Lassa fever few months after it was subdued in various part of Nigeria has made its way back into the country. On Tuesday, Lassa fever killed two patients who were at the Lagos State University Teaching Hospital (LUTH) at Idi-Araba.
Given this fresh outbreak, it is vital and necessary to have a little knowledge about the disease.
Here are the ten things you need to know:What is Lassa fever?
What is Lassa fever?
According to www.who.int Lassa fever is an acute viral haemorrhagic illness with an incubation period of 2-21 days that occurs in West Africa. The Lassa virus is transmitted to humans through contact with food or household items contaminated with rodent’s urine or faeces. The overall case-fatality rate is 1%. Observed case-fatality rate amongst patients hospitalised with severe cases of Lassa fever is 15%. The virus which is a member of the virus family Arenaviridae is zoonotic or animal-borne. About 80% of Lassa fever infections in humans are without symptoms; the other cases develop chronic multiple organ diseases, where the virus affects some organs in the body, such as the spleen, liver and kidneys.
Where can Lassa fever be found?
Lassa fever is endemic in Ghana, Benin, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, but it probably exists in other West African countries too. It was first identified in 1969 in Nigeria. However, because rat species that house the virus are mostly found throughout West Africa, the actual geographic range of this disease may extend to countries within the region.
How is Lassa fever transmitted?
The carrier or host of the Lassa virus is the “multimammate rat” also called Mastomys natalensis which possesses a lot of breasts and whose habitat is the bush and around homes and residential areas. The virus is shed in the faeces and urine of the rats. Hence it can be transmitted through direct contact, touching of objects or eating foods that are contaminated with these materials or through cuts, injuries or sores. Person-to-person infections and laboratory transmission can also take place, especially in hospitals that lack the adequate infection prevention and control measures.
Who stands at risk?
Lassa fever occurs in all age grades and both sexes (male and female). The persons who are at the greatest risks are those that reside in the rural areas where Mastomys are usually found, most especially in communities with very poor hygiene or crowded living conditions. Health workers are also at risk of Lassa fever if it is not suspected or while catering for Lassa fever patients in the absence of proper barrier nursing and infection control practices.
What are the signs and symptoms?
At the onset of the disease, when it is symptomatic, it usually gradual, beginning with fever, general body weakness, joint and muscle pains, malaise and prostration. After a few days, sore throat, chest pain, headache, nausea, vomiting, diarrhoea, cough, muscle pain and abdominal pain may follow. In critical cases, facial swelling, bleeding from the mouth, nose, vaginal or gastrointestinal tract, low blood pressure and fluid in the lung cavity may occur. Protein may be discovered in the urine. Seizures, shocks, tremor, disorientation and coma may be observed in the later stages. 25% of patients who survive the disease may become deaf. In half of these cases, the patient might regain his/her hearing ability after 1 – 3 months. During recovery, temporary hair loss and gait disturbance may occur. As a result of shock, the patient may die.
Lassa virus infections can only be diagnosed precisely in a Virology laboratory using the following test: the reverse transcriptase polymerase chain reaction (RT-PCR) assay, testing for IgM, antigen detection tests and virus isolation by cell culture. These tests can be carried out at a Virology Reference Laboratory, and the Lagos State University Teaching Hospital, Idi-Araba, Lagos has this laboratory.
How can Lassa fever be managed?
The only precise treatment for Lassa fever is Ribavirin which may be effective if administered within the first six days of the illness. It should be administered intravenously for ten days. Some supportive treatments include: Paracetamol, Heamacel, Vitamin K (Phytonadione), antimalarial, antibiotics and Ringers lactate, start by an intravenous method. You can consider transfusion if the patient is severely anaemic.
Is there a vaccine or cure?
Currently, no known vaccine protects against Lassa fever.
How do I prevent Lassa fever?
Lassa fever can be avoided by adopting and encouraging good community hygiene to discourage rodents from entering houses. Some effective measures include storing grain and other foodstuffs in containers that are rodent-proof, disposal of garbage far away from residential areas and maintaining a clean environment and household.
In the healthcare sector, prevention is by standard precautions where all the blood and body fluids are considered to be potentially infectious. Some of the standard precautions apply to all patients include hand hygiene, the use of appropriate personal protective equipment (PPE), disposal of waste, safe injection practices, cleaning and disinfection of medical equipment and environment.
Who to call or what numbers to call?
In any case, Lassa fever is suspected or discovered, notify the response team in Lagos state University Teaching Hospital, LUTH on 08058019466, 07035521015, 08058744780 and 08023299445 or call 911 or 112 emergency numbers.