The Latest Situation on Meningoccal Infection and Preventive Measures

Since December last year, meningococcal infection cases were continuously found in Anhui province of China and its neighbouring provinces. It is suspected there has been meningococcal epidemic in Wuhu, Chuzhou, Anqing, Chaohu and Hefei of Anhui province. According to the Ministry of Health, 62 cases of meningococcal infection were reported in Anhui province as at 18:00 of 30 January (an increase of 14 cases compared to the same period last year) with 16 being death cases. The epidemic started in schools and then sporadic cases occurred in the community. The characteristics of the meningococcal infection this time is that it occurs sporadically with multiple sources and most patients aged between 13 and 18. Among the overall incidence, 77% of which took place on students, in particular primary and secondary students, with the main killer being serogroup C meningococcus which is a recently found strain. According to the emergency notice issued by the Ministry of Health on 31 January, from November 2004 till 30 January 2005, 546 cases of meningococcal infection were reported in China, with 258 infection cases and 16 death cases being reported in January. The number of incidence was 94 more than that occurred in the same month last year. The top five provinces with the highest incidence are Anhui, Henan, Hebei, Jiangsu and Sichuan respectively. In Guangdong, there is no indication of outbreak as there are only a few reported cases. There was a small outbreak of meningococcal infection in Baguio City of the Philippines end of last year. From October 2004 till 28 January 2005, 98 cases were reported and 32 were dead. Since 1988, the only recorded meningococcal infection case in Macao took place in 2001 and that was strain B meningococcal septicaemia. The disease surveillance system in Macao is constantly monitoring the situation of meningococcal infection. With the current situation in mainland, the Department of Health is going to issue some guidelines to the front line medical workers with the aim of early detection of the disease and better management of isolation arrangement. In addition, the Department of Health is going to enhance the information exchange with the departments of health in mainland. They will also monitor the situation of the disease in the neighbouring regions closely. The Department of Health is ready to revise their preventive strategies and measures against the disease at any time. Though, there is no sign of having an outbreak in neighboring districts, with consideration of the possible progress of the epidemic, the Department of Health is going to purchase a batch of vaccines by urgent procedures for future use. Meningococcal infection is caused by meningococcus and it can be in the forms of meningitis or meningococcal septicaemia without meningitis. Meningococcus (Neisseria Meningitidis) encompass serogroups A, B, C, W-135, X, Y and Z. There is no cross immunization amongst serogroups, which means the immunization against one serogroup cannot be used to prevent the infection of another serogroup. Pandemics are mostly caused by serogroups A, B and C, with serogroup A as the most common cause. In China, 90% of the previous meningococcal infection cases were caused by strain A meningococcus. The sub-Saharan Africa is named as meningitis belt as meningococcal pandemics always occur in the area. The incubation period of the disease is around 3-4 days (the shortest period can be 2 days while the longest can be as long as 10 days). Meningococcal infection is transmitted by direct person-to-person contact or through inhalation of droplets from the mouth and pharynx of infected persons or asymptomatic carriers. Most infected persons contacted the infection in the nasopharyngeal areas where no symptoms or only upper respiratory tract symptoms similar to that of cold can be found. Few infected ones suffer from sudden onset of fever, severe headache, stiff neck, nausea and vomiting. In addition, purpura fulminans, coma and death can rapidly be developed. Meningococcal infection often takes place in winter. The disease affects all age groups while distribution of age group may vary in different epidemics and outbreaks. At present, the widely-used vaccines include bivalent polysaccharide vaccine which can prevent serogroups A and C, tetravalent polysaccharide vaccine which can prevent serogroups A, C, Y and W-135 and, conjugate vaccine which can prevent serogroup C. In Macao, as this disease is rarely found in recent years, the vaccine against meningococcus is not included in the vaccination plan. Under such circumstances, most of the Macao citizens should not be immunized against meningococcal infection. Thus, the Department of Health calls on all citizens to adopt the following preventive measures against meningococcal infection: -Keep enclosed areas ventilated, avoid working and leisure places being overcrowded;
-Wash hands often, maintain personal hygiene, cover mouth and nose when coughing and sneezing and, handle droplets with care;
-Maintain balanced diet, avoid smoking, exercise regularly, take good rest, so as to increase resistance against diseases;
-Visit doctors immediately in case of fever, or accompanied with headache and rash; infected children should stop attending schools or child-care centres; go to Emergency Departments of hospitals immediately in case of severe headache, stiff neck and changes in consciousness;
-When traveling to epidemic areas, avoid staying in overcrowded and unventilated places and, avoid contact with infected persons.