Implementation of HIV early infant diagnosis and HIV type 1 RNA viral load determination on dried blood spots in Cameroon: challenges and propositions

Evaluation of Prevention of Mother to Child Transmission Programme at a Tertiary Healthcare Facility in Southwestern Nigeria

Most children acquire human immunodeficiency virus (HIV) infection through mother-to-child transmission (MTCT). The risk of MTCT of HIV is generally 15%-40% without prophylaxis. MTCT has been responsible for approximately 370,000 infant HIV infections worldwide, with Nigeria accounting for 30% of cases. The study evaluated the effectiveness of a prevention program for MTCT of HIV infection by determining the rate of MTCT of HIV in infants who underwent the program by reviewing health records of mother-infant pairs at the Olabisi Onabanjo University Teaching Hospital. This cross-sectional study conducted over 12 years used medical records of 545 mother-infant pairs. The rate of MTCT of HIV infection was 2.9% in this study compared to 7.1% reported by the center earlier. The rate of MTCT of HIV infection was the lowest among mother-infant pairs who received prophylaxis. Ages at recruitment are a strong determinant of the risk of infection. Late usage of the MTCT prevention service is a risk for HIV infection in exposed infants.

The mother-to-child transmission of HIV-1 and profile of viral reservoirs in pediatric population: A systematic review with meta-analysis of the Cameroonian studies

BACKGROUND

The mother-to-child transmission of HIV-1 (MTCT) remains on the major route of HIV-transmission among pediatric populations in Africa. Though a prevention of MTCT (PMTCT) high-priority country, data on the MTCT burdens in Cameroon remains fragmented.

OBJECTIVE

We sought to assess the pooled MTCT rate, its risk-factors, and to characterize viral reservoirs of infected-children in Cameroon.

METHODS

All relevant observational cohort and cross-sectional studies conducted in Cameroon were searched from PubMed, African Journals Online, Google scholar, ScienceDirect and academic medical education databases. Heterogeneity and publication bias were respectively assessed by the I2 statistic and the Egger/funnel plot test. Meta-analysis was performed using the random effects model. MTCT rate >5% was considered as "high". This review was registered in the Prospero database, CRD42021224497.

RESULTS

We included a total of 29 studies and analyzed 46 684 children born from HIV-positive mothers. The overall rate of MTCT was 7.00% (95% CI = 6.07-8.51). According to regions, the highest burden was in Adamaoua-region (17.51% [95% CI:14.21-21.07]) with only one study found. PMTCT option-B+ resulted in about 25% reduction of MTCT (8.97% [95% CI: 8.71-9.24] without option-B+ versus 2.88% [95% CI: 5.03-9.34] with option-B+). Regarding risk-factors, MTCT was significantly associated with the absence of PMTCT-interventions both in children (OR:5.40 [95% CI: 2.58-11.27]) and mothers (OR: 3.59 [95% CI: 2.15-5.99]). Regarding viral reservoirs, a pro-viral DNA mean of 3.34±1.05 log10/mL was observed among 5/57 children and archived HIV drug resistance mutations were identified in pro-viral DNA marker among 21/79 infected-children.

CONCLUSION

In spite of the dropdown in MTCT following option-B+ implementation, MTCT remains high in Cameroon, with substantial disparities across regions. Thus, in this era of option-B+, achieving MTCT elimination requires interventions in northern-Cameroon. The variation in pro-viral load in infected-children underlines the relevance of characterizing viral reservoirs for possible infection control in tropical settings.

Enhanced passive surveillance dengue infection among febrile children: Prevalence, co-infections and associated factors in Cameroon

Dengue virus (DENV) causes a spectrum of diseases ranging from asymptomatic, mild febrile to a life-threatening illness: dengue hemorrhagic fever. The main clinical symptom of dengue is fever, similar to that of malaria. The prevalence of dengue virus infection, alone or in association with other endemic infectious diseases in children in Cameroon is unknown. The aim of this study was to determine the prevalence of dengue, malaria and HIV in children presenting with fever and associated risk factors.

