By IPS Correspondents
GENEVA, Feb 23 1997 (IPS)

Though the situation has stabilised in Namwala, Zambia, where bubonic plague has killed up to 30 people in recent weeks, there is much to be learnt from a close study of the circumstances of the original outbreak.

No more deaths are being recorded, according to Zambian ministry of health spokesman Dr Ben Phiri. In a report referred to the World Health Organisation (WHO) he attributes the initial high death rate to the fact that the wrong medication was given to patients in the early stages of the outbreak.

When the first reports of an unusual disease outbreak were received on Jan. 24, health authorities established treatment centres in the outbreak focus in Kantengwa and satellite centres in Makobo, Chilala and Kabulamwanda.

Drugs, medical supplies and protective material were dispatched to the affected area, patient contacts followed up and treated, infected households are disinfected and rodents and fleas destroyed.

Bubonic plague is transmitted by the rat flea. It is the mildest of three clinical forms of the disease, the other two being pneumonic and septicemic plague.

In the 14th century, plague, then known as the Black Death, killed some 25 million people — a quarter of the population of Europe. The Great Plague of London in 1664-65 resulted in more than 70,000 deaths in a population estimated at 460,000.

And in 1894 an outbreak in Canton and Hong Kong killed 100,000 spreading over the next 20 years from the southern Chinese ports throughout the world and resulting in more than 10 million deaths.

Usually, plague is a disease of rodents, but when an outbreak reduces the rodent population in the vicinity of human habitation fleas from the dead animals are unable to find another rodent host and begin to infest man. In Zambia infected dead rats have been found in bore holes and in water drawn from wells.

Flooding had forced them from their normal habitats to human settlements.

The illness in man varies from mere indisposition to violent death. Bubonic plague starts with shivering, then vomiting headache, giddiness, intolerance to light; pain in the back and limbs followed by sleepiness, apathy, or delirium.

The temperature rises rapidly but then falls two or three degrees on the second or third day, with marked prostration. Constipation is usual but diarrhoea occurs in severe cases. The disease gets its name from the black swellings that appear in the groin and armpits.

Bubonic plague, unlike the other two forms, is not directly infectious from man to man and is transmitted only by fleas.

The clinical diagnosis was established by the South West Regional Office and confirmed by a team of experts from the University Teaching Hospital in Lusaka. The strain of plague — Yersinia pestis — which has been isolated has been shown to be sensitive to tetracycline and streptomycin, but is unaffected by penicillin.

According to the World Health Organisation, a total of 267 cases have been reported in Namwala District in the Southern Province and 25 patients are still under treatment. All the deaths occurred before Jan. 26

At first, admits Phiri, some local health staff in the area had thought the disease was a sexually transmitted one and applied inappropriate drugs.

“The situation however changed when a proper diagnosis of the disease was carried out by the laboratory staff from Lusaka, and we have not recorded any deaths since we started applying the correct drug,” he says.

Namwala entry and exit points now have medical personnel manning them to prevent spread of the disease. Some centres are having problems, however. The health centre at Maala which was treating 60 cases, ran out of drugs and had to appeal to the Namwala authorities to send a new supply.

The final accounting of cases and deaths is still going on, though no more deaths have been reported from the first site of the outbreak, Makobo and Kantengwa.

In reports to the WHO, Alex Mubita, a clinical officer at Kantengwa, says patients in isolation wards in Kantengwa and Makobo and have been responding to treatment. In total, 25 new patients were admitted to the two centres but most have now been discharged.

According to Dr Yevgeny Tikhomirov of the WHO’s Division of Emerging Viral and Bacterial Disease Surveillance and Control (EMC) in Geneva, the situation is now under control and all the necessary drugs and insecticides have been made available.

Plague is endemic in 15 countries in southern Africa where natural ‘reservoirs’ of the disease still exist, including neighbouring Angola, Malawi, Mozambique, Tanzania and Zimbabwe, but also in Madagascar, Namibia and South Africa. Before the present outbreak, the last case in Zambia was in 1987.

However there were outbreaks in Zimbabwe in 1982, 1985 and 1994 and Tanzania reports cases each year.

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