Yellow fever, a viral infection is a disease caused by a virus, which is spread to humans through the bite of an infected mosquito. It is called ‘yellow fever’ because in serious cases, the skin or eyes turn yellow in colour. ISIOMA MADIKE, in the story, recounts an encounter with the mother of someone who recently died of the diseases
Chinenye, 21, a final year student at the University of Benin, appeared healthy when he travelled to the village to spend the Christmas holiday with other members of his family. He participated in the annual village soccer competition that lasted for four days. He was awarded the outstanding left full back laurel by the competition organisers. He was handsome, athletic and someone many could describe as lady’s man. However, two days after the soccer competition, the young man took ill.
The sickness at the time wasn’t serious enough to elicit panic of any sort. He was not the type that fall sick at random as the last known time he was ill was in 2004. Even at that his mother didn’t want to take chance as he was her last child.
She quickly took him to the village general hospital where he was diagnosed with malaria fever, which the doctors treated, discharged and handed him some drugs he was to take for three more days. At this point, there was a sign of relief, but it turned out to be temporal.
A day after they returned from the hospital, his body temperature went abnormally high, forcing his mother to rush him back to the hospital the second time. At the hospital, many more texts were done, but none reveled anything tangible. The doctors in their wisdom had to refer the boy to the Federal Medical Centre (FMC) in Asaba, the Delta State capital.
A day after they got to the FMC, his condition got worse as his eyes became yellowish, an indication that made the doctors to suspect hepatitis or what many prefer to call adult jaundice. The mother then put a call through to his father, who took night bus straight to Asaba to see things for himself. “When I saw his condition, I requested for a referral back to another hospital in Lagos, but I was assured it was something the doctors at the FMC could handle.
They moved him to the Intensive Care Unit (ICU) for close monitoring and requested us to do many more texts. He was talking, playing with me and seemed to be responding to treatment when all of a sudden, he changed.” The mother, who recounted Chinenye’s last moment in tears, said: “He was vomiting and stooling at the same time, which made us to suspect diarrhea.
But we were wrong; it was something bigger than what we imagined. Within minutes his body turned yellow and the doctors at this point told us it was yellow fever. Even at that, they were still assuring us it could be reversed.
“They tried all they could as they battled without success. His organs: kidney and liver had already packed up by then. He finally gave up the ghost on the second day. It was something we never expected; we were devastated,” Like Chinenye, many more Nigerians might have died of this scourge without knowing as there are insignificant numbers of people with the needed information about yellow fever across the country, especially in small towns and villages. The disease, however, has been with the populace unannounced.
For instance, in May 2019, according to reports, more than 55-suspected cases were reported across eight local government areas in Ebonyi State, with the most hit at the time reported from Izzi Local Government Area. Nine of those suspected cases had samples that tested positive for Yellow fever.
The outbreak had resulted in a high number of deaths as 20 of the suspected cases died with the Case Fatality Ratio (CFR) put at 40 per cent. The situation elicited concern from the authorities as they moved in to Izzi LGA and the surrounding LGAs with contiguous borders such as, Abakaliki,Yala LGA in Cross River State, as well as Ada and Oju LGAs in Benue State. A rapid response team (RRT) under the leadership of National Primary Health Care Development Agency (NPHCDA) and Nigeria Centre for Disease Control (NCDC), composed of Ebonyi State health authorities, the World Health Organisation (WHO) and other partners, was deployed to investigate the cases, strengthen efforts to control virus circulation and sensitize health workers and communities on prevention methods against the deadly virus.
The response of the outbreak in Ebonyi State was said to be part of the global strategy to Eliminate Yellow Fever Epidemics (EYE) by 2026. With the support from WHO, UNICEF, Gavi, the Vaccine Alliance and more than 50 partners, Nigeria had developed a 10- year strategic elimination plan to improve yellow fever diagnosis capacity, childhood immunisation and overall population immunity in all states.
Nigeria is said to be a priority country for the EYE strategy and it is expected that more than 75 million people will be protected against yellow fever in the country by the end of 2021.
