On 19 September, 2022, a case of Ebola Virus Disease (EVD) was confirmed in Mubende District, Uganda. On that same day, Dr. Alex Ario, the Director of the Uganda National Institute of Public Health (UNIPH), received a call from the Ministry of Health (MoH) requesting a team of Public Health Fellowship Program (PHFP) fellows to immediately engage in the EVD response. A response team of six fellows and two supervisors with backgrounds in medicine, nursing, pharmacy, statistics, medical microbiology, and infection prevention and control (IPC) was rapidly assembled. The team travelled to the field the next morning.
EVD requires very rapid response to reduce disease spread. Some of the most important public health components include active case search and identification, detailed case investigations, contact tracing, and contact follow-up. Detection of a single case of EVD often means more cases of EVD exist that have not yet been detected, or that cases will appear soon. This is especially true when a person is already very sick when they are diagnosed, because the patient has usually been in contact with both clinical and family caretakers. Because the disease can look like other common, less dangerous diseases and thus isn’t suspected to be Ebola, these caretakers are rarely using appropriate personal protective equipment (PPE) to prevent virus transmission.
PHFP fellows were tasked with setting up a team to find previous and current cases, investigate the cases, and list their contacts. The team divided into two groups: one went to the Ebola treatment unit (ETU) in Mubende Regional Referral Hospital (MRRH) and the other to the field to actively look for unrecognized cases. Such cases might look like people with fever who are not responding to treatment, unexplained deaths of multiple people in one family, or unexplained bleeding.
The team began by talking to health workers manning the ETU, who provided access to the suspected cases (with fever non-responsive to treatment for usual causes of fever and had unexplained bleeding tendencies in isolation at the time. The team found that most of the suspected cases, as well as the index (first) case, were from Madudu Subcounty, located in the northeastern side of Mubende District, making this a key area to look for additional cases. The team then went to Madudu Subcounty with guidance from the subcounty health assistant, where they visited the index case’s home and interacted with the family members. The purpose of this interaction was to understand the course of illness of the index case, the possible source of infection, and identify persons who had had contact with any of his body fluids during his illness and were at risk of developing EVD themselves. The interviewees also indicated that there had been other unexplained deaths in this village and neighboring villages in the last two months. These clues were followed to conduct active case search, case investigation, contact listing, and contact tracing in the subcounty.
Almost immediately, the team began hearing about surviving people who had syndromes that sounded like they might be EVD. To keep track of those possible cases, the team put them on a ‘line list’, or a list of cases and their locations, symptoms, and outcomes. Information on the line list was shared with other response pillars so that they could start planning to expand case investigations, isolation where needed, and facilitate contact tracing efforts. Later, the PHFP team became involved in other response activities including coordination, alert line management, and data management and analysis.
Beyond the six original fellows and two supervisors, other PHFP fellows, PHFP graduates, and staff from MoH, CDC, AFENET, Africa CDC, and others joined the investigation. As of the time of writing this report, response has extended from Mubende to Kyegegwa, Kassanda, Kakumiro, Kagadi Districts, and Fort Portal City.
Field experience
As first responders, the team needed to investigate and profile all cases in the Ebola Treatment Unit (ETU) as soon as possible, as well as look for possible cases in the community. This meant capturing data on demographics, clinical signs and symptoms, epidemiological risk factors and exposures, and laboratory results. As the team learned about cases, they began trying to identify chains of transmission, or lines between people who were the source of a new case’s infection and those who became infected from a known case. Linking cases to known chains is important, because it helps put together the picture of how infections happened. Finding new cases that do not fit into any known transmission chain is concerning, as it indicates that there is undetected transmission ongoing. Identifying the source of infection and illness among a known case’s contacts is critical to disease containment. On September 21, 2022, the team began conducting interviews (physical and phone interviews) with cases at the ETU in Mubende Regional Referral Hospital to better identify the chains and find the sources.
The team listed the home villages of all the suspected and confirmed cases and visited the families of the cases to obtain more information on the case’s onset of symptoms, a detailed history of their illnesses, and possible exposures, and list their contacts. The community’s beliefs and perceptions about the illness varied; some perceived it as witchcraft and poisoning. Some people did not feel comfortable sharing information and many were scared. To help gather the critical information, the team needed to gently explain its importance to the families and help them see how it would help others.
From these investigations, the team learned that 10 suspected cases and one confirmed case (the index case), had visited a single private health facility (St Florence Medical Clinic) in Madudu Subcounty to seek medical care during August 6 – September 20, 2022. St Florence Medical Clinic is the largest clinic in the subcounty, and most ill persons in the subcounty seek medical care there before being referred to the regional referral hospital, as needed. Healthcare workers reported that many of the probable cases had initially come to the facility for treatment of illnesses suspected to be caused by malaria, diabetes, hypertension, and chickenpox, among others. A few days after discharge, the probable cases returned with fever and bleeding tendencies. Unfortunately, the attending nurse reported that all these cases had died shortly after being referred to Mubende Regional Referral Hospital for further management. These cases including one of the facility’s nurses, who fell ill on September 6, 2022. The onset of his illness suggested that he had likely been exposed while working with a probable case, rather than being the source of the outbreak.
The team attempted to identify the earlier cases to find out where transmission began. During interviews, the team found that some of the cases had contact with body fluids of a child who had died with unexplained bleeding (probable case). This child was not on the initial outbreak line list. The probable case was a seven-year-old female who had died following a two-week history of illness characterized by fever and non-response to anti-malarial drugs. Her illness progressed to bloody diarrhoea, vomiting of blood, and nose bleeding. Her possible source of infection remains under investigation.
In following the information about the cases to their different villages, the team discovered several additional clusters of cases in the district and beyond. The epidemiological linkages in the clusters were then established and hypotheses generated about the source and spread of the illness. One hypothesis is that an initial case visited St. Florence Medical Clinic, potentially infecting other patients and staff members, and the infections amplified from there. It is also possible that seeking care from traditional healers and engaging in cultural practices during burials such as touching and washing dead bodies may have allowed the virus to spread to residents in other districts when people in contact with the body became ill.
This information guided the national response team to develop an Ebola transmission tree, which shows the links between the known infections and establish the size of the outbreak and identify new districts affected and those at risk. While many more patients are now on admission, a small light of hope shone on September 30, 2022, when our hearts filled with joy and delight as two of the first case-patients, now fully recovered, were discharged from the Mubende ETU.