Dengue overall prevalence was 20.2%, Malaria cases were 52.7% and HIV cases represented 12.6%. The prevalence of dengue-HIV co-infection was 6.0% and that of Malaria-dengue co-infection was 19.5%. Triple infection prevalence was 4.3%. Dengue virus infection is present in children and HIV-Dengue or Dengue- Malaria co-infections are common. Dengue peak prevalence was between August and October. Sex and age were not associated with dengue and dengue co-infections. However, malaria as well as HIV were significantly associated with dengue (P = 0.001 and 0.028 respectively). The diagnosis of dengue and Malaria should be carried out routinely for better management of fever.

Fever is a symptom common to several infectious diseases such as malaria, yellow fever, dengue fever and typhoid which are all present in Cameroon. In most cases, fever in Cameroon is assumed to be due to malaria and treated as such. This study present the prevalence of dengue fever among febrile children. Dengue fever as well as malaria is common among Cameroonian children. Since Cameroon is endemic for malaria, fever may indicate either malaria or dengue. Clinicians should be aware of the presence of dengue in Cameroon. Knowing the risk factors, parents are encouraged to use the bed net to protect their children and clean stagnant water from their environment. Children could be co-infected by dengue, malaria as well as HIV. Management of patients with dengue fever and HIV infection should be studied, especially in infants where both viral diseases are more severe. Close monitoring may prevent complications among HIV-infected individuals who contract dengue fever.

Alteration of the gut fecal microbiome in children living with HIV on antiretroviral therapy in Yaounde, Cameroon

Multiple factors, such as immune disruption, prophylactic co-trimoxazole, and antiretroviral therapy, may influence the structure and function of the gut microbiome of children infected with HIV from birth. In order to understand whether HIV infection altered gut microbiome and to relate changes in microbiome structure and function to immune status, virological response and pediatric ART regimens, we characterized the gut microbiome of 87 HIV-infected and 82 non-exposed HIV-negative children from Yaounde, a cosmopolitan city in Cameroon. We found that children living with HIV had significantly lower alpha diversity in their gut microbiome and altered beta diversity that may not be related to CD4+ T cell count or viral load. There was an increased level of Akkermansia and Faecalibacterium genera and decreased level of Escherichia and other Gamma proteobacteria in children infected with HIV, among other differences. We noted an effect of ethnicity/geography on observed gut microbiome composition and that children on ritonavir-boosted protease inhibitor (PI/r)-based ART had gut microbiome composition that diverged more from HIV-negative controls compared to those on non-nucleoside reverse-transcriptase inhibitors-based ART. Further studies investigating the role of this altered gut microbiome in increased disease susceptibility are warranted for individuals who acquired HIV via mother-to-child transmission.

Use of an Indeterminate Range in HIV Early Infant Diagnosis: A Systematic Review and Meta-Analysis

BACKGROUND

Expanded access to HIV antiretrovirals has dramatically reduced mother-to-child transmission of HIV. However, there is increasing concern around false-positive HIV test results in perinatally HIV-exposed infants but few insights into the use of indeterminate range to improve infant HIV diagnosis.

METHODS

A systematic review and meta-analysis was conducted to evaluate the use of an indeterminate range for HIV early infant diagnosis. Published and unpublished studies from 2000 to 2018 were included. Study quality was evaluated using GRADE and QUADAS-2 criteria. A random-effects model compared various indeterminate ranges for identifying true and false positives.

RESULTS

The review identified 32 studies with data from over 1.3 million infants across 14 countries published from 2000 to 2018. Indeterminate results accounted for 16.5% of initial non-negative test results, and 76% of indeterminate results were negative on repeat testing. Most results were from Roche tests. In the random-effects model, an indeterminate range using a polymerase chain reaction cycle threshold value of ≥33 captured over 93% of false positives while classifying fewer than 9% of true positives as indeterminate.

CONCLUSIONS

Without the use of an indeterminate range, over 10% of infants could be incorrectly diagnosed as HIV positive if their initial test results are not confirmed. Use of an indeterminate range appears to lead to substantial improvements in the accuracy of early infant diagnosis testing and supports current recommendations to confirm all initial positive tests.