The impact of the EYE strategy is already tangible, with more than 35 million people vaccinated during outbreak response and preventive mass campaigns aimed at establishing high population immunity. Efforts are said to be continuing towards full implementation of the EYE 10-year plan to eliminate yellow fever outbreaks.
“Thanks to the leadership of the Nigeria Centre for Disease Control, yellow fever surveillance has strengthened and improved, enabling quick outbreak detection and rapid response,” said Thabani Maphosa, Gavi Country Programmes Managing Director. “However, the global vaccine stockpile is our last line of defense against the growing threat of yellow fever outbreaks.
The most important long-term strategy is high coverage of yellow fever vaccination during preventive campaign and in routine immunisation, so, every child is protected, preventing outbreaks from happening in the first place,” he added.
For the record, from the onset of the outbreak in September 2017, to December 2018, 3,902 suspected cases were reported from all 36 states and the FCT in Nigeria. Out of the 3,295 samples collected and tested, 185 were presumptive positive in country and were sent for confirmation to the Institute Pasteur (IP) Dakar for further testing.
From the results, 78 positive cases from 14 states, Kwara, Kogi, Kano, Zamfara, Kebbi, Nasarawa, Niger, Katsina, Edo, Ekiti, Rivers, Anambra, FCT, and Benue states, were confirmed at IP Dakar, according to NCDC Source.
Gavi-supported yellow fever preventive mass vaccination campaigns were also conducted in six other states: Borno, Kebbi, Niger, Plateau, Sokoto and the FCT, between November 22, and December 2, 2018, bringing the total states covered by preventive mass vaccination campaign in Nigeria, according to reports, to 12. In spite of this laudable effort to stem the tide of yellow fever spread, about 43 people lost their lives to the killer disease in July, 2018.
This followed the confirmation by health authorities that another patient died in the country’s northeastern state of Bauchi in the same July. Since then, there had been cases of yellow fever in all parts of Nigeria, but local officials, according to reports, only recorded deaths in the southeastern state of Ebonyi and the northeastern state of Bauchi. Reports quoted Rilwanu Mohammed, head of the State Primary Healthcare Development Agency as saying that the deaths were recorded in Alkaleri, a town in Bauchi.
The additional death brought to 17 deaths out of the 20 yellow fever cases recorded in 11 local government areas of the state, Mohammed further said. The outbreak of yellow fever in Bauchi was said to have occurred first on August 29, 2018, in Alkaleri, before spreading to other parts of the state. Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes.
The “yellow” in the name refers to the jaundice that affects some patients. Symptoms of yellow fever include fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue. Vaccination is the most important means of preventing yellow fever.
To prevent further spread, pre-emptive vaccination campaigns are required in neighbouring areas not directly affected by the outbreak and reactive campaigns, but face heightened risk and vulnerability. Director, Disease Control and Immunisation, National Primary Health Care Development Agency (NPHCDA), Dr Joseph Oteri, was quoted to have implored people to protect themselves and their families despite the fact that vaccination remains the best-known measure for keeping people protected for life. According to him, “Reducing exposure to mosquitoes, including the use of insect repellent to avoid bites both during the day and at night and removing potential breeding sites such as standing water containers are also effective.”
The yellow fever virus, according to medical experts, is transmitted to humans via bites from mosquitoes belonging to the Aedes and Haemagogus species. It also infects forest monkeys, in a mosquito-monkey-mosquito cycle, which can occasionally also include humans.
Following a one-week incubation period, the disease typically begins with fever, chills, muscular pain and headaches. At this point, it could be confused with flu, dengue or malaria. Most people infected will experience no symptoms.
For those who do become ill, symptoms include fever, chills, headache, nausea and loss of appetite. Other symptoms may include muscle pains, particularly in the back. In severe cases, a person may develop high fever, Jaundice (a condition that involves yellow discolouration of the skin and the eyes), internal bleeding (especially from the digestive tract), leading to eventual shock and failure of many organs like the kidney and liver.
Most patients recover after about four days, though approximately 15 per cent experience a second, more serious, phase of the illness. Although, signs and symptoms may disappear for a day or two following the acute phase, some people with acute yellow fever could enter a toxic phase.
