Vaginal colonization with virulent and methicillin resistant Staphylococcus aureus among Ugandan women in Labour.

BACKGROUND: Staphylococcus aureus (S. aureus) often colonizes the human skin, upper respiratory and genital tracts. In the female genital tract, it can be passed on to the newborn during vaginal delivery leading to either ordinary colonization, or neonatal infections notably umbilical stump sepsis, scalded skin syndrome, arthritis, or bacteraemia/sepsis. These infections are mediated by staphylococcal virulence factors such as (i) Staphylococcal Enterotoxins A, B, C, D, and E encoded by the sea, seb, sec, sed, see genes, (ii) Exfoliative Toxins A and B encoded by the eta and etb genes, (iii) Toxic Shock Syndrome Toxin 1 (TSST-1) encoded by the tst gene, (iv) Panton-Valentine Leukocidin (PVL) encoded by the pvl gene, and (v) Hemolysins alpha and delta encoded by the hla and hld genes, respectively. We determined the prevalence of S. aureus possessing one or more virulence factor genes and of methicillin resistant Staphylococcus aureus (MRSA) in this population. METHODS: This was a cross-sectional study, which used 85 S. aureus isolates from the Chlorohexidine (CHX) clinical trial study in Uganda. The isolates had been obtained by culturing vaginal swabs (VS) from 1472 women in labour, frozen at minus 80oC, then thawed, sub-cultured, and tested for the selected virulence genes sea, seb, sec, sed, see eta, etb, tst, pvl, hla and hld, and for the methicillin resistance determining gene (mecA). Data were analyzed using SPSS version 20. RESULTS: Of the 85 S. aureus isolates 13 (15.3%) were positive for one or more virulence factor genes, as follows: pvl 9/85 (10.6%), hld 5/85 (5.9%), sea 1/85 (1.2%) and seb genes 1/85 (1.2%). The other virulence genes (sec, sed, see, eta, etb, hla and tst) were not detected in any of the isolates. MRSA was detected in 55.3% (47/85) of the isolates, but only two of these carried the pvl virulence gene. CONCLUSION: This study demonstrated that 15% of the S. aureus colonizing the female lower genital tract of mothers in labour in central Uganda carried one or more virulence genes, mostly pvl, indicating potential for newborn infection with S. aureus acquired in the maternal birth canal. More than half of the isolates were MRSA.

Prevalence of Histoplasma Antigenuria among Outpatient Cohort with Advanced HIV in Kampala, Uganda.

In sub-Saharan Africa, an estimated 25% of people with HIV present with advanced HIV and are at high risk of opportunistic infections. Whereas histoplasmosis has occasionally been seen in Uganda, the understanding of the local risk of acute infection is limited. We sought to determine the prevalence of Histoplasma antigenuria using an enzyme immunoassay (EIA, clarus Histoplasma GM EIA, IMMY; Norman, OK, USA) in a cohort of outpatients with advanced HIV disease in Kampala, Uganda. Among the persons with positive urine Histoplasma antigen tests, we assessed their clinical presentation and outcomes. The EIA was run on stored urine samples as per the manufacturer's instructions. Specimens ≥1 EIA units were considered positive. Among the 388 tested urine samples, 4 (1.2%) were positive for Histoplasma antigen. The histoplasmosis prevalence among participants with a CD4 < 100 cells/mcL was 2.5% (4/158). Three of the four participants with a positive Histoplasma antigen test reported systemic symptoms consistent with histoplasmosis. All four participants had a positive urine lipoarabinomannan test and were treated for tuberculosis. By the four-week follow-up visit, all participants were clinically improved, alive, and in care without antifungal therapy. In advanced HIV, the clinical presentations of tuberculosis and histoplasmosis overlap. The value of histoplasmosis screening and pre-emptive treatment is an area of future research.

Chronic pulmonary aspergillosis in patients with active pulmonary tuberculosis with persisting symptoms in Uganda.

BACKGROUND: The occurrence of chronic pulmonary aspergillosis (CPA) among drug sensitive pulmonary tuberculosis (PTB) patients on optimal therapy with persistent symptoms was investigated. METHODS: We consecutively enrolled participants with PTB with persistent pulmonary symptoms after 2 months of anti-TB treatment at Mulago Hospital, Kampala, Uganda, between July 2020 and June 2021. CPA was defined as a positive Aspergillus-specific IgG/IgM immunochromatographic test (ICT), a cavity with or without a fungal ball on chest X-ray (CXR), and compatible symptoms >3 months. RESULTS: We enrolled 162 participants (median age 30 years; IQR: 25-40), 97 (59.9%) were male, 48 (29.6%) were HIV-infected and 15 (9.3%) had prior PTB. Thirty-eight (23.4%) sputum samples grew A. niger and 13 (8.0%) A. fumigatus species complexes. Six (3.7%) participants had intracavitary fungal balls and 52 (32.1%) had cavities. Overall, 32 (19.8%) participants had CPA. CPA was associated with prior PTB (adjusted odds ratio [aOR]: 6.61, 95% CI: 1.85-23.9, p = .004), and far advanced CXR changes (aOR: 4.26, 95% CI: 1.72-10.52, p = .002). The Aspergillus IgG/IgM ICT was positive in 10 (31.3%) participants with CPA. CONCLUSIONS: Chronic pulmonary aspergillosis may cause persistent respiratory symptoms in up to one-fifth of patients after intensive treatment for PTB. The Aspergillus IgG/IgM ICT positivity rate was very low and may not be used alone for the diagnosis of CPA in Uganda.