About 60 people have been confirmed dead across Nigeria this year following the outbreak of Lassa fever while hundreds more are under surveillance in hospitals.
More people are suspected to have the disease, but there are very limited diagnosis centres in the country to enable early detection.
In its Week 29 (July 17-23) epidemiological report, the Nigeria Centre for Disease and Control, NCDC, noted that 338 suspected cases of the fever were presented in the previous 28 weeks of 2017, with laboratory tests confirming 85 cases. It said 55 deaths were reported from 66 local government areas in 22 states across the country.
The figures are lower than were reported by the same time in 2016, but more cases have been recorded this year after the agency’s report.
Chikwe Ihekweazu, the Executive Director of NCDC, said the agency had to review the National Guidelines on Infection Prevention and Control of Viral Haemorrhagic Fever, VHF, (which includes Lassa Fever) because of the emergence and re-emergence of the group of diseases in Nigeria and the West African sub-region.
He said VHF poses a great challenge to public health globally, due to the high infectivity, morbidity and mortality associated with the group of diseases.
The sporadic occurrence and viral nature of the disease’s transmission has presented challenges in case management and infection control.
Mr. Ihekweazu said health care workers’ infection is being recorded and that the workers most times had to be placed on surveillance after the patients had been discharged or died.
Lassa fever is endemic in West Africa. In fact, it got its name from Lassa, the village in Nigeria were it was first identified in 1969.
In Nigeria, the disease was seasonal, occurring between December and June. But recent outbreaks are continuing beyond the normal season.
With the increase in pocket outbreaks across the country, the Kwara State chairman of the Nigerian Medical Association, Tunde Olawepo, last month warned the government not to let its guard down against the disease.
Mr. Olawepo was worried that government and Nigerians had relaxed on the preventive measures that contained the spread of Ebola in 2013.
The World Health Organisation, in its Lassa fever report on Nigeria as at June 9, stated that 501 suspected cases, including 104 deaths, had been reported since the onset of the current Lassa fever season in December 2016.
“Of the reported cases, 189 were further classified, 175 laboratory confirmed, including 59 deaths and 14 probable cases (all dead)”, it stated.
According to the international health agency, 17 Nigerian states have reported at least one confirmed case in the current outbreak of the fever.
These are Anambra, Bauchi, Borno, Cross River, Ebonyi, Edo, Enugu, Gombe, Kaduna, Kano, Kogi, Nasarawa, Ogun, Ondo, Plateau, Rivers, and Taraba).
The outbreak is still active in nine states as at June 9. These are Anambra, Bauchi, Cross-River, Edo, Taraba, Nasarawa, Ondo, Plateau, and Kano.
After the WHO report, more states have reported cases and deaths.
Although there is constant population movement among the states, a large-scale disease transmission or outbreak spread has, however, not been reported.
Abdulfatah Ibrahim, a Medical Laboratory scientist, advised government to focus more on early detection of the disease, as most times results of tests do not come out until patients are discharged or died.
Mr. Ibrahim said Nigeria does not have enough laboratories to conduct tests. Blood samples collected often have to be sent to Lagos for screening.
“Blood samples from suspected patients, irrespective of the location in the country are mostly taken to Lagos, and this is not good enough for a country where Lassa fever has become a yearly occurrence,” Mr. Ibrahim said.
“There is no reason why we cannot have enough laboratories in the country to aid quick screening and confirmation of the blood status. This will ease lots of stress on the medical personnel treating the patients and ease the stress on the facilities when suspected people who have been in contact with infected persons have to be quarantined for surveillance,” he said.
Mr. Ibrahim urged government to invest in the new commercial kits on Lassa fever detection developed by the Redeemer’s University, Ede in Osun State.
The test kit, Pan-Lassa Rapid Diagnostics Test, PL RDT, tests urine, faeces and blood samples of humans or multimammate rats for Lassa fever in 10 minutes.
He said the kits should be made available to all primary health care centres in the country, especially in states where cases of Lassa fever are prevalent.
The government can also invest in researches to develop vaccines for diseases associated with African countries, he further counselled.
“This will go a long way in saving cost and stress placed on health facilities and personnel in the country”.
TRANSMISSION OF LASSA FEVER
Lassa fever is transmitted to humans via contact with food or household items contaminated with rodent urine or faeces.
Person-to-person infections and laboratory transmission can also occur. This occurs most especially when a person comes in contact with the virus in the blood, tissue, secretions or excrement of an infected individual.
The host of Lassa virus is the “multimammate rat” called Mastomys natalensis, which has many breasts and lives in the bush and around residential areas.
The virus is shed in the urine and droppings of the rats, hence can be transmitted through direct contact, touching objects or eating food contaminated with these materials or through cuts or sores.
Transmission also occurs in health facilities where infection prevention and control practices are not observed.
Signs and symptoms
Chris Bode, a professor and Chief Medical Officer, Lagos University Teaching Hospital, said symptoms of the disease include fever, general weakness, muscle and joint pains, prostration malaise, headache, sore throat, muscle pain and chest pain.
He said nausea, vomiting, diarrhoea, cough, and abdominal pain may follow.
In severe cases, according to Mr. Bode, facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract and low blood pressure may develop.
He added that protein may be noted in the urine.
“Shock, seizures, tremor, disorientation, and coma may be seen in the later stages and deafness occurs in 25 per cent of patients who survive the disease.
“In half of these cases, hearing returns partially after 1-3 months. Transient hair loss and gait disturbance may occur during recovery. Patients may die from shock,” he said.
RISK ASSESSMENT OF THE DISEASE
WHO in its risk assessment for Lassa fever in Nigeria noted that overall, the current risk assessment of the diseases outbreak shows a declining trend of outbreaks.
This was attributed to the different ongoing response measures, which focused on preparedness and response in general. Further risk of large scale outbreaks is not very high, it said.
The international health agency, however, advised a close follow-up, active case searching, tracing, laboratory support and disease awareness in communities and for health workers.
Kehinde Mofolorunso, in a research paper published in the Pan African Medical Journal, said due to the absence of vaccine against the virus and the impractical control of the rodent host population, control measures are limited to keeping rodents out of homes and food supply and also maintaining proper personal hygiene.
Eating rodents was also discouraged.
Five ways of preventing Lassa Fever
- Nigerians should pay more attention to personal hygiene.
- Keep environment clean and rodent-free.
- Food stuff should be kept in tight lid containers.
- Drying food stuff on highways should be discouraged as rats can defecate or urinate on them.
- In health-care settings, staff should always apply standard infection prevention and control precautions when caring for patients, regardless of their presumed diagnosis.