Low rate of early vertical transmission of HIV supports the feasibility of effective implementation of the national PMTCT guidelines in routine practice of referral hospitals in Cameroon

Background: Vertical (VT) transmission of HIV remains a public health concern in sub-Saharan Africa. Objective: To investigate the VT rate and factors associated with transmission in routine practice in three referral hospitals in Cameroon. Methods: All HIV-infected mothers who delivered in maternity wards or sought paediatric services during the first postnatal week from November 2007 to October 2010 were invited to participate in the ANRS-Pediacam cohort. Their infants were followed at 6, 10 and 14 weeks of life and HIV status was determined from the 6th week of life using real-time PCR. For those who were breastfed and negative at the first PCR, a second test was performed 6 weeks after breast-feeding was stopped. Logistic regression was performed to identify the independent risk factors of VT. Results: Overall, 2053 HIV-exposed infants were enrolled. Of these, 1827 were tested for HIV including 1777 before the age of 3 months, and 59 were HIV-infected, resulting in an overall early VT rate of 3.3% (CI 2.5-4.3). The VT rate was significantly associated with the type of maternal exposure to ART (0.5%, 2/439, p<0.001, CI 0.0-1.6) in mothers who commenced HAART before pregnancy, 1.9% (6/321, CI 0.7-4.0) in mothers who commenced HAART during pregnancy, 4.1% (34/837, CI 2.8-5.6) in those on short-course ART and 11.1% (17/153, CI 6.6-17.2) in mothers not receiving ART. On multivariate analysis, the type of exposure to ART remained significantly associated with being small for gestational age (aOR 5.0, CI 2.4-10.3, p < 0.001) and female gender (aOR 2.1, CI 1.2-3.8, p = 0.01). Conclusion: The successfully low rate of VT transmission of HIV in mothers who commenced HAART in early pregnancy strongly supports the need to improve access to diagnosis and early treatment of all women of childbearing age with HIV through the national PMTCT programme. Abbreviations: ANRS: French National Agency for Research on AIDS and Viral Hepatitis; ART: antiretroviral therapy; ARV: antiretroviral; AUDIPOG: Association des Utilisateurs de Dossiers Informatisés en Pédiatrie, Obstétrique et Gynécologie; CHM/MCC-CBF: The Central Hospital Maternity/Mother and Child Centre of the Chantal Biya Foundation; EHC: Essos Hospital Centre; EPI: Expanded Programme on Immunization; HAART: highly active antiretroviral therapy; HBV: hepatitis B virus; IQR: interquartile range; LH: Laquintinie Hospital; MTCT: mother-to-child transmission; NVP: nevirapine; Pediacam: Pediatrie Cameroun; PMTCT: prevention of mother-to-child transmission; SGAG: small for gestational age and gender; UNAIDS: Joint United Nations Program on HIV/AIDS; WHO: World Health Organization; ZDV: zidovudine; 3TC: lamivudine.

Maternal age, infant age, feeding options, single/multiple pregnancy, type of twin sets and mother-to-child transmission of HIV

BACKGROUND

Some risk factors for mother-to-child transmission (MTCT) of HIV have been identified. To further reduce MTCT, other risk factors were evaluated.

MATERIALS AND METHODS

A retrospective study on early infant diagnosis was conducted. Two-sided chi-square test was used to assess associations with infant HIV status.

RESULTS

A total of 15 233 HIV-infected mothers and 15 404 infants were recruited. MTCT rate was 9.34%. Only 3.8% of infants born to mothers on antiretroviral treatment were infected. Under nevirapine, 4.1% of infants were infected. MTCT increased with infant' age at testing. Younger mothers tend to transmit more HIV (P = 0.003). More children were infected in single pregnancies compared with multiple pregnancies, P < 0.001. There were more infections in male-female twins' sets (P = 0.037).

CONCLUSIONS

Maternal age, type of pregnancy and twins' sets are new MTCT risk factors. Strategies to further decrease transmission through family planning, pre/post natal consultations and clinical practices are needed.

