Nigeria: Tackling the Outbreak of Lassa Fever - allAfrica.com Nigeria: Tackling the Outbreak of Lassa Fever more Forty-five years after the first outbreak of Lassa Fever in Nigeria, the health sector is still grappling with the scourge currently ravaging some cities in the country. Martins Ifijeh writes The smile on the faces of Nigerians since the containment of Ebola Virus Disease (EVD) over a year ago is being threatened by the recent outbreak of Lassa Fever, which has so far spread from Taraba to Rivers, Nassarawa, Bauchi, Kano, Plateau, Gombe, Niger, Oyo and Edo State, killing several persons in a space of two months. This, again has brought Nigerians into a familiar scenario of fear and uncertainty, as people express deep concern whenever there are disease outbreaks in the country, considering that every epidemic of this nature leave scores dead, while several others struggle with treating themselves. As at the last count, available information suggests that over 40 persons have been said to had lost their lives to the disease which has assumed epidemic proportions with over 90 persons already infected, this year alone.

According to the World Health Organisation (WHO), Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus, a member of the arenavirus family of viruses. It is transmitted to humans from contacts with food or household items contaminated with rodent excreta. The disease is endemic in the rodent population in parts of West Africa. Person-to-person infections and laboratory transmission can also occur, particularly in the hospital environment, in the absence of adequate infection control measures. Though it was first discovered in the 1950s, the virus causing Lassa fever was not identified until 1969 in a town named Lassa in Borno State. Apart from Nigeria, Lassa fever is also endemic in other African countries like Liberia, Sierra Leone, Guinea, Central African Republic and Congo DR. Experts are of the opinion that the government should as a matter of urgency embark on massive sensitisation programmes across the country in other to forestall further spread of the disease.

Speaking with THISDAY, a Virologist, Professor Sobowale Oludare, said if the country had upgraded its surveillance system, as well as laboratory support facilities after the last Ebola outbreak, it would have been much easier to quell the growing spread of Lassa Fever currently in several states of the federation, adding that until the country get it right, there will continuously be outbreaks. "With our surveillance system in place, it would be much easier to predict various outbreaks and then promptly address it before it snowball into taking several lives, which is unfortunate for a country that prides itself as the giant of Africa," he explained. According to the virologist, over 80 per cent of infected persons may not present symptoms, but that about 20 per cent of those infected will present symptoms, adding that on majority of cases, the symptoms could be mistaken for malaria, cold or flu. "Early symptoms of the disease occur within the first and third week after being infected, and they include fever, diarrhea, vomiting, abdominal pain, headache, chills, nausea, sore throat, conjunctivitis, backache, facial swelling, mucosal bleeding, and joint pains.

Late symptoms include bleeding from the mouth and rectum, bleeding from the eyes, ears and nose, eye swelling, swelling of the genitals and rashes all over the body that often contain blood, coma and even death. In some patients, temporary or permanent neurological problems may occur," he noted. He said with the several symptoms presented by the virus, it was best to carry out diagnosis whenever any of the symptoms was noticed, so as not to confuse other illnesses like typhoid and malaria for Lassa Fever. But how can the virus be transmitted and what should be done to prevent it? Prof. Oludare provides a guide. According to him, not all types of rats present the Lassa virus, "the mastomys rodents, often known by locals as the rat with the long mouth, is the specific type of rat that carry the virus. Though it's a bush rat, it can also live within and around homes or anywhere they find food. Homes with poorly stored food could be a ready host for them," he explained. He said apart from their fluids, urine or faeces in foods, other ways they can infect humans are when they are killed and prepared for food. "It can also spread through person-to-person contact.

When body fluids, blood, urine or semen of an infected person gets in contact with an uninfected person's fluid, there is the possibility of transfer of the virus through such medium. "Lassa fever transmission can also occur when one comes in contact with fluid discharge from dead bodies," noting that it could also remain in the semen of an infected person for up to three months. With the fatality rate associated with the disease, coupled with the frequency of occurrence in the country, one wonders if the various governments are doing enough to tackle the scourge which has taken the lives of thousands of Nigerians. Available information suggests that there are only two laboratories in the country with the capacity to screen blood for Lassa fever. The Irrua Specialist Teaching Hospital (ISTH) in Irrua, Edo State and the Lagos University Teaching Hospital (LUTH). However, the federal government has consistently said there were other centres where the tests can be done, but the level of capacity of these centres still remain subjects of debate. In addressing the current outbreak in the country, the Federal Government, through the Ministry of Health has said that it was putting all measures in place to quell the growing epidemic now confirmed by laboratories to be Lassa Fever Viral Disease.

