Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.

Integrated Impact of Climate Change and Socioeconomic Development on the Evolution of Camel Farming Systems.

In Sub-Saharan countries, climate change has already been observed for several decades and is characterized by the decrease in mean rainfall with extensive periods of drought followed by short but severe rains. The dromedary camel, adapted to arid lands and low nutritive natural resources, follows the aridification of ecosystems as she/he did so when moving into Africa through the Sinai Peninsula at the beginning of the Christian era. Thus, the on-going desertification in Northern Africa increases the camel distribution area, both geographically and socially, e.g. with regard to its use by people who are not traditionally camel keepers. Elsewhere, camels are used differently, i.e. for their products (milk, agricultural work) rather than for their traditional uses (packing or riding). On the other hand, facing more contrasted crop ecosystems and an unbalanced climate, which seem to contribute to emerging diseases with complex and often unknown aetiologies, caused high unexplained deaths. These global trends would trigger more changes of camel farming systems in Sahelian countries if climate change intensifies continuously in the next decades.

Testicular and epididymal parameters of Sahel buck in the humid zone of Nigeria / Parámetros testicular y epididimal de cabras Sahel en la zona húmeda de Nigeria

The testicular and epididymal parameters of Sahel bucks in the humid zone of Nigeria was investigated. Twenty goats (30-54 months) weighing 23.48-32.03kg were used for the experiment. The scrotal circumference of the buck was measured. The bucks were then slaughtered and the testicles as well as the epididymides collected. The testicular weight, testicular diameter, testicular length and epididymal length were measured using a non-stretchable measuring tape. These parameters were correlated with one another and the values of the right testis and epididymis were compared with those of the left. The scrotal circumference was positively correlated with the testicular weight (r = 0.769, P<0.01), testicular diameter (r = 0.827, P<0.01), testicular length (r=0.671, P<0.05) and the epididymal length (r = 0.664, P<0.05). It was concluded that the scrotal circumference is a reliable guide in the selection of the sahel buck for breeding in the humid zone of Nigeria.

Fueron investigados los parámetros testicular y epidídimario de las cabras Sahel en la zona húmeda de Nigeria. Se utilizaron para el experimento 20 cabras (30-54 meses) con un peso entre 23,48-32,03kg. Se midió la circunferencia escrotal de las cabras. Los animales fueron sacrificados y se recolectaron los testículos, así como el epidídimo de cada uno. Fueron medidos el peso de los testículos, diámetro testicular, longitudes testicular y epididimaria utilizando una cinta métrica no extensible. Estos parámetros fueron correlacionados entre sí y los valores obtenidos a cada lado de testículos y epidídimos fueron comparados entre sí. La circunferencia escrotal se correlacionó positivamente con el peso testicular (r = 0,769, P <0,01), diámetro testicular (r = 0,827, P <0,01), longitud testicular (r = 0,671, P <0,05) y la longitud del epidídimo (r = 0,664, P <0,05). Se concluyó que la circunferencia escrotal es una guía confiable en la selección de la cabra Sahel para la cría en la zona húmeda de Nigeria.

Clinical and Microbiological Assessment of Trachoma in the Kolofata Health District, Far North Region, Cameroon

Background and aims: Trachoma is a sight-threatening process triggered by the infection of the conjunctiva with <i>Chlamydiae</i>. Blindness associated with trachoma was reported in Sahelian areas of Cameroon. However, data on the prevalence of this neglected infection in the Far North Region are not available. The aim of this study was a) to assess clinical trachoma and b) to detect <i>Chlamydia</i> in the conjunctiva of trachomatous populations living in the Far North Regions of Cameroon.Methods: A total of 2,423 randomly selected children (1–10 years) and 1,590 women over 14 from randomly selected villages from the Kolofata Health District (115,000 inhabitants) were included in a cross-sectional study in February 2009. Trained staff examined and obtained conjunctival swabs from trachomatous subjects. DNA was extracted and amplified to detect <i>Chlamydia</i> DNA by real-time PCR. The quality of sampling was assessed by quantifying the number of epithelial cells.Results: Children (2,397 or 98.9% of the predicted number) and women (1,543; 97.0%) were examined. The prevalence of follicular trachoma (TF) in children was 21% (95% CI 17.8–24.5) and of intense inflammatory trachoma (TI) 5.2% (95% CI 3.6–7.3). Among the women, trichiasis (TT) was observed in 3.4% (95% CI 2.4–4.7), corneal opacities (CO) in 1.4% (95% CI 0.8–2.3) and trachoma-related blindness in 0.9% (95% CI 0.4–1.8). Conditions related to income, illiteracy, latrines, water supply and animals wandering close to dwellings were similar in all the villages. PCR was positive in 35% of children with active trachoma and in 6% of adult females presenting TT and/or related corneal opacities.Conclusion: The prevalence of trachoma and the severe trachoma <i>sequelae</i> found during this survey underline the urgent need to implement efficient blindness prevention interventions to improve the visual future of the people in the Sahelian region.

