Plague – Democratic Republic of the Congo

In the Rethy Health Zone in Ituri Province, Democratic Republic of Congo, there has been an increase in plague cases since June 2020. The first case, a 12-year-old girl, was reported on June 12 at a local health center for headache, fever, cough and swollen lymph node. She died the same day, and further deaths from the community due to suspicious cases of plague were subsequently reported.

From June 11 to July 15, six of the 22 health areas were affected within the Rethy Health Zone (11 villages), and there were a total of 45 cases, including nine deaths (death rate per case: 20%). All nine (9) deaths died from signs of headache, fever, and painful nodules; four (4) out of nine (9) cases had a cough.

The health zone team conducted an investigation that resulted in five positive rapid diagnostic tests (RDT). Nine additional samples were taken and shipped to the Institut National de Recherche Biomédicale (INRB) laboratory in Kinshasa. Of the 45 reported cases, two showed signs of septic plague; all other cases were diagnosed as having renal plague. According to the available information, all three types of clinical presentation of plague (bubonic, septicemia, and pneumonia) are likely to be present.

The distribution by gender shows that 58% (26/45) are male and 93% (42/45) are older than five years. Of the 45 reported cases, nine of which died, four had a cough among the symptoms – a sign that indicates potential progression from bubonic plague to pulmonary plague. This was especially noticeable among the deceased.

The plague is endemic in the province of Ituri. Since the beginning of 2020, Ituri Province has reported a total of 64 cases of plague and 14 deaths (CFR: 21.8%) in five health zones, namely Aungba, Linga, Rethy, Aru and Kambala health zones. This compares to 10 cases and 5 deaths (50.0% mortality) during the same period in 2019, all in one zone.

The current COVID-19 epidemic affects seven of the country’s 26 provinces. Ituri also reported on COVID-19 cases¹ which can further interrupt the reaction activities due to locking. These are in addition to the long-standing public health challenges identified in the region, including lack of resources and insecurity. Although it is reported that there is no significant impact of the COVID-19 context on activities taking place in this area, little information is available on the current approach to health care. This includes whether or not the Ituri population needs to seek care in Uganda, as well as the availability of human resources, medicines and personal protective equipment (PPE). Furthermore, the reference laboratory in Bunia, Ituri province is currently not functioning, which could delay the confirmation of suspicious cases and response efforts.

Public health response

• The National Rapid Response Team (RRT) has been deployed to the affected health zone to conduct an epidemic investigation and conduct initial response activities.
• UNICEF is responding on the ground to the humanitarian situation in Bunia, working on community engagement and safe and dignified funeral practices.
• WHO guidelines for plague, including case definitions, have been distributed to health facilities to improve case detection.
• WHO supports plague endemic areas by monitoring, investigating cases, and training health workers and community members in the prevention, early detection, and management of plague cases.
• Doxycycline prophylaxis was applied to these contacts.
• In some villages, internal home spraying with deltamethrin is applied.
• Safe and dignified burials (SDB) were performed by the district health team.
• Through local radio the sensitivity of the population to plague prevention measures in the affected villages.

WHO risk assessment

Plague infection can cause severe illness resulting in high human mortality, especially if not recognized early. Plague can occur in three forms: bubonic, septicemic, and pneumonic. If left untreated, bubonic plague can develop into pneumonic plague. Early diagnosis and treatment are key to survival and reduction of complications.

The Rethy Health Zone is endemic for plague and regularly registers cases of enzootic variants Yersinia pestis, in most of the wild rodent population. The first report was recorded in February 2020 with cases imported from the Linga health zone based in the Godjoka health area.

At the security level, there are reports of crimes and violence related to the CODECO militia, which continues to affect the population of this territory (Đuga and surroundings). There were mass displacements of the population within the territories of Dugu and Mahaga. Currently, Rethy Health Zone has received about 112,714 internally displaced persons (IDPs), most of whom came from Ziba and Ling Health Zones. Growing insecurity affects the traffic flow between villages and the willingness of the population to stay or work in the area. There has also been a deterioration in water, hygiene and sanitation conditions in reception areas and internally displaced areas.

Early detection and reporting of the current epidemic of health workers shows that a functioning surveillance system is in place. The province of Ituri had a reference laboratory in Bunia that is no longer operational. The National Laboratory for Biomedicine (INRB) of the Kinshasa-based Institute / DRC has the ability to conduct laboratory tests for suspected cases. However, delays in shipping samples from Rethy to Bunya and then in Kinshasa, and delays in testing in the Kinshasa INRB due to the high workload and overload associated with the COVID-19 samples being tested, may jeopardize monitoring and response. Ongoing efforts are needed to ensure that any other cases are immediately detected, isolated and investigated to avoid the establishment of local transmission.