According to the Minister of Health, Prof. Isaac Adewole, he said the outbreak would be brought to a timely end in the shortest possible time, adding that since the first case of the recent current outbreak was reported from Bauchi in November, 2015, the ministry has not been unaware of how to tackle it. He stressed that "in response to these reported outbreaks, the Health Ministry has taken the following measures to curtail further spread and reduce mortality among those affected: Immediate release of adequate quantities of ribavirin, the specific antiviral drug for Lassa fever to all the affected states for prompt and adequate treatment of cases, including deployment of rapid response teams from the ministry to all the affected states to assist in investigating and verifying the cases as well as tracing of contacts, clinicians and relevant healthcare workers had been sensitised and mobilised in areas of patient management and care in the affected states." He also advised the affected states to intensify awareness creation on the signs and symptoms of the disease, including preventive measures such as general hygiene. The minister assured Nigerians that the country has the capability to diagnose Lassa fever, adding that all cases reported so far were confirmed by our laboratories.

"However, due to the non-specific nature of Lassa fever symptoms and varied presentations, clinical diagnosis is often difficult and delayed, especially in the early course of the disease outbreak," Adewole said. He explained that the Nigeria Centre for Disease Control (NCDC) was already coordinating all response activities, while they report to him. He advised healthcare workers seeing patients suspected to have Lassa fever to immediately contact the State Epidemiologists or call the Nigeria Centre for Disease Control and Federal Ministry of Health using the following numbers: 08093810105, 08163215251, 08031571667 and 08135050005. Meanwhile, the Lagos State Government has also called on its residents to be vigilant and imbibe basic proper hygiene, as well as avoid contact with rats and store foods in rat proof containers.

"Lagosians should observe good personal hygiene, including hand washing with soap and running water regularly, while also disposing waste properly in order to discourage rodents from entering the house." The State Government also called on the public to report cases of symptoms or persistent high fever to the nearest health centre, as fluids from an infected person can be extremely dangerous. Copyright © 2016 This Day. All rights reserved. Distributed by AllAfrica Global Media ( allAfrica.com ). To contact the copyright holder directly for corrections — or for permission to republish or make other authorized use of this material, click here. AllAfrica publishes around 800 reports a day from more than 140 news organizations and over 500 other institutions and individuals , representing a diversity of positions on every topic. We publish news and views ranging from vigorous opponents of governments to government publications and spokespersons. Publishers named above each report are responsible for their own content, which AllAfrica does not have the legal right to edit or correct. Articles and commentaries that identify allAfrica.com as the publisher are produced or commissioned by AllAfrica . To address comments or complaints, please Contact us .

WHO | Lassa fever Lassa fever Updated March 2016 Key facts Lassa fever is an acute viral haemorrhagic illness of 2-21 days duration that occurs in West Africa. The Lassa virus 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, particularly in hospitals lacking adequate infection prevent and control measures. Lassa fever is known to be endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, but probably exists in other West African countries as well. The overall case-fatality rate is 1%. Observed case-fatality rate among patients hospitalized with severe cases of Lassa fever is 15%. Early supportive care with rehydration and symptomatic treatment improves survival. Background Though first described in the 1950s, the virus causing Lassa disease was not identified until 1969. The virus is a single-stranded RNA virus belonging to the virus family Arenaviridae. About 80% of people who become infected with Lassa virus have no symptoms.

1 in 5 infections result in severe disease, where the virus affects several organs such as the liver, spleen and kidneys. Lassa fever is a zoonotic disease, meaning that humans become infected from contact with infected animals. The animal reservoir, or host, of Lassa virus is a rodent of the genus Mastomys, commonly known as the “multimammate rat.” Mastomys rats infected with Lassa virus do not become ill, but they can shed the virus in their urine and faeces. Because the clinical course of the disease is so variable, detection of the disease in affected patients has been difficult. When presence of the disease is confirmed in a community, however, prompt isolation of affected patients, good infection prevention and control practices, and rigorous contact tracing can stop outbreaks. Lassa fever is known to be endemic in Benin (where it was diagnosed for the first time in November 2014), Ghana (diagnosed for the first time in October 2011), Guinea, Liberia, Mali (diagnosed for the first time in February 2009), Sierra Leone, and Nigeria, but probably exists in other West African countries as well.

Symptoms of Lassa fever The incubation period of Lassa fever ranges from 6–21 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. In severe cases 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 noted in the urine. Shock, seizures, tremor, disorientation, and coma may be seen in the later stages. Deafness occurs in 25% 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. 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% of cases during the third trimester. Transmission Humans usually become infected with Lassa virus from exposure to urine or faeces of infected Mastomys rats.

