Ebola, Nipah and animals

EBOLA or Ebola virus disease and Nipah virus infection are named after the African and Asian areas where these life-threating diseases were first identified. Ebola was first located in 1976 in two outbreaks in villages alongside the Ebola River in then Zaire (now the Democratic Republic of Congo). Twenty-two years later, Nipah virus was found in Kampung Sungai Nipah, Negeri Sembilan.

Recently in The Borneo Post, there was a report on a suspected Ebola carrier returning from work in the Congo to Malaysia. Fortunately, the person concerned had acquired another virus with symptoms not dissimilar to Ebola. With a recent outbreak of Nipah virus in Kerala, southern India, a soldier based there returned on leave to Kolkata where he sadly died. Both diseases have taken their toll as outbreaks have suddenly occurred in other countries in West Africa and Southern Asia.

These two diseases together with the Zika virus are ranked in the world’s top 10 of infectious diseases for which accredited vaccines have yet to be fully deployed. The Zika outbreak occurred in Brazil shortly before the Rio Olympic Games of 2016. For both Ebola and Nipah, the death rates are estimated at between 50 to 90 per cent of those infected.

Ebola

This virus spreads through direct contact with bodily fluids of infected animals and humans. The 2013 to 2016 outbreak in West Africa saw volunteer medical staff and their patients dying from this disease. In many West African states, ape populations too suffered a decline. It was in 1976 that a Belgian medical researcher, Dr Pierre Pinot (now director of the London School of Tropical Medicine) first identified this disease in the blood of a nun, who had been working in Zaire. The extensive outbreak in West Africa of a few years ago originated in Guinea where, in December 2013, a two-year-old boy played with a fruit bat he had found lying on the ground – four days later he died. In that brief period his family had tried to nurse him back to health but they too were infected. We all remember the harrowing scenes brought to our TV sets by brave reporters and their camera crews during that pandemic. The press and the medical care teams are too often forgotten in such grim situations.

This particular Ebola pandemic caused 2,500 deaths in Guinea and nearly 12,000 deaths in other West African nations. A volunteer Scottish nurse contracted the disease and whilst at times near death’s door eventually recovered in a UK special intensive care unit. In parts of Central and Western Africa ‘bush meat’, from the hunting of wild animals, is a necessary source of protein. Chimpanzee and gorilla carcasses, too, were found to be infected with the Ebola virus. As Guinea is essentially a Muslim country then how were so many people infected? That was the conundrum that medical researchers faced. The answer lay with fruit bats, who may have nibbled a bit of fruit in a tropical rainforest riverine area for the primates, to include humans, eating the rest of the fruit. Whilst the fruit bats are the vectors of this disease, it appears that they carry antibodies and thus do not die from the disease.

In the Republic of the Congo, over 60 per cent of the land area is covered in virgin lowland rainforest. There, zoologists in one forest reserve have observed that Ebola has destroyed 94 per cent of the gorilla population. Based on sound scientific investigation, in the field in Central Africa, it is thought that another 5,000 gorillas and 80 per cent of the chimpanzee population have succumbed to this virus. Thanks to deforestation, agriculture and urban expansion, most of Africa’s great apes live in ‘forest island reserves’. When Ebola strikes it has the capability of wiping out all apes in such enclaves.

Solutions

While trial vaccines are being used on humans, the problem with trialling apes with a vaccine is faced with insurmountable difficulties. Trials with proto-vaccines usually first involve laboratory animals in countries where new laws to pacify animal rights lobbyists prevail. However, researchers at Cambridge University, UK, are working on a proto-vaccine for gorillas and chimpanzees but even if a suitable vaccine is produced the question then remains as how to administer such to apes living in remote and often inaccessible rainforest environments?

Nipah

The Nipah virus outbreak in 1998 in Negeri Sembilan bit deeply into that state’s economy when pigs were first seen to die in large numbers. Eventually 115 out of 265 infected people died. Fearing that the disease would spread like wildfire, over one million pigs were slaughtered putting 30,000 farmworkers into unemployment and tens of thousands more out of work. The pigs were the intermediaries in the transmission of this virus through the contamination of their swill by fruit bats.

In Malaysia, these fruit bats include the grey headed ‘flying fox’ (Pteropus poliocephalus), whilst in Bangladesh and India the species Pteropus giganteus are the vectors. Again, these fruit bats may transmit the disease without harm to themselves. Like the Ebola virus, humans’ respiratory and nerve systems are hard hit with eventually the brain, in the form of encephalitis, collapsing through swelling up.

Several years ago, I visited the Indian Ocean’s Seychelles Islands and later to an island in northern Madagascar and innocently marvelled at the size of the fruit bats as they rested upside down by day hanging from branches of trees. Little then did I know! I stress that fruit bats are not blood suckers as immortalised in ‘Dracula’ films.

Like chimpanzee populations in Central and Western Africa, so fruit bats once lived well away from humans, who have systematically encroached upon their natural habitats. Outbreaks of Nipah in Southern and Southeast Asia seem to occur between the months of December and May, possibly related to the bats’ seasonal migrations in search of harvested date palm sap. In Bangladesh the 2001 to 2007 outbreaks of Nipah were attributed to local people drinking raw date palm sap that the fruit bats had already sipped at night and thus contaminated. Mangoes, too, were infected as fruit bats’ equally favourite food.

Spread of disease and care

Whether we like it or not, embryo viruses exist within our bodies but they need a catalyst to turn on the disease. Since the original outburst in Kampung Sungai Nipah in 1998, where pigs were transient transporters of the disease, the new 2018 outbreak in Southern India is not at all related to swine according to the Indian Department of Health. The World Health Organization (WHO) is financing research together with drug companies into the development of a suitable human vaccine.

In the meantime, only intensive support care to all victims together with appropriate education and containment should be given in regional hospitals. Critical infection facilities should be provided for patients and suitably dressed protection for medical staff and also burial attendants duly accorded.

The battle, I am sure, will be eventually won through modern medical advancements in protecting us from such scourges as the Ebola and Nipah viruses. Some of us are old enough to remember how outbreaks of polio, cholera, and measles were eventually overcome. Where there is hope, there is life. Conservationists rightly maintain that fruit bats should not be victimised for they are natural rainforest pollinators in those ecosystems. Perhaps we all need to be more aware of what we eat and where our houses are located. I profess to readers that I am not a medical expert but simply a geographer, who plots outbreaks of these insidious diseases on maps.