Random Analytica

Random thoughts, charts, infographics & analysis. Not in that order

Tag: South Sudan

Random Analytica: Rift Valley Fever 2000 to January 21, 2018

Over the African summer there have been several small outbreaks of Rift Valley Fever in both South Sudan and Uganda. In Yirol East, Eastern Lakes District in South Sudan an outbreak has resulted in six confirmed cases with three deaths. In Uganda there have been five cases spread over a wide area in that countries cattle corridor resulting in five cases and four deaths.

Here are the key facts about Rift Valley Fever via the World Health Organisation (updated July 2017).

  • • Rift Valley fever (RVF) is a viral zoonosis that primarily affects animals but can also infect humans.
  • • The majority of human infections result from contact with the blood or organs of infected animals.
  • • Human infections have also resulted from the bites of infected mosquitoes.
  • • To date, no human-to-human transmission of RVF virus has been documented.
  • • The incubation period (the interval from infection to onset of symptoms) for RVF varies from 2 to 6 days.
  • • Outbreaks of RVF in animals can be prevented by a sustained programme of animal vaccination.

While most human cases are relatively mild, a small percentage of patients develop a much more severe form of the disease. This usually appears as 1 or more of 3 distinct syndromes: ocular (eye) disease (0.5–2% of patients), meningoencephalitis (less than 1% of patients) or haemorrhagic fever (less than 1% of patients).

According to WHO, since 2000 there have been 15 significant outbreaks of Rift Valley Fever which have impacted 13-countries and at least one case was exported to China.

Here is a look at the Rift Valley Fever outbreaks by country since 2000.

RiftValleyFever - 180121

NOTE: The 2007 Sudan outbreak occurred prior to the creation of South Sudan but the outbreak was limited to districts within modern day Sudan.

The latest South Sudan update via the World Health Organisation. Integrated Disease Surveillance and Response (IDSR). Epidemiological Update W2 2018 (Jan 8-Jan 14). Excerpt (from page 14):

Epidemics – Update (RVF, Yirol East)

A Rift Valley Fever (RVF) outbreak reported in Thonabutkok village, Yali Payam, Yirol East county with the initial case dating back to 7 December 2017.

As of 21 January 2018, a total of 15 suspect RVF human cases have been reported in Eastern Lakes State. Out of the 15 suspect human cases reported since 7 December 2017, three human cases have been confirmed, three died and were classified as probable cases with epidemiological linkage to the three confirmed cases, four were classified as none-cases following negative laboratory results for RVF, and laboratory testing is pending for the other five suspect cases.

At the moment – field investigation (human, animal, entomological) are ongoing; supportive care to suspect cases; and social mobilisation and risk communication. Discussions on a joint Ministry of Health and Ministry of Livestock and Fisheries outbreak declaration are ongoing at the highest levels of Government.

The latest Uganda update again via the World Health Organisation. Government of Uganda confirms outbreak of Crimean-Congo hemorrhagic and Rift Valley fevers. Excerpt:

The Ministry of Health in Uganda confirmed an outbreak of the Crimean-Congo Hemorrhagic Fever and Rift Valley Fever in Nakasseke and Luwero respectively.

Regarding RVF, a total of five patients including four deaths have been confirmed in this outbreak. Cases have been sporadic, with no epidemiological link, and are spread out in diverse geographical areas in the cattle corridor. This is the second time RVF cases are confirmed in Uganda.

During a press conference at the Uganda Media Centre, the Minister of Health, Dr Jane Ruth Aceng informed the media that the government has employed rapid interventions to manage and control the outbreaks. She also revealed that a National Rapid Response Team of expert epidemiologists, clinicians, veterinarians, communicators and laboratory specialists was deployed in the affected districts to establish and support the response structures.


Random Analytics: Ebola! (2013)

***** Please note that the infographics/charts of Ebola were updated with public source information to 12 July 2013 EST *****

I continue to remain morbidly fascinated by Ebola.

The World Health Organisation (WHO) states that EHF is a severe acute viral illness often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding. Laboratory findings show low counts of white blood cells and platelets as well as elevated liver enzymes. People are infectious as long as their blood and secretions contain the virus. Ebola virus was isolated from seminal fluid up to the 61st day after the onset of illness in a laboratory acquired case. The incubation period (interval from infection to onset of symptoms) varies between 2 to 21 days. During EHF outbreaks, the case-fatality rate for the three fatal strains has varied from outbreak to outbreak between 24.8% and 89.5%.

