Evidence of the impact of monovalent rotavirus vaccine on childhood acute gastroenteritis hospitalization in Togo.

BACKGROUND: Monovalent rotavirus vaccine (RV1) was introduced in the immunization schedule of Togo in June 2014. We evaluated the impact of rotavirus vaccines on acute gastroenteritis (AGE) and rotavirus-associated hospitalizations in Togolese children. METHODS: Sentinel surveillance for AGE (defined as ≥3 liquid or semi-liquid stools/24 h lasting <7 days) hospitalizations among children <5 years of age was conducted in two sites in the capital city, Lome. ELISA was used for diagnosis of rotavirus infection in children with AGE. Additionally, review of hospitalization registers was performed at five hospitals to assess trends in AGE hospitalizations among children aged <5 years. For the vaccine impact assessment, pre-rotavirus vaccine introduction (July 2010-June 2014) and post-rotavirus vaccine introduction (July 2014-June 2016) periods were compared for annual changes in proportions of hospitalizations associated with AGE and rotavirus. RESULTS: During the pre-vaccine period, sentinel surveillance showed that 1017 patients were enrolled and 57% (range, 53-62%) tested positive for rotavirus, declining to 42% (23% reduction) in the first post-vaccine year and to 26% (53% reduction) in the second post-vaccine year; declines were most marked among infants. The patient register review showed that, compared with pre-vaccine rotavirus seasons, declines in hospitalizations due to all-cause AGE during post-vaccine rotavirus seasons were 48% among <1 year age-group in both first and second years following vaccine introduction. Among 1-4 year olds no reduction was noted in the first year and a 19% decline occurred in the second year. CONCLUSIONS: We report rapid and marked reduction in the number of AGE hospitalizations and the proportion of AGE hospitalizations attributable to rotavirus in the first two years post- RV1 implementation in Togo. It is necessary to monitor long-term vaccine impact on rotavirus disease burden through continued surveillance.

Genetic diversity and genotype multiplicity of Plasmodium falciparum infections in symptomatic individuals in the maritime region of Togo.

OBJECTIVE: To assess the genotype prevalence and the multiplicity of Plasmodium falciparum infections in the maritime region of Togo. METHODS: We enrolled 309 symptomatic individuals aged from 6 months to 15 years from Bè/Lomé and Tsévié, two malaria endemic zones. The number and the proportions of merozoite surface proteins 1, 2 and 3 genotypes in patients were determined using capillary electrophoresis genotyping. We further investigated the possible association between transaminases and homocysteine, and the severity of the disease. RESULTS: Of the 309 samples genotyped, 210 tested positive to msp-1, 227 to msp-2 and 193 to msp-3. The nested PCR revealed 22 different alleles for the allelic family msp-1, 33 for msp-2 and 13 for msp-3. At each locus, the family distribution was 54.58% of K1, 25% of MAD20 and 20.42% of RO33 for msp-1, and 51.71% and 48.29% of FC27 and 3D7, respectively, for msp-2. For all these allelic variants, the distribution was associated with neither the severity of malaria nor the zone of habitation. Pearson correlation coefficients between either the levels of homocysteine or the transaminase and the severity of the disease were very low. CONCLUSION: The severity of malaria was not associated with higher multiplicity of infections and did not appear restricted to particular genotypes. More comprehensive explorations including immunity, genetic factors, nutritional and sociologic status of the population could clarify the situation.