Effects of syphilis infection among HIV-1-positive individuals on suppressive antiretroviral therapy.

INTRODUCTION: Incident syphilis leads to changes in plasma HIV-1 RNA and CD4 + T-cell level in people with HIV (PWH) with viraemia. Its effect in PWH on suppressive antiretroviral therapy (ART) is less clear. METHODS: PWH on suppressive ART (plasma HIV-1 RNA < 50copies/mL) followed at the Queen Elizabeth Hospital, Hong Kong, China were regularly screened for syphilis. Their plasma HIV-1 RNA, CD4 + and CD8 + T-cell, and total lymphocyte levels before syphilis, during syphilis, and after successful treatment were compared. RESULTS: Between 2005 and 2020, 288 syphilis episodes from 180 individuals were identified; 287 episodes were related to male, with a median age of 41 at diagnosis; 221 (77%) were syphilis re-infection. The rates of plasma HIV-1 suppression were statistically unchanged across the time-points (97% pre-syphilis, 98% during syphilis, and 99% post-treatment). Total lymphocyte, CD4+ and CD8+ T-cell levels decreased during incident syphilis (p<0.01), and rebounded post-treatment (p<0.01). VDRL titre was associated with declines in CD4+ T-cell (p=0.045), CD8+ T-cell (p=0.004), and total lymphocyte levels (p=0.021). Pre-syphilis CD4/CD8 ratio was associated with increases in CD8+ T-cell (p=0.001) and total lymphocyte levels (p=0.046) during syphilis. Syphilis re-infection was associated with an increase in total lymphocyte level (p=0.037). In the multivariable analysis, only pre-syphilis CD4/CD8 ratio was independently associated with increases in CD8+ T-cell (p=0.014) and total lymphocyte levels (p=0.039) during syphilis. CONCLUSIONS: Among virally-suppressed PWH, total lymphocyte, CD4+, and CD8+ T-cell levels declined during incident syphilis but rebounded post-treatment. The status of plasma HIV suppression was unaffected by syphilis.

Cognitive screening in treatment-naïve HIV-infected individuals in Hong Kong - a single center study.

BACKGROUND: HIV-associated neurocognitive disorder (HAND) remains prevalent in the era of combination antiretroviral therapy (cART). The prevalence of HAND in Hong Kong is not known. METHODS: Between 2013 and 2015, 98 treatment-naïve HIV-1-infected individuals were referred to and screened by the AIDS Clinical Service, Queen Elizabeth Hospital with (1) the International HIV Dementia Scale (IHDS), a screening tool that targets moderate to severe HAND, (2) the Montreal Cognitive Assessment (MoCA), a frequently used cognitive screening test and (3) the Patient Health Questionnare-9 (PHQ-9), a 9-item questionnaire that evaluates depression symptoms. Within the study period, 57 of them completed the second set of IHDS and MoCA at 6 months after baseline assessment. RESULTS: Most participants were male (94%), with a median age of 31 years. At baseline, 38 (39%) and 25 (26%) of them scored below the IHDS (≤10) and MoCA (25/26) cut-offs respectively. Poor IHDS performers also scored lower on MoCA (p = 0.039) but the correlation between IHDS and MoCA performance was weak (r = 0.29, p = 0.004). Up to a third of poor IHDS performers (13/38) showed moderate depression (PHQ-9 > 9). In the multivariable analysis, a lower education level (p = 0.088), a history of prior psychiatric illness (p = 0.091) and the presence of moderate depression (p = 0.079) tended to be significantly associated with poor IHDS performance. At follow-up, 54 out of 57 were on cART, of which 46 (85%) had achieved viral suppression. Their blood CD4+ T-lymphocytes and IHDS scores were higher at follow-up compared to baseline values (both p < 0.001) but their MoCA performance was similar at both assessments. Of note, 17 participants in this subgroup scored below the IHDS cut-off at both assessments. CONCLUSIONS: Poor IHDS performance, and likely cognitive impairment, was frequently observed in treatment-naïve HIV-infected individuals in our locality. A considerable proportion continued to score below the IHDS cut-off at 6 months after cART. Depression was frequently observed in this vulnerable population and was associated with poor IHDS performance.

Molecular Identification of Spirometra erinaceieuropaei Tapeworm in Cases of Human Sparganosis, Hong Kong.

Human sparganosis is a foodborne zoonosis endemic in Asia. We report a series of 9 histologically confirmed human sparganosis cases in Hong Kong, China. All parasites were retrospectively identified as Spirometra erinaceieuropaei. Skin and soft tissue swelling was the most common symptom, followed by central nervous system lesions.

A novel Dirofilaria species causing human and canine infections in Hong Kong.

Dirofilariasis is globally the commonest manifestation of zoonotic filariasis. We report the detection of a novel canine species causing human and canine dirofilariasis in Hong Kong. Three human cases occurring over 10 months were identified, one presenting with cervical lymphadenopathy, one with an abdominal subcutaneous mass, and one with a subconjunctival nodule. Transected worms recovered from the resected abdominal subcutaneous mass were morphologically compatible with Dirofilaria. The cox1 gene sequences of the three human isolates were identical; however, they were only 96.2% and 89.3% identical to the cox1 gene of Dirofilaria repens and Dirofilaria immitis, respectively. Sequencing of the 18S-ITS1-5.8S gene cluster was successful in the intact worm, and the nucleotide sequences were 94.0% and 94.9% identical to those of D. repens and D. immitis, respectively. Screening of the blood samples from 200 dogs and 100 cats showed the presence of the novel Dirofilaria species in 3% (6/200) of the dogs' but none of the cats' blood samples. Nucleotide sequences of the cox1 gene and 18S-ITS1-5.8S gene clusters of the dogs' samples were identical to those in the human samples. The sera of canines infected by this novel Dirofilaria species were negative when tested with the SNAP 4Dx D. immitis detection kit, except in the case of dogs with a mixed infection with D. immitis as detected by PCR. The results from this study suggest that this novel Dirofilaria species is a cause of filarial infection in humans and dogs in Hong Kong. We propose to name this Dirofilaria species "Candidatus Dirofilaria hongkongensis."