Posted on 03RD APR 2017
tagged Lassa Fever, West Africa; Nigeria

A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases

In this update:
[1] Taka-Lafiya village, Tudun-Wada local government area, Kano State, Nigeria
[2] Nigeria Centre for Disease Control Weekly Epidemiological Report

[1] Taka-Lafiya village, Tudun-Wada local government area, Kano State, Nigeria
Date: Thu 30 Mar 2017
Source: Daily Trust [edited]

In the Taka-Lafiya village of Tudun-Wada local government area of Kano State, 8 people have died from suspected Lassa fever.

The District Head of Tudun-Wada Local Government, Dankadai of Kano, Dr. Bashir Muhammad Dankadai, said yesterday [29 Mar 2017] while briefing the Emir of Kano, Muhammadu Sanusi II, that the disease was detected in the village about 3 weeks ago following the mysterious deaths of 4 persons.

The district head explained that when he reported the case to the local government authority, a team of medical personnel was deployed to the village, and it was discovered that many people in the village were having serious high temperatures.

"The 3 people whose condition was critical at that time were rushed to 'Yar-Gaya Infectious Disease Isolation Center for further investigation. One of them later died in the hospital, taking the total number of casualties to 5; 2 other patients died again [sic; subsequently], and the last victim died yesterday [29 Mar 2017], bringing the total of deaths to 8," he said.

Also commenting on the discovery, a medical official in charge of Tudun-Wada local government, Mallam Lawan Maikano, informed the emir that 51 others who had direct contact with the infected persons in Taka-Lafiya had been placed under surveillance.

"When the case of the severe fever was reported to us, a team of health workers was mobilized to the village. Later, we informed the state ministry for health, which also sent a team of medical personnel to the village. The result of the blood samples we sent to Lagos state for tests confirmed that it was Lassa fever," Maikano said.

Responding, the Emir of Kano called on the people to improve on their personal hygiene and urged the state government to intensify efforts towards curtailing the situation.

When contacted, the State Commissioner for Health, Dr. Ibrahim Getso, who also confirmed the deaths of 8 people, said that out of 3 people whose blood samples were sent to Lagos for testing, 2 were confirmed positive for Lassa fever, and the other was negative.

"One of the 2 people confirmed positive died in the hospital, and the other is still on admission. So, medically, I can say that out of the 8 deaths, only one is confirmed [to have died of] Lassa fever, while the remaining 7 we call suspects for Lassa fever," he said.

[Byline: Yusha'u A. Ibrahim]

Communicated by:
ProMED-mail from HealthMap Alerts

[2] Nigeria Centre for Disease Control Weekly Epidemiological Report
Date: Fri 17 Mar 2017
Source: Nigeria Centre for Disease Control Weekly Epidemiological Report 7 (10) [edited]

The Lassa fever outbreak remains active in 13 states in Nigeria, as no new states have reported any outbreak.

In the reporting week (week 11), 15 suspected cases were reported from 4 states; 2 of these cases were confirmed positive for Lassa fever. No death was recorded. A total of 283 suspects have so far been reported since onset of the outbreak in December 2016. A total of 99 cases have been classified: 93 confirmed cases and 6 probable cases. The total number of deaths has remained the same in the last 2 weeks, 46 deaths, of which 40 were confirmed cases and 6 probable cases. The case fatality rate for confirmed/probable is 46.5 percent and for all cases is 19.8 percent.

The Nigeria Centre for Disease Control (NCDC) has continued to coordinate response in affected states. Further support has been provided through re-distribution of ribavirin to affected states for continued case management of confirmed cases. The NCDC team in Borno State has been onsite in the last 3 weeks, providing support for the outbreak response.

Figure 1 [map]. States with confirmed cases, December 2016 to March 2017 (updated as of 17 Mar 2017), N = 99

Preparedness for an outbreak of Lassa Fever
In 1969, the Lassa fever virus was 1st discovered in Lassa town, Borno State. With this discovery, there have been recurrent outbreaks of the disease over the years. Lassa fever is a seasonal disease, which occurs during the dry season. The last few years have seen this outbreak occur in states that have been previously unaffected. This brings to question the level of preparedness at the state level. It is important that all states attain a high level of preparedness to contain any possible outbreak, as this will go a long way in ensuring a good outcome, should an outbreak occur.

At the beginning of the dry season, a checklist developed by the NCDC was provided to all state epidemiologists to enable them to assess their level of preparedness in the event of an outbreak of Lassa fever or cerebrospinal meningitis, which usually occurs during this season. It is expected that gaps identified post-administration of the checklist are bridged prior to the onset of an outbreak.

The identification of gaps in a clear and systematic way will go a long way in motivating all stakeholders, including the leadership at the state level, to carry out assigned responsibilities in outbreak response.

The efforts put in by the states over the years are highly commendable, particularly in the face of limited resources. However, it is important for state governments to take ownership of outbreak management and response activities in the state while working with partners and other stakeholders in a collaborative manner. The NCDC will continue to provide support in every way it can as we all work towards achieving a surveillance system that will effectively protect the health of Nigerians.

1. Lassa fever
Please note that the data reflect the routine reports, i.e. all suspected cases including the laboratory positive and negative cases.

1.1. 6 suspected cases of Lassa fever with 2 laboratory-confirmed cases and one death (CFR, 16.7 percent) were reported from 5 LGAs [local government areas] (4 states) in week 10, 2017 compared with 8 suspected cases with one laboratory-confirmed case and one death (CFR, 12.5 percent) from 6 LGAs (6 states) during the same period in 2016 (Figure 2).