[12-months efficacy of option B+ for prevention of mother-to-child transmission of HIV in Yaoundé, Cameroon]

BACKGROUND

Cameroon has adopted the option B+ for the prevention of mother-to-child transmission (MTCT) program of HIV in August 2014 in order to eradicate MTCT of HIV.

OBJECTIVE

To analyze in routine life settings, efficacy of option B+ for PMTCT and associate factors.

METHODS

We conducted a cross-sectional study over a 6-month period in the ESSOS hospital center. Study population comprised HIV-positive mothers and their infants aged 0-24 months. Variables included were : moment of HIV maternal testing, timing of commencement of maternal antiretroviral therapy (ART) and self-reported adherence to ART. Efficacy was measured through early and late MTCT rate and associated factors.

RESULTS

We included 200 mothers and 124 infants. Under option B+, the rate of transmission was at 4.20% at 6 weeks and 5.83% at 12 months. The rate of HIV transmission in breastfed infants stood at 3.7%. In unadjusted analysis, bottle-feeding, term at birth, early screening and management during pregnancy were associated with lower risk of HIV transmission. After adjustment, term at delivery after 37 weeks adjusted odds ratio (AOR) [0.059; (0.0061; 0.56)] was protective; while lack of prophylaxis was among HIV-exposed infants emerged as the main factor associated with residual transmission of HIV [AOR 117.23 ; (3.55 ; 3874.9)].

CONCLUSION

In this setting of Yaoundé, routine option B+ posted laudable results at 12 months even amongst breastfed children and should therefore be made sustainable.

Accessibility of Early Infant Diagnostic Services by Under-5 Years and HIV Exposed Children in Muheza District, North-East Tanzania

Introduction: Early infant diagnosis (EID) of Human Immunodeficiency Virus (HIV) provides an opportunity for follow up of HIV exposed children for early detection of infection and timely access to antiretroviral treatment. We assessed predictors for accessing HIV diagnostic services among under-five children exposed to HIV infection in Muheza district, Tanzania.

Methods: A cross sectional facility-based study among mother/guardian-child pairs of HIV exposed children was conducted from June 2015 to June 2016. Using a structured questionnaire, we collected information on HIV status, socio-demographic characteristics and other relevant data. Multiple regression analyses were used to investigate associations of potential predictors of accessing EID services.

Results: A total of 576 children with their respective mothers/guardians were recruited. Of the 576 mothers/guardians, 549 (95.3%) were the biological mothers with a median age of 34 years (inter-quartile range: 30–38 years). The median age of the 576 children was 15 months (inter- quartile range: 8.5–38.0 months). A total of 251 (43.6%) children were born to mothers with unknown HIV status at conception. Only 329 (57.1%) children accessed EID between 4 and 6 weeks of age. Children born to mothers with unknown HIV status at conception (AOR = 0.6, 95% CI 0.4–0.8) and those with ages 13–59 months (AOR = 0.4, 95% CI 0.2–0.6) were the significant predictors of missed opportunity to access EID. Children living with the head of household with at least a high education level had higher chances of accessing EID (AOR = 1.8, 95% CI 1.1–3.3). Their chances of accessing EID services was three-fold higher among mothers/guardians with good knowledge of HIV infection prevention of mother to child transmission (AOR = 3.2, 95% CI 2.0–5.2) than those with poor knowledge. Mothers/guardians living in rural areas had poorer knowledge of HIV infection prevention of mother to child transmission (AOR = 0.6, 95% CI 0.4–0.9) than those living in urban areas.

Conclusion: Accessibility of EID services among children below 5 years exposed to HIV infection in Muheza is low. These findings stress the need for continued HIV education and outreach services, particularly in rural areas in order to improve maternal and child health.

