Discover more from On the Dot: The Global.health Newsletter
Marburg in Equatorial Guinea: Curation Challenges in Tracking Viral Haemorrhagic Fever Outbreaks
First Marburg outbreak in Equatorial Guinea.
On February 13th, 2023, a first-ever outbreak of Marburg Virus Disease (MVD) was declared in Equatorial Guinea. The index case died January 7th, 2023. The Ministerio de Sanidad y Bienestar Social de la República de Guinea Ecuatorial (MINSABS) was notified one month later, on February 7th. The World Health Organization (WHO) was officially notified on February 13th after a sample from Kie-Ntem Province tested positive for MVD. Marburg poses a significant public health threat, particularly in a resource-constrained setting and for a country with no previous experience tackling a MVD outbreak. A coordinated response from public health experts and organizations was needed to help reinforce local response, mitigate disease spread, and lessen the impact of the outbreak among vulnerable populations.
MVD is a severe haemorrhagic fever caused by the Marburg Virus (MARV), which is highly virulent with a case fatality rate of up to 88%. Marburg is a part of the filovirus family, which includes Ebola. Its reservoir host is a type of Egyptian fruit bat, Rousettus aegyptiacus, found across sub-Saharan Africa. Human-to-human transmission following an animal-to-human spillover event occurs through direct contact with an infected person’s blood or other bodily fluids, or through objects contaminated with bodily fluids from the sick or dead. Burial practices that involve direct contact with the corpse can contribute to transmission and have been shown to contribute to continued community transmission; similar patterns have been observed with Ebola. Risk communication and community engagement (RCCE) are critical to controlling MVD outbreaks. There are currently no approved vaccines or antiviral treatments for MVD; early intervention with supportive care however has been shown to improve survival.
The recent outbreak in Equatorial Guinea is the 3rd most deadly MVD outbreak on record. As of May 4th, there are a total of 17 confirmed cases, including 12 deaths and an additional 23 probable cases, all of whom died. Confirmed cases have been detected in four provinces (MINSABS data): Kie-Ntem (Ebibeyin) [3 confirmed, 2 dead], Centro-Sur (Evinayong) [2 confirmed, 2 dead], Wele-Nzas (Nsork) [1 confirmed, 1 dead], and Litoral (Bata - urban commercial capital, main port) [11 confirmed, 7 dead]. On June 8th, 2023, the WHO declared the end of the outbreak, bringing our 100 days of coverage for this event to conclusion.
Early in the outbreak (from declaration through March 23rd), there was little publicly available case information to build an epidemiological line-list. Therefore, Global.health aimed to support international health agencies through researching key indicators including, but not limited to, epidemiological data (e.g., cases and deaths, case definitions, geography, demographics, affected or at-risk populations, lab results); healthcare capacity and infrastructure (e.g., number and type of healthcare facilities, workforce, surveillance and testing capacity, information systems); environmental factors (e.g., climate change and weather patterns, vectors, food security, access to clean water, sanitation facilities); and behavioral data (e.g., information on the demand for medical care, treatment, or diagnostic tests, acceptance of traditional versus modern medicine), to provide additional contextual information.
On March 23rd, 2023, over a month after the declaration of the outbreak, MINSABS made available a line-list that became our primary source for describing the event. Specifically, individual-level case data released in the Official Communication No. 3 from MINSABS National Committee for Health Emergencies was the start of our line-list. Standardized epidemiological updates have been released by MINSABS with outbreak information; however, this data is presented in aggregate form which makes it difficult, if not impossible, to update individual cases in our line-list. Our line-list also includes publicly available data from the WHO (see source list), and we created a briefing report to derive epidemiological insights from these integrated case data. These data were used to infer delay distributions and incubation period of Marburg.
A concurrent outbreak of Marburg in Tanzania.
On March 21st, 2023, Tanzania declared its first-ever Marburg outbreak in the country [9 cases including 6 deaths as of May 28th]. Global.health closely monitored the outbreak and internally tracked cases through WHO’s declaration of the end of the outbreak on June 2nd, 2023. This marked 42 days (equivalent to two incubation periods) after the last patient tested negative for the second time. This is the first time that there have been two concurrent MVD outbreaks in Africa. These two outbreaks are thought to represent independent animal-to-human spillover events as there currently is no evidence to show that the outbreaks are epidemiologically linked; however, viral genetic sequencing is ongoing.
Curation Challenges in Tracking Viral Haemorrhagic Fever Outbreaks.
