25 July 2020
Providing context for COVID-19 numbers in the Arab region
Published online 3 April 2020
Nature Middle East asked Ghina Mumtaz1 , an epidemiologist working in Lebanon, about the spread of COVID-19 in the Arab region.
It is difficult to predict the course of the COVID-19 pandemic in regions such as the Middle East and Africa, where epidemic spread appears to still be limited. But current official numbers in Arab countries, which fall far behind those in the US, Spain and Italy, for example, could be a reflection of a delay in the introduction of the virus as a result of differences in global travel movements and patterns.
Another potential explanation for these currently smaller numbers could be the lower levels of testing and reporting in some Arab countries. Lower income countries will not have sufficient resources to scale up testing, will have limited laboratory capacity, and weak surveillance systems. This means there might be undocumented transmission. Differentials in testing are observed even within regions and are usually linked to available resources. For example, many of the Arab Gulf countries, such as the UAE, Bahrain, and Qatar, rank among the highest in the world in terms of the number of tests per one million population, while the rest of the Arab world has conducted little testing, comparatively. It is not surprising that these three countries have the highest number of reported cases per one million inhabitants in the region (figure).
There is a lot of speculation about the potential effect of seasonality and warmer weather on the spread of the virus, with some arguing that the epidemic has not spread much in the African continent because of warmer weather. However, the effect of seasonality is still not known. Even if warmer weather might slow the spread of the infection, it is unlikely that, alone, this could prevent an epidemic from happening. This is especially applicable in the case of SARS-CoV-2 infection, the virus causing COVID-19, due to its high reproduction number (R0) of about 2.5, compared with seasonal influenza’s R0 of about 1.3. The reproduction number is the average number of secondary infections caused by one infected person at the beginning of an epidemic. It provides an indication of the intrinsic potential of an infectious agent to spread in a given population.
The delay in the overall timeline of the global epidemic has also provided countries with a window of opportunity for the early introduction of prevention interventions. Some Arab countries started imposing early containment measures as a reaction to the crises that were taking place in more advanced countries such as Italy, the US, and Spain. Many Arab countries are aware of their incapacity to deal with such a rapidly growing epidemic. For example, although Lebanon was going through a very difficult economic crisis amidst a popular uprising, the government announced school closures shortly after the first few cases were documented, and imposed a lockdown when the number of cases rose to just below 100. Jordan also imposed strict border controls shortly after the first case was documented, then followed this with a lockdown of the population.
Finally, while mortality is affected by the quality of care, the currently observed low death rates in some Arab countries might be explained by the protective effect of age. Based on published epidemiological evidence, the severity of COVID-19 has strong links to advanced age. The proportion of cases who develop severe or critical disease increases steadily with age. The demographic profile in developed countries, in terms of age structure, is very different compared to developing countries. The latter, including most of the Arab world, have much younger populations, and could be expected to have less critical disease cases and hence lower mortality. Italy, which has documented a high death toll, has one of the oldest populations in the world. However, one has to keep in mind that it could take up to eight weeks following the initial onset of symptoms before people develop critical complications and death.
Since the infections in Arab countries could be lagging behind those in other regions, it may be premature to think that mortality is low in this part of the world.
- Ghina Mumtaz is assistant research professor of epidemiology and population health at the American University of Beirut. She has a PhD in infectious disease epidemiology from the London School of Hygiene and Tropical Medicine. Her current research work is on a UK-funded project, called RECAP, which focuses on improving the response to humanitarian crises and epidemics. Her research work has informed policy and programming decisions at key international organizations, such as the World Health Organization, UNAIDS, and the World Bank.