A Proposed Framework for the Implementation of Early Infant Diagnosis Point-of-Care

Early diagnosis of HIV infection in infants and children remains a challenge in resource-limited settings, with approximately half of all HIV-exposed infants receiving virological testing for HIV by the recommended age of 2 months in 2015. To reduce morbidity and mortality among HIV-infected children and close the treatment gap for HIV-infected children, there is an urgent need to evaluate existing programmatic and laboratory practices for early infant diagnosis and introduce strategies to improve identification of HIV-exposed infants and ensure access to systematic, early HIV testing, with early linkage to treatment for HIV-infected infants. This article describes progress made in follow-up of HIV-exposed infants since 2006, including remaining unmet laboratory and programmatic needs, and recommends strategies for improvement, especially those related to the implementation of point-of-care technology for early infant diagnosis.

Obstetrical, maternal characteristics and outcome of HIV-infected rapid progressor infants at Yaounde: a retrospective study

BACKGROUND

Rapid progressors are exposed to HIV infection at an early stage of life, and the prognosis is poor without treatment. Reducing the proportion of infants who are rapid progressors, require strengthening strategies to achieve the highest level of performance for the PMTCT program.

METHODS

This was a retrospective study carried out on HIV infected infants aged less than 12 months, clinically classified stage 4 (WHO) or having CD4 count <25%. We described maternal and obstetrical characteristics of HIV-infected rapid progressors using univariate and bivariate analysis. Patients' survival was monitored from the inclusion time to the end of the study. We then estimated their probability of survival with or without anti-retroviral (ARV) treatment from birth using the Kaplan-Meier method.

RESULTS

The characteristics of the mothers of the 150 rapid progressors infants we included were: low level of education (OR=3.87; P=0.016), CD4 count less than 200/mm(3) (OR=43.3; P=0.000), absence of ARV prophylaxis (OR=6.02; P=0.043), or treatment with HAART (OR=5.74; P=0.000) during pregnancy. In the children, the most important findings were lack of co-trimoxazole prophylaxis (OR=11.61; P=0.000) and antiretroviral prophylaxis (OR=2.70; P=0.0344). The survival rate was 84.3% in infants who were receiving HAART as opposed to 43.3% in those who were not (P<0.05).

CONCLUSIONS

HIV infected women who are eligible should start antiretroviral treatment prior to a pregnancy, in order to improve their immunological status. This measure associated to cotrimoxazole prophylaxis and ART could improve their survival.

Estimating HIV Incidence during Pregnancy and Knowledge of Prevention of Mother-to-Child Transmission with an Ad Hoc Analysis of Potential Cofactors

BACKGROUND

We determined the incidence of HIV seroconversion during the second and third trimesters of pregnancy and ad hoc potential cofactors associated with HIV seroconversion after having an HIV-negative result antenatally. We also studied knowledge of PMTCT among pregnant women in seven health facilities in Fako Division, South West Region, Cameroon.

METHOD

During the period between September 12 and December 4, 2011, we recruited a cohort of 477 HIV-negative pregnant women by cluster sampling. Data collection was with a pretested interviewer-administered questionnaire. Sociodemographic information, knowledge of PMTCT, and methods of HIV prevention were obtained from the study population and we did Voluntary Counselling and Testing (VCT) for HIV.

RESULTS

The incidence rate of HIV seroconversion during pregnancy was 6.8/100 woman-years. Ninety percent of the participants did not use condoms throughout pregnancy but had a good knowledge of PMTCT of HIV. Only 31.9% of participants knew their HIV status before the booking visit and 33% did not know the HIV status of their partners.

CONCLUSION

The incidence rate of HIV seroconversion in the Fako Division, Cameroon, was 6.8/100 woman-years. No risk factors associated with HIV seroconversion were identified among the study participants because of lack of power to do so.

Dried blood spot specimen quality and validation of a new pre-analytical processing method for qualitative HIV-1 PCR, KwaZulu-Natal, South Africa

BACKGROUND

Poor quality dried blood spot (DBS) specimens are usually rejected by virology laboratories, affecting early infant diagnosis of HIV. The practice of combining two incompletely-filled DBS in one specimen preparation tube during pre-analytical specimen processing (i.e., the two-spot method) has been implemented to reduce the number of specimens being rejected for insufficient volume.

OBJECTIVES

This study analysed laboratory data to describe the quality of DBS specimens and the use of the two-spot method over a one-year period, then validated the two-spot method against the standard (one-spot) method.

