HIV This Week

de Walque D. Do unsafe tetanus toxoid injections play a significant role in the transmission of HIV/AIDS? Evidence from seven African countries. Sex Transm Infect. 2008 ;84(2):122-5.

Although sexual transmission is generally considered to be the main factor driving the HIV epidemic in Africa, recent studies have claimed that iatrogenic transmission should be considered as an important source of HIV infection. In particular, receipt of tetanus toxoid injections during pregnancy has been reported to be associated with HIV infection in Kenya. The objective of this paper is to assess the robustness of this association among women in nationally representative HIV surveys in seven African countries. The association between prophylactic tetanus toxoid injections during pregnancy and HIV infection was analysed, using individual-level data from women who gave birth in the past five years. These data are from the nationally representative Demographic and Health Surveys, which included HIV testing in seven African countries: Burkina Faso 2003 (N = 2424), Cameroon 2004 (N = 2600), Ethiopia 2005 (N = 2886), Ghana 2003 (N = 2560), Kenya 2003 (N = 1617), Lesotho 2004 (N = 1278 ) and Senegal 2005 (N = 2126). Once the odds ratios (OR) were adjusted for five-year age groups and for ethnic, urban and regional indicators, the association between prophylactic tetanus toxoid injections during pregnancy and HIV infection was never statistically significant in any of the seven countries. Only in Cameroon was there an association between previous tetanus toxoid injection and HIV positivity but it became weaker (OR 1.53, 95% CI 0.91 to 2.57) once urban location and ethnic group were adjusted for. Although the risk of HIV infection through unsafe injections and healthcare should not be ignored and should be reduced, it does not seem that there is, at present and in the seven countries studied, strong evidence supporting the claim that unsafe tetanus toxoid injections are a major factor driving the HIV epidemic.

Editors’ note: After simple adjustment for age, location, and ethnicity in these Demographic and Health Survey datasets from seven countries, there were no correlations found between tetanus toxoid injections during pregnancy and HIV infection. Injection safety is important in healthcare settings in Africa, as it is everywhere, but it should not detract from concerted efforts to address the main mode of HIV transmission in these countries – sexual transmission.

Thomson and colleagues aimed to determine the prevalence and types of penile modification and describe the circumstances surrounding this practice among a sample of young methamphetamine users in Thailand. A mixed methods study was conducted in Chiang Mai, Thailand in 2005-6. One hundred young men were surveyed for the quantitative study and in-depth interviews were administered to 9 men, 11 women and 1 transgender. The prevalence of penile modification was 51%, with the most common type being inlaying with muk(s) (61%). The majority of modifications were performed in prison or juvenile detention (80%) by a friend (90%). Motivations for penile modification included peer pressure and perceived enhanced female sexual pleasure. In prison, the practice was veiled in secrecy, the conditions under which modification was performed were unhygienic, sometimes leading to infection, and sharing equipment was common. Men and women reported that condom use was more difficult post modification as condoms were more likely to break or leak and less likely to fit correctly. In addition, sexual intercourse was often painful for the female partner. In conclusion, penile modification is prevalent in this group of young methamphetamine users and is associated with behaviours and consequences that could facilitate the spread of HIV and other sexually transmitted infections.

Editors’ note: Penile modification practices in Thailand date back to the fourteenth century among the aristocracy but today are associated with prisons, the army, and the working class. Over half of one hundred consecutive male participants in a trial to reduce harms associated with methamphetamine use had penile modifications that had been performed in unhygienic settings. The risk of infection, including with blood borne pathogens transmitted through sharing of equipment at the time of the procedure, painful intercourse with trauma experienced by the receptive partner during intercourse, and condom breakage/leakage all raise concerns of increased risk for HIV acquisition and transmission.

Ansah JK, Acquaye J. Ten years of preoperative autologous blood donation in Accra. Ghana Med J 2006;40:142-7.