Lassa virus may also be spread between humans through direct contact with the blood, urine, faeces, or other bodily secretions of a person infected with Lassa fever. There is no epidemiological evidence supporting airborne spread between humans. Person-to-person transmission occurs in both community and health-care settings, where the virus may be spread by contaminated medical equipment, such as re-used needles. Sexual transmission of Lassa virus has been reported. Lassa fever occurs in all age groups and both sexes. Persons at greatest risk are those living in rural areas where Mastomys are usually found, especially in communities with poor sanitation or crowded living conditions. Health workers are at risk if caring for Lassa fever patients in the absence of proper barrier nursing and infection prevention and control practices. 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 virus isolation by cell culture. Treatment and prophylaxis 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. Prevention and control Prevention of Lassa fever relies on promoting good “community hygiene” to discourage rodents from entering homes. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home, maintaining clean households and keeping cats. Because Mastomys are so abundant in endemic areas, it is not possible to completely eliminate them from the environment. Family members should always be careful to avoid contact with blood and body fluids while caring for sick persons.

In health-care settings, staff should always apply standard infection prevention and control precautions when caring for patients, regardless of their presumed diagnosis. These include basic hand hygiene, respiratory hygiene, use of personal protective equipment (to block splashes or other contact with infected materials), safe injection practices and safe burial practices. Health-care workers caring for patients with suspected or confirmed Lassa fever should apply extra infection control measures to prevent contact with the patient’s blood and body fluids and contaminated surfaces or materials such as clothing and bedding. When in close contact (within 1 metre) of patients with Lassa fever, health-care workers should wear face protection (a face shield or a medical mask and goggles), a clean, non-sterile long-sleeved gown, and gloves (sterile gloves for some procedures). Laboratory workers are also at risk. Samples taken from humans and animals for investigation of Lassa virus infection should be handled by trained staff and processed in suitably equipped laboratories under maximum biological containment conditions. On rare occasions, travellers from areas where Lassa fever is endemic export the disease to other countries.

Although malaria, typhoid fever, and many other tropical infections are much more common, the diagnosis of Lassa fever should be considered in febrile patients returning from West Africa, especially if they have had exposures in rural areas or hospitals in countries where Lassa fever is known to be endemic. Health-care workers seeing a patient suspected to have Lassa fever should immediately contact local and national experts for advice and to arrange for laboratory testing. WHO response The Ministries of Health of Guinea, Liberia and Sierra Leone, WHO, the Office of United States Foreign Disaster Assistance, the United Nations, and other partners have worked together to establish the Mano River Union Lassa Fever Network. The programme supports these 3 countries in developing national prevention strategies and enhancing laboratory diagnostics for Lassa fever and other dangerous diseases. Training in laboratory diagnosis, clinical management, and environmental control is also included. Health: Lassa Fever Transmission in West Africa – All you need to Know « Biatimes News February 18, 2016 What is Lassa Fever?

Lassa fever is an acute hemorrhagic viral illness caused by the Lassa virus, a single-stranded RNA virus belonging to the virus family Arenaviridae, first described in the 1950s but finally identified only in 1969 in Lassa town, Nigeria. The disease is known to be endemic in Benin, Guinea, Liberia , Sierra Leone and parts of Nigeria, but probably exists in other West African countries as well. The Lassa virus 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, particularly in hospitals lacking adequate infection prevent and control measures.It is estimated that Lassa feveraffects between 100,000 to 300,000 patients in West Africa per year, with approximately 5,000 deaths.In about 80% of people who become infected with Lassa virus, symptoms are mild and are usually undiagnosed. One in fiveinfections result in severe disease, where the virus affects several organs such as the liver, spleen and kidneys. The overall case fatality rate is about 1%.

Observed case fatality rate among patients hospitalized with severe cases of Lassa fever approaches 15%. How is it possible to catch Lassa Virus? Lassa fever is a zoonotic disease; the virus is found in a rodent known as the multimammate rat, which, once infected, is able to excrete virus in the urine for an extended time period, maybe for the rest of its life. In addition to the numerous amount in wild environment, this rodent is known to colonize human homes and areas where food is stored, spreading the infection. Infected rats with Lassa do not become sick, but they can shed the virus in their urine and feces, and direct contact with these materials, through touching soiled objects, eating contaminated food, or exposure to open cuts or sores, can lead to infection. The virus is transmitted mainly by ingestion or inhalation through the following modalities: 1) To be in contact with infected rat’s urine or faeces; 2) Eating food contaminated with rat’s excreta or contaminated rats 3) Inhalation of air (i.e., aerosols) contaminated with rodent excretion (e.g.

