Monkeys – Democratic Republic of the Congo

From 1 January to 13 September 2020, a total of 4,594 suspected cases of monkeypox were reported, including 171 deaths (mortality rate 3.7%), in 127 health zones from 17 of the 26 provinces in the Democratic Republic of Congo. The first peak of the epidemic was observed in early March 2020 (epi week 10), with 136 cases reported per week (Figure 1). From January 1 to August 7, the Institut National de Recherche Biomédicale (INRB) received 80 samples from suspected cases of monkeypox, of which 39 samples were confirmed by polymerase chain reaction. Four of the 80 specimens were skin lesions (crusts / vesicles), the remaining specimens were blood. There are currently no further data on the outcome of these 80 patients whose samples were tested. Affirmative testing is still ongoing.

In the same period in 2019, 3,794 suspicious cases and 73 deaths (CFR 1.9%) were reported in 120 health zones from 16 provinces, while a total of 2,850 suspicious cases (CFR 2.1%) were reported in 2018.

Figure 1: Distribution of suspected monkeypox cases and mortality rate cases, by epi weeks, from 1 January 2019 to 13 September 2020.

The provinces that report the highest number of suspicious cases include Sankura with 973 (21.2%) suspected cases, Mai-Ndombe with 964 (21%) suspected cases, Equater with 586 (12.8%) suspected cases, Tshuapa with 520 (11, 3%) of suspected cases and Mongolia with 518 (11.3%) suspicious cases (Figure 2). From 1 January to 13 September, Kwilu Province reported the highest mortality rate of 16.7% (1 death / 6 suspected cases), followed by Tshopo 8.1% (17 deaths / 211 suspected cases) and Mai-Ndombe 7, 8% (75 deaths / 964 suspicious cases).

Active attacks on the province of Mai-Ndombe (located south of the province of Equator, in the northwest of the country) have been recorded since January 2020. The epidemic in the Inongo health zone (province of Mai-Ndombe) is one of the most important epidemics affecting a quarter of its territory. This outbreak has been going on since June 2020, covering 65% of the total number of suspected cases with an estimated mortality rate of 10%. Moreover, the Inongo Health Zone borders the Bikoro Health Zone (Ecuador Province); The province of Ecuador is the site of the current Ebola outbreak, and now it is the outbreak of monkeypox.

In the Democratic Republic of the Congo, the majority of suspected cases (58%) are older than five years; however, the mortality rate of children under the age of five was 4.2% higher (80 deaths / 1,907 suspected cases) compared to 3.4% in cases older than five years (91 deaths / 2,687 suspected cases).

Figure 2: Distribution of cases by provinces from 1 January to 13 September 2020 (epi weeks from 1 to 37).

Source: Integrated Disease Control (IDS) Report for the Democratic Republic of the Congo, Epidemiological Week 37, 2020.

Cases of monkeypox have been reported in health zones that also have multiple outbreaks of the disease, including measles, polio due to cVDPV, malaria, cholera and COVID-19, with a constant outbreak of Ebola in Ecuador province which continues to experience armed conflict and violence . The security situation in the Democratic Republic of Congo remains volatile, further hampering surveillance efforts and response activities. The regions affected by this epidemic continue to have armed conflict and displacement.

Potential exposure may be associated with the proximity of a forest with many possible animal reservoirs, including hunting activities.

With the global circulation of the virus causing COVID-19 and the constant insecurity in the region, there is a risk of disrupting access to health care due to the burden associated with COVID-19 on the health system. As of 16 September 2020, a total of 10,401 COVID-19 cases have been reported in DR Congo, including 267 deaths.

Public health response

The WHO is working with national authorities to obtain more information on cases and laboratory capacity. Investigating and confirming suspicious cases will help further understand the reach of the virus in DRC.

Technical support is provided to the Ministry of Health for the rapid development and implementation of a comprehensive response plan to strengthen surveillance at the national and local levels, including further outbreak investigations and response activities.

One of the main challenges of the current state of emergency involves inadequate funding to respond to the country’s multiple epidemics. Weaknesses in surveillance and laboratories, along with large numbers of refugees crossing the border from Kasai province to Angola, could contribute to the further spread of the epidemic.

The support of partners such as the Centers for Disease Control and Prevention (CDC), the United Nations High Commissioner for Refugees (UNHCR) and non-governmental organizations (NGOs) will be crucial to controlling this epidemic.

