Sunday, March 24, 2002		Fitness

Ways to combat plague
B.K. Sharma

ONE cannot call it an epidemic. The recent plague outbreak was local and was mercifully short lived and hopefully over now. The credit for the quick identification and control of the disease undoubtedly goes to the PGI where the departments of Internal Medicine, Community Medicine and Microbiology acted quickly and decisively.

Plague is a notifiable disease not only at the local and national levels but also at the level of the World Health Organisation. Between 1980 to 1996 nearly 24000 cases of human plague and over 2100 deaths were reported by various countries. This includes 20 plague cases and 27 deaths in the USA. Plague, therefore, has not been eliminated from the world neither it is likely to be eliminated because reservoir of plague bacteria persist in wild rodents, including squirrels, rats and other burrowing rodents. Given suitable environmental conditions, these bacteria invade the human habitat. However, there has been a change in the epidemiological pattern and outbreaks are now mostly limited to rural areas to begin with and reach the urban centers later. In Gujarat in 1994, at seemed as if plague had suddenly appeared in Surat but for months preceding the outbreak bubonic plague cases were occurring in the earthquake-hit areas of Maharashtra.

Plague is caused by a bacteria, yersinia pestis, named after Alexander Yersin from Hongkok, who first cultured this bacteria. It survives indefinitely among the wild rodents and the fleas of these rodents which are themselves resistant to the disease. Only when due to a disturbance in the environment, they are transmitted to susceptible rodents, other animals and finally humans, the outbreak starts. In fact, one of the signs that an outbreak is imminent is when the susceptible rodents start dying and the fleas look for other hosts. The disease spreads to humans when the fleas bite people exposed to flea bites such as trackers, campers, wood cutters and hunters (as was the case in the present outbreak) and in certain countries, visitors to public parks in natural surroundings. Plague can also be transmitted by handling infected wild animals such as rodents, hares, wild cats and dogs. In fact, this route is much more dangerous and more often results in the penumonic or septicemic plague. Although the exact details are not known but the index case in Rohru this time was not a case of bubonic plague due to flea bite as the patient exhibited respiratory symptoms and very quickly infected his family. Occasionally, the infection can spread by eating infected animals, which occurs more often in wild animals than in humans.

The clinical varieties of plague have been well publicised in the Press and include the bubonic plague in which lymph nodes enlarge (bubos) in the groin or the armpits or the neck depending upon the location of flea bite. This may remain limited to these areas or reach the lungs through the blood and become pneumonic plague or spread to multiple organs through blood known as septicemic plague. As mentioned above, the pneumonic and septicemic plagues can occur independently of bubonic plague and are much more severe and deadly as compared to the bubonic plague. The incubation period of pneumonic and septicemic types of plague is much shorter (2-4 days) as compared to bubonic which is 4-6 days. Plague is a lethal disease and unless treated with antibiotics progresses rapidly, resulting in shock, multiple organs failure and death. The patient suffers from high fever, rapid pulse rate, low blood pressure, extreme prostration and finally death occurs. The diagnosis can be made relatively easiers, provided the disease is suspected. The bacteria can be isolated from the blood, sputum or the lymph node swelling. It can be isolated from the dying and dead rodents, if available. In the Surat epidemic there was a problem in the diagnosis. This time round the diagnosis was established quickly.

A public health problem

The diagnosis and treatment of plague has become simple and very effective antibiotics are now available both for treating the people at risk as well as the patients. But taking adequate preventive measures leaves much to be desired. Whenever such diseases spread, the normal reaction is to rush to the PGI or AIIMS and in some cases the NICD, Delhi. Whereas there is nothing wrong in involving these institutes and they can provide all help and guidelines, but communicable diseases, including plague, are local public health problems. Unless the state governments strengthen the epidemiology and preventive health wings, these outbreaks will keep occurring. Since the area of Rohru was known to have some outbreaks earlier, was this information internalised by the local health authorities?

Did they monitor the local disease pattern and checking the available rodents on a regular basis. Where the health officers at various levels advised and reminded of these possibilities? This, in fact, applies to the entire country, including the urban areas. If you see the slum areas even in towns as new and as "beautiful" as Chandigarh, you can see the epidemics waiting to happen. Every summer there are reports in the Press about the outbreaks of cholera, typhoid, gastroenteritis, malaria and so on. A feverish activity starts and ends as quickly. The administration, the Press and the public very conveniently forget and wait for the next one. We think that local rodents are not infected. But if the infection does reach the rodents, the vast slum areas and garbage spread all over would assist the spread of the disease. There are financial, administrative, social and political difficulties in grappling with these but these problems are not insurmountable. Public health departments and medical officers at the states, districts and primary health centers need to be made aware of all the local epidemiologically potentials and take the preventive action. At least nobody should be taken by surprise when the problem arises. This requires financial allocation, involvement of NGOs and community education. All such measures must cover the rich as well as the poor. We may feel safe in our air-conditioned houses and cars, but there are no barriers to communicable diseases. The raging epidemic of multi-drug resistant tuberculosis is an example of this.

The ministry of health was very actively involved during this outbreak of plague and the health minister himself travelled to Chandigarh to have a look at these patients. But we do hope that the central ministry and the state government go beyond this and look into the breeding grounds of these epidemics of communicable diseases viz plague, malaria, tuberculosis, typhoid, hepatitis, cysticercosis and numerous other infections. guidelines should be provided to handle such outbreaks at all levels, to contain as well as treat the epidemics and not react in panic, letting the people spread around and infect others.