during sweeping in or around houses infested with contaminated rats) 4) Person-to-person transmission is common in health care settings, where proper personal protective equipment (PPE) is not available or not used. The infection may be spread through contaminated medical equipment, such as reused needles. Casual contact (including skin-to-skin contact without exchange of body fluids) does not spread Lassa virus What are the symptoms of Lassa fever disease? Signs and symptoms of Lassa fever typically occur after an incubation period of 1-3 weeks after the infection. For the majority of Lassa fever virus infections (approximately 80%), symptoms are mild and develop gradually, including: fever, general malaise and weakness, and headache. After a few days, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough, and abdominal pain may follow. In severe cases, facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract, and low blood pressure may develop. Proteins may be noted in the urine. Shock, seizures, tremor, disorientation, and coma may be seen in the later stages.

Death usually occurs within 14 days after onset in fatal cases. The disease is especially severe late in pregnancy, with maternal death and/or fetal loss occurring in greater than 80% of the cases during the third trimester. Deafness occurs in 25% of patients who survive to the disease. In half of these cases, hearing returns partially after 13 months. Transient hair loss and gait disturbance may occur during recovery. How to diagnose Lassa Fever? Clinical diagnosis of the disease is difficult due to varied and non–specific symptoms, which may be confused with those of other diseases (e.g. malaria, typhoid fever, yellow fever), especially early in the course of the disease. It is also difficult to proceed with a differential diagnosis from other viral haemorragic fevers such as Ebola Definitive diagnosis requires tests that are available only in specialized laboratories. Laboratory specimens should be handled with care, as they may be hazardous. Definitive tests to diagnose Lassa Fever are:  antibody enzyme-linked immunosorbent assay (ELISA)  antigen detection tests  reverse transcriptase polymerase chain reaction (RT-PCR) assay  virus isolation by cell culture.

Treatment and immunization: Ribavirin, an anti-viral drug, seems to be partially effective in the treatment of Lassa fever, especially when given early in the course of the illness. Supportive care is normally required, including fluids and electrolyte balance, oxygen supply, and treatment of any other complicating infections Currently, there is no available vaccine that protects against Lassa fever How to prevent it? First line of protection is related to the improvement of housekeeping and strong application of general and food related hygienic measures. Is also important to apply barriers aimed to discourage and prevent rodents from entering houses. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the house, maintaining clean households, and keeping cats. Because Mastomys rats are so abundant in endemic areas, it is not possible to eliminate them from the environment.

Additional preventive measures include: 1) Avoid eating food of unknown origin 2) Avoid going into places with stored wheat or millet seeds 3) Avoid eating “bush suya” 4) Normal hygiene measures, including frequent hand washing 5) Trapping in and around homes 6) Family members who are caring sick persons should be careful to avoid contact with blood and body fluids. 7) Asking immediately for medical advice in case of suspicion of Lassa Fever infection 8) In healthcare settings, staff should always apply standard infection prevention and control precautions when caring for patients, regardless of their presumed diagnosis. These include basic hand hygiene, respiratory hygiene, use of personal protective equipment (to avoid contamination with splashes or other contact with infected materials), safe injection practices, and safe burial practices. 9) Moreover, in medical environments, it is fundamental to perform complete equipment sterilization, and to isolate infected patients, preventing contact with unprotected persons until the disease has run its course. Things to Remember: The most important thing is to maintain a good hygienic condition, to store the food in adequate stores, and to keep the rats away. Family members and health care personnel should always be careful to avoid contact with blood and body fluids while caring for sick persons.

Routine barrier nursing precautions probably protect against transmission of Lassa virus in most circumstances. Lassa fever Lassa fever Source: The World Health Organization Lassa viral haemorrhagic fever is an acute illness of 1-4 weeks duration that occurs in West Africa. Though first described in the 1950s, the virus causing the disease was not identified until 1969. The virus is a single-stranded RNA virus belonging to the virus family Arenaviridae. Lassa fever is known to be endemic in Guinea (Conakry), Liberia, Sierra Leone and parts of Nigeria, but probably exists in other West African countries as well. Signs and symptoms About 80% of human infections are asymptomatic; the remaining cases have severe multi-system disease, where the virus affects several organs in the body, such as the liver, spleen and kidneys. The incubation period of Lassa fever ranges from 6-21 days. The onset of the disease 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 may follow.

