Lassa Fever in Nigeria: Understanding the disease and improving patient care

Lassa fever is a hemorrhagic fever occurring in West Africa, particularly Nigeria, Sierra Leone, Guinea, Liberia, and neighboring countries. Similar to Ebola, Lassa fever is caused by a viral infection but is less well-known and only poorly understood. Can you give us some more background on Lassa fever in Nigeria?

In 2018, Nigeria experienced one of the largest outbreaks of Lassa fever in its history. 23 out of the 36 states were affected. Almost 3,500 suspected cases were reported, and 45 healthcare workers got infected. Among confirmed cases, 27% of patients died. Lassa fever is endemic to Nigeria, but unlike the more unpredictable Ebola outbreaks, Lassa fever has been reported repeatedly over the last years. 

Disease surveillance is not performed uniformly, so estimates of Lassa cases are not exact. In addition, there may be a shift in the seasonal outbreak pattern. For example, in 2018, there was a spike in the number of cases early in the calendar year, and this year, the season has started earlier. During my stay in Ebonyi state, patients were already being admitted and several cases had been confirmed. The number of cases in 2019 is higher than in similar weeks in 2018, and the Nigerian Ministry of Health has declared the outbreak to be a public health emergency.

The virus is carried by Mastomys rats (multimammate rats), and people become infected after being exposed to the urine or feces of infected rats, or through direct contact with the blood or body fluids of an infected person. Approximately 80% of patients have mild symptoms and are not diagnosed correctly. Patients often experience fever, muscle and chest pain, vomiting, diarrhea, seizures, and hearing loss, while deafness occurs in one-third of patients and can be permanent. Some individuals may develop additional symptoms, such as severe bleeding from the nose, eyes, and mouth.

One of the major challenges in treating Lassa fever is the identification and confirmation of the disease itself – the initial symptoms are similar to those of malaria, and only three laboratories in Nigeria run the tests needed to confirm the disease. Furthermore, there is no vaccine available yet, and delayed treatment can cause the patient’s condition to worsen.

MSF joined the response to the 2018 outbreak in March of last year, and continues to support the Federal Teaching Hospital, Abakaliki (FETHA) in Ebonyi state, which was the third most affected during the outbreak. What support does MSF provide in Ebonyi state?

To help Ebonyi state be better prepared for future outbreaks, MSF has been improving infection prevention and control measures, upgrading personal protective equipment, providing tools and guidelines for case identification and management, and providing information about Lassa fever to communities.

Because person-to-person transmission is common in healthcare settings, doctors and visiting family members need to wear protective outfits to protect themselves from getting infected. Last year, two doctors died after being exposed to Lassa fever patients in the FETHA hospital, so improving infection prevention and control measures, such as supplying protective equipment and improving hand hygiene, to prevent further transmission in hospitals has been a really important safety initiative.

But using these personal protective outfits is challenging: they’re bulky, not easy to move around in, and cover your face and your entire body.  Patients can only see doctors or relatives who are wearing face masks, which doesn’t allow patients to have face-to-face interactions during their isolation in the high risk zone.

To improve that, an orange fence is set up to direct the “flow” of visitors and healthcare workers in the FETHA hospital to decrease the chances of infection spreading. By standing behind the orange fence and looking through a window from a safe distance to avoid disease transmission, family members can visit their sick relatives in the hospital without needing to wear protective outfits.

You were also in Ebonyi state to provide support on data collection and the documentation of clinical care. What does your support entail?

Patient information at the Abakaliki hospital is only collected in a patient’s file – doctors write the information on blank pages, but there are no standard forms or databases to collect this information. Therefore, information can go missing or may not be systematically collected, making it difficult to compile data from different patients, analyze it, and draw conclusions. In order to better understand the factors that contribute to the disease and to improve care for patients, we needed a better way to collect data in a systematic and timely manner, which is what we are working on.

We know there are a lot of knowledge gaps surrounding the epidemiology of Lassa fever, such as the factors involved in the transmission of the disease between rats and humans, as well as their associated behavioral factors. This information is key to help control the disease.

You attended the conference in Abuja on Fifty Years of Lassa Fever together with several international experts, where the need for appropriate equipment and training for healthcare workers as well as further research was at the center of discussions. What are future steps to take to decrease the occurrence and spread of Lassa fever in Nigeria?

An important step is to obtain a more accurate estimate of the real number of Lassa fever cases in Nigeria, which will contribute to increased understanding of Lassa’s epidemiology. Another important measure is to improve the diagnostics available, continue with the development of vaccines, and to start working on clinical trials. In my opinion, we should continue the focus on improving the care and conditions of healthcare workers, as we are doing in the Ebonyi project, where infection prevention and control measures were a top priority to prevent further hospital acquired transmission. These measures included supplying protective outfits and building an incinerator to safely dispose of infectious waste.

In collaboration with other hospitals and local and international partners, the first step of the Lassa research agenda in Ebonyi is to start a study to determine which clinical symptoms and results from laboratory blood tests (evaluating liver and kidney function, for example) are linked to the survival of infected patients. This research is expected to provide insights to guide the design of future clinical trials.

LuxOR is also supporting the research capacity of the health staff who manages Lassa fever patients every day. For example, the Infectious Disease specialist in the FETHA hospital is a participant in a Structured Operational Research Training Initiative (SORT IT) course jointly coordinated by MSF and the World Health Organization Special Program for Research and Training in Tropical Diseases (WHO/TDR), where she is conducting a retrospective analysis of the cases admitted to the hospital during the 2018 outbreak.