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Malaria outbreak among illegal Ethiopian immigrants in Al-barzah village of Makkah province, KSA; A study of environmental and behavioral risk factors

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Authors
Volume: 10
Year: 2003
Month: October
Issue: 4
Reference: Alswaidi F., Al-Rabeah A., Alhamdan N., .Saudi Epidemiology Bulletin. 2003;10(4):.
Makkah city is a malaria-free area, but the valleys surrounding it are endemic with malaria, where P. vivax is the predominant species accounting for over 50% of cases.[1] In 3/2/2003, the Field Epidemiology Training Program was informed through the malaria control department in Makkah of an unusual increase in malaria cases reported from Al-barzah area in the previous three months. Al-barzah is situated 120 Km away from Makkah, with a population of about 6000.
A cross-sectional study was conducted to determine and evaluate the environmental and behavioural risk factors for this outbreak. A self-administered questionnaire was distributed to residents of the main residential areas on the basis of simple random sampling. Illiterate individuals and those who did not speak Arabic were directly interviewed. We couldn't meet with most of the registered cases because they were not permanent residents of Al-Barzah, and most were illegal Ethiopian immigrants. Many of them had already left Al-Barzah, and no medical records were available for them at Al-Barzah primary health care center (PHCC). Only four cases were found for interviewing.
In Makkah central laboratory, we obtained information on the total malaria cases reported from different areas of Makkah province including Al-Barzah village in the same study period. Few entomological reports were available in the malaria control department in Makkah to evaluate the density of mosquitoes in the area, so our reference in that regards was the reports from the MOH in Riyadh. Reports from the malaria control department regarding the fogging of insecticides for adult mosquitoes and spraying in the breeding sites were also reviewed. Al-Barzah PHCC laboratory results showed that 47 malaria cases had been registered from November 2002 to February 2003. Most of the cases were illegal Ethiopian immigrants, 41 cases (87.2%), 2 Bangladeshis (4.2%) and 4 Saudis (8.5%). 41 cases (87.2%) had P. falciparum and 6 (12.8%) had P. vivax.
Malaria has been reported in this area in different rates in the previous years, where P. vivax was the predominant parasite in the last five years (61.6%). Cases were reported from different areas of Makkah province in the same study period, but the majority (47 cases or 67.1%) were from Al-barzah, where the total malaria cases at the end of 2002 constituted about 15% of the total malaria cases of Makkah province. However, the trend of malaria in Al-Barzah was similar to that of Makkah province and the whole of Saudi Arabia. The estimated annual parasite incidence rate in Al-Barzah is 1-3/1000 population.
Albarzah is situated on the edge of Mawed valley where many farms are scattered among the residential areas. These farms are surrounded by exposed wells, concrete ponds and many swamps bordered by abundant grass.
Humidity in the area is'20%-30% and the temperature ranges from 18-40°C all year. The rainy season is usually from September to November with average rain gauge of 220 milliliters.2 Entomology reports showed the presence of the vectors Anopheline Sergenti, An. Arabeinsis and non-vectors An. d. taili and culix.[2]
The total number of responses to 350 distributed questionnaires were 301. Males were 299 (99.3%). Only 2 females (0.7%) participated. Age ranged between 16-85 years (mean 46, SD 17). There were 258 (85.7%) Saudis, 28 (9.3%) Ethiopians, and 5% other nationalities.
Those who reported malaria in the past among relatives, neighbors or friends were 65 (21.6%); 283 (94.4%) reported mosquito bites, only 99 (33.4%) of who did not use anti-mosquito methods, 34 (34.3%) of who were young people 16-26 years old.
The rest used repellent smoke 91%, bed nets 6% and repellent cream 3%.
Sixty five (18.6%) slept in exposed areas (50% of them were illegal Ethiopians). All the Ethiopians who were interviewed (9.3%) represented the area where the majority of cases had appeared (Mawed) and were living in simple sheds without using any anti-mosquito methods. 136 (45.6%) lived beside stagnant water; wells 75%, swamps 16.9% and concrete ponds 8.1%. 39 (13%) were working as farmers. None stated visiting malaria endemic areas inside or outside the Kingdom before November 2002. Risk factors for Malaria infection are presented in Table 1.

