Introduction
A disease is described as a condition/disorder that interferes with the normal functioning of the body. Communicable diseases are those diseases that are easily spread from person to person by way of contact, food, water, contaminated objects or even through the air. They are also referred to as infectious diseases. This relatively easy mode of transmission makes the control and containment of these diseases fairly hard. (Anderson & May 1991) Some communicable have a high morbidity and sometimes a high mortality rate. That is to say they are likely to infect lots of people in a very short time and may also result in their deaths also after a very short time.
Measles is a communicable disease caused by a virus, paramyxovirus from the genus Morbillivirus. The disease is spread through respiration; for example, contact with fluid from an infected person’s mouth or nasal organs. It can also be spread directly in the environment through aerosol transmission. Its salient characteristics on the infected victims include total body skin rash and flu-like symptoms that include running nose, fever and cough. Since the causative agent of measles is a virus, its symptoms usually disappear on their own even without proper medication once the virus has completed its life cycle. Perhaps this is the reason why the disease is persistent in many developing countries where medication is usually provided piecemeal and is terminated when the symptoms seem to disappear.
Measles is very rare in developed countries such as USA and Australia. In the USA, the occurrence of measles is almost nil due to widespread immunizations. Hence, the number of measles cases has declined rapidly in the last 50 years. For example, there were thousands of cases of patients suffering from the disease in the 1950s, but in 2002, only 44 cases were reported. The majority of patients affected by the disease are children (Cronan 2005).
A stark contrast exists in the developing countries where immunization programs are in many cases moribund. The disease poses serious challenges in countries in regions such as sub-Saharan Africa and South East Asia where most of the developing countries lie. Among the challenges to eradication of measles is the desire to achieve and certify global eradication or to reduce measles in countries where it is commonplace. In addition, improving coverage of surveillance and strengthening management are key issues that need to be reviewed in order to eradicate the scourge. Since the World Health Organization, WHO, set goal to eradicate measles, the measures that it put in place to meet this objective were campaign strategies such as “Catch-up, Keep-up, Follow-up.” Active surveillance is an important component of implementing these measures. The strategies used by WHO and its affiliate bodies to eradicate measles are steadily evolving and therefore require a high level of flexibility in the equipment, staff and measures used. Quality surveillance and implementation of the key findings is therefore the key to eradicating measles (Anderson & May 1991).
Surveillance System
Measles has some key aspects that need to be out into consideration when designing a system of surveillance to control it. To begin with, human beings are the only hosts for the disease. This means that the disease is not zoonotic and therefore not likely to be transmitted by animals. In addition, despite the effort to eradicate it, measles is still a threat to humanity, being one of the top ten most important causes of death and one of the most common vaccine-preventable diseases in children. Several factors make measles harder to tackle than other diseases such as smallpox. The factors include its higher rate of infection, the difficulty in administering a vaccine for it and in carrying out surveillance and detecting infected individuals (Griffin & Moss 2006).
The main importance of disease surveillance is to identify the prevalence of an infectious disease such as measles and to draw a plan to prevent it from becoming a threat to the public. Surveillance results should contain information on morbidity and mortality among people in a community or state. They should also show possible impacts of immunization strategies and the disease trends in the society. The following are some of the useful surveillance systems. Their applicability varies from place to place due to their attributes such as financial implications and availability of proper surveillance equipment (Griffin & Moss 2006).
Prevention
The most important step in surveillance is to find methods that would prevent the occurrence of measles. For effective surveillance towards prevention, anti-measles campaigns should start at the community level. At this level, the communities should be enlightened on the threat of measles, its implication and the need to eradicate the disease. In most of the countries where measles is still a threat, the affected populations are usually concentrated in highly populated areas such as outskirts of town centers or busy rural areas (Oxford 1985). These areas need public awareness in order to facilitate efficient collection of information. The information collected, such as samples, should be analyzed at district or state hospitals or other health facilities in order to obtain conclusive findings on the possible occurrence of measles and the measures that should be enforced to control the situation. The national authorities should act on the findings in order to educate the communities on the need for eradicating the scourge. In the process, individuals found to be carriers of the disease can be isolated and subjected to medication before the disease shows full impact. Vaccination programs for children 6 to 8 months after birth could serve as a sufficient preventive measure (Anderson & May 1991).
Treatment
Where the disease has already taken course the best solution is to provide appropriate medication and ensure that the full dose is taken to avoid recurrence of the disease. During surveillance, cases of measles identified should be treated in isolation since the disease could spread to others within the same household, as they may have not been vaccinated. Most vaccines achieve only 90 per cent immunity and therefore leave a chance for infection (Griffin & Moss 2006).
Routine monitoring
Apart from prevention and treatment, surveillance should also entail routine monitoring in order to successfully seal the possibilities of outbreaks. This involves regular collection of samples and figures concerning the measles cases. Perhaps the reason why the occurrence of measles is rare in Australia is its health department’s routine monitoring and survey. The Department of Communicable Diseases in Victoria within the Department of Health Services (DHS) has a core function of managing surveillance programs through routine monitoring. Routine monitoring of measles is resource intensive, both in terms of time consumption and staff. Therefore, to carry out the process effectively, public health resources need to be more effectively directed towards this strategy.
Using the Australian case, physicians and laboratories are required to notify the DHS upon any diagnosis of presumptive measles. Other specimens too are collected for analysis. For example, blood serum is collected from people for analysis in case they are carriers of measles. The serum is specifically tested for measles specific immunoglobin. Other specimens collected are nose and throat swabs, which are tested for measles though ribonucleic acid (RNA) by a polymerase chain reaction method (WHO 2006).