The risk at national level is considered moderate if we keep in mind: the evolution of the current situation threatens to deteriorate rapidly (case mortality rate: 20%), notification of pneumonia cases, challenges with the surveillance system and delays between sample collection and laboratory confirmation, and the volatile security situation and the existence of other ongoing epidemics in the country, which prevents a more comprehensive response. Furthermore, the health zone currently does not have enough PPE, body bags and materials needed for decontamination. Malteser International, a non-governmental organization that supplies the health zone with medicines, had difficulty entering products into the zone due to uncertainty on the RN27 road.

Principles of control are known and implemented (early treatment with recommended antibiotics, isolation of pneumological cases, chemoprophylaxis close contact with the latest, rodent and flea control, safe and dignified burial and prevention of nosocomial transmission) but resources are limited and the health system cannot manage cases in the most appropriate way . Antibiotics used in the treatment of cases are doxycycline, ciprofloxacin and cotrimoxazole. For the case of pulmonary or septic form, Gentamycin was used. The lack of laboratory confirmation is worrying, but the use of rapid diagnostic tests (RDT) in the field ensures minimal confirmation among suspicious cases. RDTs are particularly reliable for confirming forms suspected of bubonic plague.

The risk at the regional level is considered small given that the epidemic appears to be contained in the Rethy health zone and that it is an isolated region. In general, the risk is considered low.

WHO advice

Bubonic plague is the most common form of plague and is caused by the bite of an infected flea. Plague plague, Y. pestis, enters the bite site and travels through the lymphatic system to the nearest lymph node where it reproduces. In the advanced stages of the infection, inflamed lymph nodes can turn into purulent open ulcers. There is no interstate transmission of bubonic plague.

Untreated, bubonic plague can progress and spread to the lungs, and it is a more severe type of plague called pneumonic plague, the most controversial form of plague. The incubation period can only be 24 hours. Anyone who has pneumonia can transmit the disease by droplets to other people. Untreated pneumonic plague, if not diagnosed and treated early, is almost always fatal. However, the likelihood of recovery is high if it is detected and treated in time (within 24 hours of the onset of symptoms).

Early diagnosis and treatment are key to survival and reduction of complications. Appropriate diagnostic specimens include blood cultures, lymph node aspirates if possible, and / or sputum, if indicated. Drug therapy should be started as soon as possible after taking laboratory samples. Post-exposure prophylaxis is indicated in persons with known plague exposure, such as close contact with a patient with pneumonic plague or direct contact with infected body fluids or tissues. The 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 treat animal carcasses. People, especially healthcare professionals, should also avoid direct contact with infected tissues, such as beetles, or close exposure to patients with pneumonic plague.

Recommended response measures for all forms of plague:

• Obtain samples to be carefully collected using appropriate infectious, preventive, and control procedures and send them to laboratories for testing. Confirmation of the plague requires laboratory testing. Best practice is to identify Y. pestis from a sample of manure from beetle, blood, or sputum. specific Y. pestis antigen can be detected by various techniques
• Ensure proper treatment: Prompt treatment with the right medications is crucial to prevent complications. Ensure that patients are given appropriate antibiotic treatment such as aminoglycosides, fluoroquinolones, chloramphenicol, tetracyclines sulfonamides, and supportive therapy. Antibiotic treatment may need to be adjusted depending on the patient’s age, medical history, medical conditions and allergies. The duration of treatment is 10 to 14 days, or up to 2 days after the fever subsides.
• Protect healthcare professionals. Inform them and train them to prevent and control infection. Workers in direct contact with pneumonic plague patients must wear fully personal protective equipment and use standard respiratory precautions. Depending on the circumstances, they may also take chemoprophylaxis with antibiotics such as doxycycline for seven days or at least while exposed to infected patients. However, chemoprophylaxis cannot replace the use of PPE and individual physical precautions.
• Isolate patients with pneumonic plague. Patients with confirmed or suspected pneumonic plague should be isolated so as not to infect others through airborne droplets. Provide masks for pneumological patients.
• Contact monitoring: identify, inform and monitor close contacts of pneumonia patients and provide them with seven-day chemoprophylaxis
• Ensure safe burial procedures. Optimal measures to prevent and control infection must be observed during funeral and funeral ceremonies. Funeral ceremonies in the homes of plague victims that may involve gathering people should be discouraged.
• To effectively and effectively combat the plague epidemic, an informed and vigilant health workforce (and community) is crucial to quickly diagnose and manage patients with infection, identify risk factors, conduct ongoing surveillance, control vectors and hosts, confirm diagnosis by laboratory tests, and communicate found with appropriate bodies.

¹As of 16 July 2020, 8,162 confirmed cases of COVID-19 were recorded in the Democratic Republic of Congo, including 191 deaths.