Developments in the Disease Worldwide 2007
2006
Use of a mobile laboratory to improve response to meningitis epidemics in Burkina Faso The Meningitis Trust has supported an innovative way of increasing laboratory facilities in Burkina Faso by the use of a mobile laboratory, which has enhanced the capacity of the Ministry of Health to improve its response to epidemic meningitis. The mobile laboratory is operated by the “Association pour l’Aide à la Médecine Préventive” (amp) and a paper on its activities was recently published in a new online Journal. This paper was also reported on inmed in the May Journal Focus. We are now pleased to report that a short documentary on the work of the mobile laboratory has been produced by the amp and is available for download in two versions from the welcome page of their website (www.aamp.org). The film “Les Sentinelles” is in French, and gives a graphic illustration of the mobile laboratory in an emergency mission to investigate an epidemic of meningitis in two districts of Burkina Faso – Kombissiri and Saponé. The film show the mobile lab going to sites at the heart of the epidemic in the remote villages of these districts where it can be as close as possible to the sick people, and where the technicians can analyse on the spot the samples of cerebrospinal fluid taken from patients with suspected meningitis. The results of these early analyses provide the vital information to allow for the care of the sick and to aid a rapid and specific vaccination response, in order to stem the epidemic as quickly as possible.
http://www.institut.veolia.org/ive/ressources/documents/1/281,Annex-II_article-proof-on-mobile-lab.pdf
Carriage of meningococci in the African meningitis belt New conjugate vaccines against Neisseria meningitidis are likely to have a large impact on the nature of the epidemics of meningitis currently experienced in sub-Saharan Africa in an area known as the “Meningitis Belt”. However to understand the potential impact of these vaccines more needs to be known about the epidemiology of carriage of these bacteria in Africa. Dr Caroline Trotter of the Department of Social Medicine, University of Bristol and Professor Brian Greenwood of the Department of Infection and Tropical Diseases, London School of Hygiene and Tropical Medicine have recently published a paper in which they address this issue by reviewing the carriage studies which have been carried out in and around the meningitis belt over the past 35 years. The meningitis belt of sub-Saharan Africa is characterised by high levels of endemic meningococcal disease and by epidemics which occur every 2-10 years. Asymptomatic carriage of meningococcal bacteria is common in most populations but invasive disease is usually rare. Understanding of the disease requires both study of the carriage and of the disease itself. Advances in study design and the use of standard microbiological techniques for culture, subgrouping and subtyping resulted in carriage studies being carried out in Burkina Faso (formerly Upper Volta) and Nigeria in the early 1970s. Few studies were carried out from the mid-1980s until the late 1990s but then interest was sparked once more by the emergence of unusual serogroups, particularly W135. The authors gather information from 31 papers relating to carriage studies within the meningitis belt to look at strain characteristics, age distribution of carriage, gender differences and carriage rates in contacts. A limited number of these papers also provide information on the duration of carriage and the effect on carriage of the presence of other Neisseria species, the season, vaccination and the epidemic/endemic situation. Although the most important pathogenic strain is serogroup A, with serogroup C and more recently serogroups W135 and X being implicated, carriage strains are more diverse with serogroups B, Y, 29E, Z and non-groupable strains being detected in addition to the recognised pathogenic strains. Patterns of carriage by age were not consistent across studies and, according to the authors, this is probably because transmission is affected by behavioural and social factors which vary across the many countries of the meningitis belt. In general, when compared with the situation in Europe, carriage in young children and older adults was more frequent. Changes in carriage where not linked to season, supporting the hypothesis that epidemics occur in the dry season because extreme environmental conditions damage the mucosal defences making it more likely that invasive disease will occur rather than asymptomatic carriage. In their conclusions the authors point out that if meningococcal conjugate vaccines are to be as effective in Africa as they have been in Europe it is essential that they reduce pharyngeal carriage, interrupt transmission and produce herd immunity. The ability of the serogroup A conjugate vaccine, currently being developed by the Meningitis Vaccine Project, to reduce carriage has yet to be shown and more studies are needed. In addition, knowledge of transmission dynamics can assist with the design and targeting of vaccination strategies so that immunisation can be targeted at the groups who constitute the largest reservoir of infection.
