Situation of onchocerciasis transmission in 2020 in the Cascades region of Burkina Faso

Faced with the focal resurgence of onchocerciasis reported since 2004 in the South-West of Burkina Faso, the Neglected Tropical Diseases Control Program adopted a resumption of biannual community-directed treatment with ivermectin, since 2011 in the Cascades region and since 2013 in the South West region. The objective of this study was to assess the situation of onchocerciasis transmission in the Cascades region, nine years after the resumption of mass drug administration. This cross-sectional and descriptive survey concerned people over 5. The traditional method of skin snip on both iliac crests was performed for the parasitological diagnosis of onchocerciasis. The Ov-16 serological test was carried out in children aged 5 to 9 years. In 22 surveyed villages, the overall prevalence of microfilariae was 0.11% and below the tolerable threshold of 5%. It was less than 5% in all the villages (n = 22), less than 1% in 21 villages (99%) and zero in 19 villages (86.36%). The community microfilarial loads varied from 0.01 to 0.05 mf/b. Out of 946 children tested for OV-16, only one 9-year-old was positive and whose skin snip examination was negative. All the positive cases came from endemical areas in Côte d'Ivoire. Population migration is a risk factor for introducing the parasite into Burkina Faso; it also is risk factor for the effective elimination of onchocerciasis which requires the joint development of a control strategy between neighboring countries.

Plasmodium falciparum Genetic Diversity and Resistance Genotype Profile in Infected Placental Samples Collected After Delivery in Ouagadougou

Purpose

Intermittent preventive treatment with sulfadoxine-pyrimethamine is widely used for the prevention of malaria in pregnant women in Africa. Known resistance cases of sulfadoxine-pyrimethamine during pregnancy need to be follow up to support IPTp implementation in Burkina Faso. However, data on the development and spread of resistance to this molecule are lacking. This study aimed to investigating the genetic diversity of P. falciparum and the mutation prevalence in the dhfr and dhps genes infected from postpartum infected placentas.

Patients and Methods

This was a prospective and cross-sectional study conducted between April 2019 and March 2020 in four health districts of Ouagadougou capital city. From the placentas collected after delivery, P. falciparum detection and mps1 and msp2 polymorphism analysis were performed by nested PCR. The resistance profile was checked after analyzing the mutation point on dhfr and dhps genes.

Results

PCR-positive samples were estimated at 96% for msp1 and 98% for msp2. The polymorphism analysis showed that the RO33 and 3D7 allelic families were the most widespread with 62.5% and 91.83%, respectively. Multiple infections by msp1 and msp2 were frequent with 12.50% and 92.92%, respectively. The prevalence of individual dhfr mutation point, 51I, 108A, and 59R, was 1.96, 15.68, and 7.84, respectively, and the dhps mutation point, 437G, was 3.92. There is no detected mutation at the point 164L and 540E. The triple (51I+108A+59R) in dhfr and quadruple (51I+108A+59R+ 437G) mutation were not found.

Conclusion

The results showed that Plasmodium falciparum has a high genetic diversity of msp1 and msp2. This suggests that dhfr and dhps mutant genotypes are potential early warning factors in the increase in the sulfadoxine-pyrimethamine resistance.

Molecular detection and quantification of Plasmodium falciparum gametocytes carriage in used RDTs in malaria elimination settings in northern Senegal

BACKGROUND

Malaria surveillance requires powerful tools and strategies to achieve malaria elimination. Rapid diagnostic tests for malaria (RDTs) are easily deployed on a large scale and are helpful sources of parasite DNA. The application of sensitive molecular techniques to these RDTs is a modern tool for improving malaria case detection and drug resistance surveillance. Several studies have made it possible to extract the DNA of Plasmodium falciparum from RDTs. The knowledge of gametocyte carriage in the population is important to better assess the level of parasite transmission in elimination settings. The aim of this study was to detect P. falciparum gametocytes from used RDTs by quantitative PCR for molecular monitoring of malaria transmission.

METHODS

DNA was extracted from 303 RDT devices (SD Bioline Malaria Pf) using the Chelex-100 protocol. qPCR was performed in a 20 μL reaction to detect and quantify transcripts of the pfs25 gene. The cycle threshold (Ct) was determined by the emission fluorescence corresponding to the initial amount of amplified DNA.

RESULTS

The study found an overall prevalence of 53.47% with an average Ct of 32.12 ± 4.28 cycles. In 2018, the prevalence of gametocytes was higher in the Ranérou district (76.24%) than in the Saint-Louis district (67.33%) where an increase in the number of gametocyte carriers in 2018 was noted, in comparison with 2017.

CONCLUSIONS

RDTs are a good source of DNA for molecular monitoring of gametocyte carriage. This method is a simple and effective tool to better understand the level of malaria transmission with a view to elimination.

First case report of Talaromyces marneffei infection in HIV-infected patient in the city of Ouagadougou (Burkina Faso)

Talaromycosis is endemic in Southeast Asia and is commonly described in HIV-infected patients. We describe the first case of Talaromycosis in HIV-infected patient in Burkina Faso. This is an 83-year-old man with skin lesions on the right foot. The thick scales were used for the mycological examination. Microscopic examination of growth allowed isolation of Talaromyces marneffei in its yeast and mold forms. The patient was treated successfully with Itraconazole (400 mg/day) for 8 weeks.

Evaluation of the effect of mass drug administration against lymphatic filariasis in three health districts and public health implications: study of 12 epidemiological surveillance sites in Burkina Faso

The implementation of mass drug administration (MDA) campaigns of albendazole (400 mg) and ivermectin (150-200 μm/kg) since 2001 has helped to change the epidemiological profile of lymphatic filariasis (LF) in many health districts in Burkina Faso. From 2002 to 2016, 14 rounds of MDA have taken place in the Central East zone, with therapeutic coverage exceeding 65%. The objective of the current study was to evaluate the impact of MDA in the fight against LF at 12 sentinel and spot-check sites. This descriptive cross-sectional study surveyed subjects aged 5 years and older between April and July 2017 at these 12 sites. The blood smear performed on nocturnal samples was used to diagnose Wuchereria bancrofti infection. The study included 4364 subjects. Their mean age was 20.55 years with a standard deviation of 14.22 and a range of 5 to 96 years. The overall prevalence of microfilaremia was 0.62% (27/4364), with rates exceeding 1% at three (3) sites. The average microfilaremia density was 106 μf/mL. The overall prevalence of morbidity was low (0.91%), predominantly lymphedema (0.60%). The MDA strategy has helped to reduce the prevalence of LF significantly in Burkina Faso, but some outbreaks still have microfilarial prevalence greater than 1%. Continuation of the additional 2-year strategy with improved adherence to treatment and vector control would help break LF transmission.