Our long history of ignoring diseases that emerge in Africa as solely of concern to the African continent has been proven wrong time and time again, but yet, we still haven’t learned. We must gain an appreciation for how interconnected the world is today. The CDC has already acknowledged that Marburg virus has spread to other parts of the world through international travel. https://www.cdc.gov/marburg/outbreaks/index.html.
I remember well, when a similar disease caused by Ebola virus that was seemingly isolated to Africa, presented to a hospital in Dallas, Texas in September of 2014 in a traveler from Liberia. Two nurses at that Dallas hospital were exposed to the patient and came down with Ebola virus disease. Fortunately, despite the high mortality rate, both nurses survived.
Marburg virus was first detected in 1967 through simultaneous outbreaks in laboratories working with African green monkeys imported from Uganda in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia. In addition to the 31 reported cases, an additional primary case was later diagnosed by blood test. There were 31 cases and 7 deaths (23 percent fatality rate).
In 1975, a man with a recent travel history to Zimbabwe was admitted to a hospital in South Africa. Infection spread from the man to his traveling companion and a nurse at the hospital. The man died, but both women eventually recovered (33 percent fatality rate).
In 1980, a patient who had recently traveled to Kenya was hospitalized with Marburg virus disease in Nairobi and subsequently died. A doctor who attempted to revive the patient developed symptoms nine days later but recovered. There were two cases and one death (50 percent fatality rate).
In 1987, a 15-year-old Danish boy was hospitalized with a 3-day history of headache, malaise, fever, and vomiting. Nine days prior to symptom onset, he had visited Kitum Cave in Mount Elgon National Park in Kenya. Despite aggressive supportive therapy, the patient died on the 11th day of illness. No further cases were detected. (100 percent fatality rate).
There was a large outbreak of Marburg virus disease between 1998 and 2000. Most cases occurred in young male workers at a gold mine in Durba, in the northeastern part of the Democratic Republic of Congo, which proved to be the epicenter of the outbreak. Cases were later detected in the neighboring village of Watsa. There were 154 cases and 128 deaths (83 percent fatality rate).
Between 2004 and 2005, an outbreak of Marburg virus disease is believed to have begun in Uige Province in Angola in October of 2004. Most cases detected in other provinces have been linked directly to the outbreak in Uige. There were 252 cases and 227 deaths (90 percent fatality rate).
In 2007, there was a small outbreak, with four cases in young males working in a lead and gold mine in Uganda. To date, there have been no additional cases identified. There was one death (25 percent fatality rate).
In 2008, a U.S traveler returned from Uganda in January 2008, became ill and fortunately survived. A diagnosis of Marburg virus disease was confirmed.
Also in 2008, a 40-year-old Dutch woman with a recent history of travel to Uganda was admitted to hospital in the Netherlands. She had visited a cave in Maramagambo forest in Uganda, at the southern edge of Queen Elizabeth National Park. Three days before hospitalization, the first symptoms (fever, chills) occurred, followed by a rapid deterioration in her health. The woman died on the 10th day of the illness (100% fatality rate).
In 2012, testing at CDC/UVRI identified a Marburg virus disease outbreak in the districts of Kabale, Ibanda, Mbarara, and Kampala in Uganda over a 3-week period. There were 15 cases and 4 deaths (27 percent fatality rate).
In 2014, one case was confirmed (fatal) and 197 contacts were followed for 21 days. Out of these 197 contacts, eight developed symptoms similar to Marburg, but all tested negative at the Uganda Virus Research Institute (UVRI) with support from CDC (100 percent fatality rate).
In 2017, a blood sample from Kween District in Eastern Uganda tested positive for Marburg virus. Within 24 hours of confirmation, a rapid outbreak response was begun. This outbreak occurred as a family cluster with no additional transmission outside of the four related cases. There were four cases and three deaths (75 percent fatality rate).
In 2021, in Guinea, one case was reported and confirmed by the Guinean Ministry of Health in a patient who was diagnosed after death. No additional cases were confirmed after more than 170 high-risk contacts were monitored for 21 days (100 percent fatality rate).
In 2022, a fatal case of Marburg disease was identified in the Ashanti region of Ghana on July 7, 2022. Marburg disease was initially detected through testing at Ghana’s national laboratory marking the first detection of Marburg disease in Ghana. Shortly after, two additional family members were also confirmed to have Marburg disease. No additional cases outside the family cluster were identified. The outbreak was declared over in September. There were three cases and 2 deaths (67 percent fatality rate).
And, now, for the first time involving this country, there is a large outbreak in Rwanda. There have already been 27 cases identified, but sadly nine of them have died. Disturbingly, more than 70 percent of these cases are in health care workers who work at either of two hospitals in the capital city of Rwanda – Kigali (population 1.7 million people). That suggests to me that the health care workers were likely exposed to Marburg virus by patients in whom the diagnosis was missed, and thus, there may be many more cases in the community. In addition, three hundred close contacts are being monitored for signs or symptoms of the disease.
The other concern is that Kigali is the home to both a regional and international airport with destinations to nearly 20 countries, including in the Middle East and Asia.
Marburg virus causes rare, but deadly infections in humans, of the hemorrhagic fever type. Marburg virus can also infect primates. Symptom onset is often sudden and can consist of fever, rash (often on the chest, back and abdomen) and severe bleeding. The natural host for Marburg virus is the Egyptian rousette bat (Rousettus aegyptiacus) and bats can then transmit the infection to people, i.e., this is a zoonotic infection. The incubation period ranges from 2 – 21 days.
The infection spills over from infected bats to humans through bat saliva, urine or feces. An infected person may then transmit the infection to a close contact who comes in contact with the infected person’s secretions or body fluids (including in the postmortem period) or contact with fomites (bedding, clothing, needles, or medical equipment used by the patient). As has been documented for the Ebola virus, Marburg virus may persist in the testes of recovered male patients and then be transmitted through sex even after the male’s recovery.
Despite the repeated outbreaks over nearly sixty years, the severity of the disease, the risk to health care workers, the emergence of infection in new African countries, and now the assessment by the World Health Organization that the risk for spread to neighboring countries is high and the acknowledgement of the risk of spread beyond East Africa (specifically, national level – high; regional level – high; global level – low), there are no approved treatments or vaccines for this disease.
This occurs at the same time that the WHO has declared a Public Health Emergency of International Concern due to an outbreak of monkeypox clade Ib virus and Mpox cases in Africa that is affecting some of Rwanda’s neighboring countries. Rwanda itself has had 4 confirmed cases as of the last update I could find from almost two weeks ago. Monkeypox clade IIb already caused a global outbreak in 2022.
Hopefully, we will devote some funding to better understanding the biology of this virus, investigating antiviral treatments, and developing vaccines. We should have learned that it is far easier and far less expensive to contain outbreaks than to respond to them on a global level.
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