Outbreak of acute hemorrhagic conjunctivitis, in male schools, Makkah city, Saudi Arabia, 1994

On 26 October 1994, the Makkah Health Directorate notified the Ministry of Health of 638 cases of acute hemorrhagic conjunctivitis (AHC) among male school students. A team from the Field Epidemiology Training Program, Ministry of Health, went to Makkah to work with school health authorities and the Makkah Health Directorate to determine the extent of the outbreak and to identify the controllable risk factors.

All four Makkah school health units (SHU) were asked to report any student with acute onset of a painful red eye and excessive tearing with one of the following: subconjunctival hemorrhage or petechiae, periorbital odema or preauricular lymphadenitis. The team also reviewed SHU log books for all previous physician diagnosed AHC from the beginning of the school term. It examined 18 new acute cases of AHC. In two schools exposures of AHC case students were compared to unaffected students selected at random from the same classroom.

From September 19 to December 24, 1994, 940 AHC cases were identified involving 126 (58%) Makkah boys' schools. The initial cases were noted at the Al-Misfalah SHU among Burmese residents of the Goz Al-Nakasah neighborhood during the week ending October 15 No new cases appeared after December 10. (Figure 1). The most heavily affected schools (attack rate [AR] >1000) served Burmese immigrants in Goz Al-Nakasah, while Goz Al-Nakasah schools not serving Burmese had AR under 10/1000. In the first selected school (AR 531/1000), all students were from Goz Al-Nakasah. AHC was associated with sharing personal items (e.g. eyeglasses, tissues, towels, clothes, pillows) with another affected person at home, or at a relative's house (odds ratio [OR] = 4.2; 95%) confidence interval [CI] 1.4-13), or at school with an affected student (OR = 5.6; 95% CI 2.115). The other school (AR 90/1000) had a student body which included Burmese and other nationalities. AHC was associated with living in Goz AlNakasah (OR=7.4, 95% CI=2.8-20). Among the Goz Al-Nakasah students, AHC was associated with sharing personal items with an affected person at home (OR= 6.5, 95% CI= 1.3-35) but not at school (OR=1.6, 95% CI 0.4-7.5). Students with AHC who did not live in Goz Al-Nakasah did not have other AHC cases at home. Among them AHC was associated with sharing personal items with other AHC cases at school (OR=inf. p<0.0001).

From the ABC cases at these two schools, the team selected 40 cooperative families to assess risk factors at home. In these homes there were 334 persons with an AR=560/1000. The median age was 11 years and the sex ratio was 1:1 for both AHC cases and unaffected persons. The 34 households with multiple AHC cases were more likely to share beds and towels among family members than households with only a single case (OR= inf., P<0.00 I). In the 34 households with multiple AHC cases, secondary cases were more likely to share towels (OR=24, 95%CI 6.3-93), tissue (OR=7.6, 95%CI 1.8-34), and beds (OR=7.0,95%Cl 2.8-18) than unaffected family members. In 14 families using eye drops to treat AHC, 42 out of 47 family members contracted AHC after treating another family member with eye drops compared with 16 of 29 family members who did not give eye drops to an AHC case (OR=9.3, 95% C1=2.4, 36).

New AHC cases fell to zero three weeks after a two day health education effort in Goz Al-Nakasah mosques and school science classes. This effort stressed the mode of transmission and not sharing personal items.

Although AHC was apparently widespread in Makkah schools, the investigation indicated that AHC transmission was highly localized to Burmese in Goz Al-Nakasah. AHC transmission in schools was probably secondary to transmission at home. AHC spread in these homes was principally due to sharing of personal items. Home medication with eyedrops added to transmission of AHC by increasing hand contact of unaffected person to the eyes of AHC cases. The contribution of other hand-to-eye contact and other skin-to-skin contact could not be assessed. Fomites and hand-eye contact have been postulated as the major mode of transmission. (1.2) Although the rapid decline in new cases following focused health education suggested that health education may have been important in stopping this outbreak, the high AR in Goz Al-Nakasah attained by the time of the health education suggests that a decrease in the pool of susceptible persons also contributed to the decline in case reports.

AHC is an epidemic infection caused by entrovirus 70 or a variant of coxsackivirus A24. It has an abrupt onset after a short (6-48 hours) incubation. Asymptomatic infection has not been described. Combined with a high infectivity, these factors typically produce explosive AHC outbreaks.

The typical presentation of an abrupt onset of a red painful eye, often with a foreign body sensation, excessive tearing, subconjunctival hemorrhages or petechiae, swelling of the lids or periorbital tissue and preauricular lymphadenitis, makes AHC easy to distinguish from other forms of conjunctivitis.[2] AHC was first documented in Ghana in 1969 [2] and it spread subsequently throughout tropical and subtropical areas of the world.[1] Coastal areas with high humidity and high population density have been major epidemic sites.[1] In Saudi Arabia, other outbreaks (1985, 1988, 1995) occurred in cities on the coast.[3,4]

In this outbreak, AHC began and multiplied in a community of legal and illegal resident aliens with limited access to primary health care clinics (PHCC) and without the means to afford treatment in the private clinics. Accordingly, AHC was first recognized in SHIJ's after it had spread widely in the Goz Al-Nakasah focus. Early detection is essential for control of many infectious diseases. It must be combined with treatment to reduce the period of infectivity with education and prophylaxis to contacts to prevent immediate spread to family members, and with epidemiologic investigation to identify controllable methods of transmission in the community. Early detection of all communicable diseases in PHCC is important in control. It should be applied to all community members for the protection of everyone. AHC is reportable weekly to the Ministry of Health.

To prevent ABC, family members and students should not share personal items (clothes, towels, pillows, eyeglasses, tissues, etc.). They should wash their hands immediately after contacting the hands or face of a person with AHC. Fresh water and soap should be used for washing hands and faces. Antibiotic eyedrops should not be used as they have no beneficial effect and increase transmission. All personal items of the infected person should be washed separately with detergent and hot water. AHC cases should be kept out of school for seven days, have a separate bed and towel at home, and if possible, a separate room.