Together with public health teams and research groups, we identified three main challenges in tracking the outbreaks of Marburg:
Low resource settings. Resource-constrained healthcare systems have limited capacity to detect and respond to outbreaks. Countries issued travel alerts for this outbreak, noting “generally poor” medical facilities, and that “for serious medical treatment, evacuation to Europe would be necessary.” [UK HSA] According to MINSABS’ National Health Development Plan (2021-25), Equatorial Guinea did not have a surveillance, alert and response plan for health emergencies and cites insufficient financial resources as one of the main barriers to improving it. Early intervention from technical teams of global public health experts could support epidemiological investigations to curb the spread of disease and strengthen local capacity by providing the necessary skills and resources to respond to outbreaks. Support for tackling the outbreak extended across the following response pillars: Coordination; Partner Support; Surveillance; Laboratory; Clinical Care; Infection, Prevention, and Control; Risk Communication and Community Engagement; Border Health and Points of Entry; Operational Support and Logistics; Readiness and Preparedness in Neighboring Countries.
Healthcare workers (HCWs) are at increased risk of infection of Marburg. HCWs are more likely to be exposed to the virus during an outbreak and require adequate infection, prevention, and control measures, and protective equipment. Loss of this skill set and workforce can destabilize an already fragile, under-resourced healthcare system. A total of 5 [3 recovered, 2 dead] of the 17 confirmed cases (nearly 30%) are among HCWs in Equatorial Guinea. Two of the 9 cases (22%) are among HCWs in Tanzania.
Little web presence. Typically, Global.health is able to gather a mix of official and non-official sources for outbreak information online. However, we were only able to gather case information from official sources of information [e.g. MINSABS, WHO] due to an absence of other local news outlets covering the outbreak in Equatorial Guinea. In the beginning of the outbreak, weeks passed between official reports [Official Communication No. 1, 2, and 3] and the government stopped reporting probable cases on March 21, 2023, which created a lack of transparency and demonstrated the need for the release of timely, publicly available information. The government also delayed official reporting of confirmed cases to the WHO. Media freedoms could be another area for exploration to identify the potential impact on access to unbiased outbreak information. Further, curators are limited to information that is made publicly available online, and internet access, connectivity, and penetration are limited in sub-Saharan Africa. There can be a rural-urban divide for the necessary infrastructure to reach locations where these outbreaks occur, which is a segway to our next challenge.
Outbreak occurs in remote locations. The MVD outbreak in Equatorial Guinea has affected remote locations and villages. Remote and rural communities within low and middle income countries (LMIC) may be at increased risk for spillover events and zoonotic disease due to socioeconomic and environmental drivers and exposure to domestic and wild animals (including reservoirs). A comprehensive One Health approach to surveillance is critical for early outbreak detection. However, these remote locations are limited in their surveillance, diagnostic, and reporting capacity — creating barriers for health workers, and potentially affecting timely case and contact identification for transmission. WHO reports that several epidemiological links and transmission chains were not detected, impacting contact tracing and potentially contributing to undetected community spread. Remote settings often lack adequate RCCE, making it difficult for accurate and timely information about the outbreak to be disseminated among the public. Lack of RCCE also contributes to various forms of stigma in the absence of accurate information arising from fear and anxiety as well as discrimination towards certain individuals or community groups. RCCE plays an important role in preventing the spread of the virus by increasing public awareness, encouraging community engagement, and promoting accountability in the response effort. Furthermore, increased awareness from RCCE can ensure safe and dignified burial practices of individuals who have died from MVD by addressing disease transmission from cultural practices and engaging with communities to build trust and cooperation.
The occurrence of two MVD outbreaks is concerning to the global community. Global.health had recently wrapped up 100 days of coverage for the 2022 Ebola outbreak in Uganda when this new MVD outbreak emerged. We transitioned from tracking one viral haemorrhagic fever to the next. Tracking VHF is important and the acting director of Africa Centers for Disease Control and Prevention, Ahmed Ogwell Ouma, stated in a post related to this outbreak that, “These emerging and re-emerging infectious diseases are a sign that the health security of the continent needs to be strengthened to cope with the disease threats”. According to the WHO, this [MVD] outbreak posed a very high risk at national, sub-regional, and regional levels, and a low risk at global levels. IHR 2005 requires VHF reporting because outbreaks have the potential to have serious effects on public health. Marburg is a high consequence biological event, listed as a Category A priority pathogen by the National Institute of Allergy and Infectious Diseases. There is a moral imperative to act quickly and effectively to protect the world from such health security threats.
This outbreak presented an opportunity for Global.health to gather requirements from the community and learn more about contextual information collected to support emergent outbreak response. The Public Health Information Services (PHIS) toolkit is a useful framework for gathering information to support rapid assessments and includes guidance, templates, and best-practices and helped to shape our analyses. This contextual data can complement our epidemiological line-list data to better understand the impact and burden on affected people. We look forward to broadening our toolkit of outbreak response datasets and scaling them to better prepare for future outbreaks.
We thank our user community for their many helpful contributions and for identifying G.h as a trusted source of information. Questions? email us, firstname.lastname@example.org
Until the next post,
The G.h Team