SOUTH AFRICA IS POISED TO BECOME WORLD EXPERT IN HAEMORRHAGIC FEVERS
The opportunity for South Africa to become world class exists because we have accumulated considerable expertise at the Joburg-based National Health Laboratory Service’s (NHLS) National Institute for Communicable Diseases (NICD), research universities (Stellenbosch and Pretoria in particular) that specialise in animal biology and health and teaching hospitals such as Cape Town’s Tygerberg as a result of having had to historically deal with the following viral haemorrhagic fevers:
1 LASSA FEVER:
Caused by a rodent-associated Arenavirus, Lassa is confined to Nigeria, Sierra Leone, Guinea and Liberia. It causes mild fever with a case fatality rate of between 1-2%. Severe versions can however drive hospitalised case fatality beyond 20%. Like Ebola, Lassa is communicated person to person by overt contact with infected tissues and bodily fluids. South Africa had a fatal case once in 2007 but no secondary infections.
2 LUJO FEVER:
It is a rodent-associated Arenavirus. Between September and October 2008 there was an outbreak of a new Arenavirus in Joburg resulting in five individuals being hospitalised, of whom four died. Lujo follows a similar clinical course to Lassa. Upon hospital admission there typically is initial improvement but it is not uncommon for rapid deterioration and death to fol-
3 CONGO FEVER:
A tick-borne Arbovirus, it is the most frequently observed haemorrhagic fever in South Africa. Farmers in the Northern Cape, Free State and North West are familiar with the bont-legged ticks that transmit it. Five to 20 cases are diagnosed a year. Incubation period is one to three days after tick bite. There is a 30 percent fatality rate after five to 14 days.
4 RIFT VALLEY
FEVER:
Mosquitoborne Arbovirus. It is a viral disease of livestock in Africa. The last major outbreak occurred in 2010 on farms in the Eastern Cape, Free State and Northern Cape. The University of Pretoria’s Onderstepoort makes a vaccine, a commercial product, for RVF.
5 MARBURG:
Caused by a bat-associated Filovirus, Marburg is confined to Africa and outbreaks have been recorded in Uganda, Kenya, DRC, Zimbabwe and Angola. Two young Australians developed Marburg disease in SA in 1975, and the treating nurse also acquired the infection. Marburg’s incubation period is typically seven to 10 days (range two to 21). There is a sudden onset of fever, severe headache, sore throat, chest or abdominal pain, myalgia, arthritis, malaise, fatigue, nausea and anorexia.
6 EBOLA:
A bat-associated Filovirus, Ebola was confined to Africa and, before the West African epidemic, outbreaks were recorded in Sudan, Democratic Republic of Congo, Uganda, Gabon, Congo Republic and Ivory Coast. Before December last year, West Africa was Ebola-free. Today reported infections are over 10 000 and fatality over 5 000. Ebola has a seven- to 10-day incubation period (range two to 21). The clinical course is almost identical to Marburg’s. Ebola’s case-fatality rate is extreme. BASED on these experiences, the NICD has specialised in the study of dangerous viral haemorrhagic fevers.
Its Centre for Emerging and Zoonotic Diseases, headed by Janusz Paweska, who also leads the national Health Department’s Ebola task team, has developed substantial capacity in the rapid detection of so-called high consequence viral and bacterial diseases.
The centre has made huge strides through the use of what is known as electron microscopy, particularly in the area of viral diagnostics. It also has the only Maximum Bio-Containment Suit Laboratory in Africa, allowing it to investigate deadly biohazard class four viruses and bacteria.
The NHLS’s mobile laboratory unit was deployed to Sierra Leone in August. That team had the task of providing support to those serving at the front line. Set up in Freetown, the unit, with a staff of four, became operational on August 25. By its fourth week of operation, it was performing diagnostic tests on more than 50 samples a day. It had tested 910 samples by September 21 and, according to the department, more than 2 000 samples by October 10.
The NICD has perfected rapid diagnosis and testing for Ebola.
Developing a vaccine that would prevent the virus from infecting the uninfected is an enterprise of US and UK laboratories enabled by public-private partnerships. While Ebola vaccine development began in 2003, serious work only really started after the West African outbreak.
The US National Institutes of Health announced that initial treatment testing of an investigational vaccine began this year. A Phase 1 trial will help investiga- tors at the institutes and the pharmaceutical company GlaxoSmithKline determine the safety and efficacy of a new vaccine.
The research facility is working with two other US-based candidate producers. Then there are another set of trials being developed by the Public Health Agency of Canada and NewLink Genetics Corp.
Post-infection therapies like ZMAPP, a product also of the North, is a cocktail based on three antibodies. Currently undergoing clinical trials, ZMAPP has been used to treat Ebola-infected American health workers, a Spanish priest who died and Liberian health workers.
The Bill & Melinda Gates Foundation have given a grant to its makers Mapp Biopharmaceutical, the Public Health Agency of Canada and Amgen to grow ZMAPP in tobacco plants in commercial quantities.
Finally, Nobel Laureates David Baltimore and James Watson have proposed that science harvest hundreds and thousands of Ebola antibodies from the blood of survivors, determine their genetic recipe, grow them in commercial quantities and combine them into a single treatment. Their proposal has been dubbed a “convalescent serum”.
Harvard University and the Massachusetts Institute of Technology’s Broad Institute decoded the genetic sequence of 12 copies of the virus in August. Baltimore and Watson’s proposal will test the interaction between the genetic actions of the human immune system and the virus.
Like so much else, innovations in the world of medicine and health are globally distributed private-public partnerships, using the best brains across sectors, space and time in a collaborative effort involving Africa (South Africa’s NICD in particular), the US, Canada and the UK.