Mass gatherings bring together people and pathogens (germs) from all over the world. Such events present unique challenges to infectious disease surveillance. Normally rare diseases may temporarily become common at the venue. Highly contagious illnesses can spread quickly in crowded conditions. To help organizers anticipate potential threats, HealthMap and BioDiaspora have collaborated to determine where participants come from and then to increase surveillance of mass media on those parts of the world. We published earlier on our efforts for the Vancouver Olympics, and some readers may recall our map for the FIFA World Cup.
This Sunday marks the start of the Hajj, the annual pilgrimage to Mecca, consisting of several rituals which symbolize the essential concepts of the Islamic faith. Muslims from around the world are traveling to Saudi Arabia for the pilgrimage. HealthMap and BioDiaspora have produced a map for this mass gathering: http://healthmap.org/hajj/
The map automatically shows alerts from the HealthMap dataset for any of the almost fifty countries whose populations are at least 50% Muslim. You may turn on and off coloured layers showing the 10 countries with the most pilgrims, or all countries with at least 20,000 expected pilrgims. As meningitis has historically been a concern during the Hajj, we have added a preset that shows any meningitis news stories in these countries.
Below, our anlaysts have summarized two interesting disease stories that could potentially impact this year’s Hajj. Please see the map for many other news stories.
Viral conjunctivitis (aka pink eye) in Egypt.
Egypt has seen a recent outbreak of viral conjunctivits in a handful of schools primarily located in Matariya (NB: if you click on the link “Matariya” translates as “rain” in Google Translate) in the Nile delta region of Daqihiliya. While the Egyptian government is reporting that the epidemic is getting under control, the outbreak has spread as far south as Aswan. Moreover, a health official working in the region reported anonymously that the extent of the outbreak is much larger than is being discussed by the media or the governments in the region, particular Sudan and Uganda. Egypt’s outbreak led to school closures in Matariya, of which newspapers published accounts that were picked up by HealthMap. Viral conjunctivitis is not a dangerous disease, per se (it is caused by viruses that cause the common cold). However, because viral conjunctivitis is easily spread and the extent of the outbreak is unclear, this outbreak presents a risk to Hajj pilgrims due to the easy transmissability of the virus in the conditions that pilgrims will likely encounter during the ritual such as close living quarters and drinking from the waters of the Zamzam spring.
Dengue in Beit al Faqih, Yemen.
An epidemic of dengue fever has also been spreading through the city of Beit al Faqih, Yemen. The government has so far denied existence of the outbreak, leading some local doctors to threaten to report to the World Health Organization itself. Because of the lack of transparency, the number of cases and deaths due to the disease is unknown, as is the extent of the outbreak. Beit al Faqih is a small village, and given that this outbreak has been spreading for a number of weeks, it is likely to have moved beyond Beit al Faqih into other municipalities in Hodaida district in western Yemen. At least 20,000 pilgrims from Yemen are expected to participate in the Hajj this year; however there are concerns that Yeminis are crossing the Saudi border illegally, increasing the risk of transmitting the disease to Saudi Arabia during this mass pilgrimage.