Editorial note:

Malaria continues to claim an estimated 2 to 3 million lives annually and to account for untold morbidity in the approximately 300 to 500 million people annually infected. It is often cited as a substantial impediment to economic and social development in endemic regions.[3] P. falciparum is responsible for the majority of deaths and most of the severe forms of disease, including cerebral malaria.[3]
In the south-western parts of Saudi Arabia, P. falciparum is the prevailing parasite and An. arabiensis is the main vector. The main constraints for malaria control, besides its heavy importation, particularly by uncontrolled migration from Yemen, are the existence of chloroquine-resistant P. falciparum and resistance of vectors to insecticides. In Saudi Arabia, local chloroquine-resistant P. falciparum cases have been reported without any history of foreign travel, blood trans fusion or drug abuse.[4] The areas freed from malaria are still receptive, and cases are introduced from time to time.
It is confirmed by this study that Al barzah is a malaria endemic area. In November 2002, the beginning of the rainy season, malaria cases began appearing in Al-barzah and within three months, 47 cases had been reported. The peak was in December when the rain gauge was at the highest level. The majority of cases were illegal Ethiopian immigrants who had arrived to Saudi Arabia to perform Omrah or Hajj and then gathered in this remote area to hide from the immigration police and work as farmers and sheep herders in adjacent farms. During Hajj season, they depart to Makkah and the Holy places looking for work. They reside on top of a mountain in primitive exposed sheds just 50 meters away from the swamps, wells and concrete ponds in the farms, without using any anti-mosquitoes methods near the breeding sites of mosquitoes.
The main vectors for transmitting malaria parasites in this endemic area, An. Sergenti and Arabeinsis, are available in reasonable density.[5] The monthly insecticide and larvecidal spraying seem not to be enough, especially during rainy seasons. The large number of swamps, which extend up to 6 kms along the valley, is the real problem in controlling malaria in this region.
Behavioural risk factors included living near to stagnant water spots, sleeping in exposed areas, working as farmer, and not using anti-mosquito methods, which seemed to be the most important risk factor. It is well known that occupation, residence location and not using anti-mosquito nets are the most important risk factors in many endemic malaria areas worldwide.[6] Presence of, and getting bitten by, mosquitoes did not have an association with malaria infection since the majority of biting mosquitoes were non-vector mosquitoes. The probability of importing malaria from Ethiopia cannot be excluded.
Malaria is a re-emerging problem in many countries and emerging in others. In both cases, illegal immigrants are the cornerstone of transmission of infection. In 1998, a malaria outbreak occurred in the Dhofar region of Oman, a region that is classified as malaria-free, due to the influx of hundreds of illegal Somali immigrants.[7]
This study documents the serious role of illegal immigrants as a focus for maintaining and spreading malaria in such areas of Saudi Arabia.
It was recommended that all swamps be buried, at least those close to residential areas. Plants and grass on the edges of swamps should be removed to ease the spraying of larvicidals. Campaigns of Active Case Detection should be carried out to identify cases early and provide necessary medications to prevent future epidemics especially among illegal residents. People should be educated on the severe complications of malaria, risk factors and preventive measures. There is a need for a well-coordinated strategy to prevent cross border transmission of diseases.
References
  1. 1. Elbushra H., Alsayed M., malaria among pligrimis to' Makkah, is it imported or locally acquired?. Saudi Epidemiol Bull 1998;5:22-23.
  2. 2. Presidency of Meteorology and Environment, KSA, Jeddah branch, Annual report 2002.
  3. 3. Eddleston M, Pierini S. Malaria. In: Oxford Handbook of Tropical Medicine. Oxford university, press, New York. 2nd edition , 2002, P. 20-22.
  4. 4. Kinsarah AJ, Abdelaal MA, Jeje OM, Osoba AO. Chloroquine-resistant P. falciparum malaria: report of two locally acquired infections in Saudi Arabia. Am J Trop Hyg. 1997, 60(4):579-80.
  5. 5. Ministry of Health, K.S.A., Malaria Control Program, Malaria cases report in Saudi Arabia. 2002.
  6. 6. Philavong K, et al. Malaria control through impregnated bednets-a pilot project in selected villages in Lao PDR. Southeast Asian J Trop Med Pub Hlth. 2000; 31 Suppl 2: 22-31.
  7. 7. Baomar A, Mohamed A. Malaria outbreak in a malaria-free region in Oman 1998: unknown impact of civil war in Africa. Public Health. 2000; 114(6): 480-3.