Severe cases may progress to show facial swelling, fluid in the lung cavity, bleeding from mouth, nose, vagina or gastrointestinal tract, and low blood pressure. Protein may be noted in the urine. Shock, seizures, tremor, disorientation, and coma may be seen in the late stages. Deafness occurs in 25% of patients of whom half recover some function after 1-3 months. Transient hair loss and gait disturbance may occur during recovery. Morbidity and mortality Some studies indicate that 300 000 to 500 000 cases of Lassa fever and 5000 deaths occur yearly across West Africa. The overall case-fatality rate is 1%, up to 15% among hospitalized patients. 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 greater than 80% of cases during the third trimester. Animal reservoir Lassa fever is a zoonotic disease, meaning that humans become infected from contact with infected animals.

The animal reservoir, or host, of Lassa virus is a rodent of the genus Mastomys, commonly known as the ï¿½multimammate rat.ï¿½ Mastomys infected with Lassa virus do not become ill, but they can shed the virus in their excreta (urine and faeces). People at risk Lassa fever occurs in all age groups and in both men and women. Persons at greatest risk are those living in rural areas where Mastomys are usually found, especially in areas of poor sanitation or crowded living conditions. Health care workers are at risk if proper barrier nursing and infection control practices are not maintained. Transmission Humans usually become infected with Lassa virus from exposure to excreta of infected Mastomys. Both direct exposure, (touching the excreta) and Lassa virus may also be spread between humans through direct contact with the blood, urine, faeces, or other bodily secretions of a person with Lassa fever. There is no epidemiological evidence supporting airborne spread between humans. Person-to-person transmission occurs in both community and health care settings, where the virus may be spread by contaminated medical equipment, such as re-used needles.

Sexual transmission of Lassa virus has been reported. 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 many other diseases which cause fever, including malaria, shigellosis, typhoid fever, yellow fever and other viral haemorrhagic fevers. Definitive diagnosis requires testing that is available only in highly specialized laboratories. Laboratory specimens may be hazardous and must be handled with extreme care. Lassa fever is diagnosed by detection of Lassa antigen, anti-Lassa antibodies, or virus isolation techniques. Treatment and prophylaxis The antiviral drug ribavirin is 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. Prevention Prevention of Lassa fever in the community centers on promoting good ï¿½community hygieneï¿½ to discourage rodents from entering homes. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home, maintaining clean households and keeping cats.

Because Mastomys are so abundant in endemic areas, it is not possible to completely eliminate them from the environment. Infection control Family members and health care workers should always be careful to avoid contact with blood and body fluids while caring for sick persons. Routine barrier nursing precautions probably protect against transmission of Lassa virus in most circumstances. However, for added safety, patients suspected to have Lassa fever should be cared for under specific ï¿½isolation precautions,ï¿½ which include the wearing of protective clothing such as masks, gloves, gowns, and face shields, and the systematic sterilization of contaminated equipment (see also detailed guidelines in ï¿½Infection Control for Viral Hemorrhagic Fevers in the African Health Care Settingï¿½) 1 Ongoing initiatives Civil unrest in many of the countries where Lassa fever is endemic has impeded effective control. However, recent peace initiatives have opened new opportunities to combat the problem. The Ministries of Health of Guinea, Liberia and Sierra Leone, WHO, the Office of United States Foreign Disaster Assistance, the United Nations, and other partners have worked together to establish the Mano River Union Lassa Fever Network.

The programme supports these three countries in developing national prevention strategies and enhancing laboratory diagnostics for Lassa fever and other dangerous diseases. Training in laboratory diagnosis, clinical management, and environmental control is also included. In addition, a new ward dedicated to the care of patients with Lassa fever is under construction in Sierra Leone, sponsored by the European Union. International public health implications On rare occasions, travellers from areas where Lassa fever is endemic export the disease to other countries. Although malaria, typhoid fever, and many other tropical infections are much more common, the diagnosis of Lassa fever should be considered in febrile patients returning from West Africa, especially if they have had exposures in rural areas or hospitals in countries where Lassa fever is known to be endemic. Health care workers seeing a patient suspected to have Lassa fever should immediately contact local and national experts for advice and to arrange for laboratory testing. Source: The World Health Organization Lassa fever - SOEHPON Lassa fever Updated March 2016 Key facts Lassa fever is an acute viral haemorrhagic illness of 1-4 weeks duration that occurs in West Africa. The Lassa virus 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, particularly in hospitals lacking adequate infection prevent and control measures. Lassa fever is known to be endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria, but probably exists in other West African countries as well. The overall case-fatality rate is 1%. Observed case-fatality rate among patients hospitalized with severe cases of Lassa fever is 15%. Early supportive care with rehydration and symptomatic treatment improves survival. Background Though first described in the 1950s, the virus causing Lassa disease was not identified until 1969. The virus is a single-stranded RNA virus belonging to the virus family Arenaviridae. About 80% of people who become infected with Lassa virus have no symptoms. 1 in 5 infections result in severe disease, where the virus affects several organs such as the liver, spleen and kidneys. Lassa fever is a zoonotic disease, meaning that humans become infected from contact with infected animals.

