Karstaedt (South Africa) presented results of a retrospective cohort analyzing the causes of death in a hospital-based cohort in Soweto (2004 through 2005).  AIDS complications (principally sepsis, tuberculosis and MAC) account for the majority of deaths.  However, their prevalence diminished following antiretroviral initiation and non-AIDS complications became a more important cause of death after the first year on ARV.

Along the same lines, Mayanja Nsubuga (Uganda) reported on the incidence, microbial etiologies of sepsis and antimicrobial drug resistance among HIV patients with sepsis in a clinical cohort from 1996 to 2007. Sepsis incidence was higher in HIV-infected than HIV-uninfected participants, remained high after HIV-infected patients started ART, and only declined after the first year on ART, consistent with slow immune recovery. The most common microbiologic etiologies were Streptococcus pneumoniae and Non typhoid Salmonella which were 91% and 75% resistant to cotrimoxazole respectively.  The implication is a need for availability of microbiologic diagnostic and antimicrobial susceptibility testing in HIV clinics in Africa.

Comparing the incidence and etiologies of bloodstream infections among HIV-infected and HIV-uninfected patients seen in a tertiary hospital in Spain, Knobel et al showed a significant difference in the spectra of causative microbiologic organisms in bloodstream infections between the two populations.  Streptococcus pneumoniae and Staphylococcus aureus being the most common etiologies in HIV+ patients while gram-negative bacteria (especially E. coli) were more common among HIV-negative patients.  They also showed that the mortality of bloodstream infections (both community-acquired and nosocomial) was higher in HIV-positive patients

Kasirye et al reported the incidence of malaria and risk factors in a cohort of 1,020 adults on ART in Uganda in patients enrolled in the DART trial over 4 years with monthly follow up. Malaria was defined as fever with smear positivity for P falciparum. Malaria incidence declined over time, with 591, 476, 259, and 153/1000 pt years in years 1, 2, 3, and 4, respectively. By univariate analysis, younger age, lower CD4 at ART initiation (below 10 CD4/ml), and lower level of education were associated with malaria incidence, and receipt of TMP-SMX was protective. As reported elsewhere at this meeting, ART response rates were very good overall.  No data on access to insecticide treated bed nets over time was available, but no change occurred in access specifically as a result of participation in the trial.  The authors concluded that malaria incidence declines over time on ART, which is an important consideration for malaria incidence and morbidity in endemic countries. These data add weight to the trend towards earlier ART initiation in resource-poor settings.  

Silverman et al assessed TB incidence in Zimbabwe from 1995 to 2008 in the context of the severe economic and political crisis. Data from two of the few mission hospitals that have remained open in the past year were analyzed and compared for consistency. In 12,778 patients, TB incidence rose from 176 to 281/100,000 between 1995 and 2001, correlating with the rise in HIV incidence, and then to 426/100,000 from 2001-2003 during severe hyperinflation; simultaneously, malnutrition, pellagra, kwashiorkor, and diarrheal illness increased substantially, occurring in 6,695 (46%) of patients.  TB incidence was then stable until 2007, and then rose again to 556/100,000 from 2003-2007, with seasonal troughs corresponding to the growing season and available sustenance, and peaks at other times. HIV incidence in antenatal clinics has been falling in Zimbabwe, from 23% to 11% from 2001 to 2008, and again to 6.5% in early 2009; possible explanations included lack of petrol for transport, decreases in sexual mixing, and increasing morbidity and mortality of HIV+ women. The urgency of this compound epidemic of TB, HIV, and malnutrition cannot be overstated. 

In an effort to quantify the spread of MDR-TB in South Africa beyond Kwazulu-Natal, Cox found a high incidence of MDR-TB in 563 culture positive patients among 1,850 suspected cases in two primary care clinics in Khayelitsha township. Of these, 259 were new cases and 249 were previously treated. HIV status was known in 427 cases (80%), and 61% were HIV positive. RFP resistance was seen in 3.8% and 4% of new HIV positive and HIV negative patients, respectively, and in 5.7% and 13% of previously diagnosed HIV positive and negative cases, respectively, with an overall estimated incidence of 50-72/100,000/year.  By univariate analysis, previous TB treatment and female gender predicted RFP resistance. Although no association with HIV infection was seen, Cox noted the important fact that high levels of RFP-resistant organisms are being transmitted, accounting for 73% of new transmissions, and that a high percentage will occur in immune compromised HIV positive patients. The lack of a specific biologic association, in this case, is trumped by the ‘twin tornados’ of the HIV and TB epidemics, which will result in high incidences of RFP resistant and MDR-TB in HIV infected individuals, in spite of the lack of this association.