During the toxic phase, acute signs and symptoms return and more-severe and life-threatening ones also appear. These can include: Yellowing of skin and the whites of eyes (jaundice), abdominal pain and vomiting, sometimes of blood, decreased urination, bleeding from your nose, mouth and eyes, slow heart rate (bradycardia), Liver and kidney failure, brain dysfunction, including delirium, seizures and coma.
The second phase of yellow fever involves high fever and liver damage that causes yellow skin. Failure of multiple organs may occur as well. Mortality rate among severe cases of the disease is estimated at 20 to 50 per cent. The time from the bite of an infected mosquito to beginning of illness (incubation period) is usually between three-six days and it is said that there is no cure for yellow fever. However, supportive treatment can be provided; medicines can be used to relieve the symptoms and may improve the outcome for seriously ill patients if presented early at health facility.
In its serious forms, there is a temporary remission after three days, followed by the onset of a hemorrhagic syndrome with black vomit, jaundice and renal problems. Death then occurs in 50 to 80 per cent of cases, after delirium, seizures and coma.
All curable forms convey lifelong immunity. There is no specific treatment for yellow fever. Rest, drugs to lower temperature and relieve vomiting and pain, along with rehydration therapy, are the only methods of treatment for this disease.
However, WHO estimates that there are 200,000 cases of yellow fever annually across the globe, with 30,000 deaths. Africa is said to be the most heavily affected continent, with 95 per cent of the world’s cases. The frequency of epidemics and isolated cases has been regularly increasing over the last few years.
African epidemics, formerly limited to grasslands and along forest fringes, are now reaching the expanding towns and cities, which are providing new mosquito habitats in old tires or containers filled with water. Yellow fever is also an imported disease: unvaccinated tourists can become infected in endemic regions and develop the disease on returning from their travels. Several fatal cases have been reported over the last few years in travelers returning home. In his reaction, a Professor of Community Medicine, Bayo Onajole, who is a consultant Public Health Physician at the Lagos University Teaching Hospital (LUTH), confirmed that yellow fever is spread by infected Aedes aegypti, mosquitoes. Containing the disease, Onajole said, involved a lot of activities including clearing environmental sanitation, clearing bases of water and tackling other things that can make the mosquitoes to breathe.
“There should be efforts to prevent mosquitoes and man, which could involve humans using insecticide treated bed nets (ITNs) as well as mosquito repellents. It is crucial to ensure that those who were down with yellow fever should be treated. There are quite lot antibiotics that could be used to treat the infection,” he added.
The Executive Secretary, Nigerian Academy of Science, Dr M. Oladoyin Odubanjo also said that Yellow Fever is a contagious disease caused by a virus and transmitted by a mosquito but not same as for Malaria. It is, according to him, a haemorrhagic disease like Ebola.
He said: “It got its name because it causes jaundice (yellowness of body parts particularly seen in the eyes). Others symptoms are as with other infectious diseases – headache, muscle pain, fatigue, nausea and vomiting. “It is prevented through vaccination.
The vaccine is very effective. Though treatment is non-specific but rather what is called supportive, that is, give whatever the patient may need, fluids and anti-fever drugs.” However, the Federal Ministry of Health through the Nigeria Centre for Disease Control (NCDC) had, on January 14, 2019, formally announced the inclusion of three new laboratories into the national yellow fever/measles/rubella laboratory network.
The three new laboratories are the University of Benin Teaching Hospital, Edo, University of Nigeria Teaching Hospital, Enugu and NCDC National Reference Laboratory, Abuja. In announcing the formal inclusion of the laboratories, Director-General of NCDC, Dr. Chikwe Ihekweazu said: “To build Nigeria’s capacity in line with global standards, we are officially activating three new laboratories, a necessary addition to our existing laboratory network for yellow fever, measles and rubella.
These laboratories are also part of the global WHO laboratory network. The new laboratories in Edo, Enugu and the FCT will improve our coverage and ensure timely detection and response.” According to Ihekweazu, yellow fever, measles and rubella are vaccine preventable diseases. It is important, he said, that Nigerians ensure their children are immunised, to prevent the spread of these diseases.