transmit the disease via droplets to other humans. Untreated pneumonic plague, if not diagnosed and treated early, is almost always fatal. However, the probability of recovery is high if detected and treated in time (within 24 hours of onset of symptoms).
Early diagnosis and treatment are essential for survival and reduction of complications. Appropriate diagnostic samples include blood cultures, lymph node aspirates if possible, and/or sputum, if indicated. Drug therapy should begin as soon as possible after the laboratory specimens are taken. Post-exposure prophylaxis is indicated in persons with known exposure to plague, such as close contact with a pneumonic plague patient or direct contact with infected body fluids or tissues. Duration of post-exposure prophylaxis to prevent plague is seven days.
Preventive measures include informing people when zoonotic plague is present in their environment and advising them to take precautions against flea bites and not to handle animal carcasses. People, especially health workers, should also avoid direct contact with infected tissues such as buboes, or close exposure to patients with pneumonic plague.
Recommended response measures for all forms of plague:
- Obtain specimens which should be carefully collected using appropriate infection, prevention and control procedures and sent to labs for testing. Confirmation of plague requires lab testing. The best practice is to identify Y. pestis from a sample of pus from a bubo, blood or sputum. A specific Y. pestis antigen can be detected by different techniques
- Ensure correct treatment: Prompt treatment with the correct medications is critical to prevent complications. Verify that patients are being given appropriate antibiotic treatment such as aminoglycosides, fluoroquinolones, chloramphenicol, tetracyclines sulfonamides and supportive therapy. The antibiotic treatment may need to be adjusted depending on a patient’s age, medical history, underlying health conditions, or allergies. Duration of treatment is 10 to 14 days, or until 2 days after fever subsides.
- Protect health workers. Inform and train them on infection prevention and control. Workers in direct contact with pneumonic plague patients must wear a full personal protective equipment and use standard precautions for respiratory diseases. Depending on the circumstances, they can also take a chemoprophylaxis with antibiotics such as doxycycline for the duration of seven days or at least as long as they are exposed to infected patients. However, the chemoprophylaxis cannot replace the use of a PPE and the individual physical precautions.
- Isolate patients with pneumonic plague. Patients with confirmed or suspected pneumonic plague should be isolated so as not to infect others via air droplets. Provide masks for pneumonic patients.
- Contact follow up: identify, inform and monitor close contacts of pneumonic plague patients and provide them with a seven-day chemoprophylaxis
- Ensure safe burial practices. Optimal infection prevention and control measures are to be observed during funeral and burial ceremonies. Funeral ceremonies in the houses of plague victims which may involve assembly of people should be discouraged.
- In order to effectively and efficiently manage plague outbreaks it is crucial to have an informed and vigilant health care work force (and community) to quickly diagnose and manage patients with infection, to identify risk factors, to conduct ongoing surveillance, to control vectors and hosts, to confirm diagnosis with laboratory tests, and to communicate findings with appropriate authorities.
1As of 16 July 2020, there have been 8 162 confirmed COVID-19 cases including 191 deaths in the Democratic Republic of the Congo.