Doris Obinna
Again, Nigeria is faced with a health challenge that is drifting to epidemic. It is a situation, which has put government, at the federal and state levels, on its toes. It has visited some states of the federation and taken casualties. It is Lassa fever (LF).
While Lassa fever is spreading like wildfire across states in Nigeria, another infectious disease, Coronavirus, has spread across China and the latest is Ivory Coast, the first African country to have tested an unnamed female passenger for Coronavirus after travelling from Beijing to the Felix-Houphouet-Boigny International Airport in Abidjan on Saturday.
The student, whom authorities have not named, is the first person to be tested for the virus on the continent. The virus has killed at least 80 people in the mainland Chinese city of Wuhan.
However, hope in the possible letup in the Lassa fever epidemic seems dashed as there has been an increase in the number of LF cases reported across the country this year. As at January 24, 2020, 195 confirmed cases and 29 deaths had been reported in 11 states, including Ondo and Kano. Given the tropical climate in Nigeria and abundance of the disease vector in our environment, we are at a high risk of infectious diseases like LF. This is also the case for other African countries with this context.
Last year, 10 states were visited by Lassa fever, with a total of 107 cases. The affected states were Ebonyi, Imo, Edo, Ondo, Bauchi, Nasarawa, Anambra, Benue, Kogi and Lagos. About 16 deaths were confirmed. Incidentally, about 10 healthcare workers were infected in Ebonyi (7), Nasarawa (1), Kogi (1) and Benue (1). Three of them died in Ebonyi State.
According to the National Centre for Disease and Control (NCDC), despite this increase, the overall Case Fatality Rate (CFR) for 2020 is lower at 14.7 per cent compared to the same period in 2019, which was 23.4 per cent. We are gradually moving towards achieving our target of having a single digit CFR. We continue to support the response activities of affected states through various means including the deployment of Rapid Response Teams (RRTs) for better case management and outcome.
Following the increasing number of Lassa fever cases, ast week, January 24, 2020, the NCDC activated a National Emergency Operations Centre (EOC). This is an inter-disciplinary Technical Working Group (TWG) for Lassa fever. They have the mandate to ensure a well-coordinated response, case management and swift control of Lassa fever outbreaks.
In the assignment, NCDC is collaborating with the World Health Organisation (WHO), Federal Ministry of Agriculture and Rural Development, Irrua Specialist Teaching Hospital, African Field Epidemiology Network, US Centers for Disease Control, University of Maryland Baltimore (UMB), Alliance for International Medical Action (ALIMA) and other agencies.
Lassa fever first occurred in Nigeria, in Borno State, in a town called Lassa, hence the name. It almost claimed a life in the community. Indeed, human arenavirus infection began in 1969 in Africa, with the mysterious death of two medical missionaries. In investigating the cause of death, an arenavirus was isolated from two of these patients and given the name of Lassa virus, after the town of Lassa, in Borno State.
Lassa fever or Lassa hemorrhagic fever (LHF) is an acute viral hemorrhagic fever caused by the Lassa virus and is a member of the arenaviridae virus family. It is a single-stranded RNA virus. It is zoonotic or animal-borne, meaning that humans become infected from contact with infected animals.
Similar to Ebola, clinical cases of the disease have been known for over a decade but have not been connected with a viral pathogen. Lassa fever is endemic in parts of West Africa and ravaged countries, like Liberia, Guinea, Nigeria and Sierra Leone. There have been isolated cases in Mali, Benin, Burkina Faso, Cote d’Ivoire and Togo.
Neighboring countries are also at risk due to the animal vector for Lassa virus. The animal is the Multimammate rat or Mastomysnatalensis, which is distributed throughout the region as a whole. In 2009, Mali reported its first case in a traveller who was living in southern Mali. Ghana reported its first cases in 2011. Isolated cases have been reported in Cote d’Ivoire and Burkina Faso.
The number of people who experience Lassa fever each year in West Africa is estimated to be between 100, 000 and 300, 000, with around 5, 000 people dying from the virus. The estimates are crude because surveillance for cases of the disease is not performed uniformly. In some areas of Liberia and Sierra Leone, approximately 10 to 16 per cent of those admitted to hospitals each year have Lassa fever, which indicates the serious impact of the virus on the population of these areas.
World Health Organisation (WHO), reveals that about 80 per cent of people who become infected with Lassa virus have no symptoms. One in five infections results in severe disease, where the virus affects several organs such as the liver, spleen and kidneys.
The Chief Executive Officer, NCDC, Dr. Chikwe Ihekweazu, said the Lassa fever is an acute viral haemorrhagic illness, transmitted to humans through contact with food or household items contaminated by infected rodents. He said person-to-person infections and laboratory transmission can also occur, particularly in hospitals lacking adequate infection prevention and control measures.
“It can also occur, particularly in hospital environment in the absence of adequate infection control measures. Health care workers in health facilities are particularly at risk of contracting the disease, especially where infection prevention and control procedures are not strictly adhered to,” he said.
Speaking on the Coronavirus, an expert, Prof Babatunde Lawal Salako said the virus is basically a zoonotic infection- something that comes from animals to man. Currently it is believed it can move from human to human.
“So the basic things are if you have people you suspect that have that kind of infection, they have to be treated with a little bit of isolation such that people who walk around will not have contact with them.
“Of course the usual aseptic cleaning methods that people use- washing of hands, using antiseptics and things like that. These are the things that people can do for now because we cannot talk about immunization yet because it is a new thing. So vaccines cannot be used for now, perhaps in the future.”
According to the World Health Organization, Coronaviruses are a family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS).
