On December 16th, 2014, HealthMap first received news reports of a mysterious outbreak of HIV in a small village in Cambodia’s Battambang province. The realization of an outbreak began with routine health checks of villagers. After 100 Roka commune villagers tested positive for HIV within the course of a week, a reasonable amount of panic ensued [1]. The source was unknown. However the pattern, or lack thereof, of infected individuals indicated it was not a normal route of exposure. Those infected have ranged in age from a four-month old infant to an octogenarian [2]. As an example of the irregularity in pattern of affected individuals, among those testing positive was a four year old boy whose twin brother was found to be uninfected [1].
The pattern of HIV infection in Roka commune appeared irregular because it did not follow the usual risk factors for the disease. Globally, there are certain groups that may be at increased risk of HIV infection: injection drug users, who share needles or syringes; men who have sex with men; those of younger age at first sexual activity; and those with low condom usage [3]. The absence of the immediate applicability of these risk factors in the outbreak in Roka commune highlighted the need for urgent investigation into its cause.
ProMED recently released a request for information on the source of the outbreak, based on the details of a January 5th article by the Cambodia Daily newspaper [4]. The article elaborates on the findings of the ongoing investigation [2]. The case count continues to rise, and currently stands at 226, among Roka commune villagers. An unlicensed doctor, who made frequent house calls in the area of the outbreak, and treated patients with injections has been jailed for his confession to reusing needles. Samples taken from HIV-infected individuals have been sent for laboratory subtyping, in order to determine the mode or course of transmission. The Cambodia Daily article goes on to highlight: “Medical experts say the reuse of syringes is unlikely to be the sole cause of the HIV outbreak, but that it is plausible a lone medical practitioner single-handedly spread the virus to hundreds of people if infection prevention protocols were not followed” [2].
However, it should be emphasized that it is not easy to transmit HIV via a needlestick. The CDC reports that 99.7% of needlestick occurrences involving HIV infected blood do not result in transmission [5]. The risk of transmission by injection does not just exist with reuse of needles and syringes. In September 2014, news broke of outbreaks of hepatitis C at three Toronto colonoscopy clinics linked to multi-use vials [6]. These vials, which contain a standardized amount of an injectable medication, are generally used for the treatment or dosing of multiple patients. Should a contaminated needle or syringe be used to draw up a dose of the medication, the contaminated material may enter the vial of medication and put the future recipients of that medication at risk of infection. This risk applies to more diseases than just hepatitis C, and could have played a role in the Roka commune HIV outbreak.
[1] Mystery HIV Outbreak Sparks Panic In Battambang – The Cambodia Daily (subscription) http://shar.es/1HB3do
[2] https://www.cambodiadaily.com/news/govt-targets-unlicensed-medics-amid-hiv-outbreak-75295/
[4] http://www.promedmail.org/direct.php?id=20150108.3079554
[5] http://www.cdc.gov/oralhealth/infectioncontrol/faq/bloodborne_exposures.htm
