•Scientific strategies from recent outbreaks to help prepare for Pathogen X
There are concerns over rising cases of emerging and re-emerging viral/infectious diseases such as Langya Henipavirus in China, West Nile Virus in America, Marburg virus in Ghana, Ebola virus in Democratic Republic of Congo, poliovirus in the US, Britain, Jerusalem (where they have been eradicated in the past), more deadly strains of monkeypox and COVID-19 to mention but a few.
Emerging and re-emerging infectious diseases threaten all countries. Schistosomiasis is re-emerging in Egypt, largely due to the building of the Aswan Dam; legionellosis was identified after an outbreak of pneumonia among individuals attending a conference in Philadelphia.
The situation has raised some questions: Why are so many viruses coming up so suddenly? Should Nigerians be concerned? What are the implications, especially on efforts to eliminate malaria? What must the government and individuals do to keep safe and preserve humanity? Studies show that these infectious diseases are leaving humans weaker- erectile dysfunction, enlarged hearts, and lungs; is the end of the human race getting closer as predicted by some schools of thought?
The World Health Organisation (WHO) warned in its 2007 report that infectious diseases are emerging at a rate that has not been seen before. Since the 1970s, about 40 infectious diseases have been discovered, including Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), Ebola, chikungunya, avian flu, swine flu, Zika and most recently COVID-19, caused by a new coronavirus, SARS Coronavirus type 2 (SARS-CoV-2).
With people travelling much more frequently and far greater distances than in the past, living in more densely populated areas, and coming into closer contact with wild animals, the potential for emerging infectious diseases to spread rapidly and cause global epidemics is a major concern.
Additionally, there is the potential for diseases to emerge as a result of deliberate introduction into human, animal, or plant populations for terrorist purposes, as discussed in the section on Bioterrorism Agents. These diseases include anthrax, smallpox, and tularemia.
There are many factors involved in the emergence of new infectious diseases or the re-emergence of “old” infectious diseases. Some result from natural processes such, as the evolutions of pathogens over time, but many are a result of human behaviour and practices. Consider how the interaction between the human population and our environment has changed, especially in the last century. Factors that have contributed to these changes are population growth, migration from rural areas to cities, international air travel, poverty, wars, and destructive ecological changes due to economic development and land use.
For an emerging disease to become established, at least two events have to occur – the infectious agent has to be introduced into a vulnerable population and the agent has to have the ability to spread readily from person to person and cause disease. The infection also has to be able to sustain itself within the population, that is more and more people continue to become infected.
Many emerging diseases arise when infectious agents in animals are passed to humans (referred to as zoonoses). As the human population expands in number and into new geographical regions, the possibility that humans will come into close contact with animal species that are potential hosts of an infectious agent increases. When that factor is combined with increases in human density and mobility, it is easy to see that this combination poses a serious threat to human health.
Climate change is increasingly becoming a factor in the emergence of infectious diseases. As Earth’s climate warms and habitats are altered, diseases can spread into new geographic areas. For example, warming temperatures allow mosquitoes – and the diseases they transmit – to expand their range into regions where they previously have not been found.
On why so many viruses coming up so suddenly, a Professor of Medical Microbiology and Immunology, a Harvard Fellow in Microbiology and Molecular Genetics, and a Fellow of the New York Academy of the Sciences, Prof. Boaz Adegboro, told The Guardian: “Because of global prosperity in the past two decades, many people keep exotic animals as pets. They also eat exotic animals like bats, shrew, monkeys, pangolins, etc. There is also an increase in undercover trade in pangolin skins and monkeys. In addition, with an increase in aquaculture there is an increase in the appetite for aquatic animals like catfish, crayfish, shrimps, crabs etc.
“These scenarios have led to the recent outbreaks of SARS-CoV-2 pandemic, and now Langya virus, which both originated from China. Langya virus is an animal virus, which belongs to a group of Ribo Nucleic Acid (RNA)/genetic material viruses called Henipaviruses. Langya virus antibodies have been discovered in some goats and dogs as well as viral RNA in a large number of shrews. It is believed that humans can be infected directly from these animals or through another animal that caught Langya virus from a shrew.”
Adegboro, also of Department of Medical Microbiology and Immunology,
Nile University of Nigeria, Abuja, said epidemics are lives of diseases. He said epidemics keep the microbial kingdom alive; and prevent the microbial world from going into extinction. “When a disease outbreak occurs, we take measures to control it. The community also develops herd immunity against the offending organism. The organism is now forgotten. However, over several years, mutation occurs in the genes of the organisms, and the community does not have immunity against the new mutants,” he said.
The microbiologists said this appears to be the situation about the recent outbreaks of Monkeypox and the haemorrhagic fevers like Marburg, Ebola viruses, Dengue fever, Hantaviruses, Rift Valley fever (RVF), Lassa fever, Lujo, Yellow Fever (YF), Kyasanur Forest disease virus, Dengue and Crimean-Congo haemorrhagic fever viruses (C-CHF).