Photo credit: UNAIDS/K.Krobe

Pre-operative autologous blood donation (PABD) is utilized to circumvent the use of allogenic blood for various reasons. Ansah and Acquaye describe the distribution in terms of demographic characteristic, trends in participation and result of screening test of the PABD programme of the Accra Area Blood Center from 1993-2003. This is a retrospective descriptive study of PABD in patients scheduled for a variety of elective surgical procedures, in different levels of institutional health care in Accra, Ghana. Data from existing records of patients who had participated in PABD were collated and analyzed. The results showed that five hundred and forty six (546) females and 89 males participated, with ages ranging between 14-74 years. Majority of the patients (76.7%) underwent gynaecological surgery. A total of 330 (52%) donated one unit only, and 299 (47.1%) donated two units. Majority of the patients (56.4%) had the surgery at the Korle-Bu Teaching Hospital. Of the donations, 21 (3.3%), 1 (0.2%), 1 (0.3%) and nil were positive for HBV, HIV I & II, HCV and VDRL respectively. A total of 848 (89.4%) autologous cross-matched units were issued out. There was a steady progressive increase in participation. In conclusion, mainly adult females scheduled for gynaecological surgeries in Korle-Bu Teaching Hospital participated, while almost equal proportions donated one or two units of blood which meets the blood needs of most elective surgeries. Therefore healthy patients going for elective surgeries in regions with limited blood supply must be encouraged to enter a Pre-operative autologous blood donation Programme. Further studies in this field should evaluate motivational factors for participation.

Editors’ note: Autologous blood transfusion, storing your own blood ahead of time in case you will need it for an elective surgical procedure, has obvious advantages for the individual but is controversial in many settings because of its potential to undermine emergency blood services if it draws resources away from them.

Stramer SL. Current risks of transfusion-transmitted agents: a review. Arch Pathol Lab Med 2007;131:702-7.

Infectious disease testing has dramatically improved the safety of blood for transfusion in the United States, especially since the introduction in 1999 of nucleic acid amplification testing. In 2004, methods (primarily culturing) for detecting bacteria in platelets were also added. Stramer’s objective is to provide current risk estimates for the likelihood of viral transmission by test-negative blood components and to illustrate the safety improvements since the introduction of bacterial testing of platelets. The author’s data sources are published literature from 1999 through 2006 and unpublished American Red Cross data sources. The author concludes that the risk of human immunodeficiency virus and hepatitis C virus transmission through blood transfusion since the introduction of nucleic acid amplification testing is approximately 1 in 2 million. Hepatitis B virus risk, for which nucleic acid amplification testing is not performed routinely, remains at 1 in 200,000 to 500,000 using a combination of anti-hepatitis B core and hepatitis B surface antigen testing. Seven cases of transfusion-transmitted West Nile virus have been reported since the introduction of nucleic acid amplification testing in 2003, but none has been reported since system-wide implementation of processes to increase the test sensitivity for use in epidemic areas. The residual risk of receiving a bacterially contaminated platelet component with clinical consequences is estimated at approximately 1 in 75,000, if culture negative and 1 in 33,000 if not tested by culture methods.

Editors’ note: The risks of acquiring transfusion-associated infectious agents have dropped significantly in the USA and other countries with the resources to devote to assuring the safety of the blood supply. However, primary prevention starts by preventing accidents in the workplace, on the highway and elsewhere, as well as by reducing the prescribing of blood transfusion in hospitals unless absolutely necessary.

O’brien SF, Yi QL, Fan W, Scalia V, Kleinman SH, Vamvakas EC. Current incidence and estimated residual risk of transfusion-transmitted infections in donations made to Canadian Blood Services. Transfusion 2007;47:316-25.

New testing methods such as nucleic acid amplification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion-transmitted infections (TTIs) has been developed. Thus, O’Brien and colleagues note that available RR estimates for Canada need to be updated. Incidence rates for known TTI markers were determined for all allogeneic whole-blood donations made to Canadian Blood Services between 2001 and 2005; they were derived from NAT conversions or seroconversions of repeat donors with at least two donations in a 3-year period. RR estimates for human immunodeficiency virus (HIV)-1 and hepatitis C virus (HCV) derived from the classical incidence/window-period model were compared to those obtained by the new method that estimates incidence from NAT-positive, antibody-negative donations (NAT-yield cases) from all donors divided by person-years. With the classical method, the RR of HIV (1 per 7.8 million donations) and HCV (1 per 2.3 million) were low; HBV RR was higher (1 per 153,000). HCV RR was significantly lower when estimated with the new method (1 per 13 million). Eleven HCV NAT-yield cases were predicted by applying the classical method to our seroconversion data but only 2 were observed (p = 0.011). Observed HIV-1 NAT-yield cases (n = 1) matched those predicted (n = 0.7). The authors conclude that new tests have reduced an already low risk of TTI in Canada. HCV RR estimates by two different methods differed but both were low.

Editors’ note: Nucleic acid amplification and chemiluminescent testing which can pick up the window period while antibody tests are still negative have virtually eliminated transfusion-transmitted HIV and hepatitis C infection through blood banks in Canada.