High incidence of intermittent care in HIV-1-infected patients in Curaçao before and after starting cART.

Retention in care is one of the major challenges to scaling up and maximizing the effectiveness of combination antiretroviral therapy (cART). High attrition rates have been reported in the Caribbean region, varying from 6% to 23%. We studied the incidence of and risk factors for intermittent care in a cohort of adult HIV-1-positive patients, who entered into care in Curaçao between January 2005 and July 2009. A total of 214 therapy-naïve HIV-1-infected patients aged 15 years or older, entered HIV care between January 2005 and July 2009. Intermittent care was defined as at least one period of 365 days or longer in which there was no HIV care contact in Curaçao. Cox regression models were used to identify characteristics associated with time to intermittent care. In all, 203 (95%) patients could be classified as having intermittent or continuous care. The incidence of intermittent care before starting cART was 25.4 per 100 person years observation (PYO), whilst it was 6.1 per 100 PYO after starting cART. Being born outside Curaçao was associated with intermittent care before and after starting cART. Time from diagnosis to entry into care was an independent predictor for intermittent care before starting cART. Younger age was independently associated with intermittent care after starting cART. Half of the patients returned to care after intermitting care. Upon returning to care, median CD4 count was 264 cells/mm(3) (IQR, 189-401) for those who intermitted care before starting cART, and 146 cells/mm(3) (IQR, 73-436) in those who intermitted care after starting cART. In conclusion, the incidence of intermitting care is high in Curaçao, especially before starting cART, and intermitting care before starting cART is an independent predictor for starting cART late.

Syncytium-inducing and non-syncytium-inducing capacity of human immunodeficiency virus type 1 subtypes other than B: phenotypic and genotypic characteristics. WHO Network for HIV Isolation and Characterization.

Positively charged amino acid substitutions at positions 11 and 25 within the loop of the third variable region (V3) of HIV-1 subtype B envelope have been shown to be associated with the syncytium-inducing (SI) phenotype of the virus. The present study was designed to examine SI and NSI-associated V3 mutations in HIV-1 subtypes other than B. HIV-1 RNA was isolated from 53 virus stocks and 26 homologous plasma samples from 53 recently infected individuals from Brazil, Rwanda, Thailand, and Uganda. The C2-V3 region of the viral envelope was converted to cDNA, amplified, and sequenced. Of 53 primary virus stock samples 49 were biologically phenotyped through measurement of the syncytium-inducing capacity in MT-2 cells (to differentiate between SI and NSI phenotypes). In addition, after passage of primary isolates through PHA stimulated donor PBMC, the replication capacity was determined in U937-2, CEM, MT-2, and Jurkat-tat cell lines (to differentiate rapid/high and slow/low phenotypes). According to the sequence analysis 9 (17.0%) of the viruses belonged to subtype A, 15 (28.3%) to subtype B, 1 (1.9%) to subtype C, 13 (24.5%) to subtype D, and 15 (28.3%) to subtype E. Sequence analysis of virus RNA, obtained from 26 homologous plasma samples, confirmed the homogeneity of sequence populations in plasma compared to primary virus isolates. Of the 49 viruses tested 12 had the SI phenotype, 5 were confirmed to be rapid/high, and 4 appeared to be slow/low pattern 3 replicating. Of 49, 29 had the NSI phenotype, 24 were confirmed to be slow/low pattern 1 or 2, and 3 appeared to be slow/low pattern 3 replicating. Analysis of mutations at V3 loop amino acid positions 11 and 25 revealed that 10/12 (83.3%) of the SI viruses had SI-associated V3 mutations and that 28/29 (96.6%) of the NSI viruses lacked these mutations. V3 loop heterogeneity, length polymorphism, and a high number of positively charged amino acid substitutions were most frequently found among subtype D variants. These results indicate that both the phenotypic distinction between SI and NSI viruses and the association of biological phenotype with V3 mutations is present among HIV-1 subtypes other than B.