On whether Nigerians should be concerned, Adegboro said the world is now a global market, with fast travel all over the world for trade, tourism and study. “This scenario encourages the quick dissemination of infectious diseases to a global epidemic. Newly emerging or re-emerging disease outbreaks can be very deadly because the population has no herd immunity. Many lives could be lost before the community reaches herd immunity. Nigeria, therefore, has to be very concerned about the new outbreaks,” he said.
On the implications, especially on efforts to eradicate malaria, Adegboro said Plasmodium species like other microorganisms, also possess the ability to mutate. “Active research and development of drugs and vaccines against this parasite causing malaria are needed. And efforts to detect new mutants and to quickly develop new drugs and vaccines against them have to be sustained,” he said.
On what the government and individuals must do to keep safe and preserve humanity, Adegboro said: “Government must fund research efforts to develop new drugs and vaccines to treat and prevent any emerging or re-emerging infectious diseases. These are very expensive ventures, and government must make adequate provisions in the budget from year to year. Where we are not able to produce, we must be quick to buy them from the developed countries.”
The microbiologist said researchers must develop proposals for new drugs and vaccines, as well as propose other community-based preventive measures. He said the population must embrace the control measures provided by the government and the research community.
On whether these infectious diseases leave humans weaker- erectile dysfunction enlarged hearts and lungs and do they signal the end of the human race, Adegboro said: “Any severely ill person has no thought of having sex until full recovery from the illness! The developed countries spend huge sums on research into drug and vaccine development against infectious diseases. They are on the frontiers of research and have shown the ability to control infectious diseases, especially in the past two centuries. Nigeria also needs to work hard to get to the frontier of knowledge in medical and other sciences.
“The human body also has a fantastic ability to adapt to the intrusion of infectious agents by mounting both innate and adaptive cellular and humoral immune responses. With little help from vaccines, drugs, and community preventive measures, the community is, therefore, able to mount herd immunity against any emerging or re-emerging infectious diseases. The use of vaccines and recommended drugs limit morbidity and mortality during pandemics. So we are very optimistic that the world will not be destroyed by infectious diseases.”
National Chairman, Clinical Pharmacists Association of Nigeria (CPAN), Dr. Joseph Madu, told The Guardian that the emergence or re-emergence of infectious agents (for example viruses, bacteria, protozoa, etc.) follow a similar pattern.
Madu, however, said infections involving viruses are peculiar probably due to relative ineffectiveness of the available antiviral agents to promptly eradicate the viral pathogens. He said most of the viral infections are usually self-limiting and/or are usually infected by the use of vaccines.
The clinical pharmacists said Nigerians should be concerned. “Yes, as a responsible nation, Nigeria ought to be concerned. Nigeria should not only be concerned but deeply worried because of the vulnerability of the nation to most outbreaks,” he said.
Madu said the recent increase in the emergence of viral diseases globally is not unconnected to the already known factors associated with the development and/or transmission (from person to person). He said these factors among others include: population growth, increase in both local and international connectivity (globalisation), poverty and malnutrition, migration for economic reasons, deforestation, and so on. “Nigeria should be concerned because the country is not insulated from the global impact of any public health matters,” he said.
Madu said the implication for Nigeria is that the country has to strengthen its surveillance and mitigation activities by strengthening institutions and creating public awareness.
He said the recent approval of community pharmacies as vaccination centres for COVID-19 in Nigeria is a laudable step by the government in the right direction. “That will reduce vaccine hesitancy and increase public awareness.
It is also recommended that the government extended the approval to other vaccine-preventable diseases aside from COVID-19,” Madu said.
The clinical pharmacist said: “What we see in recent times about reemergence and increasing incidences of new strains could be more associated with sophistication and advances in health or medical sciences whereby diseases (probably in existence for a long time ago) are being discovered.”
He said increasing human interaction with animals; the use of immune suppressants and other changing human behavior could be responsible linkages. “We have seen how the world has vehemently rejected physical distancing and the use of facemasks, sometimes sparking off protests all over the world,” Madu said.
The clinical pharmacist said vaccination (immunization) is a part of the most effective and proven ways to eradicate these viruses. He said the government should encourage vaccination for those infections that already have approved safe vaccines.
Madu said the case of polio in America was in an unvaccinated adult. “In many countries, for instance in some states in America, vaccination for kids of school age is a requirement for admission to schools (though a few states still leave it to parents as well as give exemption for religious or medical reasons).
Mass campaigns via religious bodies, community development centres, community pharmacies, etc. should be done to encourage people and debunk myths surrounding vaccines,” he said.
Madu said the situation does not mean the end of the human race is not getting closer, rather advances in science and technology have led to increased discoveries and reportage. He said Nigeria only needed to borrow a leaf from countries with better health indices.