Unilateral cryptorchidism in Nigerian sahel bucks / Criptorquidia unilateral en cabras sahel nigerianas

Out of 1608 Nigerian Sahel male goats (bucks) examined for cryptorchidism in an abattoir, 9 (0.6 percent) had right unilateral cryptorchidism. The coat colour-specific prevalence was highest among the brown bucks (2.1 percent); and was 0.8 percent, 0.6 percent, and 0.3 percent among black, white, back-and-white bucks, respectively. The condition was not found among bucks with brown-and-black, brown-and-white, and multiple coat colours. The right and left testes of normal bucks and the descended testes of cryptorchid bucks had comparable gross testicular measurements, but the retained cryptorchid testes were smaller in size. The estimates of the testicular measurements showed that testicular weights (with the entire epididymes), peripheral longitudinal lengths and mid-circumferences of the cryptorchids were reduced by 5.8-6.5, 1.8-1.9, and 1.7-1.8 folds, respectively, when compared with the normal values; an indication that reduction in weight was the most remarkable index of change in testicular size. In 2 cases (20 percent), cryptorchid testes were at a subcutaneous location, embedded in a subcutaneous fascia in the ventral perineal region, while in the other 8 cryptorchid cases (80 percent), the testes were in the abdomen. Histopathological changes in the cryptorchid testes included hypoplasia, degeneration, interstitial non-suppurative inflammation and fibroplasia. This is the first report of cryptorchidism in the Sahel goat and the first evidence that cryptorchid testis may be located subcutaneously in the goat.

De las 1608 cabras Sahel Nigerianas macho examinadas para criptorquidismo en un matadero, 9 (0,6 por ciento) tuvieron criptorquidia unilateral derecha. La prevalencia en relación al color específico del pelaje fue mayor entre las cabras marrones (2,1 por ciento), y fue de 0,8 por ciento, 0,6 por ciento y 0,3 por ciento entre cabras de color negro, blanco, y blanco/negro respectivamente. La condición no fue encontrada entre las cabras con pelajes marrón y negro, marrón y blanco, y pelajes de múltiples colores. Los testículos derecho e izquierdo de las cabras normales y los testículos descendentes de las cabras con criptorquídia tuvieron mediciones testiculares comparables, pero los testículos retenidos por criptorquídia fueron de menor tamaño. Las estimaciones de las mediciones testiculares mostraron que los pesos testiculares (con todo el epidídimo), la longitud periférica y la circunferencia media de las criptorquídicas fueron reducidas por 5,8-6,5; 1,8-1,9 y 1,7-1,8 pliegues respectivamente, en comparación con el los valores normales; una indicación que la reducción de peso fue el índice de cambio más notable en el tamaño testicular. En 2 casos (20 por ciento), los testículos criptorquídicos se encontraron en una ubicación subcutánea, inmersos en una fascia subcutánea en la región perineal ventral, mientras que en los otros 8 casos criptorquídicos (80 por ciento), los testículos fueron encontrados en el abdomen. Cambios histopatológicos en los testículos criptorquídicos incluyeron hipoplasia, degeneración, inflamación intersticial no supurativa y fibroplasia. Este es el primer informe de criptorquidia en cabras Sahel y la primera evidencia de que los testículos criptorquídicos pueden ser localizados por vía subcutánea en la cabra.