Conjugate vaccine against four serogroups of meningococci, A, C, Y and W135 reported to be immunogenic in infants Dr Scott Halpin, professor of paediatrics at Dalhousie University, Halifax, Canada, and his team reported the results of a Phase II clinical trial at the recent 5th World Congress of the World Society for Paediatric Infectious Diseases in Bangkok, Thailand. Meningococci (Neisseria meningitidis) are responsible for a large burden of disease world wide, with young children being one of the most vulnerable groups. Five serogroups (A, B, C, Y, and W135) are responsible for the bulk of disease and while a broad coverage vaccine for serogroup B remains elusive, polysaccharide and protein-conjugate vaccines are available alone or in combination against one or more of the remaining four serogroups. Currently available quadrivalent vaccines have their limitations; for example the polysaccharide vaccine against A, C, Y, and W135 does not provide long term protection and is poorly immunogenic in children under two years of age, and the only quadrivalent conjugate vaccine available is not licensed for use in children under 2y. The Phase II clinical trial reported by Prof. Halpin investigated the safety and immunogenicity of a novel meningococcal ACWY-CRM conjugate vaccine (MenACWY-CRM) currently under development. One hundred and seventy five infants were enrolled in the study at 6 or 12 months of age and received either two doses of MenACWY-CRM at 6 & 12 months (n=64), one dose at 12 months (n=61), or one dose of a conjugate serogroup C vaccine (MenC) at 12 months followed by a single booster dose of MenACWY-CRM at 18 months of age. Blood samples were collected immediately before vaccination and 28 days after each vaccination, and immunogenicity evaluated using human serum bactericidal assay (hSBA) geometric mean titre (GMT) and hSBA titre ≥1:4. Safety and tolerability were monitored throughout the trial. The results showed that both vaccines used in the study were well tolerated. Mild local and systemic reactions recorded for seven days after immunisation were similar between groups while the frequency of adverse events was very low; medically significant adverse events (bronchiolitis and lethargy) were reported in only two infants following the first dose of MenACWY-CRM. Nine serious adverse events were reported in seven infants but all were assessed as unrelated to the study treatment. MenACWY-CRM was shown to be immunogenic when administered as a single dose at 12 months of age, as two doses at six and 12 months or as a booster at 18 months of age. For serogroup C the immune responses following two doses of MenACWY-CRM at six and 12 months were an order of magnitude higher, as measured by GMT one month after vaccination, than a single dose of either MenACWY-CRM or MenC administered at 12 months of age. The percentage of infants with hSBA titre ≥1:4 for serogroup C was 100% after two doses of MenACWY-CRM at 6 and 12 months and after one dose of MenC at 12 months with a booster of MenACWY-CRM at 18 months. The percentage of infants with hSBA titre ≥1:4 for serogroup C after one dose of MenACWY-CRM or MenC at 12 months of age was very similar (96% and 92% respectively). For the remaining serogroups, after two doses of MenACWY-CRM the percentage of infants with hSBA titre ≥1:4 was 100% for W135 and Y and 86% for A, after a single dose at 12 months was 93% for W135, 79% for Y and 75% for A, and after the dose at 18 months the percentages for serogroups A, W135 and Y were 62%, 84% and 81% respectively. The MenACWY-CRM vaccine appears to provide broad coverage against meningococcal serogroups A, C, W135 and Y in infants aged less than two years and within a flexible dosing regimen.
Introduction of Pneumococcal Conjugate Vaccine in New Zealand On Monday, 7th May 2007, the New Zealand Government announced that the pneumococcal conjugate vaccine (Prevenar) will be added to the National Immunisation Schedule. Vaccinations will begin in June 2008 and all babies born from 1st January 2008 will be eligible to receive the vaccine at six weeks, three months, five months and 15 months. The schedule will be adjusted depending on the age at which the baby receives the first dose of the vaccine. New Zealand has relatively high rates of invasive pneumococcal disease, which includes pneumococcal meningitis, particularly among Maori and Pacific children. It is expected that the vaccine will prevent around 80% of pneumococcal disease. The vaccine has been successfully used in the USA since 2000 and was introduced into the UK childhood immunisation programme in September 2006. Source: New Zealand Government
Meningococcal Disease in the African Meningitis Belt During the first twelve weeks of the 2007 meningitis season, the World Health Organisation has received a total of over 25,000 reports of suspected cases of meningococcal disease from most countries in the African meningitis belt. The reporting systems vary from country to country so all figures should be considered as provisional. Burkina Faso has been hardest hit, reporting over 15,000 cases with 1,100 deaths. Concern has been raised that the current trend is similar to the situation in 1996 where 43,000 cases led to over 4,300 deaths. In Sudan, the Ministry of Health of the Government of Southern Sudan has reported almost 7,000 suspected cases with 430 deaths. A high number of cases have also been reported in Uganda and the Democratic Republic of Congo. The World Health Organisation, together with its partners and local organisations, is assisting with disease surveillance, treatment and prevention. Sources: www.who.int and www.reliefweb.int
Enteroviral Meningitis Outbreak, Kosovo From 1st July to 13th September 2006, a total of 878 cases of acute neurological syndrome were reported to the National Institute of Public Health, Pristina. Preliminary epidemiological analysis indicates that 80% of cases were in children under 15 years of age, and 66% were in males. Enterovirus was detected by cell culture and confirmed by PCR (polymerase chain reaction) tests in over half of the samples investigated at the WHO Reference Laboratory in Rome. Control measures have been implemented by regional health authorities and include enhanced surveillance, hospital screening, case management and awareness campaigns to improve basic hygiene practices. A dedicated information package has been developed for schools by the Ministry of Health and the Ministry of Education.