Key Facts (issued August 2012 via the WHO):

  • The Ebola virus causes severe viral haemorrhagic fever (VHF) outbreaks in humans.
  • Viral haemorrhagic fever outbreaks have a case fatality rate of up to 90%.
  • Ebola haemorrhagic fever outbreaks occur primarily in remote villages in Central and West Africa, near tropical rainforests.
  • The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission.
  • Fruit bats of the Pteropodidae family are considered to be the natural host of the Ebola virus.
  • There is no treatment or vaccine available for either people or animals.

There were three outbreaks of EHF in 2012, two occurring in August and a later outbreak in November.

The first two were almost concurrent outbreaks, one of Ebola Sudan in Uganda and another of Ebola Bundibugyo in the Democratic Republic of Congo. The Uganda outbreak, in the Kibaale District would infect 24 and kill 17 including 12 members of the same family. The DRC outbreak, in the Province Orientale would eventually infect 77 and kill 36.

Barely a month after calling and end to Kibaale outbreak (and coincidentally an outbreak of Marburg) the Ugandan Ministry of Health had to deal with a second Ebola Sudan occurrence. The 2nd Ugandan outbreak, this time in the Luweero and Kampala Districts would infect seven and kill four.

As recently as late May 2013 it was thought that another outbreak had occurred in the DRC. Although there was an occurrence of some disease testing found that it was not EHF as noted by the CIDRAP News scan on the 4th June 2013.

There has also been some discussion about the possible progress in the fight against Ebola via an FDA research program in late June 2013 (a good abstract on this via H5N1) I thought it might be time to review one of my first WordPress articles, a piece on Ebola completed in October 2012.

Here is some spruced up analysis and analytics, including some updated data from the 2012 outbreaks in Uganda and the Democratic Republic of Congo.


The following infographic looks at some of the key dates and incidents in the history of the Ebola Haemorrhagic Fever (EHF). If you also want an idea of what the virus looks like I have included a photo of the disease under an electron micrograph (top right hand corner!).

01 - Ebola_Infographic_130713

Cases by Country and EHF strain

This infographic packs in a lot of information. First of all the circle sizes represent the amount of cases per country, split according to colour representing the four known strains of the disease. The known strains found in Africa are:

  • EBOV: Ebola Zaire (or the Ebola Virus). Colour: Orange;
  • SUDV: Ebola Sudan (or the Sudan Virus). Colour Green;
  • BDBV: Ebola Bundibugyo (or the Bundibugyo Virus). Colour Violet;
  • TAFV: Ebola Ivory Coast (or the Tai Forest Virus). Colour Brown.

Each country has additional details including total number of cases, fatalities and Case Fatality Rate (CFR).

It should be noted that I have not included a number of known laboratory incidents which have occurred outside of Africa and have resulted in at least one death (Koltsovo, Russia). I also have not included any details about the Ebola Reston which was exported in Philippine crab-eating macaque monkeys to the United States and Italy from 1989 through to 1992. Ebola Reston is not known to be dangerous to humans.

Note: I have created this infographic using Tableau Public software which can be viewed here.

02 - Ebola_CasesbyCountry_130713

CFR by Year and Strain

The final infographic looks at the Case Fatality Rates.

Each line represents a known occurrence of Ebola by onset year. If the outbreak has not completed within a calendar year the data is included from the date of the first onset. Thus the Dec 2008 – Feb 2009 Kasai-Occidental Ebola Zaire outbreak in the Democratic Republic of Congo which infected 32 and killed 15 is included as the 2008 EBOV line.

03 - Ebola_CFRbyTypeOnsetYear_130713

Final Thoughts

Although there have been no known outbreaks of EHF in 2013 it remains a highly visible reminder of our inability to completely dominate our natural space. Many other diseases infect, damage and kill more people but Ebola seems to have a special place in our high-speed mythology. No doubt this is due to its awful characteristics and super high case fatality rates. Amplification by movies such as Outbreak (made in 1995 but still watchable today) or by the writings of Tom Clancy and others who consistently turn the disease into a weapon adds to its macabre allure.

We are just a month away from August, the onset timings for both the opening 2012 outbreaks.

Will 2013 prove to be another deadly year?

Acknowledgements: The new and improved analysis could not have happened without Crawford Kilian and his H5N1 blog and the writings of Tara C. Smith (including her early work via Stanford University) but more recently her articles for National Geographic. Each disease I look at brings out a couple of new, highly specialised subject matter experts and Tara’s writings are excellent.