WHO risk assessment

Shrimp monkeys are a sylvatic zoonosis with occasional human infections that occur sporadically in the rainforests of central and West Africa. It is caused by the monkeypox virus (MPXV), which belongs to the Orthopoxvirus family, the same group of viruses as smallpox.

There are two different types of monkeypox virus, the log in the Congo Basin and the West African log. Smallpox due to the log virus in the Congo Basin recorded mortality in up to 10% of cases, while West African logs usually show deaths in less than 1% of cases. HIV infection appears to increase the risk of death in people infected with the monkeypox virus.

The animal tank remains unknown. However, the evidence suggests that native African rodents could be potential sources. Contact with living and dead animals through hunting and bush meat are presumed triggers of human infection. The disease is only limited, and the symptoms usually subside within 14-21 days. Severe cases are more common among children and the immunocompromised population, especially people living with HIV, and are related to the extent of virus exposure, the patient’s health status, and the severity of complications. The mortality rate varied between epidemics, but was between 1% and 10% in documented events. There is no specifically allowed treatment for monkeypox, and the recently approved vaccine is not yet widely available to the public sector.

From the identification of the first case of monkeypox in humans in 1970 in the Democratic Republic of Congo (then known as Zaire) in a 9-month-old boy, until 1986, 95% of cases worldwide were reported in DR Congo. Cases of monkey shrimp have also been reported from other African countries – Benin, Cameroon, the Central African Republic, Gabon, Ivory Coast, Liberia, Nigeria, the Republic of the Congo, Sierra Leone and South Sudan. In 2003, an epidemic broke out in the United States after the import of infected animals. Cases of individual imports were identified in Israel and the United Kingdom in 2018, and in Singapore in 2019, all followed by diagnoses in travelers from Nigeria. In the UK, a secondary case of a healthcare worker has been confirmed.

With the eradication of smallpox and the subsequent cessation of routine smallpox vaccination, human measles has become more common in unvaccinated populations.

The risk is assessed high at the national level, moderate at the regional level and low at the global level.

WHO advice

Several orthopoxviruses, particularly the monkeypox virus, circulate among wildlife populations and sporadically spill over to affect humans. Reducing contact and reliance on wildlife will intensify efforts to prevent zoonoses affecting wildlife, including smallpox.

Cross-border cooperation with neighboring countries (Republic of Congo, Democratic Republic of Congo and Central African Republic) needs to be strengthened, including the exchange of data and information.

Residents and travelers to endemic areas / countries should avoid contact with sick, dead or living animals that may have the monkeypox virus (rodents, marsupials, primates) and should refrain from eating and handling shrubs. The importance of hand hygiene with soap and water or an alcohol-based disinfectant should be emphasized. Hand washing stations and infection control initiatives, such as the use of disinfectants, should be established in a hospital setting. Any illness during the trip or upon return should be reported to healthcare professionals, including information on recent travel and immunization history.

Timely contact search, surveillance measures and awareness raising with healthcare providers are key to preventing secondary cases and effectively managing smallpox epidemics. Infection control in healthcare facilities is crucial. Healthcare professionals caring for patients with suspected or confirmed monkeypox should implement standard precautions, contact and droplet protection.

Samples taken from humans and animals suspected of being infected with the monkeypox virus should be handled by trained personnel working in appropriately equipped laboratories. The confirmation of monkeypox depends on the type and quality of the sample and the type of laboratory test. Therefore, samples should be packaged and shipped in accordance with national and international requirements. Polymerase chain reaction (PCR) is the preferred laboratory test due to its accuracy and sensitivity. For this, the optimal diagnostic samples of monkey shrimp are skin lesions – roof or fluid from vesicles and pustules and dry bark. PCR blood tests are often not definitive due to the short duration of viremia relative to the time of sampling after symptoms begin. Serology is not indicated for the detection of acute infection. For these reasons, blood should not be routinely taken from patients unless it is part of an investigation or wider investigation of an outbreak that involves the identification of previous cases.

The vaccine used during the smallpox eradication program also protected against monkeypox. Some countries and the WHO keep emergency vaccines against smallpox (vaccinia) in an emergency. The new safer third-generation vaccine (known as the modified Ankara vaccine vaccine) approved in 2019 for the prevention of monkeypox is not yet widely available to the public sector. Antivirals are also being developed.

The WHO does not recommend any restrictions on travel and trade with the Democratic Republic of the Congo based on available data at this time.

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