These viruses are transmitted between animals and people. SARS, for instance, was believed to have been transmitted from civet cats to humans while MERS travelled from a type of camel to humans.
Identified by Chinese authorities on January 7 and currently named 2019-nCoV, is a new strain that had not been previously identified in humans. Little is known about it, although human-to-human transmission has been confirmed.
Signs and symptoms
The incubation period of Lassa fever ranges from 6 to 21 days. The onset of the disease, when it is symptomatic, is usually gradual, starting with fever, general weakness, and malaise. After a few days, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough, and abdominal pain may follow.
Also, in severe cases, there is facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract and low blood pressure may develop.
Protein may be noticed in the urine. Shock, seizures, tremor, disorientation, and coma may be seen in the later stages.
Deafness occurs in 25 per cent of patients who survive the disease. In half of these cases, hearing returns partially after one to three months. Transient hair loss and gait disturbance may occur during recovery. Death usually occurs within 14 days of onset in fatal cases.
The disease is especially severe late in pregnancy, with maternal death and or fetal loss occurring in more than 80 per cent of cases during the third trimester.
Other signs may include; abdominal pain, back pain, conjunctivitis, mucosal bleeding and proteinuria.
Diagnosis
Because the symptoms of Lassa fever are so varied and non-specific, clinical diagnosis is often difficult, especially early in the course of the disease. Lassa fever is difficult to distinguish from other viral haemorrhagic fevers, such as Ebola virus disease as well as other diseases that cause fever, including malaria, shigellosis, typhoid fever and yellow fever.
Definitive diagnosis requires testing that is available only in reference laboratories. Laboratory specimens may be hazardous and must be handled with extreme care.
Lassa virus infections can only be diagnosed definitively in the laboratory using the following tests: reverse transcriptase polymerase chain reaction (RT-PCR) assay, antibody enzyme-linked immunosorbent assay (ELISA), antigen detection tests and virus isolation by cell culture.
Treatment
Ribavirin, is an antiviral drug that has been used with success in people affected by Lassa fever. It has been shown to be most effective when it is administered early in the course of the illness. People should also receive supportive care that consists of maintenance of, Oxygenation, blood pressure, treatment of complicating infections and appropriate fluid and electrolyte balance. The antiviral drug ribavirin seems to be an effective treatment for Lassa fever if given early on in the course of clinical illness. There is no evidence to support the role of ribavirin as post-exposure prophylactic treatment for Lassa fever. There is currently no vaccine that protects against Lassa fever. When contacted, see your doctor or a specialist immediately.
Prevention
Lassa fever, according to Ihekweazu, can be prevented through practicing good personal hygiene and proper environmental sanitation. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home, maintaining clean households, and other measures to discourage rodents from entering homes. Hand washing should be practiced frequently.
He said: “Health care workers are again reminded that Lassa fever presents initially like any other disease causing a febrile illness, such as malaria; and are advised to practice standard precautions at all times, maintaining a high index of suspicion. Rapid Diagnostic Test (RDT) must be applied to all suspected cases of malaria. When the RDT is negative, other causes of febrile illness, including Lassa fever should be considered. Accurate diagnosis and prompt treatment increase the chances of survival.
“Family members who are providing care for patients with Lassa fever should take extra caution. In addition, States are encouraged to ensure safe and dignified burial practices for patients who die from Lassa fever.”
Protecting yourself from Coronavirus
Experts have advised that Nigerians remain calm. Travelers from Nigeria to Wuhan, China, are advised to avoid contact with sick people, animals (alive or dead), an animal markets. Travelers from Wuhan to Nigeria, may be asked questions upon arrival by the Port Health Services unit at points of entry about symptoms of illness and travel history, and are advised to report immediately to NCDC if they feel ill after a trip to Wuhan.
To reduce the risk of spread of Coronavirus, members of the public are advised to adhere to the following measures:
• Wash your hands regularly with soap under running water
• Cover your mouth and nose properly with handkerchief or tissue paper when sneezing and/or coughing.
• You may also cough into your elbow if a handkerchief is not available.
• Avoid close contact with anyone showing symptoms or respiratory illness such as coughing and sneezing.
• Avoid self-medication, report to the nearest health facility when you experience any of the above-mentioned symptoms.
• Healthcare workers are always advised to observe standard infection prevention and control measures when attending to patients and take a travel history.
Stop of spread
There is no vaccine for the new virus. Chinese authorities effectively sealed off Wuhan suspending flights and trains out of the city and telling residents they could not leave without a special reason, state media said.
The move is meant to “resolutely contain the momentum of the epidemic spreading” and protect lives, the central city’s special command centre against the virus said, according to state broadcaster CCTV.
Chinese authorities have stepped up monitoring and disinfection efforts ahead of the Lunar New Year break, which formally starts on Friday and is when many of the country’s 1.4 billion people will travel domestically and overseas.
Airport authorities across Asia, including Japan, Hong Kong, Thailand, Singapore, South Korea and Malaysia quickly stepped up screening of passengers from Wuhan.
In Europe, the United Kingdom and Italy have said they will introduce enhanced monitoring of flights from Wuhan, while Romania and Russia are also strengthening checks. Some airports in the United States have also begun checks.
Origin of virus
Chinese health authorities are still trying to determine the origin of the virus, which they say came from a seafood market in Wuhan where wildlife was also traded illegally. The WHO also says an animal source appears most likely to be the primary source of the outbreak.
There is evidence of respiratory transmission of the virus from patient to patient and Chinese authorities have also said 15 medical staff in the country has been infected.
Experts particularly worry when health workers get sick during new outbreaks because this can suggest the disease is becoming more transmissible and because spread in hospitals can often amplify the epidemic.