Electronic disease surveillance system
This system of surveillance is advanced and more appropriate for the regions that are prone to measles outbreaks. It is a method that promotes the use of data and information standards to integrate the surveillance systems in all regions or states in a country. The USA has been active in using this type of surveillance to monitor disease conditions, particularly measles, through its health body- Centers for Disease Control (CDC). The system detects outbreaks rapidly and monitors the general health of the nation. It also collects and monitors disease trends in order to facilitate preparedness for outbreaks or control (CDC 2007).
Sensitivity and Specificity of Measles
The measles pathogen has characteristics that make it easy to eliminate. As earlier mentioned, the virus has specificity only to human beings. Therefore, once it is eliminated from the human population, it has no chance to survive elsewhere. In addition, its transmission occurs only when illness is apparent. Isolation of patients is therefore the key to curbing its spread. Another advantage of this is that the disease can easily be spotted and hence eliminated. Furthermore, its transmission in remote areas usually stops spontaneously (maybe be due to sparse population) and a vaccine once injected against it, provides protection for a long period of time.
There are variations in the specificity of measles to antibodies. During monitoring, the variations should be considered so as to avail proper medication. For example, measles specific IgM antibodies appear at the time of the beginning of rash and may persist for 28 days. Furthermore, measles specific IgG antibodies appear around the same time as IgM antibodies. The specificity of the measles virus to antibody material is vital in administering medication or vaccination (Nelson & Williams 2006).
Possibly, measles is still widespread in some Asian and African countries because of the deficiency of some vital food components. Vitamin A, to which the measles virus and vaccine are sensitive, is deficient in these countries. Its availability is in the range of 0.3-1 percent. Yet it is recommended that the vitamin should be available for effective functioning of the measles vaccine. WHO therefore advises health experts to provide Vitamin A supplements when the measles vaccine is availed to a patient (WHO 1999).
Some vaccination programs have been blamed for their adverse effects on children when they are applied. The latest edition of the book produced by the National Heath and Medical Research Council of Australia, called ’Australian immunization hand book,‘ gives succinct guidelines about the side effects that arise with vaccination for measles. In Australia, many children have been denied vaccination due to reactions at the site of injection, fever or irritability after vaccination or having a history of egg allergy. Sensitivity of children to the measles vaccine should therefore be given priority when implementing the measles surveillance program. For example, it is evident that children who are allergic to eggs are sensitive to the measles vaccine and an alternative vaccine should therefore be sought which would suit them (Anderson & May 1991).
Pertussis
A case definition of pertussis is regarded as situation where a person develops a cough that prolongs for more than two weeks. This cough is characterized by the following conditions:
- Inspiratory whooping.
- Vomiting after coughing.
- Paroxysm of coughing.
Surveillances of pertussis entail routine surveillances for cases where DTPS is less than 90%. This routine surveillance involves reporting all the aggregate clinical data each month. This is done both at the peripheral and intermediate levels. The information reported includes the venerable age which is between one to four years. The immunization status should also be incorporated. Where the DTPS is greater than 90%
The routine surveillance should cover the venerable age, immunization and mortality rate. In case of an outbreak of Peturssis the WHO should be informed and appropriate information given such information comprise of date of outbreak, immunization and the mortality. Pertussis surveillances in some situation also encompass sentinel surveillances where microbiology studies are conducted.
Contrast of measles with pertussis
Pertussis has not been given equal treatment of surveillance like measles despite its major causes of thousands of deaths yearly. This is attributed the difficulties associated with its monitoring process. In some cases pertussis surveillances goes as far as conducting some studies to establish the pertussis epidemiology in a given area. This is in contrast with measles that is easier to monitor as the measles pathogen has characteristics that makes it easier to monitor as it is only transmissible to human beings only (WHO 1999).
Conclusion
Measles is still prevalent in sub-Saharan Africa and South East Asia countries. Surveillance for the disease requires concerted effort in prevention, treatment, education and routine monitoring. Vaccination programs in countries that experience food shortages are supposed to go hand in hand with provision of vitamin A supplements, to which the measles virus is sensitive. Sensitivity of children to the measles vaccine should be given priority. Some vaccines cause rashes at the sites of injection; others cause stress and irritability in the children involved. Children who are allergic to eggs should be considered for special vaccines, as there may be contraindications due to ordinary vaccines.
Pertussis, as opposed to measles, requires more frequent monitoring since it occurs more frequently than measles. Pertussis requires specialized surveillance such as sentinel surveillance in hospitals to determine the trend of the disease.
References
Anderson, RM & May RM 1991, Infectious diseases of humans: dynamics and control Oxford University Press, Oxford CDC 2007,’National electronic disease surveillance system,’ Web.
Cronan, K 2005, Infections: measles, 2008. Web.
Griffin, DE & Moss WJ 2006, ‘Can we eradicate measles?’ Microbe, Vol.1, No.9.
Needham, C & Canning R 2003, Global disease eradication: the race for the last Child, ASM Press, Victoria.
Nelson, K E & Williams CM 2006, Infectious disease epidemiology: theory and practice, Jones & Bartlett Publishers, New York.
Oxford, JS 1985, Conquest of viral diseases: a topical review of drugs and vaccines, Elsevier, New York.
WHO 2006, ‘Measles surveillance in Victoria’, Bulletin of the World Health Organization, 2008. Web.
WHO 2000,’Pertussis surveillance,’ A global meeting, Geneva, 2008. Web.
WHO 1999, ‘Strategies for control of measles in SEAR countries,’ Report of an inter-agency consultation, New Delhi.