1.2. Laboratory results of the 6 suspected cases were 2 positive for Lassa fever (Edo state), 3 negative for Lassa fever and other VHFs (Gombe and Nasarawa states), while one result is pending (FCT-1).

1.3. Between weeks 1 and 10 (2017), 166 suspected Lassa fever cases with 40 laboratory-confirmed cases and 24 deaths (CFR, 14.5 percent) from 33 LGAs (11 states) were reported compared with 517 suspected cases with 50 laboratory confirmed cases and 68 deaths (CFR, 13.2 percent) from 110 LGAs (26 states) during the same period in 2016 (Figure 2).

1.4. Between weeks 1 and 52, 2016, 921 suspected Lassa fever cases with 109 laboratory-confirmed cases and 119 deaths (CFR, 12.92 percent) from 144 LGAs (28 states and FCT) were reported compared with 430 suspected cases with 25 laboratory confirmed cases and 40 deaths (CFR, 9.3 percent) from 37 LGAs (14 states and FCT) during the same period in 2015 (Figure 3).

1.5. Investigation and active case search ongoing in affected states with coordination of response activities by the NCDC with support from partners.

1.5.1. National Lassa Fever Working Group meeting and weekly National Surveillance and Outbreak Response meeting ongoing at NCDC to keep abreast of the current Lassa fever situation in the country.

1.5.2. Response materials for VHFs prepositioned across the country by NCDC at the beginning of the dry season.

1.5.3. New VHF guidelines being developed by the NCDC

1.5.4. Ongoing reclassification of reported Lassa fever cases

1.5.5. Ongoing review of the variables for case-based surveillance for VHF

1.5.6. VHF case-based forms completed by affected states are being entered into the new VHF management system. This system allows for the creation of a VHF database for the country.

1.5.7. Confirmed cases are being treated at identified treatment/isolation centers across the states with ribavirin and necessary supportive management also instituted.

1.5.8. Onsite support was earlier provided to Ogun, Nasarawa, Taraba and Ondo States by the NCDC and partners.

1.5.9. The NCDC has deployed a team to Borno state to support the outbreak response and coordinate case management of patients and support implementation of IPC measures amongst healthcare workers.

1.5.10. NCDC distributed ribavirin tablets to Cross-River State.

1.5.11. States are enjoined to intensify surveillance.

Figure 2: Map of Nigeria showing areas affected by Lassa fever, week 1-10, 2016 & 2017

Figure 3: Map of Nigeria showing areas affected by Lassa fever, week 1-53, 2015

Table of cases by state, Cumulative Data Wk 01-10:
Cases / Lab Cfd / Deaths
Bauchi / 7 / 3 / 2
Ebonyi / 3 / 1 / 0
Edo / 57 / 6 / 5
FCT / 1 / 0 / 0
Gombe / 13 / 0 / 0
Nasarawa / 21 / 6 / 2
Ogun / 7 / 1 / 0
Ondo / 11 / 6 / 2
Plateau / 5 / 4 / 3
Rivers / 6 / 1 / 0
Taraba / 35 / 12 / 9
TOTALS / 166 / 40 / 24

Communicated by:
Olutayo Olajide Babalobi
Lecturer and Consultant Epizootiologist,
(One Health, Participatory Epizootiology and Veterinary ICT Research Group),
Department of Veterinary Public Health and Preventive Medicine,
Faculty of Veterinary Medicine,
University of Ibadan, Ibadan,

[Dr. Olutayo Olajide Babalobi is thanked for sending in this report.

Because many areas in Nigeria are endemic for Lassa virus, one can expect individual or small clusters of cases to pop up in several states during the transmission (dry) season, as illustrated by the cluster in Kano state, above.

Nigeria has begun to expand its surveillance with laboratory support to speed up diagnosis and response to Lassa fever and other diseases.

As noted in earlier comments, Lassa fever remains a problem in Nigeria because the virus is endemic there. Virus transmission to humans occurs when people are in contact with the reservoir rodent host, the multimammate mouse (in the genus _Mastomys_) or their excreta. Transmission also occurs in health facilities when personal protection equipment is not employed and barrier nursing practices are not adequate to protect staff from blood and secretions of infected patients.

As noted in earlier, prevention and control of Lassa fever in nature depends on control of the rodent reservoir, which occurs across Nigeria and beyond. Reduction of populations of this rodent will require active participation at the village level. That will necessitate mounting a public education program with support of rodent control technicians. Preventing entry of rodents into the home and keeping food materials tightly covered are helpful measures to prevent infection. Elimination of these rodents completely is probably not possible.

The Weekly Epidemiological Report above contains several interesting maps of Lassa fever distribution.

Images of _Mastomys_ mice can be seen at

Maps of Nigeria can be accessed at and - Mod.TY]

See Also
Lassa fever - West Africa (13): update 20170328.4931422
Lassa fever - West Africa (12): Nigeria 20170327.4929174
Lassa fever - West Africa (11): Nigeria 20170319.4911462
Lassa fever - West Africa (10): Benin, Togo, Burkina Faso 20170312.4896305
Lassa fever - West Africa (09): Nigeria (BO) 20170302.4875164
Lassa fever - West Africa (08): Benin 20170301.4872702
Lassa fever - West Africa (07): Nigeria (BA) 20170225.4864837
Lassa fever - West Africa (06): Nigeria 20170225.4862689
Lassa fever - West Africa (05): Nigeria (NA) 20170215.4842179
Lassa fever - West Africa (04): Liberia 20170209.4827934
Lassa fever - West Africa (03): Nigeria (RI) 20170122.4782917
Lassa fever - West Africa (02): Nigeria (NA) 20170118.4773375
Lassa fever - West Africa (01): Nigeria (OG) 20170101.4735363