METHODS

Data on HIV-1 PCR test requests submitted in 2014 to the Department of Virology at Inkosi Albert Luthuli Central Hospital in KwaZulu-Natal province, South Africa were analysed to describe reasons for specimen rejection, as well as results of the two-spot method. The accuracy, lower limit of detection and precision of the two-spot method were assessed.

RESULTS

Of the 88 481 specimens received, 3.7% were rejected for pre-analytical problems. Of those, 48.9% were rejected as a result of insufficient specimen volume. Two health facilities had significantly more specimen rejections than other facilities. The two-spot method prevented 10 504 specimen rejections. The Pearson correlation coefficient comparing the standard to the two-spot method was 0.997.

CONCLUSIONS

The two-spot method was comparable with the standard method of pre-analytical specimen processing. Two health facilities were identified for targeted retraining on specimen quality. The two-spot method of DBS specimen processing can be used as an adjunct to retraining, to reduce the number of specimens rejected and improve linkage to care.

Factors associated with non-adherence to scheduled medical follow-up appointments among Cameroonian children requiring HIV care: a case-control analysis of the usual-care group in the MORE CARE trial

BACKGROUND

A better understanding of why HIV-exposed/infected children fail to attend their scheduled follow-up medical appointments for HIV-related care would allow for interventions to enhance the delivery of care. The aim of this study was to determine characteristics of the caregiver-child dyad (CCD) associated with children's non-adherence to scheduled follow-up medical appointments in HIV programs in Cameroon.

METHODS

We conducted a case-control analysis of the usual-care group of CCDs from the MORE CARE trial, in which the effect of mobile phone reminders for HIV-exposed/infected children in attending follow-up appointments was assessed from January to March 2013. For this study, the absence of a child at their appointment was considered a case and the presence of a child at their appointment was defined as a control. We used three multivariate binary logistic regression analyses. The best-fit model was the one which had the smallest chi-square value with the Hosmer-Lemeshow test (HLχ²). Magnitudes of associations were expressed by odds ratio (OR), with a p-value <0.05 considered as statistically significant.

RESULTS

We included 30 cases and 31 controls. Our best-fit model which considered the sex of the adults and children separately (HL χ²=3.5) showed that missing scheduled medical appointments was associated with: lack of formal education of the caregiver (OR 29.1, 95% CI 1.1-777.0; p=0.044), prolonged time to the next appointment/follow-up (OR [1 week increase] 1.4, 95% CI 1.03-2.0; p=0.032), and being a female child (OR 5.2, 95% CI 1.2-23.1; p=0.032). One model (HLχ²=10.5) revealed that woman-boy pairs adhered less to medical appointments compared to woman-girl pairs (OR 4.9, 95% CI 1.05-22.9; p=0.044). Another model (HLχ²=11.1) revealed that man-boy pairs were more likely to attend appointments compared to woman-girl pairs (OR 0.23, 95% CI 0.06-0.93; p=0.039). There were no statistical associations for the ages of the children or the caregivers, the study sites, or the HIV status (confirmed vs. suspected) of the children.

CONCLUSION

The profile of children who would not attend follow-up medical appointments in an HIV program was: a female, with a caregiver who has had no formal education, and with a longer follow-up appointment interval. There is a possibility that female children are favored by female caregivers and that male children are favored by male caregivers when they come to medical care.

Molecular HIV screening

Nuclear acid testing is more and more used for the diagnosis of infectious diseases. This paper focuses on the use of molecular tools for HIV screening. The term 'screening' will be used under the meaning of first-line HIV molecular techniques performed on a routine basis, which excludes HIV molecular tests designed to confirm or infirm a newly discovered HIV-seropositive patient or other molecular tests performed for the follow-up of HIV-infected patients. The following items are developed successively: i) presentation of the variety of molecular tools used for molecular HIV screening, ii) use of HIV molecular tools for the screening of blood products, iii) use of HIV molecular tools for the screening of organs and tissue from human origin, iv) use of HIV molecular tools in medically assisted procreation and v) use of HIV molecular tools in neonates from HIV-infected mothers.

