Identify the country with the largest number of Ebola cases.

Identify the country with the largest number of deaths.

Analysis of the data suggests that the number of deaths from EVD is not related to the total population size. State one piece of evidence from the data that would support this analysis.

Based on the mode of transmission of the Ebola virus, suggest a possible reason for the relationship between population density and the number of Ebola cases in these four countries.

Based on the data, compare and contrast the progress of the epidemic in Liberia and Guinea.

Suggest two possible reasons for the drop in the daily numbers of newly infected cases after October 2014 in Liberia.

Based on these data, outline the evidence that T-705 has potential to be used as a treatment for EVD.

District administrators combatting the 2014 Ebola epidemic in West Africa were assisted by international organizations such as the World Health Organization, who provided data on the progress of the epidemic. Suggest one other way in which international organizations can assist with combatting an epidemic of Ebola.

Sierra Leone ✔

Liberia ✔

country with biggest population/Mali has lowest number of deaths
OR
country with smallest population/Liberia has biggest number of deaths ✔

OWTTE

greater density means more frequent contact with infected people/animals ✔

Need both greater density and frequency of contact

a. overall pattern similar in both/both show a rise and a fall in the infections ✔

b. both countries show an increase during 2014
OR
neither country shows an increase in 2015 ✔

c. both show a sudden drop at one point
OR
sudden drop earlier «Oct–Nov 14» in Liberia than in Guinea «Dec 14, Jan 15» ✔

d. Guinea fluctuates whereas Liberia rises to a peak and then decreases/no fluctuations ✔

e. epidemic starts earlier «in April 14» in Guinea than in Liberia «in June 14» ✔

f. epidemic peaks earlier «Sept 14» in Liberia than in Guinea «Dec 14» ✔

g. epidemic lasts longer in Guinea than it does in Liberia
OR
last case recorded in Liberia Feb 15 while cases continue «at least» until May 15 in Guinea ✔

h. numbers of cases in Guinea generally lower than in Liberia
OR
number of cases higher in Liberia than in Guinea ✔

a. improved medical care/support/supplies/equipment/training of staff/hygiene/distribution of vaccine ✔

b. improved understanding of how to avoid infection «amongst public»/greater awareness in society/better education✔

c. rise in number of deaths means fewer infectious individuals ✔

d. impact of disease control measures/control policies/quarantine/isolation ✔

e. drop in the number of fruit bats ✔

f. maybe seasonal changes/weather changes ✔

g. people may have left the area ✔

h. international aid arrives ✔

OWTTE

a. cells not killed/few cells killed «even at high concentrations» ✔

b. «T-705» effective/viruses reduced/viruses killed at 100 μM
OR
«T-705» very effective/viruses much reduced/nearly all viruses killed at 1000 μM ✔

c. virus concentration decreases as T-705 concentration increases ✔

d. drug has «high» potential for treatment «at high enough concentration» ✔

raise awareness/provide information for local population/supply health workers/equipment/ train local staff/share expertise/provide financial support/provide vaccine/travel ban alert to affected country ✔

This set of data-based questions produced the best showing among candidates. Teachers are to be commended for developing these skills in their students. Many candidates showed confidence in looking at unfamiliar data and formulating answers. Some weaknesses included not being careful with what they were writing when there were similar aspects in the data set (total population size and population density), comparing and contrasting - many students finding this difficult and simply writing descriptions of the data set rather than focussing on similarities and differences. Also giving information on part of a data set where some aspects of the data set may be similar in name but fundamentally different (e.g. Total population and population density) – Some candidates used incorrect parts of data sets rather than those that had been asked about - for example, talking about Ebola cases rather than Ebola deaths, total population size rather than population density.

Most candidates correctly used high density and frequency of contact to describe the relationship. Very few responses discussed high density but did not relate it to the frequency of contact. Others focused on modes of transmission alone and did not relate it to density.

Data is described rather than interpreted e.g. epidemic starts in April for Guinea and in June for Liberia instead of epidemic starts earlier in Guinea than in Liberia

This was a well answered response where almost all students got full marks. Students were able to identify more than three marking points here mp a, b, c and d were most common. Some students provided mp e and f. Few used mp g and h.

Graph was well read and understood by most. The question was answered with more insight than expected, especially when alluding to the implications of live cells at high drug concentrations

Again, most students got a mark here for correct reasoning. Those who lost a mark made references to research. Research was not accepted as it might have future benefits, but not likely to help in the immediate epidemic.