The changing malaria landscape in Aseer region, Kingdom of Saudi Arabia: 2000–2015

Abstract

BackgroundIn 2004, a revised action plan was developed, supported by the World Health Organization, to eliminate malaria from Saudi Arabia by preventing re-introduction of malaria into regions since declared malaria free, eliminating foci of transmission in the Mecca and Medina areas and a concerted effort of foci surveillance and control, to eliminate malaria from the regions of Jazan and Aseer. This paper provides the context, activities, progress, and possible contributions toward malaria elimination in the Aseer region since 2000, with a more detailed analysis of the spatial location of locally acquired case incidence since 2012.MethodsThis is a descriptive study of all available Ministry of Health surveillance data and process reports since 2000, with higher spatial resolution analysis of data between 2012 and 2015.ResultsIn 2000, there were 511 cases of Plasmodium falciparum locally acquired infection. The following 4 years witnessed a dramatic decline in cases to only 18 locally acquired infections reported in 2005. A resurgence in local infections was reported in 2006 (93) and 2007 (165), thereafter (2008–2014) local cases continued to decline to fewer than 40 per year across the region. However, in 2015, a small rise was noted (51). All locally acquired infections were P. falciparum. There has been a constant flow of imported infections into Aseer since 2000, mostly among immigrant labour from Pakistan, India, Sudan, and Yemen. Imported infections have included both Plasmodium vivax and P. falciparum. The spatial extent of malaria appears to be changing, but there remain two intractable areas Sarat Abeda and Dhran Aljanub, where risks per reporting centre have changed little since 2001, remaining above 0.5 per 10,000 population. Only seven villages contributed 55% of all locally acquired infection since 2012.DiscussionAseer has reached a state of very low incidence of locally acquired infections, despite a constant source of imported infections from outside the country. How many of the local infections are F2 generations from imported infections or how many are a result of residual active transmission between asymptomatic carriers of infections transmitted by pockets of existing Anopheles arabiensis populations remains unknown. A more detailed investigation of the spatial and temporal patterns of infected hosts, parasites and vectors would help define whether this region has managed to effectively prevent local transmission of new infections.

Decreasing trend of imported malaria cases but increasing influx of mixed P. falciparum and P. vivax infections in malaria-free Kuwait

“…The highest number of malaria cases (1012; 52.9%) were detected among Indians which also form the biggest single ethnic group among expatriate residents in Kuwait [ 13 ]. Similar data have also been reported from other Arabian Gulf countries, such as Qatar, Bahrain, United Arab Emirates and Saudi Arabia which also have large expatriate population, particularly from the Indian sub-continent [ 17 – 19 , 23 , 24 ].…”

“…The majority of malaria cases were detected among male subjects and during the summer and fall months (May-October), which coincides with the rainy season/peak malaria infection period in the home countries of expatriate workers who either came or returned to Kuwait after summer holidays. Males also comprised >90% of all imported malaria cases in Qatar [ 19 ], UAE [ 23 ] and Saudi Arabia [ 24 ]. Furthermore, similar seasonal trend was also reported from other GCC countries with most imported cases detected during the months of August-September [ 18 , 23 , 25 ].…”

“…falciparum malaria is more common in locally acquired malaria cases while an increasing proportion of imported cases were caused by P . vivax in Saudi Arabia [ 7 , 20 , 24 ]. Mixed P .…”

“…in locally acquired malaria cases while an increasing proportion of imported cases were caused by P. vivax in Saudi Arabia [7,20,24]. Mixed P. falciparum and P. vivax infections occurred in only~7% of malaria cases in one study [8], while in another study, nearly 2% of PCR-confirmed malaria cases (n = 369) were due to mixed infections that were missed by microscopic analysis alone [34].…”

Cross-border movement, economic development and malaria elimination in the Kingdom of Saudi Arabia

“…Epidemics were reported during the mid-late 1990s in the south-western regions, coincidental with a congruence of emerging chloroquine resistance and El Nino-related flooding, and malaria case incidence began to rise [ 5 , 6 ]. Renewed efforts to achieve malaria pre-elimination were launched in 2004 [ 5 , 6 , 38 , 42 , 43 , 44 ], when malaria transmission was eventually constrained to Qunfudha and Al Lith Governorates of Makkah region and Aseer and Jazan regions. No locally acquired cases have been detected outside of Jazan and Aseer regions for 7 years.…”