Tuesday, 4th of November 2014 |
E.E Isere1 and A.A Fatiregun1
Ann Ib Postgrad Med. Jun 2014 12(1): 15–21.
The Federal Ministry of Health recommendations for response during measles epidemics in Nigeria previously focused on case management using antibiotics and Vitamin. A supplements and did not include outbreak response immunization (ORI) campaigns. However, with the revision of the existing national technical guideline on measles casebased surveillance and outbreak response in Nigeria in 2012 in line with the World Health Organization recommendation on response to measles outbreak in measles mortality reduction settings, there is a need to update members of the Nigerian public health community on these revisions to ensure appropriate implementation and compliance. This article therefore seeks to provide clinicians and other public health professionals in Nigeria with updates on recent developments in measles case-based surveillance and outbreak response in Nigeria
Keywords: Measles surveillance, Outbreak response, Clinicians, Nigeria.
Measles outbreaks pose a continuing public health problem in Africa and other developing nations of the world1. Measles case fatality has been estimated to be between 3 to 5% in developing countries and may be as high as 10% during epidemics2. Despite the efforts made at increasing immunization, measles remains a leading cause of under-five mortality in Africa3. There were about 139, 300 measles deaths globally in 2011 representing nearly 380 deaths every day or 15 deaths every hour4. Nigeria presently together with other developing countries accounts for about 94% of global deaths caused by measles annually5.
In an effort to address the high mortality caused by measles annually in Africa, countries in the World Health Organization, (WHO) African region in 2001 adopted the accelerated measles control activities using the measles mortality reduction strategies recommended by the WHO and the United Nations Children’s Fund (UNICEF). These strategies includes (1) achieving and maintaining e” 80% coverage with routine measles vaccination of infants, (2) providing a second dose of measles vaccine through supplemental immunization activities (SIAs), (3) intensified measles case-based surveillance with laboratory confirmation and (4) improve measles case management during outbreaks6-7. In Nigeria, literatures on measles outbreaks investigation have shown that outbreaks of measles annually are detected too late resulting in either no or late response with minimal impact8. This could partly be attributed to poor awareness among clinicians and public health professionals of the measles case based surveillance process and their role in immediate case notification using the standard case definition. Also, between epidemiological weeks 1 to 43 of 2013, about six hundred and forty-three measles outbreaks were confirmed in 83% of the seven hundred and seventy four Local Government Areas (LGAs) in Nigeria with outbreak response conducted in few of these LGAs according to the revised national measles technical guideline9. However, with the strengthening of the measles case based surveillance in the country with laboratory support to enhance early outbreak detection, there is a need to update clinicians and public health professionals on the measles case based surveillance process, their roles and on the recent developments in the conduct of measles outbreak response activities in Nigeria to ensure proper implementation during subsequent measles outbreaks in Nigeria.
The success of prevention and control programmes in reducing morbidity and mortality from vaccine preventable diseases can only be measured if there is a reliable disease surveillance system in place10. In 2006, measles case based surveillance became operational in Nigeria using the resources and infrastructure of the already established surveillance for Acute Flaccid Paralysis3,7. The case-based surveillance system was put in place to detect cases and outbreaks of measles. It involves immediate reporting and investigating any suspected case of measles by clinicians using standard case definition, evaluating immunization efforts and predicting outbreaks through the identification of geographical areas and age group at risk11. A suspected measles case is any person with generalized maculopapular rash and fever plus one of the following: cough, coryza (runny nose) or conjunctivitis or in any person in whom a physician suspect measles8. For every suspected measles case, an individual case investigation form (Fig. (Fig.11 and and2)2) should be completed and a blood specimen collected and sent to the national reference laboratory for testing for measles-specific immunoglobulin M (IgM) antibody. The designated Local Government Area (LGA) Disease Surveillance and Notification Officer (DSNO) at the LGA Primary Health Care (PHC) Department is responsible for the completion and transportation of the specimen6, 8. A laboratory confirmed case of measles is defined as a suspected case with serological confirmation of measles specific IgM antibody in a person who had not received measles vaccination within 30days before the specimen collection8. While a measles associated death is defined as any death from illness in a confirmed case of measles within 1month after the onset of rash8. The national guideline on measles surveillance in Nigeria defines a suspected outbreak as the occurrence of ≥ 5 reported suspected cases of measles in a health facility or district in a month and a confirmed outbreak of measles as the occurrence of ≥ 3 laboratory confirmed measles cases in a health facility or district in one month8. After an outbreak has been confirmed as measles, subsequent cases are also investigated with serum sample collected alongside nasopharyngeal swabs of at least 5cases identified within 5days of onset of rash for viral isolation8. All other new cases from which serum specimens are not collected are linelisted and are confirmed by epidemiological linkage.6, 8 In the context of a measles outbreak, an epidemiologically linked case is one without a blood specimen collected and is linked in person, place and time to a laboratory confirmed case.6, 8