Systematic review of the use of dried blood spots for monitoring HIV viral load and for early infant diagnosis

BACKGROUND

Dried blood spots (DBS) have been used as alternative specimens to plasma to increase access to HIV viral load (VL) monitoring and early infant diagnosis (EID) in remote settings. We systematically reviewed evidence on the performance of DBS compared to plasma for VL monitoring and EID.

METHODS AND FINDINGS

Thirteen peer reviewed HIV VL publications and five HIV EID papers were included. Depending on the technology and the viral load distribution in the study population, the percentage of DBS samples that are within 0.5 log of VL in plasma ranged from 52-100%. Because the input sample volume is much smaller in a blood spot, there is a risk of false negatives with DBS. Sensitivity of DBS VL was found to be 78-100% compared to plasma at VL below 1000 copies/ml, but this increased to 100% at a threshold of 5000 copies/ml. Unlike a plasma VL test which measures only cell free HIV RNA, a DBS VL also measures proviral DNA as well as cell-associated RNA, potentially leading to false positive results when using DBS. The systematic review showed that specificity was close to 100% at DBS VL above 5000 copies/ml, and this threshold would be the most reliable for predicting true virologic failure using DBS. For early infant diagnosis, DBS has a sensitivity of 100% compared to fresh whole blood or plasma in all studies.

CONCLUSIONS

Although limited data are available for EID, DBS offer a highly sensitive and specific sampling strategy to make viral load monitoring and early infant diagnosis more accessible in remote settings. A standardized approach for sampling, storing, and processing DBS samples would be essential to allow successful implementation.

TRIAL REGISTRATION

PROSPERO Registration #: CRD42013003621.

TB and HIV in the Central African region: current knowledge and knowledge gaps

PURPOSE

Reliable and comprehensive data on the HIV/AIDS and TB co-pandemics from Central Africa remain scarce. This systematic review provides a comprehensive overview on current and past research activities in the region and provides a basis for future research work to close knowledge gaps.

METHODS

The scientific literature was searched for publications meeting the following search terms: "tuberculosis" or "HIV" or "acquired immunodeficiency syndrome", combined with "Central Africa", or the names of individual countries within the region. Original studies, reviews and case series were included, and a selection of relevant articles was made.

RESULTS

Most research in the field of HIV and TB has been conducted in Cameroon, where the epidemics have been described fairly well. The Democratic Republic of Congo ranked second on the amount of publications, despite the civil wars over the past several decades. Very little has been published on HIV and TB in the other countries, possibly due to the poor infrastructure of health care systems, lack of scientific capacity building or shortage of laboratory equipment.

CONCLUSIONS

Despite the relatively high burden of HIV and TB in the Central African region, the amount of research activities on these topics is limited. A better understanding of the co-epidemics in this region is urgently needed. The occurrence of opportunistic infections, treatment complications and drug resistance in TB and HIV need to be better described; the failure of public health systems needs to be understood, and research infrastructure needs to be developed. Only then will it be possible to turn the tide against the HIV and TB epidemics in this region.

Rapid detection of HIV-1 proviral DNA for early infant diagnosis using recombinase polymerase amplification

Early diagnosis and treatment of human immunodeficiency virus type 1 (HIV-1) infection in infants can greatly reduce mortality rates. However, current infant HIV-1 diagnostics cannot reliably be performed at the point of care, often delaying treatment and compromising its efficacy. Recombinase polymerase amplification (RPA) is a novel technology that is ideal for an HIV-1 diagnostic, as it amplifies target DNA in <20 min at a constant temperature, without the need for complex thermocycling equipment. Here we tested 63 HIV-1-specific primer and probe combinations and identified two RPA assays that target distinct regions of the HIV-1 genome (long terminal repeat [LTR] and pol) and can reliably detect 3 copies of proviral DNA by the use of fluorescence detection and lateral-flow strip detection. These pol and LTR primers amplified 98.6% and 93%, respectively, of the diverse HIV-1 variants tested. This is the first example of an isothermal assay that consistently detects all of the major HIV-1 global subtypes.