The animal reservoir, or host, of Lassa virus is a rodent of the genus Mastomys, commonly known as the “multimammate rat.”Mastomys rats infected with Lassa virus do not become ill, but they can shed the virus in their urine and faeces. Because the clinical course of the disease is so variable, detection of the disease in affected patients has been difficult. When presence of the disease is confirmed in a community, however, prompt isolation of affected patients, good infection prevention and control practices, and rigorous contact tracing can stop outbreaks. Lassa fever is known to be endemic in Benin (where it was diagnosed for the first time in November 2014), Ghana (diagnosed for the first time in October 2011), Guinea, Liberia, Mali (diagnosed for the first time in February 2009), Sierra Leone, and Nigeria, but probably exists in other West African countries as well. Symptoms of Lassa fever The incubation period of Lassa fever ranges from 6–21 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. In severe cases 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 noted in the urine. Shock, seizures, tremor, disorientation, and coma may be seen in the later stages. Deafness occurs in 25% 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. 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% of cases during the third trimester. Transmission Humans usually become infected with Lassa virus from exposure to urine or faeces of infected Mastomys rats. Lassa virus may also be spread between humans through direct contact with the blood, urine, faeces, or other bodily secretions of a person infected with Lassa fever. There is no epidemiological evidence supporting airborne spread between humans.

Person-to-person transmission occurs in both community and health-care settings, where the virus may be spread by contaminated medical equipment, such as re-used needles. Sexual transmission of Lassa virus has been reported. Lassa fever occurs in all age groups and both sexes. Persons at greatest risk are those living in rural areas where Mastomys are usually found, especially in communities with poor sanitation or crowded living conditions. Health workers are at risk if caring for Lassa fever patients in the absence of proper barrier nursing and infection prevention and control practices. 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 virus isolation by cell culture. Treatment and prophylaxis 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. Prevention and control Prevention of Lassa fever relies on promoting good “community hygiene” to discourage rodents from entering homes. Effective measures include storing grain and other foodstuffs in rodent-proof containers, disposing of garbage far from the home, maintaining clean households and keeping cats. Because Mastomys are so abundant in endemic areas, it is not possible to completely eliminate them from the environment. Family members should always be careful to avoid contact with blood and body fluids while caring for sick persons. In health-care settings, staff should always apply standard infection prevention and control precautions when caring for patients, regardless of their presumed diagnosis.

These include basic hand hygiene, respiratory hygiene, use of personal protective equipment (to block splashes or other contact with infected materials), safe injection practices and safe burial practices. Health-care workers caring for patients with suspected or confirmed Lassa fever should apply extra infection control measures to prevent contact with the patient’s blood and body fluids and contaminated surfaces or materials such as clothing and bedding. When in close contact (within 1 metre) of patients with Lassa fever, health-care workers should wear face protection (a face shield or a medical mask and goggles), a clean, non-sterile long-sleeved gown, and gloves (sterile gloves for some procedures). Laboratory workers are also at risk. Samples taken from humans and animals for investigation of Lassa virus infection should be handled by trained staff and processed in suitably equipped laboratories under maximum biological containment conditions. On rare occasions, travellers from areas where Lassa fever is endemic export the disease to other countries. Although malaria, typhoid fever, and many other tropical infections are much more common, the diagnosis of Lassa fever should be considered in febrile patients returning from West Africa, especially if they have had exposures in rural areas or hospitals in countries where Lassa fever is known to be endemic.

Health-care workers seeing a patient suspected to have Lassa fever should immediately contact local and national experts for advice and to arrange for laboratory testing. WHO response The Ministries of Health of Guinea, Liberia and Sierra Leone, WHO, the Office of United States Foreign Disaster Assistance, the United Nations, and other partners have worked together to establish the Mano River Union Lassa Fever Network. The programme supports these 3 countries in developing national prevention strategies and enhancing laboratory diagnostics for Lassa fever and other dangerous diseases. Training in laboratory diagnosis, clinical management, and environmental control is also included. Cart Nigeria: Scientists Establish Link Between Lassa Fever, - allAfrica.com Nigeria: Scientists Establish Link Between Lassa Fever, more By Chukwuma Muanya As the Lassa fever epidemic continues to spread in Nigeria and the report of World Health Organisation (WHO)-confirmed case of the Ebola Virus Disease in Sierra Leone on Friday, there are fresh concerns of possible new outbreak of the virus in West Africa.