Pneumococcal Vaccine Introduced On 12th July 2006, the Department of Health announced that a vaccination programme to protect children against pneumococcal disease is to be launched in the UK on 4th September 2006. As part of a nationwide catch-up campaign, every child up to the age of two will also be offered the vaccine. Invasive pneumococcal infection affects over 500 children under the age of two years each year, killing 50 and leaving many disabled. The new routine vaccination schedule: 2 months DTaP/IPV/Hib + pneumococcal vaccine 12 months Hib/Men C Catch up Pneumococcal vaccine will be offered to all children under the age of two years. DTaP/IPV/Hib is a single vaccine that protects against diphtheria, tetanus, pertussis, polio and Hib. The vaccine was introduced in the US five years ago, but has been delayed in the UK because of concerns over its cost. The vaccine costs £34.50 per dose, more than all the other childhood vaccines put together. Source: www.doh.gov.uk Meningococcal Disease in the African Meningitis Belt During the first ten weeks of the 2006 meningitis season there have been outbreaks of the disease in seven countries in the African Meningitis Belt. Major vaccination programmes are ongoing in the following three areas:
Source: www.who.int
Kenya Between 1st January and 26th February 2006, the Ministry of Health has reported 74 cases and 15 deaths in four areas of West Pokot. These areas border the epidemic districts of Uganda. Where laboratory testing has been performed, Neisseria meningitidis serogroupW135has been identified as the cause. The International Coordinating Group on Vaccine Provision for Epidemic Meningitis Control (ICG) has provided 200,000 doses of trivalent vaccine, together with oily chloramphenicol and rapid tests. An immunisation campaign began on 7th March 2006, implemented by the Ministry of Health and supported by UNICEF, WHO and Medecins sans Frontieres. NigerBetween 1st January and 26th February 2006, the Ministry of Health has reported 614 cases and 44 deaths. The epidemic threshold has been reached in two neighbouring districts. Where the CSF has been tested, Neisseria meningitidis serogroup A has been identified as the cause. The ICG has provided 750,000 doses of bivalent vaccine and 7800 doses of oily chloramphenicol to assist in disease management. An immunisation campaign has started in the two districts. Source: www.who.int
Pneumococcal Vaccine On 8th February 2006, the Department of Health announced plans to introduce important changes to the childhood immunisation programme. The proposed changes are:
There are over 500 cases per year of invasive pneumococcal disease in children under two years of age, and about a third of these are cases of pneumococcal meningitis. At least 50 children under two years of age will die each year from invasive pneumococcal disease, with two thirds of these deaths being caused by pneumococcal meningitis. When the vaccine is introduced, it will be offered routinely to children at two, four and 13 months of age. A catch-up programme will be introduced to ensure that all children up to two years of age will be offered the vaccine. Source: www.doh.gov.uk
Meningococcal Disease in Uganda Between 28th December 2005 and 23rd January 2006, 163 suspected cases of meningococcal disease have been reported from the Nakapiripirit region of north-eastern Uganda. Where laboratory testing has been performed, Neisseria meningitidis serogroup A has been identified as the cause. The Ministry of Health has constituted a national task force to plan and co-ordinate a response, strengthen surveillance and raise awareness. A mass vaccination programme is planned to start this week as soon as vaccines are delivered. The situation has been exacerbated by the extremely dry weather, which has forced nomadic populations into temporary, crowded settlements, thereby contributing to the spread of disease. Source: www.who.int Back To Top
Further Update on the Meningococcal Group B Immunisation Programme in New Zealand Following on from the update in December 2005, the Ministry of Health has now introduced a fourth dose of the MeNZB vaccine for all infants who received their first dose before they were six months old. Clinical trials have shown that in young babies there is an increased immune response following a fourth dose of the vaccine. This extra dose will be given to babies once they are at least ten months old, and a minimum of four months after their third dose. The immediate introduction of this fourth dose is aimed to provide optimum protection before the winter months, when meningococcal disease is most prevalent. Source: www.moh.govt.nz Back To Top