“For instance, the government can take better care of her health personnel and also provide better training of health care professionals and work infrastructure. The use of community pharmacies as primary healthcare facilities to cover all vaccine-preventable diseases is a useful project for the government to embark upon because of their accessibility, and use as the first point of call by most members of the public,” Madu said.
Meanwhile, the WHO Research and Development (R&D) Blueprint is organising a consultation to apply scientific lessons learned during the Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2) global pandemic and other recent outbreaks to address the research needs for unknown agents capable of future pandemics – Pathogen X.
Main discussion points include the following, with reference to research and development leading to safe and effective vaccines and therapeutics: Review of previous pandemics with an emphasis on COVID-19. What relevant scientific information did the world have before the pandemic? What scientific strategies were successful? What scientific strategies could be improved? What will the next pandemic look like? What research will facilitate the identification of the next pandemic? What needs to be done to prepare for possible pathogens, including unexpected or re-emerging pathogens (for example, Antimicrobial Resistance, AMR)? What can be done in advance of the next pandemic? What are the scientific and research gaps? And how can they be met? How can scientific and research findings facilitate vaccine and therapeutic development? How can other approaches, such as Target Product Profiles (TPPs) and regulatory convergence, facilitate response to a future pandemic?
Health authorities in the Democratic Republic of the Congo had on August 23, declared a resurgence of Ebola following confirmation of one case in the country’s eastern province of North Kivu.
A 46-year-old woman died on 15 August 2022 in Beni, a town located in North Kivu. She received care at the Beni Referral Hospital, initially for other ailments, but subsequently, exhibited symptoms consistent with Ebola virus disease.
Both the Beni and Goma branches of the country’s National Institute of Biomedical Research (INRB) confirmed Ebola virus in samples taken from the patient. Analyses showed that the case was genetically linked to the 2018-2020 Ebola outbreak in North Kivu and Ituri Provinces—the country’s longest and largest.
Polio reemergence in the US, UK, and Israel years after eradication
For years, global health officials have used billions of drops of an oral vaccine in a remarkably effective campaign aimed at wiping out polio in its last remaining strongholds — typically, poor, politically unstable corners of the world.
Now, in a surprising twist in the decades-long effort to eradicate the virus, authorities in Jerusalem, New York, and London have discovered evidence that polio is spreading there.
There is no cure, but since a vaccine was found in the 1950s, polio is entirely preventable. Globally, the wild form of the disease has almost disappeared.
Afghanistan and Pakistan are now the only countries where the highly infectious disease, spread mainly through contact with fecal matter, remains endemic. But this year, imported cases were also found in Malawi and Mozambique, the first in those countries since the 1990s.
There are two main forms of poliovirus. Alongside the wild type, there are also rare cases of what is known as vaccine-derived polio.
It is this second form detected in wastewater in the British capital, London, and in New York in the United States, with one case of paralysis reported in New York State. A genetically similar virus has also been found in Jerusalem, Israel, and scientists are working to understand the link, the Global Polio Eradication Initiative (GPEI) said.
While vaccine-derived polio is almost unheard of in the above locations, it is a known—albeit rare—threat in other countries, causing outbreaks every year, including 415 cases in Nigeria in 2021.
It stems from the use of an oral polio vaccine containing a weakened live virus. After children are vaccinated, they shed the virus in their feces for a few weeks. In under-vaccinated communities, this can then spread and mutate back to a harmful version of the virus.
While countries including Britain and the United States no longer use this live vaccine, others do—particularly to stop outbreaks—which allows for global spread, particularly as people began to travel again after COVID-19, experts said.
But experts agree that the major driver behind both vaccine-derived and wild polio outbreaks remains under-vaccinated populations, said Derek Ehrhardt, global polio lead at the United States Centers for Disease Control and Prevention (CDC).
Vaccine hesitancy was a growing problem before the pandemic; then COVID-19 caused the worst disruption to routine immunisation in a generation, according to the United Nations.
In 2020, there were 1,081 vaccine-derived polio cases, around three times as many as the previous year. In 2022 so far, there have been 177 cases, after major efforts to get polio vaccination campaigns back on track.
But the wastewater findings are still a wake-up call for parents with one key message, according to scientists around the world, including David Heymann, an epidemiologist at the London School of Hygiene and Tropical Medicine: Protect children by getting them vaccinated.
Langya: New virus infects 35 people in eastern China
Scientists are tracking a new, animal-derived virus in eastern China that has infected at least several dozen people.
The novel Langya henipavirus (LayV) was found in 35 patients in the Shandong and Henan provinces. Many had symptoms such as fever, fatigue, and a cough.
They are thought to have contracted the virus from animals. There is no evidence so far that LayV can transmit among humans. Researchers detected the virus predominantly in shrews.
The discovery was highlighted in a letter written by researchers from China, Singapore, and Australia and published in the New England Journal of Medicine this month.