In fact, the WHO, in a statement, on Friday, said there is ongoing risk of new flare-ups of the virus in affected countries even as the latest death from Lassa fever in Rivers State and new confirmed case in Lagos bring the total number of deaths to over 43 with over 90 cases in 12 states of the federation. WHO stressed in a statement on Thursday, that Guinea, Liberia and Sierra Leone remain at high risk of additional small outbreaks of Ebola in the coming months due to the virus persisting in survivors after recovery. The Guardian's investigation had revealed that the fresh outbreaks of another haemorrhagic fever (Lassa fever) might be a prelude to possibly another outbreak of Ebola. The Guardian's investigation revealed that Nigeria and indeed West Africa are presently in the peak season for Lassa fever. It was reliably gathered that the viral haemorrhagic fever has been largely forgotten in the Ebola crisis, and health workers are warning that they may not have the resources to deal with the disease if cases increase. It was also gathered that at first sight the symptoms of Lassa are identical to Ebola; there can be bleeding, vomiting and fever. But whereas Ebola is a new outbreak, Lassa is a constant presence.

According to the WHO, every year it infects from 300,000 to 500,000 people, killing up to 20,000. The Guardian learnt that all of the countries worst hit by Ebola are home to Lassa fever and that there is one main difference between an outbreak of Ebola and Lassa. Rats cause a Lassa outbreak. The rodents carry the disease into homes and food stores, especially in the dry season running from November to April. Once infected, Lassa can spread from person-to-person. Not everyone who catches it becomes seriously ill, but fatality rates have been known to be as high as 70 per cent. It is less easily transmitted than Ebola, but nonetheless patients must still be treated in complete isolation. The remaining health workers in West Africa are already overstretched with Ebola. As cases of a second haemorrhagic fever begin to rise, some are worried that Lassa may go undiagnosed and untreated. Prof. Christian Happi of Redeemer's University, Ogun State, told journalists: "Attention has completely shifted now from Lassa to Ebola. There are cases of Lassa fever being actually considered to be Ebola cases in many places.

In that regard it is a very complicated situation for us, especially in Liberia and in Sierra Leone." It has been shown that Lassa fever is less fatal than Ebola and can be treated with a drug. Ribavirin is used to help patients recover but it is useless for Ebola and is only given once Lassa has been confirmed. Rapid tests are not widely available and without them only a laboratory can tell the difference between an Ebola patient and a Lassa patient. Delays in treatment can be fatal. The Guardian investigation also found that Ebola, Lassa fever, Dengue fever and Yellow fever are some of the haemorrhagic fevers that have been reported in Nigeria in the last three years; and that an outbreak of Lassa fever in early 2014 in Edo State and some other states heralded the Ebola outbreak in Lagos and Port Harcourt. Several studies have shown that the spread of Lassa fever in a number of communities in different parts of the country was as a result of poor personal hygiene. The primary animal host of the Lassa virus is the Natal multimammate mouse (Mastomys natalensis), an animal found in most of sub-Saharan Africa.

The virus is probably transmitted by contact with the faeces or urine of animals accessing grain stores in residences. Also, a new study published Tuesday in PLOS suggests that areas of increased poverty are associated with higher rates of Ebola virus transmission. It was also gathered that at first sight the symptoms of Lassa are identical to Ebola; there can be bleeding, vomiting and fever. But whereas Ebola is a new outbreak, Lassa is a constant presence. According to the WHO, every year it infects from 300,000 to 500,000 people, killing up to 20,000. The Guardian learnt that all of the countries worst hit by Ebola are home to Lassa fever and that there is one main difference between an outbreak of Ebola and Lassa. Rats cause a Lassa outbreak. The rodents carry the disease into homes and food stores, especially in the dry season running from November to April. Ebola and Lassa fever belong to the same family. They are called viral haemorrhagic fever. It is a general term for a severe illness, sometimes associated with bleeding, that may be caused by a number of viruses.