Update on the Meningococcal Group B Immunisation Programme in New Zealand Further to the information given in June 2005, the Ministry of Health has recently published an update on this programme:
The programme director, Dr Jane O’Hallahan, has highlighted these impressive figures but has also stated that there is still hard work to be done in the following areas:
Source: www.immunise.moh.govt.nz Back To Top
The increase in Hib disease in Ireland Since 1992, infants have been routinely immunised against Haemophilus influenzae type b (Hib) at two, four and six months of age. The introduction of this vaccine led to a dramatic decrease in Hib disease, from approximately 100 cases/year in the late 1980s to less than 10 cases/year in 2002. The recent cause for concern in Ireland has been the steady increase in the number of children getting Hib disease despite being fully vaccinated. This increase has progressed from three cases in 2003, to six in 2004 and 10 to date in 2005. In response to this increase, the National Immunisation Advisory Committee (NIAC) recommended a catch up booster Hib vaccine for all children under the age of four years. The Health Service Executive (HSE) has now approved this and 48,000 doses of the vaccine will be available by mid October. Further batches of the vaccine will be available later in the year. This emerging pattern of disease in Ireland appears to be similar to that which occurred in the UK in 2003, where a Hib booster campaign proved successful and resulted in a significant reduction in the level of disease. Source: Hib Disease in Ireland. Health Protection Surveillance Centre. Back To Top
New Guidelines for the Prevention and Control of Meningococcal Disease Published in Canada The Public Health Agency of Canada has recently published new guidelines for the prevention and control of Meningococcal Disease. These guidelines replace the previous guidelines that were published in 1994. Back To Top
Progress for the Meningococcal Group B Immunisation Programme in NZ The Ministry of Health (MOH) in NZ has recently reported three major milestones for the Meningococcal Group B Immunisation Programme. The programme director, Dr Jane O’Hallahan, has stated the tremendous achievement of the programme to date; with the first half a million children vaccinated, over a million doses given overall and vaccination now taking place in all District Health Boards. Although uptake of the vaccine is promising, the MoH has published an open letter in the NZ newspapers, in an attempt to clarify inaccurate information that has been circulating in the media. Source: www.moh.govt.nz Back To Top
Over 65’s to be offered jab against pneumococcal infection in the UK The chief medical oficer, Sir Liam Donaldson, recently announced that older people aged 65 and over will soon be offered a routine vaccination to help protect them against pneumococcal infection. Pneumococcal bacteria can cause serious diseases in older adults such as pneumonia, meningitis and septicaemia. Doctors will be inviting patients for their vaccination from April, however, people can be vaccinated at any time during the year. Most people will only need to have the vaccine once, although a second dose may be needed for those patients with certain medical conditions such as a damaged spleen or kidney problems. Source:www.dh.gov.uk/PublicationsAndStatistics Back To Top
New Recommendation for Meningococcal Vaccine for Adolescents and College Freshmen in the USA The Advisory Committee on Immunization Practices (ACIP) to the Centers for Disease Control and Prevention (CDC) this week recommended that children 11-12 and teenagers entering high school, as well as college freshman living in dormitories receive a newly licensed meningococcal vaccine. The new vaccine offers protection against meningococcal groups A, C, W135 and Y. Every year in the USA 1,400 to 2,800 people get meningococcal disease. Ten to 14 percent of people with meningococcal disease die, and 11-19 percent of survivors have permanent disabilities (such as mental retardation, hearing loss, and loss of limbs). It should be remembered however, that the vaccine does not protect people against meningococcal group B disease. This group of bacteria causes one-third of meningococcal cases. More than half of the cases among infants aged <1 year are caused by “type B,” for which no vaccine is licensed or available in the United States. The U.S. Food and Drug Administration (FDA) licensed the new meningococcal vaccine on January 14, 2005 for use in people 11-55 years of age. Source:Centers for Disease Control and Prevention website: www.cdc.gov/nip/vaccine/meningitis Back To Top |
