Patterns of Disease Over Decades - Essay Example

Patterns of disease over decades This report examines the results of graphs which have been presented on the incidence of three different diseases over the decades. These diseases are (a) food poisoning (b) meningococcal meningitis and (c) meningococcal septicaemia. In the first instance, there is a discrepancy between the incidence of reported food poisoning cases and those which were otherwise ascertained, because while the numbers of the former were higher in earlier decades, they are equalized in recent decades. In the case of meningococcal septicaemia, there was a sudden sharp rise in the notifications of the disease in the year 1999, after which the figures have been falling steadily. The disease meningococcal meningitis reflects a similar trend, however as opposed to the septicaemia, the rise is not a sudden, sharp one reflected in one year only but reflects initial high figures which have been decreasing steadily over the years. Food poisoning: The graph on food poisoning shows that the number of people who have been afflicted with the disease appears to have increased over the years. The significant aspect of this graph however lies in the discrepancy between the number of cases that were formally notified and the number of cases which were otherwise ascertained. It may be noted that the number of food poisoning cases ascertained by other means was considerably lower initially, but shows a gradual increase until the two graph lines meet and run concurrently during the years 2000 to 2006 after which there is a trend towards an increase. The inference that may be drawn is that the incidence of food poisoning has shifted to a mass pattern rather than individually occurring cases. There has been a dramatic rise in the incidence of food poisoning because of the centralization and industrialization of food production (Isle, 2001:9). The incidence of food poisoning requiring hospitalization has jumped in recent years in Great Britain; while the overall number of cases of food borne diseases has fallen, such decreases arise mainly in the case of milder infections (GB, 1982:13). But the greatest incidence of food poisoning has been infection with salmonella, followed by Listeria monocytogenes. In explaining this rise, it may be noted that in the developed countries in particular, where food poisoning was not as widespread as in the developing countries, the food supply system has seen structural changes, such as extensive geographical food distribution systems. More processed food is available and is often prepared in large, centralized food processors, which in effect means that if one sample is contaminated, it is likely to affect the entire batch of the processed food, such as the 1985 incident where 185,000 people in Chicago contracted salmonellosis from contaminated, pasteurized milk that was distributed from one plant. This could explain why the incidence of food pollution incidents which have been otherwise ascertained has increased so dramatically, because several people all the world over consuming one batch of processed food which is contaminated would all tend to suffer from the same type of food poisoning; in particular salmonella poisoning (Isle, 2004). This could be caused by eating processed meat which is contaminated and packed into tins, and since the number of people eating tinned food has also increased, the food poisoning would occur in large numbers which might not all be reported. Where Listeria poisoning is concerned, the high incidence may be due to elderly people eating food that has passed its use-by date (Trickett, 2002). Meningococcal septicaemia: This disease is caused by bacteria and is the same as meningococcal meningitis, except that in the former the inflammation occurs in the membranes covering the brain and the spinal cord, while in the case of Meningococcal Septicaemia, the infection settles in the blood stream. The onset of the disease could be sudden and might result in complications such as gangrene, loss of limbs, brain damage and even death.(Trickett, 2002) The graph shows that the incidence of this disease was quite high in 1999, tapering off slightly in the next two subsequent years before registering a significant decline. In this context, Johnson (2001) has discussed the incidence of Meningococcal meningitis and septicaemia in Alberta, Canada and points out that an epidemic broke out in this region in 1999, due to the emergence of a novel serogroup C clone version of the bacteria that causes the disease. This necessitated the use of a mass immunization campaign to tackle the disease. Most of the incidence of this disease however, occurs in what is known as the meningitis belt of sub-Saharan Africa, where epidemics occur on a regular basis, generally occurring due to the serogroup A or serogroup C (Greenwood, 1999). It appears quite likely that since there were outbreaks of this disease in different parts of the world in 1999 and 2000, this is the factor responsible for the steep rise in numbers afflicted with this disease in the graph for these particular years. The decline shown in the graph is likely to be the result of use of vaccines against the disease. During the epidemic of 1999, the vaccines against the various strains of the disease would have been used and thereby brought about a reduction. The significant factor however, is that an infant immunization schedule has been initiated in many European countries as well as Canada, wherein infants are immunized with a single dose in the second year of life or a three dose course in the first year of life (Segal and Pollard, 2005). This would have contributed to prevention of onset of the disease. Meningococcal Meningitis: This is a disease that is caused by bacteria, and it causes swelling of the brain tissue. While several different kinds of bacteria could cause this disease, Neisseria meningitides is the one that has the potential to cause large outbreaks of the disease. There are twelve different serogroups of this bacteria which have been identified, of which five (A,B,C, W135 and X) can all cause epidemics. From the graph, it can be seen that the incidence of the disease closely parallels the meningococcal septicaemia, although the number of cases reported are not as high as in the case of septicaemia. The epidemics of this disease tend to occur on a more regular basis, rather than as a sudden, very high outburst; as a result the graph for this disease moves along in a more regular way as compared to the previous disease. Comparison of all three graphs: When all the three graphs are compared, it must be noted that the food poisoning graph differs from the other two in that incidence of food poisoning are much higher in the summer time, while they taper out in the winter. The reasons for this could be that food tends to spoil much faster in the summer and while processing, even one ingredient that is slightly spoilt could contaminate the entire sample. As opposed to this, the meningococcal graphs show a higher incidence in the winter, because the symptoms of these diseases are similar to the flu, which tends to be more common during the winter season. References: Great Britain, 1982 “Food poisoning: the investigation and control of food poisoning in England and Wales”, Stationary Office Books. Greenwood, B, 1999. “Manson lecture: Meningococcal meningitis in Africa”, Transactions of the Royal Society of Tropical medicine and Hygiene, 93(4): 341-53. Isle, Mark, 2001. “Everything you need to know about food poisoning”, Rosen Publishing Group Johnson, Marcia, 2001. “Meningitis – outbreak of meningococcal disease due to a novel serogroup C”, Vaccination Risk Awareness Network, Retrieved March 31, 2010 from: http://vran.org/vaccines/meningitis/men-alberta.htm “Meningococcal meningitis and septicaemia”, Retrieved March 31, 2010 from: http://www.buzzle.com/articles/meningococcal-meningitis-and-septicemia.html Segal, S and Pollard, A J, 2005. “Vaccines against bacterial meningitis”, British Medical Bulletin, 72(1): 65-81. Read More