The term is usually applied to disease caused by Arenaviridae (Lassa fever, Junin and Machupo), Bunyaviridae (Crimean-Congo haemorrhagic fever, Rift Valley Fever, Hantaan haemorrhagic fevers), Filoviridae (Ebola and Marburg) and Flaviviridae (yellow fever, dengue, Omsk haemorrhagic fever, Kyasanur forest disease). Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus, a member of the arenavirus family of viruses. It is transmitted to humans from contacts with food or household items contaminated with rodent excreta. The disease is endemic in the rodent population in parts of West Africa. Person-to-person infections and laboratory transmission can also occur, particularly in the hospital environment in the absence of adequate infection control measures. Diagnosis and prompt treatment are essential. Lassa fever is an acute viral haemorrhagic illness of one to four weeks duration that occurs in West Africa. The Lassa virus 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, particularly in hospitals lacking adequate infection prevent and control measures. Lassa fever is known to be endemic in Benin (where it was diagnosed for the first time in November 2014), Guinea, Liberia, Sierra Leone and parts of Nigeria, but probably exists in other West African countries as well. The overall case-fatality rate is one per cent. Observed case-fatality rate among patients hospitalized with severe cases of Lassa fever is 15 per cent. Early supportive care with rehydration and symptomatic treatment improves survival. WHO's Special Representative for the Ebola Response, Dr. Bruce Aylward, said: "We are now at a critical period in the Ebola epidemic as we move from managing cases and patients to managing the residual risk of new infections. "We still anticipate more flare-ups and must be prepared for them." Sierra Leone is still in a 90-day period of enhanced surveillance following the declaration on November 7, 2015 of the end of Ebola transmission in the country. This period is designed to ensure no hidden chains of transmission have been missed and to detect any new flare-ups of the disease. The Sierra Leone government acted rapidly to respond to this new case.

Through the country's new emergency operations centre, a joint team of local authorities, WHO and partners are investigating the origin of the case, identifying contacts and initiating control measures to prevent further transmission. The WHO had said all known chains of transmission in West Africa have been stopped, as they declared the most recent outbreak of Ebola virus disease in Liberia to be over. However, there is evidence the Ebola virus can persist in the bodies of survivors after they have recovered from the disease. This is not the first time Liberia has been declared free of Ebola transmission - the WHO made a similar announcement in May 2015, but the virus returned twice, once in June and then again in November. What makes this occasion different is that the other two countries most affected by the recent outbreak - Guinea and Sierra Leone - have also been declared free of Ebola. The WHO declared Sierra Leone free of Ebola in early November, and Guinea achieved the same status in late December. For the first time since the start of the epidemic two years ago, say WHO, all three countries have reported zero cases for at least 42 days.

To be declared free of Ebola, a country must achieve 42 days (two 21-day incubation cycles of the virus) since the last confirmed patient tests negative for the disease two times. The recent outbreak in West Africa is unprecedented in world history. It has infected over 28,500 people and claimed over 11,300 lives. It has devastated families and communities and significantly weakened the health systems and economies of all three countries. Risk of additional Ebola outbreaks continues While praising the monumental efforts of the governments and people of the countries affected, and the organizations that have partnered with WHO in bringing the epidemic to an end, the UN agency warns that "the job is not over" and "strong surveillance and response systems will be critical in the months to come," as it is likely that flare-ups will occur. There is a high risk that small outbreaks of Ebola - like the most recent one in Liberia - will occur. The WHO say 10 of the flare-ups that have occurred were not part of the original outbreak and were likely a result of Ebola persisting in survivors who have recovered.

There is evidence that while the Ebola virus may disappear from the bloodstream of survivors relatively quickly; it can survive in "niches" in the body. For example, it can survive in men's semen for seven to nine months and in the eye for two months after recovery. Aylward said the epidemic is in a critical period as countries move from managing infected patients to managing the risk of new infections. He noted that the risk of new infections is gradually reducing as the virus clears from the survivor population, but "we still anticipate more flare-ups and must be prepared for them." Aylward added: "A massive effort is under way to ensure robust prevention, surveillance and response capacity across all three countries by the end of March." Looking after survivors is an important part of this phase. As well as screening for persistent virus, they will need medical and psychological care, and support to help them return to normal life in their families and communities, who will also need education and help to reduce stigma and minimize risk of Ebola virus transmission. One of the factors that appears to have hampered control of the recent Ebola epidemic in West Africa, and made it difficult to apply aggressive quarantine programmes, is the lack of maps or census data.

This was the conclusion of a review on the role of mapping in preventing epidemics that Medical News Today reported recently. Copyright © 2016 The Guardian. All rights reserved. Distributed by AllAfrica Global Media ( allAfrica.com ). To contact the copyright holder directly for corrections — or for permission to republish or make other authorized use of this material, click here. AllAfrica publishes around 700 reports a day from more than 140 news organizations and over 500 other institutions and individuals , representing a diversity of positions on every topic. We publish news and views ranging from vigorous opponents of governments to government publications and spokespersons. Publishers named above each report are responsible for their own content, which AllAfrica does not have the legal right to edit or correct. Articles and commentaries that identify allAfrica.com as the publisher are produced or commissioned by AllAfrica . To address comments or complaints, please Contact us .

Question: In which African country is the town of Lassa, where Lassa fever was first identified?
Answer: Nigeria